JP5579545B2 - Large pellicle frame, large pellicle, and method for manufacturing large pellicle frame - Google Patents

Description

  The present invention is used for manufacturing semiconductor devices such as IC (Integrated Circuit), LSI (Large Scale Integration), TFT LCD (Thin Film Transistor, Liquid Crystal Display), etc. The present invention relates to a frame for a large pellicle used for preventing foreign matter from adhering to a photomax or a reticle used in a lithography process.

  2. Description of the Related Art Conventionally, in manufacturing semiconductor circuit patterns and the like, dust prevention means called a pellicle is disposed on both sides of a photomask or reticle to prevent foreign matter from adhering to the photomask or reticle.

  As a general structure of a pellicle, a transparent thin film such as a polymer or glass is pasted on one side of a metal, ceramic, or polymer frame, and an adhesive layer for pasting on a mask on the opposite side. What provided (adhesive material) is mentioned. For example, a pellicle is formed from a transparent polymer film such as nitrocellulose or a cellulose derivative having a thickness of 10 μm or less on one edge surface of a frame of about several millimeters thick having a shape matched to the shape of a photomask or a reticle. A pellicle film is spread and bonded, and is attached to the other edge surface of the frame body on the surface of a photomask or reticle via an adhesive material.

  When foreign matter adheres to the surface of a photomask or reticle, the foreign matter forms an image on the photoresist formed on the semiconductor wafer and causes a circuit pattern defect. However, the pellicle must be formed on at least the pattern surface of the photomask or reticle. When the is placed, the foreign substance adhering to the surface of the pellicle is out of focus, so that it does not form an image on the photoresist formed on the semiconductor wafer and the circuit pattern will not be defective.

  In recent years, with the widespread use of various multimedia, there is a demand for a large pellicle applicable to a large photomask used in the photolithography process of a large color TFT LCD capable of high-quality and high-definition display.

  In such a large pellicle, there is a problem that the frame body is easily bent inward by the tension of the stretched pellicle film, and the effective exposure area becomes small. Therefore, in Patent Documents 1 and 2, the long side of the large pellicle frame is formed in a drum shape that curves outward, and the side of the large pellicle frame is made straight by the tension of the stretched pellicle film. Has been proposed.

Japanese Patent No. 4004188 Japanese Patent No. 40433232

  However, as in Patent Documents 1 and 2, since it is technically difficult to curve the entire side of the large pellicle frame in a curved shape, there is a problem that the manufacturability of the large pellicle frame is greatly reduced. . In addition, since it is technically difficult to bend with high dimensional accuracy, there is a possibility that some bends may remain in the vicinity of the corner after the large pellicle film is stretched depending on variations. For this reason, depending on the size of the bending portion, there is a possibility that the bending portion may be pressed when the mounter is affixed, which may cause film wrinkles and foreign matter.

  Accordingly, an object of the present invention is to provide a large pellicle frame body and a large pellicle that can suppress the reduction of the effective exposure area while ensuring ease of manufacture, and do not leave a large curved portion near the corner. .

A large pellicle frame according to the present invention is a large pellicle frame that is formed in a substantially rectangular shape and supports a large pellicle film, and is formed on a part of a side that constitutes the large pellicle frame. A bent portion that is bent toward is formed.

  According to the frame for a large pellicle according to the present invention, the bent portion can be formed by a simple method in which a part of the side is bent outward. Then, since the straight continuity of the side is cut by the bent portion, when the large pellicle film is spread on the large pellicle frame, the side of the large pellicle frame is bent inward by the tension of the large pellicle film. Even so, the maximum displacement amount of the side entering the inside of the large pellicle frame can be reduced. Thereby, reduction of the exposure effective area can be suppressed while ensuring ease of manufacture. When the large pellicle membrane is stretched, the amount of bending inward of the large pellicle frame can be easily kept within the tolerance range (within the specified range), and a straight line extends from the corner to the bent portion of the frame. Therefore, when mounting the mounting jig for the mounter between the corner portion and the bent portion, it is possible to prevent the mounter from causing a problem.

  Moreover, it has a pair of opposing long side and a pair of short side which opposes, and it is preferable that the bending part is formed in at least one long side. As described above, by forming the bent portion on at least one long side, it is possible to suppress the bending of the most easily bent portion, and thus it is possible to effectively suppress the reduction of the effective exposure area.

  A large pellicle according to the present invention includes the large pellicle frame described above and a large pellicle film stretched and supported by the large pellicle frame.

  According to the large pellicle of the present invention, even if the large pellicle film is stretched on the large pellicle frame while ensuring the manufacturability of the large pellicle frame by having the large pellicle frame described above. Reduction of the effective exposure area can be suppressed.

  A method for manufacturing a large pellicle frame according to the present invention is a method for manufacturing a large pellicle frame that is formed in a substantially rectangular shape and supports a large pellicle film, and includes a part of a side of the large pellicle frame. A bent portion that is bent toward the outside is formed.

  According to the large pellicle frame manufacturing method of the present invention, the bent portion can be formed by a simple method in which a part of the side is bent outward. The large pellicle frame manufactured by this manufacturing method has a straight continuity of the sides due to the bent portion. Therefore, when the large pellicle film is spread on the large pellicle frame, the large pellicle film is stretched by the tension of the large pellicle film. Even if the side of the frame is bent inward, the maximum amount of displacement of the side entering the inside of the large pellicle frame can be reduced. Thereby, reduction of the exposure effective area can be suppressed while ensuring ease of manufacture.

  According to the present invention, it is possible to suppress the reduction of the effective exposure area while ensuring ease of manufacture.

It is a perspective view showing an embodiment of a large pellicle. It is the schematic plan view which looked at the frame for large pellicles from the top. It is a figure for demonstrating the manufacturing process of a large pellicle. It is a figure for demonstrating the manufacturing process of a large pellicle. It is a figure for demonstrating the exposure effective area.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a perspective view showing an embodiment of a large pellicle, and FIG. 2 is a schematic plan view of the large pellicle frame body as viewed from above. As shown in FIGS. 1 and 2, the large pellicle 1 includes a substantially rectangular annular large pellicle frame 2 and a large pellicle film 3 bonded to the upper edge surface 2 e of the large pellicle frame 2. Yes. Although not shown, the large pellicle 1 includes an adhesive layer applied to the lower edge surface of the large pellicle frame 2, and a protective film that adheres to the adhesive layer and protects the adhesive layer. Is further provided.

  The large pellicle frame 2 includes a pair of opposing long sides 2a and 2b and a pair of opposing short sides 2c and 2d shorter than the long sides 2a and 2b. A substantially rectangular opening 4 is formed on the inner side surrounded by the pair of long sides 2a and 2b and the pair of short sides 2c and 2d. For this reason, the pair of long sides 2 a and 2 b and the pair of short sides 2 c and 2 d constitute the peripheral portion of the opening 4. The large pellicle frame 2 is provided with a groove portion 7 along the longitudinal direction (side direction) on the side surface 6 on the short side 2c, 2d side.

Opening area of the opening portion 4, preferably 1000 cm ² or more, more preferably 3000 cm ² or more, more preferably 5000 cm ² or more, preferably the upper limit is 35,000 ² or less.

  The width A of the long sides 2a and 2b and the width B of the short sides 2c and 2d are preferably as thin as possible from the viewpoint of securing the exposure area. There is a concern that the large pellicle frame 2 may be bent by tension. Since the width takes into account the rigidity of each side, the width A of the long sides 2a and 2b and the width B of the short sides 2c and 2d can be about 3 mm to 25 mm.

  The thickness C of the large pellicle frame 2 is lighter and easier to handle as it is thinner. However, if the thickness C is too thin, the tension of the large pellicle film 3 is used for the large pellicle when the large pellicle film 3 is expanded. There is a possibility that the problem that the frame 2 is bent occurs. From the balance between the two sides 2a to 2d, the thickness C of the large pellicle frame 2 is preferably about 3.5 mm to 12 mm.

  More specifically, the pair of long sides 2a and 2b are formed with the same dimensions, for example, a column member having a width A of 9.0 mm and a length of 800 mm. The pair of short sides 2c and 2d are formed with the same dimensions, for example, a column member having a width B of 7.0 mm and a length of 480 mm. That is, the width B of the short sides 2c and 2d in plan view (top view) is narrower than the width A of the long sides 2a and 2b. The curvature of the corner 5 of the large pellicle frame 2 is, for example, R = 2 mm.

  Then, bent portions 10a and 10b that are bent outward are formed at the center of the pair of long sides 2a and 2b.

  The bent portions 10a and 10b may have any shape as long as the bent portions 10a and 10b are bent toward the outside. From the viewpoint of ease of manufacture, the bent portions 10a and 10b are preferably triangular. . The bent portions 10a and 10b may be formed by bending the long sides 2a and 2b into a polygonal shape. The bent portions 10a and 10b can be formed, for example, by applying an external force toward the outside at the center portions of the long sides 2a and 2b formed in a straight line, for example, by punching. it can.

  Here, a method of forming by applying an external force toward the outside is preferable because manufacturing simplicity is better than cutting out a bent shape. When cutting out a bent shape, in the process of processing a large pellicle frame, the frame is an elastic deformation region and the dimensional accuracy may be slightly deteriorated. In some cases, some correction process is required. On the other hand, when forming by applying external force, since it becomes a plastic deformation area | region, a dimensional accuracy becomes better than a curved dimensional accuracy, and such a correction process becomes unnecessary.

  The protrusion width E of the bent portions 10a and 10b with respect to the long sides 2a and 2b is preferably 0.01 to 5.00% of the length A of the long sides 2a and 2b, more preferably the length A of the long sides 2a and 2b. 0.01 to 3.00%, more preferably 0.03 to 1.00% of the length A of the long sides 2a and 2b. It is.

Large pellicle frame body 2 formed in such a shape is, for example, aluminum, aluminum alloys (5000 series, 6000 series, 7000 series, etc.), iron and iron alloys, ceramics (SiC, AlN, Al2O3, etc.), Composed of a composite material of ceramic and metal (Al-SiC, Al-AlN, Al-Al ₂ O ₃ etc.), carbon steel, tool steel, stainless steel series, magnesium alloy, or resin such as polycarbonate resin, acrylic resin, It has a substantially rectangular shape in plan view. Since the pellicle sticks to the mask through the adhesive layer, and preferably has a high rigidity and a relatively small weight, aluminum, an aluminum alloy, a magnesium alloy, a resin, and the like are more preferable materials.

  As the surface treatment of the large pellicle frame body 2, alumite treatment, painting, paint coating, plating treatment, low melting point glass frit treatment, CVD treatment, PVD treatment by a sputtering method, etc. can be considered.

  The large pellicle film 3 constituting the large pellicle 1 is made of a transparent polymer film such as nitrocellulose, a cellulose derivative, a fluorine polymer, or a cycloolefin polymer, and the thickness thereof is, for example, 10 μm or less and 0.1 μm or more. Is preferred.

  The large pellicle film 3 is stretched on the upper edge surface 2e so as to cover the opening 4 of the large pellicle frame 2, and is attached to and supported by the large pellicle frame 2.

  The adhesive for bonding the large pellicle film 3 to the upper edge surface 2e of the large pellicle frame 2 is, for example, a fluorine-based adhesive such as an acrylic resin adhesive, an epoxy resin adhesive, a silicone resin adhesive, or a fluorine-containing silicone adhesive. Polymers can be used.

  In addition, as an adhesive material to support adhesion, styrene ethylene butylene styrene, styrene ethylene propylene styrene, or olefin-based hot-melt adhesive material, silicone adhesive material, acrylic adhesive material, or foam-based adhesive material Tape can be used. The thickness of the adhesive material layer is set so that the sum of the thickness of the large pellicle frame 2 and the thickness of the adhesive material does not exceed the specified distance between the large pellicle film 3 and the photomask. Below 0.01 mm or more is preferable.

  In addition, if a space exists inside the adhesive layer when the large pellicle film 3 is attached to the photomask, there is a possibility that foreign matter may stay in the space. Therefore, when applying an adhesive to the lower edge surface of the large pellicle frame 2, considering that the pressure-sensitive adhesive layer is crushed and spread by the pressure applied when the large pellicle 1 is attached to the photomask, It is preferable to apply to the inside of the opening 4 of the large pellicle frame 2 so that the adhesive does not protrude into the opening 4 during pressurization. Specifically, it is preferable to apply so that the space inside the adhesive layer is within 0.35 times the application width of the adhesive layer. The application width of the pressure-sensitive adhesive layer is preferably 0.3 to 0.6 times the width of each side 2a to 2d of the large pellicle frame 2, and extends along each side 2a to 2d of the large pellicle frame 2. It is preferable to apply.

  As a protective film for protecting the adhesive material, a film made of polyethylene terephthalate resin or polyethylene resin can be used. Further, a release agent such as a silicone release agent or a fluorine release agent may be applied to the surface of the protective film according to the adhesive strength of the adhesive material. The thickness of the protective film is preferably, for example, 1 mm or less and 0.01 mm or more.

  Next, a method for manufacturing the large pellicle 1 will be described.

  3 and 4 are diagrams for explaining the manufacturing process of the large pellicle. 3 and 4 show a method of manufacturing the large pellicle 1 using the large pellicle frame 2 shown in FIG.

  First, as shown in FIG. 3A, the frame body 21 is cut out from the base material that is the base material of the large pellicle frame body 2. As will be described later, since the long sides 2a and 2b of the frame body 21 are bent due to the formation of the bent portions 10a and 10b, the cut-out length of the frame body 21 is calculated by taking into account the portion shortened by the bending. To do.

  Next, as shown in FIG. 3B, the bent portions 10a and 10b are formed by bending the central portion of the long side of the frame body 21. As shown in FIG. As a result, the large pellicle frame 2 is formed.

  Next, as shown in FIG. 4, a large pellicle film 3 is stretched and bonded to the large pellicle frame 2. Then, the long sides 2a and 2b of the large pellicle frame 2 are bent inward by the tension of the extended large pellicle film 3, and the effective exposure area is reduced.

  Here, with reference to FIG. 5, with respect to the degree of reduction of the effective exposure area, when a large pellicle film is stretched on a conventional large pellicle frame in which no bent portion is formed, and for the large pellicle according to the present embodiment The case where a large pellicle film is spread on the frame is compared. In FIG. 5, the alternate long and short dash line indicates the conventional large pellicle frame 2 ′, and the solid line indicates the large pellicle frame 2 according to the present embodiment.

  As shown in FIG. 5, in the conventional large pellicle frame 2 ′, the long sides 2a and 2b are formed in a straight line, so that the maximum of the long sides 2a and 2b due to the tension of the stretched large pellicle film 3 is maximized. A displacement point becomes the center part of long side 2a, 2b. For this reason, when the large pellicle film 3 is spread on the conventional large pellicle frame 2 ', the central portions of the long sides 2a and 2b are greatly bent inward by the tension, and the effective exposure area is greatly reduced.

  In contrast, in the large pellicle frame body 2 according to the present embodiment, the central portions of the long sides 2a and 2b serving as the maximum displacement points are bent outward by the bent portions 10a and 10b. Even if the long sides 2a, 2b of the large pellicle frame 2 are bent inward by the tension of the stretched large pellicle film 3, reduction of the exposure effective area is suppressed.

  Thus, according to the present embodiment, the bent portions 10a and 10b can be formed by a simple method in which a part of the long sides 2a and 2b is bent outward. Since the straight continuity of the long sides 2a and 2b is cut by the bent portions 10a and 10b, when the large pellicle film 3 is stretched on the large pellicle frame 2, the tension for the large pellicle film 3 is used. Even if the long sides 2a and 2b of the frame 2 are bent inward, the maximum displacement amount of the long sides 2a and 2b entering the inside of the large pellicle frame 2 can be reduced. Thereby, reduction of the exposure effective area can be suppressed while ensuring ease of manufacture.

  Here, the large pellicle frame 2 is preferably subjected to a heating step or the like in order to release residual stress generated when it is manufactured by cutting out from a sheet-like base material.

  Further, by forming the bent portions 10a and 10b at the central portions of the long sides 2a and 2b serving as the maximum displacement points, it is possible to effectively suppress the reduction of the effective exposure area while minimizing the work man-hours. Can do.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the embodiment described above, the bent portion is formed on both of the pair of long sides, but the bent portion may be formed only on one long side.

  In the above embodiment, the bent portion is described as being formed only on the long side. However, the groove may be formed on the short side as long as it can be held by a handling jig (not shown) in the groove formed on the short side. .

  Moreover, although the said embodiment demonstrated as what one bending part was formed in the center part of a long side, there is no restriction | limiting in the formation position and number of a bending part, For example, in the center part and both ends of a long side Two bent portions may be formed.

  In addition, when one bending part is formed in the center part of a long side, length D (refer FIG. 2) of bending part 10a, 10b, Preferably it is 20-100 of the length A of long side 2a, 2b. %, More preferably 30 to 100% of the length A of the long sides 2a and 2b.

  DESCRIPTION OF SYMBOLS 1 ... Large pellicle, 2 ... Large pellicle frame body, 2a, 2b ... Long side, 2c, 2d ... Short side, 2e ... Upper edge surface, 3 ... Large pellicle film, 4 ... Opening, 5 ... Corner, 6 ... side face, 7 ... groove part, 10a, 10b ... bent part, 21 ... frame.

Claims (4)

A frame for a large pellicle that is formed in a substantially rectangular shape and supports a large pellicle membrane for spreading,
A large pellicle frame , wherein a bent portion bent outward is formed in a part of a side constituting the large pellicle frame, and the bent portion has a triangular shape . A pair of opposing long sides and a pair of opposing short sides;
The frame for a large pellicle according to claim 1, wherein the bent portion is formed on at least one of the long sides. A frame for a large pellicle according to claim 1 or 2,
A large pellicle membrane stretched and supported by the large pellicle frame;
A large pellicle characterized by comprising: A method of manufacturing a frame for a large pellicle that is formed in a substantially rectangular shape and supports a large pellicle film to stretch,
A method for manufacturing a large pellicle frame, comprising forming a triangular bent portion in which a part of a side of the large pellicle frame is bent outward.

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