TWI537674B - Mask mask film, mask mask and mask mask the use of the box - Google Patents

Description

Method for using reticle protective film frame, reticle protective film and reticle protective film frame

The present invention relates to a frame which is a component of a photomask cover film, and is used for preventing LSI (Large Scale Integration) and a thin film transistor (TFT, Thin) which constitutes a liquid crystal display (LCD). Foreign matter is attached to a reticle or a reticle used in a lithography step at the time of manufacture such as a film filter or a color filter (CF, Color Filter), and the present invention relates in particular to a long side length exceeding 1400 mm. The components of the ultra-large reticle protective film are the reticle protective film frame, the reticle protective film using the reticle protective film frame, and the use method of the reticle protective film frame.

The present invention relates to a technique of a frame member and a mask film which are constituent members of a mask film, and first, a mask film will be described.

Conventionally, in the manufacture of semiconductor circuit patterns and the like, a dustproof mechanism called a mask film has been generally used to prevent foreign matter from adhering to the mask or the reticle. The reticle film is, for example, a frame having a thickness of about several millimeters having a shape conforming to the shape of the reticle or the reticle, and a nitrocellulose or cellulose derivative having an adhesion thickness of 10 μm or less or fluorinated. A transparent polymer film such as a polymer (hereinafter referred to as a photomask film) is coated with an adhesive under the frame, and the protective film is adhered to the adhesive with a specific adhesive force.

The adhesive material is used for fixing the reticle film to the reticle or the reticle, and the protective film is used to protect the adhesive surface of the adhesive material during the use of the adhesive material to maintain the adhesive material. Sticky force.

Generally, such a reticle film is provided by a manufacturer of a reticle film to a manufacturer of a reticle or a reticle, and is then provided after the reticle film is adhered to the reticle or the reticle. Manufacturers of lithography such as semiconductor manufacturers and panel manufacturers.

In recent years, with the spread of various multimedia, a large-color TFT LCD (Thin Film Transistor-Liquid Crystal Display) capable of high-definition/high-definition display is required. Accordingly, there is a need for a large reticle film that can be applied to large reticle or reticle used in the photolithography step.

As a frame of a reticle film which can be applied to a large reticle or a reticle used in a photolithography step of a large TFT LCD (Thin Film Transistor Liquid Crystal Display), generally has a long side and a short side. Rectangular. When the mask film is attached to the frame, the side of the frame may be deformed inward due to the tension of the mask film, and the effective exposure area of the mask or the reticle may be caused by the deformation. This becomes small, and this phenomenon becomes remarkable as the expanded area of the mask film becomes large (the mask film becomes large). The above-described phenomenon can be solved by increasing the rigidity of the mask cover frame in a state in which the area inside the frame of the mask film is maintained as much as possible (hereinafter referred to as an effective area) (for example, refer to Patent Document 1) ).

[Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2001-109135

However, in recent years, as the large-scale development has further developed, new problems have arisen.

The above-mentioned new problem means that the development of the large-scale in recent years requires that the reticle or the reticle (hereinafter referred to as the reticle) itself is also large-sized, and the reticle that has no problem in the enlargement of the reticle has been further large by itself. This causes the mask itself to bend due to its own weight.

That is, there is a problem in that since the reticle film is used in a state of being closely attached to the reticle, when the reticle film cannot follow the reticle, the reticle and the reticle film are attached. The attachment surface will be peeled off, resulting in an air path between them, so the use of the reticle film cannot be obtained. In particular, the reticle film adhered to the reticle or the like is often operated in the operation step in the short side of the reticle to operate each reticle film. Therefore, the frame of the reticle film is required to be Follow the curvature of the mask on the long side.

As described above, in the case of increasing the size of the mask film, the problem of not bending the mask film itself is to improve the rigidity of the mask film, but the mask film is provided. Further enlargement (large size) requires not only an increase in the rigidity of the mask film but also a change in the curvature of the mask itself due to the enlargement of the mask itself to which the mask film is attached, in particular, Follow the bending of the long side in the work step. In other words, for the oversized reticle film, both rigidity and flexibility are required.

As described above, the oversized size of the photomask has created a new problem for the ultra-large photomask film used therein.

The present invention is for solving a new problem caused by the increase in the size of the mask film. The problem of the mask cover frame of the first invention is that the mask cover is formed by the cover film. When the frame is not attached to the mask, the mask film itself can follow the self-weight of the mask itself.

Further, in the case of the ultra-large reticle film, it is also required to have a characteristic that the frame body does not deform when the reticle film is unfolded and adhered to the reticle film frame until the operation is attached to the reticle. The problem of the photomask cover film of the second aspect of the invention is that the frame of the photomask cover is not deformed when the photomask cover is unfolded, and the cover film is spread and adhered to the cover film frame. After that, the frame body will not be deformed until the operation of attaching to the reticle. Further, after the reticle film is attached to the reticle, the reticle cover itself can follow the self-weight of the reticle itself. Bending.

In order to solve the above problems, the inventors of the present invention have found that the above problems can be solved by limiting the deformability α and the followability β of the frame of the ultra-large reticle film. The first invention of the present invention has been completed.

Moreover, the inventors of the present invention have found that the above problem can be solved by widening the width Wb of the short side 1b of the mask cover frame by a specific ratio with respect to the width Wa of the long side 1a, thereby completing the second aspect of the present invention. invention.

That is, the present invention is as follows.

(1) A reticle cover film frame which is a rectangular reticle cover film frame, and the deformability α of the reticle cover film frame is 0.06% or less, which is represented by the following general formula (1) The followability β of each side of the mask film frame is 3 mm or more, and the followability β of the long side of the mask film frame is 32 mm or less, and the length of the long side of the frame body is 1400 mm or more and 2100 mm or less. The area inside the mask film casing is 15000 cm ² or more, β = (1/the amount of bending of the mask film) × thickness × width (1).

(2) The mask film frame of (1), wherein a width of a short side of the mask film frame is 1.05 times or more and 1.50 times or less of a width of the long side.

(3) A reticle cover film frame which is a rectangular reticle cover film frame, and a width Wa of a long side of the reticle cover film frame is 13.0 mm or more and 30.0 mm or less, and a width Wb of a short side The ratio Wb/Wa to the width Wa of the long side is 1.05 or more and 1.50 or less, the length of the long side is 1400 mm or more and 2100 mm or less, and the area inside the casing is 16000 cm ² or more.

(4) The photomask cover film according to any one of (1) to (3), wherein the material constituting the photomask cover is aluminum or an alloy thereof.

(5) The reticle shield frame according to any one of (1) to (4), wherein the surface of the reticle shield frame is formed by an alumite treatment, a blackening treatment, and an alumite treatment. The opening is subjected to a plugging process and is substantially free of microcracks.

(6) A reticle film obtained by spreading the reticle film on the reticle casing of any one of (1) to (5).

(7) A method of using a reticle shield frame, which holds the reticle described in (6) The mask film is attached to the mask at least one of the short sides of the short side of the mask and the mask film frame, and then the light of the mask film is attached The cover is used in the exposure process.

The reticle protective film frame of the invention has moderate rigidity and flexibility, so that the frame body does not deform when the reticle protective film is unfolded and adhered to the reticle protective film frame, and the reticle protective film is not reduced. The effective exposure area indicated by the inner area. Further, after the photomask cover is attached to the photomask, the curvature of the photomask can be followed, so that no air path is formed on the adhesive surface of the photomask and the photomask.

Further, in the second aspect of the invention, after the mask film is unfolded and adhered to the mask film casing, the frame body is not deformed until the operation is performed on the mask.

Furthermore, the photomask cover film of the present invention is also effective in the case of a super-large photomask cover film, specifically, in the case of an ultra-large photomask cover film having an effective area of 15,000 cm ² or more. Significant effect.

1‧‧‧Photomask cover

1a‧‧‧Longside

2a‧‧‧ Short side

1a1, 1b1‧‧‧ attached surface

1a2, 1b2‧‧‧ planar inclined surface

2‧‧‧Photomask

10‧‧‧ Large mask film

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing the configuration of a photomask cover film of the present invention and a photomask cover film using the same; Fig. 2 is a cross section of the long side of the photomask cover film of Fig. 1 perpendicular to the longitudinal direction thereof; Figure 3 is a cross-sectional view of the short side of the mask cover film of Figure 1 perpendicular to the longitudinal direction thereof; Figure 4A is an explanatory view showing the initial length of the measurement side of the mask cover; Figure 4B FIG. 4C is an explanatory view showing a state in which the mask cover frame is supported and bent; FIG. 4C is an explanatory view showing a length after the measurement side of the mask cover is supported; and FIG. 5 is a mask cover. An illustration of the state supported by the platform.

Hereinafter, embodiments for carrying out the invention will be described. The following embodiments are intended to illustrate examples of the invention and are not intended to be limiting.

The shape of the reticle shield frame of the present invention is a rectangle similar in shape to the reticle. The long side of the reticle frame refers to the longest side of the frame, and the short side of the reticle frame refers to the shortest side of the frame. More specifically, in the case of a rectangular shape, the longer one of the two orthogonal sides is the long side, and the shorter side is the short side, and in the square, the four sides are equal lengths. When you are in a square, you can define either side as the long side and the short side.

The deformability α is represented by the following general formula (2). This deformability α was measured by the following method. Hereinafter, a method of measuring the deformability α will be described with reference to FIGS. 4A, 4B, 4C, and 5.

First, the length (the length of the initial state) L1 (shown in FIG. 4A) of one side of the mask cover 1 to which the deformability α is to be measured is measured. Thereafter, as shown in FIG. 5, the support cover frame 1 is supported by the base 20, and it is not necessary to measure the lower side of the two sides of the deformability α (without contacting the upper surface). At this time, it is not necessary to measure the entire side of the deformability α from the lower side, and the end portion of the photomask cover 1 is supported up to 15 mm. For example, when measuring the short side of the reticle shield casing 1, the entire long side is supported by the pedestal 20 from below so that the long side is not bent. When the long side of the reticle shield casing 1 is measured, the entire short side is supported by the pedestal 20 from below. Hold it for 10 minutes in this state (as shown in Figure 4B), then stop the support, and place the mask cover frame straight on the flat platform. After 10 minutes, you need to measure the length of one side (support) After the length (after the force generated by the self-weight is applied) L2 (as shown in Fig. 4C), the measurement is performed again, and the elongation L1 of the length L2 after the support relative to the initial state is calculated as the deformability α according to the following formula. . The temperature at the time of measurement was 23.8 ° C, and the relative humidity was 74% RH. [(Length length L2 / initial state length L1) - 1] × 100 (%) (2).

Further, since there are four sides in the rectangular mask film casing, the same measurement is performed on each side, and the maximum value of the deformability α is used as the deformability α of the mask film casing. Again, when When the width of the middle side and the bottom side of the bottom surface are different, the side having a wider width is faced downward, and the deformability α is measured. The lower limit of the deformability α of the mask film frame is 0% or more, and the upper limit is 0.06% or less, preferably 0.02% or less, and most preferably 0.01% or less.

Further, the followability β of the photomask cover film to the follower of the mask is expressed by the following general formula (1), and the lower limit of β of each side of the mask cover is 3 mm or more, more preferably 4 mm. As described above, the upper limit of the followability of the long side of the mask film frame is 32 mm or less, preferably 25 mm or less. The follow-up of the short side of the mask film frame is preferably 100 mm or less, more preferably 80 mm or less, particularly preferably 50 mm or less, β = (1/bending of the mask film) × thickness × width (1).

The method of measuring the followability β is as follows.

First, as shown in FIG. 5, the lower surface of the mask cover 1 in which the relative tracking β is not measured is supported by the base 20. At this time, the entire side where the followability β is not measured is supported from the lower side, and the end portion of the photomask cover 1 is supported up to 15 mm. For example, when measuring the short side of the reticle shield casing 1, the entire long side is supported by the pedestal 20 from below so that the long side is not bent. When the long side of the reticle shield casing 1 is measured, the entire short side is supported by the pedestal 20 from below. After holding for 10 minutes in this state, as shown in FIG. 4B, the amount of change in the position of the most curved portion of the side to be measured with respect to the initial state was measured, and the amount of change was used as the amount of bending of the mask film ΔT. . Next, the reciprocal of the amount of bending ΔT is multiplied by the thickness and width of the side to be measured as the followability β. The measurement of the follow-up β is performed on all sides of the mask cover 1 . Further, when the width of the upper side and the bottom side of the bottom surface are different, the side having a wider side is made downward, and the followability β is measured.

The measurement of the follow-up β is performed simultaneously with the measurement of the above-described deformability α.

The follow-up β is an indicator of flexibility, which indicates how much the curvature of the reticle casing can follow the curvature of the reticle. Therefore, the smaller the value, the higher the followability. However, when the follow-up property is too high, wrinkles are generated during the development or operation of the mask film, and therefore the followability must be within the above range.

Further, the lower limit of the thickness of the mask film casing is preferably 4.0 mm or more, more preferably 5.0 mm or more, and particularly preferably 6.0 mm or more. On the other hand, the upper limit is preferably 10 mm or less, more preferably 8 mm or less, further preferably 7 mm or less, and particularly preferably 6.5 mm or less.

The width of the mask film frame is preferably 13 mm or more, more preferably 14 mm or more, and still more preferably 16 mm or more. On the other hand, the upper limit is preferably 30 mm or less, more preferably 25 mm or less, and still more preferably 19 mm or less. Furthermore, in terms of width, the width of either side of the long side and the short side may be equal, or may be independent widths.

Furthermore, the width of the side of the reticle shield frame is as shown in Figs. 2 and 3, and refers to the maximum width of each side such as Wa and Wb.

The cross-sectional shape of each side of the mask film casing is rectangular, H-shaped, T-shaped, etc., and is not particularly limited, but is preferably a rectangular shape. The profile can be a hollow structure.

The more the ultra-large size of the photomask cover film of the present invention, the more remarkable the effect. Specifically, when the length of the long side of the photomask cover is 1400 mm or more, especially 1700 mm or more and 2100 mm or less, and the light The effective area of the cover film is 16,000 cm ² or more, 24,000 cm ² or more, and particularly 25,000 cm ² or more, which has a remarkable effect.

Further, the reticle shield frame of the present invention has a remarkable effect if it is large, but the upper limit of the effective area is 35,000 cm ² in accordance with the size required for the reticle or the like used in the manufacture of the TFT LCD.

In the case of a large reticle film having a long side of 1400 mm or more, in order to improve the degree of freedom in the operation step, it is preferable to operate only one side of the short side 2 sides or the long side 2 sides. Especially when considering the work efficiency, it is preferable to hold the gripping method of the short side 2 sides. If the ratio Wb/Wa of the width Wb of the short side of the mask film frame to the width Wa of the long side is 1.05 or more, when the operation is performed by the holding method of the two sides of the short side, the rigidity can be generally high. The grip is held on the side to suppress the occurrence of wrinkles during operation. When the reticle film can be operated from the short side of the width, the grip portion at the time of gripping becomes large, and the convenience is also improved. From the viewpoint of improving the operability, it is particularly preferable to form the convex portion and the concave portion for gripping on the short side of the mask film casing. In addition, when Wb/Wa is 1.50 or less, even if the mask cover frame is erected (when the long side is perpendicular to the ground and the short side is parallel to the ground), deformation on the long side can be suppressed. Therefore, the occurrence of wrinkles can be suppressed. In the ultra-large reticle film having an effective area of the reticle protective film of 16,000 cm ² or more, in terms of work efficiency, it is preferred to rotate the reticle film to perform foreign matter inspection on the surface of the reticle film. In this case, the step of erecting the mask cover frame is performed. However, if Wb/Wa is 1.50 or less, deformation on the long side can be suppressed, and wrinkles of the mask film can be suppressed in the foreign matter inspection step or the like. .

The width Wb of the short side 1b of the photomask cover 1 is specifically a ratio (Wb/Wa) of the width Wb of the short side 1b to the width Wa of the long side 1a, preferably 1.05 or more. It is 1.1 or more, and the upper limit is preferably 1.50 or less, more preferably 1.25 or less, and particularly preferably 1.2 or less.

Examples of the material constituting the reticle casing of the present invention include carbon steel for mechanical construction (SC series, etc.), and tool steel (carbon tool steel SK series, high speed tool steel SKH series, alloy tool steel SKS series). , SKD series, SKT series, etc.), Ma Tian loose iron series stainless steel series (SUS403, SUS410, SUS410S, SUS420J1, SUS420J2, SUS429J1, SUS440A, SUS304, etc.), aluminum, aluminum alloy (5000 series, 6000 series, 7000 series, etc.) Metal; ceramic (SiC, AlN, Al203, etc.); composite material of ceramic and metal (Al-SiC, Al-AlN, Al-Al203, etc.), and examples thereof include aluminum or an alloy thereof, and more specifically, aluminum. Alloys with magnesium, alloys of aluminum and magnesium and niobium, alloys of aluminum and zinc and magnesium.

Further, since each of the above-mentioned steel materials is a magnetic material, it can be fixed by a magnet, and particularly in the case of a large-sized photomask cover, the processing operation is good and can be preferably used. Black chrome plating, black acid-resistant aluminum, blackening, etc. can also be applied to the surface of the reticle cover. Processing.

Among them, the black alumite treatment will be described.

As the support frame for the mask film, a 5000-series aluminum alloy is generally used. Therefore, an aluminum alloy will be described as an example.

In the ordinary black alumite treatment, after the photomask support frame is formed by an aluminum alloy, the alumite treatment is performed, and the micropores generated by the treatment are filled with a blackening agent, and then the plugging is performed. The micropore is sealed and treated with black alumite treatment. However, the surface of the support frame produced by the conventional method as described above was observed by an electron microscope, and the occurrence of fine cracks (microcracks) was confirmed. Such micro-cracks are further developed in the miniaturization of the pattern, and the wiring width is further narrowed, and the fall of the extremely small foreign matter entering the crack will also become a problem. Therefore, as a method of preventing the occurrence of the above microcracks, it is preferred to employ the method described below.

First, the surface of the reticle shield frame is subjected to an alumite treatment. The alumite treatment is carried out in the following range: a sulfuric acid concentration of 10 to 20%, a current density of 1 to 2 A/dm ² , an electrolyte temperature of 15 to 30 ° C, and an energization time of 10 to 30 minutes. At this time, a large number of micropores (50 to 200 Å in diameter and 500 to 1500 Å in pitch) are regularly formed on the surface of the alloy. Thereafter, the hole is used for blackening treatment. Since the blackening treatment is performed to prevent reflection of light from the housing, it is not limited to black, and includes dark colors such as brown or dark blue which are close to black. Examples of the blackening treatment include dyeing, electrolytic coloring, and the like. The dyeing is a method of obtaining a chromaticity by immersing the liquid in a liquid in which a black dye is dissolved, and the electrolytic coloring is performed by electrically depositing a metal element in the pore to obtain a chromaticity. The dyeing can be carried out, for example, under the conditions of a dye concentration of 3 to 10 g/L and a dyeing liquid temperature of 50 to 65 °C.

Then, a sealing treatment for sealing the hole is performed. In this treatment, for example, a boiling water of 6 to 12 g/L of a Hard Wall 3 (trade name) plugging aid manufactured by Rihua Chemical Industry Co., Ltd., which is called a low temperature sealing agent, is used.

Filling the pores on the surface of the acid-resistant aluminum film with the sealing hole at this time, the acid-resistant aluminum film is continuously changed It is dense, but as long as the sealing temperature is slightly lower than 100 ° C, for example, 70 to 95 ° C, and more preferably 80 to 90 ° C for sealing treatment, it can be made to have a very uniform surface and substantial A photomask cover with no micro-cracks.

Further, the presence or absence of the microcrack was judged by a line obtained by magnifying the surface of the support frame by a magnification of 1000 times with an electron microscope, and a straight line of 10 cm (actual size: 0.1 mm) was drawn, and the number of cracks crossing the straight line was calculated. The width of the crack is listed by the electron micrograph, that is, the crack width is 0.1 μm or more. The larger the value, the higher the density of cracks can be judged.

An adhesive material (acrylic, vinyl acetate, lanthanum, rubber, etc.) or lubricating oil (polyacrylic acid) for capturing foreign matter may be applied to the inner wall surface or the entire surface of the reticle casing as needed. Oxygen, fluorine, etc.).

Further, if necessary, a micropore that penetrates the inside and the outside of the photomask cover can be opened, and the difference in pressure between the inside and the outside of the space formed by the photomask and the mask can be eliminated, and the film can be prevented from being swollen or recessed.

Further, in this case, if the foreign matter removing filter is attached to the outside of the micropores, it is possible to adjust not only the air pressure but also the foreign matter from entering the space formed by the mask film and the mask, which is preferable.

When the volume of the space formed by the reticle film and the reticle is large, if a plurality of such holes or filters are provided, the recovery time of the expansion or depression of the film due to the change of the air pressure becomes shorter, so it is better. .

The photomask cover frame of the present invention can have appropriate rigidity and flexibility by satisfying the above-mentioned requirements, so that the frame body is not deformed due to the deployment of the mask film, and the mask can be followed not only by the operation mask. The film is bent at the time of the film, and can also follow the bending of the reticle itself in the operation after being attached to the reticle. As a result, wrinkles are not generated on the mask film, and the curvature of the mask can be followed, so that an excellent effect of the air path is not obtained.

Although the photomask cover film of the present invention has been described above, the photomask cover of the present invention can further improve the reliability of the cover film frame by the following structure.

For example, when the widths of the long side 1a and the short side 1b of the mask cover 1 shown in FIG. 1, FIG. 2 and FIG. 3 are the same Wa and Wb, the attachment of the mask film 2 can be formed. A structure in which the relationship between Wa=Wb>Wc=Wd is satisfied between the widths Wc and Wd of the faces 1a1 and 1b1. As described above, when the widths Wa and Wb of the mask cover 1 are larger than the widths Wc and Wd of the attachment surface, the adhesive of the mask 2 and the mask cover 1 can be adhered. The agent application device is applied quantitatively, for example, by an XY automatic dispenser, and the adhesive can be uniformly applied to the entire attachment surface. Further, by setting the attachment width to be smaller than the width of the frame 1, the coating unevenness and the coating residue of the adhesive can be suppressed, and as a result, the coating unevenness and the space in the residual portion can be prevented from depositing foreign matter. . Further, if Wc = Wd, it is preferable to coat all the sides without changing the coating amount on the long side and the short side.

As described above, as a method of manufacturing a structure satisfying the relationship of Wa=Wb>Wc=Wd, as long as an inclined surface is formed on the attachment surface side of the mask film of the mask cover 1, the step can be formed without a step. Inclined surface. Furthermore, the inclined surface may also be curved.

Since the difference between Wa=Wb>Wc=Wd is set between the width of the mask cover 1 and the width of the mask cover surface as described above, it also has a film adhesion preventing the adhesive from the frame 1. The effect that the surface 1b1 overflows and hangs on the inner peripheral portion of the casing 1 is obtained. In addition, although the case of Wa=Wb has been described, even if the long side 1a and the short side 1b of the mask cover 1 are not Wa and Wb having the same width, as long as Wa>Wc, Wb>Wd, The above effect can be obtained. Further, if Wc = Wd, it is possible to coat all the sides without changing the coating amount on the long side and the short side, which is preferable.

In particular, the photomask cover film according to the first aspect of the present invention preferably has a length along the long side of the mask as a length of the long side of the mask cover and a length of the long side of the mask cover +150 mm or less. The length of the short side is longer than the short side length of the reticle cover and the short side of the reticle cover A mask with a degree of +200 mm or less. The thickness of the photomask can be used to withstand the weight of the reticle casing (without damaging the reticle) after attaching the reticle casing. Further, as the material of the mask, soda lime glass, alkali-free glass, low-alkali glass, quartz glass or the like can be considered, but the photomask cover of the first invention can preferably follow the material of the mask. Photomask.

The configuration of the photomask cover film of the first invention has been described above.

Next, a second invention of the present invention will be described.

The width of the photomask cover 1 of the second invention will be described. The lower limit of the width Wa of the long side 1a of the mask cover 1 shown in Fig. 2 is 13.0 mm or more, preferably 14.0 mm or more, and most preferably 16.0 mm or more. On the other hand, the upper limit is 30.0 mm or less, preferably 25.0 mm or less, more preferably 19.0 mm or less.

Further, the width of the side of the mask film casing, for example, as shown in Figs. 2 and 3, refers to the maximum width of each side such as the widths Wa and Wb.

The width Wb of the short side 1b of the reticle casing 1 shown in Fig. 3 must be at least larger than the width Wa of the long side 1a, specifically, the ratio of the width Wb of the short side 1b to the width Wa of the long side 1a ( The lower limit of Wb/Wa) is 1.05 or more, preferably 1.1 or more, and the upper limit is 1.50 or less, preferably 1.25 or less, and most preferably 1.2 or less. Therefore, the width Wb of the short side of the mask film frame is set to a value of 13.65 mm or more and 45.0 mm or less.

For the large-scale mask film with a long side length of 1400 mm or more, in order to improve the degree of freedom of the operation steps, it is preferable to hold only one of the short side 2 sides or the long side 2 sides, especially when considering In the case of work efficiency, it is preferable to hold the gripping method on the short side. If the ratio Wb/Wa of the width Wb of the short side of the mask film frame to the width Wa of the long side is 1.05 or more, when the operation is performed by the holding method of holding the short side 2 sides, it is usually self-rigid. The high side is held to prevent wrinkles during operation. When the reticle film can be operated from the short side of the width, the grip portion at the time of gripping is wide, and the convenience is also improved. From the viewpoint of improving the operability, it is particularly preferable to form the convex portion and the concave portion for gripping on the short side of the mask film casing. In addition, when Wb/Wa is 1.50 or less, deformation of the long side can be suppressed even when the mask cover frame is erected (the long side is perpendicular to the ground and the short side is parallel to the ground). Therefore, the occurrence of wrinkles can be suppressed. In the ultra-large mask film having an effective area of the mask film of 16,000 cm ² or more, in terms of work efficiency, it is preferred to rotate the mask film to perform foreign matter inspection on the surface of the mask film. In this case, the step of erecting the mask cover frame is performed. However, if Wb/Wa is 1.50 or less, deformation on the long side can be suppressed, and wrinkles of the mask film can be suppressed in the foreign matter inspection step or the like. .

Further, the thickness of the frame 1 is preferably 4.0 mm or more, more preferably 5.0 mm or more, and still more preferably 6.0 mm or more. Further, the upper limit is preferably 10.0 mm or less, more preferably 8.0 mm or less, further preferably 7.0 mm or less, and most preferably 6.5 mm or less.

The cross-sectional shape of each side of the mask film casing may be rectangular, H-shaped, T-shaped or the like, and is not particularly limited, but is preferably a rectangular shape. The profile can also be a hollow structure.

The larger the size of the photomask cover 1 of the present invention, the more remarkable the effect. Specifically, the length La of the long side 1a of the mask cover 1 is 1400 mm or more, especially 1700 mm or more and 2100 mm or less. At this time, the effective area of the mask film is 16,000 cm ² or more, 24,000 cm ² or more, and particularly 25,000 cm ² or more, which has a remarkable effect. Further, the present invention protect the photomask film housing 1 if it has large effect of significant, but depending on the size of the mask TFTLCD and the like used in the manufacture of the required upper limit of the effective area is sufficient if it is sufficiently 35000cm ² .

However, in the large reticle film having a long side of 1400 mm or more, in the operation of attaching the reticle film to the reticle, in the operation step, in most cases, not only the short side of the reticle but also the short side of the reticle is held. It is to hold at least one of the short sides 1b of one of the short sides 1b of the mask cover 1 together with the reticle, so that the work efficiency can be improved, and at this time, the reticle is generated by its own weight. The bending is not the same in the long side and the short side. Specifically, the curvature of the mask that is not gripped in the direction toward the long side 1a becomes large. Therefore, it is required that the curvature of the mask cover frame follows the curvature in the longitudinal direction. The photomask cover of the second invention can also fully follow The curvature of the mask of this particularity.

The photomask cover frame of the present invention can have appropriate rigidity and flexibility by satisfying the above requirements, so that the frame body is not deformed by the deployment of the mask film, and can not only follow the operation of the mask film alone. Bending, and can also follow the curvature of the reticle itself in the operation after it is attached to the reticle.

As a result, since the effective area of the mask film is not reduced due to deformation of the mask film frame formed when the mask film is spread on the mask film frame, the curvature of the mask can be followed. Therefore, the excellent effect of the air path is not achieved.

Further, since the short side is wider than the long side, it is easy to hold the short side of the mask film casing when the mask film is operated. As a result, since it is easy to operate the mask film from the same side as the grip portion when the mask is operated, work efficiency is improved.

In the photomask cover 1 of the present invention, it is preferable that the widths Wc and Wd of the attachment faces 1a1 and 1b1 of the long side 1a and the short side 1b of the frame 1 are substantially equal. . The widths Wc and Wd of the attachment faces 1a1 and 1b1 of the mask 1a and the mask 1b of the short side 1b are substantially equal, and refer to the film attachment faces 1a1 and 1b1 of the long side 1a and the short side 1b. The difference between the widths Wc and Wd is smaller than the difference between the widths Wa and Wb of the long side 1a and the short side 1b. That is, referring to the cross-sectional views of FIGS. 2 and 3, Wb-Wa>Wd-Wc is shown.

Usually, the adhesive film of the photomask film 2 and the photomask cover 1 is applied by an adhesive application device such as an X-Y automatic dispenser or the like. At this time, the amount of the adhesive applied per unit length on the long side 1a and the short side 1b is equal. Therefore, if Wc < Wd, the mask film 2 is attached to the mask cover 1 and sometimes As a result, the adhesion amount in the long side 1a is large, so that the adhesive overflows from the film attachment surface 1a1 of the frame 1 and hangs on the inner periphery of the frame 1.

Moreover, the adhesive amount of the short side 1b is insufficient to uniformly spread over the entire surface of the film attachment surface 1b1, and on the inner side, a narrow gap is formed between the mask film 2 and the mask cover frame 1, the gap Sometimes there are foreign objects inside.

From the above viewpoints, as described above, by attaching the film of the long side 1a and the short side 1b The widths Wc and Wd of 1a1 and 1b1 are substantially equal, and a better mask film can be obtained even if a simple adhesive applicator of the prior art is used.

As a method of making the widths Wc and Wd of the film attachment surfaces 1a1 and 1b1 of the long side 1a and the short side 1b substantially equal, at least the mask film 2 of the long side 1a of the housing 1 of the mask cover is provided. When the inclined surface is formed on the side of the attachment surface, the inclined surface can be formed without the step, thereby preventing foreign matter from being deposited on the mask cover. Moreover, the inclined surface may be curved.

Further, by providing the inclined surface, the adhesive can be prevented from hanging on the inner peripheral portion of the casing. The size of the inclined surface is preferably such that the rigidity and flexibility of the mask film frame are not substantially affected.

Then, by the deployment of the mask pellicle of the present invention is adhered to the second area of the inner membrane of the mask protective housing of the invention is 16000cm ² or more large photomask pellicle frame of the first invention is obtained The ultra-large reticle protective film can be produced in the following manner, and therefore will be described below.

As the mask film, a cellulose derivative (nitrocellulose, cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, or the like, or a mixture of two or more thereof), a fluorine-based polymer (for a fluorine-based polymer) can be used. A terpolymer of tetrafluoroethylene-vinylidene fluoride-hexafluoropropylene and a polymer having a cyclic structure in the main chain, namely Teflon AF (trade name) manufactured by DuPont, and Cytop (trade name) manufactured by Asahi Glass Co., Ltd. A polymer such as Algoflon (trade name) manufactured by Ausimont Co., Ltd., etc.

As the reticle film, a film formed of, for example, a polymer solution can be used. The film has tension. On the other hand, it is necessary to have this tension so as not to bend or wrinkle the mask film.

When the reticle film is bent or wrinkled, when the foreign matter adhering to the reticle film is removed by the air blower, the reticle film will generate a large vibration and it is difficult to remove the foreign matter. Moreover, since the height of the mask film varies depending on the location, the foreign body inspection machine of the mask film cannot function normally. Further, there is a problem that an error occurs in the measurement of the optical height of the mask film.

Ultra-high pressure mercury lamp as a light source in the one-time exposure liquid crystal exposure machine currently used In terms of light resistance and cost, cellulose acetate propionate or cellulose acetate butyrate can be preferably used.

The film thickness of the mask film is preferably about 0.5 μm to 10 μm. In view of the large mask film of the present invention, the film thickness is higher than the thickness of the mask film and the convenience of manufacturing the film. Good is 2μm~8μm. The above polymer can be made into a polymer solution by a solvent (ketone system, ester system, alcohol system, fluorine system, etc.) which is suitable for each.

The cellulose acetate propionate or cellulose acetate butyrate is preferably an ester system such as ethyl lactate. The polymer solution can be filtered by a depth filter, a membrane filter or the like as needed.

The film formation method of the polymer solution may be a spin coating method, a roll coating method, a knife coating method, a cast coating method, or the like. However, from the viewpoint of uniformity and foreign matter management, a spin coating method is preferred. After the film is formed on the film formation substrate by spin coating, the solvent can be dried by a hot plate, a dust-free oven, or (far) infrared heating or the like as needed to form a uniform film. As the film formation substrate at this time, synthetic quartz, fused silica, alkali-free glass, low alkali glass, soda lime glass, or the like can be used.

Since the substrate for film formation of the large-sized photomask film of the present invention has a large size, the film formation substrate may be broken due to temperature unevenness during drying. In order to prevent this from occurring, the thermal expansion coefficient of the substrate for film formation is preferably as small as possible. Particularly preferably, the linear expansion coefficient of 0 ° C to 300 ° C is 50 × 10 ^-7 m / ° C or less.

Further, on the surface of the substrate for film formation, a release treatment can be carried out in advance by a material such as a polyfluorene-based or fluorine-based material. Moreover, since a layer having a lower refractive index than the mask film (ie, an anti-reflection layer) is formed on one side or both sides of the mask film, the transmittance for the exposure light is improved, so that it is preferable. .

As a material of the antireflection layer, a fluorine-based polymer (tetrafluoroethylene-vinylidene fluoride-hexafluoropropylene terpolymer, a polymer having a cyclic structure in the main chain, that is, a Teflon AF manufactured by DuPont) can be used. (trade name), Cytop (trade name) manufactured by Asahi Glass Co., Ltd., Algoflon (trade name) manufactured by Ausimont Co., Ltd., polyfluorinated acrylate, etc.), or calcium fluoride, fluorinated A material having a lower refractive index such as magnesium or barium fluoride.

When the antireflection layer is a polymer, it can be formed by the same spin coating method as described above, and when the antireflection layer is an inorganic material, it can be formed by a film formation method such as vacuum deposition or sputtering. From the viewpoint of foreign matter, a spin coating method of a polymer solution is preferred. Teflon AF (trade name) manufactured by DuPont and Algoflon (trade name) manufactured by Ausimont Co., Ltd. are preferred because of their small refractive index and high antireflection effect.

The mask film formed on the film formation substrate by the above method may be peeled off from the film formation substrate by reattaching the adhesive sheet to a template obtained by attaching the aluminum alloy, stainless steel, resin, or the like to the film. Required on the reticle cover. Further, the desired photomask cover can be peeled off from the film formation substrate after the desired photomask cover is adhered to the film formation substrate.

The large reticle film obtained by the above method is attached to the reticle casing by the action of the tension by the adhesive.

If the tension of the film is within an appropriate range, the large reticle film can be inhibited from expanding or sagged toward the vertical direction of the film surface of the large reticle film due to its own weight or the difference in pressure between the inside and outside of the large reticle film. Prevents poor exposure. Further, it is possible to solve the problem that when the foreign matter adhering to the mask film is removed by the air blower, the mask film is largely vibrated and it is difficult to remove the foreign matter, and further, the height of the mask film can be corrected depending on the place. The foreign matter inspection machine of the reticle film cannot function normally, and the problem of error in measuring the optical height of the reticle film can be solved. Moreover, it is possible to ensure the follow-up performance of the air pressure fluctuation inside and outside the large reticle film.

The film adhesive for adhering to the reticle protective film and the reticle protective film frame can be appropriately selected according to the material of the reticle protective film and the material of the reticle protective film frame. For example, an adhesive such as an epoxy-based, acrylic-based, polyfluorene-based or fluorine-based adhesive can be used.

Further, the curing method of the adhesive may be a curing method (thermosetting, photohardening, anaerobic hardening, etc.) suitable for each adhesive. From the viewpoint of dusting, cost, and workability, an acrylic ultraviolet curable adhesive is preferred.

The reticle adhesive material for attaching the reticle cover to the reticle can be made of a self-adhesive heat-melting system (rubber-based or acrylic), and the two sides of the substrate are coated with an adhesive. For the adhesive tape, a sheet such as an acrylic or PVC (polyvinyl chloride) or a foam such as a rubber, a polyolefin or a polyurethane may be used, and a rubber or acrylic may be used as the adhesive. , sticky materials such as polyoxymethylene).

In the large-sized photomask cover film of the present invention, in order to enable the photomask cover film to be attached to the photomask with low load and uniformly, the photomask adhesive material preferably uses a relatively soft hot melt material or a foam. When a foam is used, dusting from the foam can be prevented by covering the cross-section with an acrylic or vinyl acetate-based adhesive material or a non-adhesive material.

The thickness of the reticle adhesive material is usually 0.2 mm or more, but in order to uniformly adhere to the reticle, it is preferably 1 mm or more. In order to protect the adhesion surface of the reticle adhesive material during attachment to the reticle, a polyester film which is subjected to release treatment by polyfluorene or fluorine may be used.

The system for transporting the reticle film is made of acrylic, ABS (acrylonitrile-butadiene-styrene), PVC, PET (Polyethylene Terephthalate, polyethylene terephthalate). A material such as an ester) is produced by injection molding or vacuum molding. These materials are antistatic, and can be kneaded with an antistatic agent, and a polymer having an antistatic structure (BAYON (trademark) manufactured by Kureha and ADION (trademark) manufactured by Asahi Kasei) can also be used.

The box for the ultra-large reticle cover film of the present invention is preferably provided with a flange structure on the lid of the box body, the tray or both, so as to avoid deformation of the box body during transportation and to protect the inside of the box body. The membrane is damaged, thereby increasing the resistance to external forces.

Further, the frame of the reticle film is required to be removed not only by the fact that it can be gripped reliably, but also when the reticle film is taken out from the container after the frame is not bent or twisted. In addition, in particular, in the case of a large-sized photomask film which is large in size and difficult to handle, it is required to be grasped not only during storage, transportation, and storage, but also when it is self-receiving. When the nano container is taken out, it can be taken out from the interface between the protective film and the adhesive material, and the photomask protective film is not deformed and bent, so that it can be directly attached to the mask or the like after being taken out.

Therefore, the convex portion or the concave portion for holding can be formed on all sides of the frame of the mask film without being restrained by the mask, thereby achieving the length of the longest side of 1.4 m to 2.1 m. The holding of the large reticle film.

In the second aspect of the invention, since the width on the short side is larger than the long side, it is easy to form the convex portion and the concave portion for holding on the short side.

The photomask cover film of the second invention can particularly preferably follow the length of the long side of the mask as the length of the long side of the mask cover and the length of the long side of the mask cover +150 mm or less, and the short side of the mask The length is the mask of the short side of the reticle shield frame and the short side of the reticle shield frame is +200 mm or less. The thickness of the photomask can be substantially increased by the weight of the reticle casing (without damaging the reticle) after attaching the reticle casing. Further, the material of the photomask may be soda lime glass, alkali-free glass, low alkali glass, quartz glass, etc., but the photomask cover of the second invention can preferably follow the mask regardless of the material of the photomask. .

Hereinafter, the present invention will be more specifically described by way of examples.

[Examples] (Example of the first invention) [Examples 1 to 99, Comparative Examples 1 to 71]

The frame 1 for the super-large reticle cover film uses the length (La) of the long side 1a, the length (Lb) of the short side 1b, the area inside the frame (effective area), and the thickness of the frame as shown in Table 1 to Table. 9 is shown. Further, the width (Wa) of the long side 1a and the width (Wb) of the short side 1b of the mask film casing are shown in Tables 1 to 9.

Furthermore, the material of the photomask cover is made of aluminum alloy, and the cross-sectional shape of the frame is a rectangular shape. Moreover, the reticle shield frame system used is treated with black alumite-resistant micro-cracks.

Therefore, the performance of the actual reticle film is evaluated using the above-described frame.

The details are as follows.

As a mask film, a polymer solution of a cellulose ester is applied onto a low alkali glass, and a main film is formed by spin coating.

Then, a fluorinated polymer solution was also applied onto the film by spin coating to form a mask film having an antireflection layer having a thickness of 4 μm. The obtained mask film is unfolded and attached to the mask film casing.

Here, the presence or absence of wrinkles generated when the reticle film was adhered to the reticle shield frame was evaluated (the result of wrinkles at the time of film development). The evaluation results are shown in Tables 1 to 9. In the mark of the evaluation result, "○" indicates a state in which no wrinkles are present at all, "△" indicates a state in which the film is slightly undulated under close observation, and "x" indicates a state in which wrinkles are slightly present.

Then, the mask cover film to which the mask film is adhered is attached to the quartz glass. At this time, the reticle adhesive material is made of a rubber-based hot-melt adhesive material of styrene-ethylene-butylene-styrene having a thickness of 1.2 mm, and the hot-melt adhesive material is applied to the reticle of the reticle protective film frame. The surface is attached to a specific position of the quartz glass. Furthermore, each component has been subjected to ultrasonic cleaning before use.

Further, the size of the quartz glass is set to be +50 mm in the long side of the mask film to which the long side of the quartz glass is attached, and the short side length of the mask film to which the short side of the quartz glass is attached is +100 mm. The dimensions and thickness of the quartz glass used are shown in Table 17.

Further, the flexibility of the mask film frame can be evaluated by measuring the followability of the mask film to the mask. The reticle attached to the reticle is placed in such a manner as to evaluate whether the reticle film has been following the curvature of the reticle due to its own weight, and the state is such that the reticle film is attached. Face down, hold the two short sides of the mask to float in the air.

The evaluation results are shown in Tables 1 to 9. The evaluation criteria for follow-up are within one year after the reticle is attached. If there is no change, the evaluation is "○". If the adhesion is slightly raised, the evaluation is made. Estimated as "△", the air path is evaluated as "X".

Further, a sample of the photomask cover having the same specifications as described above was used, and a sample of the adhesive cover film was developed under the same conditions as described above, and the long side was held using the sample, and the above measurement conditions were used. The deformability α and the followability β of the same side were measured, and the results are shown in Tables 1 to 9.

In the comprehensive assessment, when "the result of the follow-up assessment" and "the result of the wrinkle at the time of film development" are "○", it is recorded as "◎". If one of them appears △, it is recorded as "○", and When it appears ×, it is recorded as "X".

(Embodiment of the second invention)

First, the evaluation method of the reticle casing of the present invention will be described.

The reticle cover frame system of the present invention has both appropriate rigidity and flexibility, and the rigidity thereof is caused by wrinkles when the reticle cover film is unfolded on the reticle cover frame, and the reticle film is subsequently formed. Whether or not wrinkles are generated during the operation for visual evaluation, and the flexibility is placed according to the reticle film attached to the reticle in the following state, and whether the reticle film follows the bending of the reticle due to its own weight The follow-up evaluation was performed in such a manner that the side of the mask covered with the mask was placed facing down, and the two short sides of the mask were held to be suspended in the air.

[Examples 100 to 197, Comparative Examples 72 to 141]

The length (La) of the long side 1a, the length (Lb) of the short side 1b, and the area (effective area) inside the frame of the frame 1 for the super large mask film used in the examples and the comparative examples are shown in the table. 10 to Table 16. Further, the width (Wa) of the long side 1a of the mask film casing, the width (Wb) of the short side 1b, and the thickness of the mask film casing are also shown in Tables 10 to 16.

Further, the material of the photomask cover can be made of an aluminum alloy, and the cross-sectional shape of the frame is a rectangular shape. Moreover, the reticle shield frame system used is treated with black alumite without microcracking.

Therefore, the performance of the frame for the photomask film using the above specifications is actually evaluated.

The mask film coats the polymer solution of the cellulose ester on the low alkali glass, and uses the spin The main film is formed by coating.

Then, the fluorinated polymer solution was also applied to the film by spin coating to form a mask film having an antireflection layer having a thickness of 4 μm. The obtained mask film is unfolded and attached to the mask film casing. Furthermore, the operation of the reticle shield frame is carried out by holding a part of each side of a set of short sides.

Here, whether or not wrinkles were generated when the reticle film was adhered to the reticle casing was evaluated (the result of wrinkles at the time of film development). The evaluation results are shown in Tables 10 to 16. In the mark of the evaluation result, "○" indicates a state in which no wrinkles are present at all, "△" indicates a state in which the film is slightly undulated under close observation, and "x" indicates a state in which wrinkles are slightly present.

Then, the reticle cover film to which the reticle film is adhered is attached to the quartz glass. At this time, the reticle adhesive material is made of a rubber-based hot-melt adhesive material of styrene-ethylene-butylene-styrene having a thickness of 1.2 mm, and the hot-melt adhesive material is applied to the reticle of the reticle protective film frame. Adhesive surface and attached to a specific position of quartz glass. Further, each component was subjected to ultrasonic cleaning before use.

Further, the size of the quartz glass is set to the length of the long side of the mask film to which the long side of the quartz glass is attached + 50 mm and the short side of the mask film to which the short side of the quartz glass is attached is +100 mm. The dimensions and thickness of the quartz glass used are shown in Table 17.

Observing the surface of the reticle film of the reticle film attached to the reticle obtained in the above manner, and also unfolding and adhering the reticle film to the reticle frame until it is attached to the reticle Whether or not wrinkles are generated in a series of operation steps (the result of wrinkles generated by the operation).

Here, a series of operation steps refers to a transfer step including assembly (expansion and adhesion of the mask film) → inspection step → packing step → shipping step → removal step → operation of attaching the mask to the mask step. In the transporting step after the assembly step, the carrier for transporting in the step is used, and the photomask is held near the four corners of the short side of the mask film frame with the gripping force of the mask film not falling. The film is transported to the inspection step. At this time, the mask film It is transported to the inspection step with the long side parallel to the ground and the short side perpendicular to the ground. In the inspection step, the mask film is rotated up and down about the horizontal axis and rotated one turn around the vertical axis, and the center of the mask film is rotated 90 degrees on the plane of the mask film to perform inspection. The mask film is transported to the packing step in a state where the long side of the mask film is parallel to the ground and the short side is perpendicular to the ground. In the packaging step, the mask film is stored in the mask film storage container in a state in which the carrier for transport in the step is attached. Thereafter, the carrier for transport in the step is removed in the storage container, and only the mask film is housed in the container. In the shipping step, the normal transportation is performed on the assumption of truck transportation. At this time, the storage container is maintained at a level. In the taking-out step, the mask film is taken out from the container in a state where the mask film frame and the floor are horizontal. When taking out, hold the vicinity of the four corners on the short side of the mask film frame with the holding force of the mask film not falling. In the attaching step to the reticle, in the state in which the reticle protective film frame and the ground are horizontal, the short side of the reticle protective film frame is held by the holding force of the reticle protective film not falling. Near the four corners, the reticle film is directly attached to the reticle by the reticle adhesive of the reticle film. The attaching force is attached tightly to the affixing force of the reticle protective film which does not change.

The evaluation results are shown in Tables 10 to 16. Furthermore, the evaluation reference is the same as when the adhesive is attached to the reticle housing.

Further, the flexibility was evaluated by the evaluation conditions of the follow-up property of the mask to the mask. The evaluation results are shown in Tables 10 to 16 (the results of the follow-up evaluation). The follow-up evaluation criterion is that after the reticle film is attached to the reticle, the reticle film is placed in the following state, and within one year, when there is no change, it is evaluated as "○", and when the embossed portion is slightly raised, the evaluation is performed. When it is "△", it is evaluated as "X" when the air path is generated. The above state is such that the surface of the mask is attached with the short side attached thereto, and the two short sides of the mask are held to be suspended in the air.

In the comprehensive assessment, "the result of the follow-up evaluation", "the result of the wrinkle at the time of film development" and "the result of the wrinkle generated by the operation" are all "○", and it is recorded as "◎". It is recorded as "○", and one of them is marked as "X" when it appears.

[Industrial availability]

When the use of the reticle shield frame, the reticle shield, and the reticle shield frame of the present invention is applied, it is applicable to a large-sized color TFT LCD (film) which can be developed in recent years and which can perform high-definition/high-definition display. Large reticle or reticle used in the photolithography step of a transistor liquid crystal display.

1‧‧‧Photomask cover

1a‧‧‧Longside

1b‧‧‧ Short side

1a1, 1b1‧‧‧ attached surface

1a2, 1b2‧‧‧ planar inclined surface

2‧‧‧Photomask

Claims (8)

A reticle cover film frame which is a rectangular reticle cover film frame, and the deformability α of the reticle cover film frame is 0.06% or less, and the reticle is represented by the following general formula (1) The followability β of each side of the film frame is 3 mm or more, the followability β of the long side of the mask cover is 32 mm or less, the followability β of the short side is 80 mm or less, and the length of the long side of the frame is 1400 mm. The above area is 2100 mm or less, and the area inside the mask film casing is 15000 cm ² or more, β = (1/the amount of bending of the mask film) × thickness × width (1). The reticle protective film frame of claim 1, wherein the short side of the reticle cover frame has a length of 1200 mm or more and 1800 mm or less. The photomask cover film of claim 1, wherein the thickness of the photomask cover is 4.0 mm or more and 10.0 mm or less. The reticle protective film frame of claim 1, wherein the width of the reticle protective film frame is 13 mm or more and 25 mm or less. The reticle shield frame according to any one of claims 1 to 4, wherein the material constituting the reticle casing is aluminum or an alloy thereof. The reticle protective film frame according to any one of claims 1 to 4, wherein the opening of the micropore formed by the alumite treatment, the blackening treatment and the alumite treatment on the surface of the reticle casing The sealing treatment is carried out, and there is substantially no microcrack. A reticle film which is obtained by unfolding a reticle film on a reticle casing of any one of claims 1 to 6. A method for using a reticle protective film frame, which is to hold at least one short side of each of a short side of a reticle cover film and a reticle cover film frame as described in claim 7 The reticle film is attached to the reticle, and then the reticle to which the reticle film is attached is used for exposure processing.