JP2012063444A - Pellicle frame, pellicle, and method of manufacturing pellicle frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pellicle frame, a pellicle, and a method of manufacturing the pellicle frame such that suppresses breakage of a coating film even when a frame member composed of divided members is coated with a coating material while size precision is secured.SOLUTION: When divided frames of a pellicle frame 2 of a pellicle 1 are coated, the coating material may have a glass transition point of 50 to 150°C. Consequently, even if the pellicle frame 2 flexes, adhesion between the pellicle frame 2 and coating material can be secured and a coating film P is therefore prevented from peeling. Further, the coating film P has predetermined strength, so the coating film P is prevented from being shaven by a handling tool etc. Breakage of the coating film P such as cracking can, therefore, be suppressed. The size can be easily adjusted because of the divided frames, so size precision can be secured.

Description

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

  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 attached to one side of a pellicle frame made of metal, ceramics, or polymer, and an adhesive for attaching to a mask on the opposite side. What provided the layer (adhesive material) is mentioned. For example, the pellicle is 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 pellicle frame having a shape matching the shape of a photomask or a reticle. A pellicle film made of is spread and bonded, and is attached to the other edge surface of the pellicle 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, a pellicle applicable to a large photomask used in the photolithography process of a large color TFT LCD capable of high image quality and high definition display has been demanded. In this regard, for example, Patent Document 1 discloses a pellicle applicable to a large photomask. Patent Document 2 discloses a frame body that uses a reinforcing material having a larger elastic coefficient than that of the frame body and the frame body in order to cope with the bending and distortion of the pellicle frame body.

  The above-described pellicle frame is usually subjected to a surface treatment so as to be black. For example, Patent Document 3 discloses that the pellicle frame body is anodized and blackened by a sealing process. Patent Document 4 discloses that the pellicle frame is blackened by electrodeposition coating.

JP 2001-109135 A JP 2006-284927 A JP-A-6-250383 JP 2007-333910 A

  By the way, the pellicle frame is manufactured by punching one sheet-like base material, and is often an integral type without a joint. This is based on the viewpoint of ensuring the flatness of the pellicle. Depending on the flatness of the base material, there is a base material that cannot be used to manufacture the pellicle frame. As the size of the pellicle frame increases, it is not easy to obtain the accuracy of the flatness of the pellicle frame. In the case of an integrated pellicle frame, it has been difficult to ensure dimensional accuracy. For this reason, the manufacturing process is time-consuming, which causes a decrease in yield and an increase in the cost of manufacturing the pellicle frame. In addition, in order to blacken the pellicle frame body, a large-scale tank is required to subject the pellicle frame body to alumite treatment and electrodeposition coating treatment. I was invited. Furthermore, with a large pellicle frame, it is difficult to uniformly carry out an alumite treatment or an electrodeposition coating treatment, and it has been difficult to improve the accuracy of flatness.

  Regarding such problems, in order to improve the dimensional accuracy, flatness, yield, and cost of the pellicle frame body, it has been considered to join and use divided frame members (hereinafter referred to as “divided members”). Yes. However, there is a tendency that the surface subjected to the alumite treatment or the electrodeposition coating treatment does not become uniform due to the gap between the joint portions. In particular, when the surface treatment is not uniformly applied, there is a possibility that a thin part of the coating is erroneously recognized as a foreign substance on the surface, or corrosion or the like occurs from a part where the treatment is not uniform.

  Therefore, it has been proposed to paint the pellicle frame. However, since the adhesion between the coating material and the frame member cannot be ensured, it is easy to peel off, and the paint is scraped when operating with a handling jig. And foreign matter were generated, and the reality was poor.

  The present invention has been made in order to solve the above-mentioned problems, and even when the coating is applied to the frame member constituted by the divided members while ensuring the dimensional accuracy, the coating film is damaged. It is an object of the present invention to provide a pellicle frame body, a pellicle, and a method for manufacturing the pellicle that can suppress the above.

  As a result of intensive studies, the present inventors have found that coating damage can be suppressed by coating a specific coating material on a frame member having at least one joint, and the present invention has been completed. .

  That is, the present invention is a pellicle frame body that stretches and supports a pellicle film so as to cover an opening having a rectangular shape in plan view, the periphery of the opening is formed by a frame member, and the frame member is at least The glass transition point of the coating material which is joined by one joining part and forms a coating film on the surface of a frame member is 50 to 150 degreeC, It is characterized by the above-mentioned.

  In this pellicle frame, the glass transition point of the coating material is set to 50 ° C. or more and 150 ° C. or less in the coating of the frame member. As a result, even when the pellicle frame is bent, the adhesion between the frame member and the coating material can be ensured, so that the peeling of the coating film can be prevented. Moreover, since it has a predetermined strength, it is possible to prevent the coating film from being scraped by a handling jig or the like. Therefore, the occurrence of breakage such as cracks in the coating film can be suppressed. Moreover, generation | occurrence | production of the outgas resulting from peeling of a coating film, etc. and a foreign material can be prevented by suppressing the damage of a coating film. As a result, haze can be suppressed. Moreover, since a large-scale apparatus is not required, cost can be reduced.

  In addition, since the frame member has at least one joint portion, the dimensions can be easily adjusted, so that dimensional accuracy (dimensional stability) can be ensured and the manufacturing process can be simplified. Moreover, by setting it as a division | segmentation frame body, a man-hour for a cutting process decreases rather than cutting out from one sheet-like base material, and the residual stress to the frame member applied at the time of a process becomes small. Further, considering the anisotropy of the material, the frame member having the same direction can be used, so that the anisotropy of the pellicle frame as a whole is reduced. Thus, since residual stress and anisotropy become small, the release | release by the stress distortion in the heating process in a pellicle manufacturing process becomes small, and the dimension as a pellicle is stabilized. For this reason, it is not necessary to perform a heat treatment or the like in advance in order to release the residual stress, and there is a manufacturing advantage that the number of processes is reduced. In addition, since the stress strain tends to open in the course of time, the divided frame body having a smaller residual stress can ensure dimensional stability even when stored for a long period of time.

  In addition, in the surface treatment for applying an electrode to the pellicle frame, such as anodized or electrodeposition coating, the electrode may not flow uniformly at the joint or the like. For this reason, coating is preferred from the viewpoint of problems such as pseudo foreign matter and appearance due to non-uniformity of the surface treatment or the like. In the case of anodizing, etc., a slight stress is applied when the electrode is applied, and there is no influence of the residual stress generated when the electrode is gripped. Furthermore, by using a coating material, unevenness in coating is reduced, and flatness can be maintained. In addition, since the coating material is often polymerized by applying heat, the heat treatment of aluminum can be performed at the same time, and the deformation of the dimensions due to the application of heat during the use of the pellicle can be prevented.

  The pencil hardness of the coating film is preferably B or more and 6H or less. By setting it as such pencil hardness, the intensity | strength which can endure the impact during handling jigs and transportation can be ensured. Moreover, since it has a predetermined strength, it is possible to use a general razor in the process of cutting an excess part of the pellicle film when the pellicle film is spread and supported on the pellicle frame. Thereby, it is not necessary to use special equipment and instruments in the manufacturing process, and an increase in facilities can be prevented.

  The coating material is preferably a coating type. Thus, by using a coating type coating material, a coating method such as air spray, electrostatic coating, dip coating, roll coating or the like can be used. Thereby, a coating film can be formed uniformly and the flatness of a pellicle frame can be ensured.

  As the coating material, an epoxy-based, acrylic-based or fluorine-based material can be used.

  The frame member is composed of a pair of opposing long sides and a pair of opposing short sides, and the thickness of the coating film of at least one corner formed by the long sides and the short sides is long or short. The thickness is preferably 20 times or less the thickness of the coating film at the center of the side. According to such a configuration, even when an excessive force is applied to the corner portion, the adhesiveness is good, and thus peeling and cracking can be suppressed.

  A pellicle according to the present invention includes any one of the above-described pellicle frame and a pellicle film that is stretched and supported so as to cover an opening of the pellicle frame. By spreading the pellicle film on the above-mentioned pellicle frame body, even if the pellicle frame body is bent, the adhesion between the frame member and the coating material can be secured, thus preventing the coating film from peeling off. it can. Moreover, since it has a predetermined strength, it is possible to prevent the coating film from being scraped by a handling jig or the like. Therefore, the occurrence of breakage such as cracks in the coating film can be suppressed.

  Further, since the frame member of the pellicle frame body has at least one joint portion, the dimensions can be easily adjusted, so that the dimensional accuracy can be ensured and the manufacturing process can be simplified. Moreover, by setting it as a division | segmentation frame body, a man-hour for a cutting process decreases rather than cutting out from one sheet-like base material, and the residual stress to the frame member applied at the time of a process becomes small. Further, considering the anisotropy of the material, the frame member having the same direction can be used, so that the anisotropy of the pellicle frame as a whole is reduced. Furthermore, since the stress strain tends to open in the course of time, the divided frame body having a smaller residual stress can ensure dimensional stability even when stored for a long period of time.

  The method for manufacturing a pellicle frame according to the present invention is a method for manufacturing a pellicle frame in which a pellicle film is stretched and supported so as to cover an opening having a rectangular shape in plan view, and the periphery of the opening is formed. A frame member having at least one joint portion is prepared, and a step of joining the joint portion of the frame member and a coating material having a glass transition point of 50 ° C. or more and 150 ° C. or less are applied to the frame member to form a coating And a step of heat-treating the coating film. By manufacturing the pellicle frame in such a process, even if the pellicle frame is bent, the adhesion between the frame member and the coating material can be secured, so the coating film can be peeled off. Can be prevented. Moreover, since it has a predetermined strength, it is possible to prevent the coating film from being scraped by a handling jig or the like. Therefore, a pellicle frame body that can suppress the occurrence of breakage such as cracks in the coating film can be produced.

  According to the present invention, while ensuring dimensional accuracy (dimensional stability), even when a frame member composed of divided members is coated with a coating material, damage to the coating film during handling is suppressed. it can. As a result, the yield can be improved and the outgas and foreign matter caused by peeling of the coating film can be prevented. Further, unevenness due to the surface treatment can be suppressed.

1 is a perspective view showing a pellicle according to an embodiment of the present invention. It is the figure which looked at the pellicle shown in FIG. 1 from the top. It is a perspective view which expands and shows the corner | angular part of a pellicle frame. It is a figure which shows a junction part. It is a figure which shows the other form of a junction part. It is a figure which shows the other form of a junction part. It is a figure which shows the other form of a junction part. It is the VIII-VIII sectional view taken on the line in FIG. It is the figure which looked at the pellicle frame which concerns on a modification from the top. It is the figure which looked at the pellicle frame which concerns on a modification from the top. It is a figure which shows the junction part which concerns on an Example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  FIG. 1 is a perspective view showing a pellicle according to an embodiment of the present invention, and FIG. 2 is a top view of the pellicle shown in FIG. As shown in each figure, the pellicle 1 includes a pellicle frame 2 and a pellicle film 3 that is stretched and supported on the upper edge surface 2e of the pellicle frame 2. Although not shown, the pellicle 1 further includes an adhesive layer applied to the lower edge surface of the pellicle frame 2 and a protective film that is adhered to the adhesive layer and protects the adhesive layer. ing. The pellicle 1 is a large pellicle, and the pellicle frame 2 is a large pellicle frame.

The pellicle frame 2 is made of, for example, aluminum, aluminum alloys (5000 series, 6000 series, 7000 series, etc.), iron and iron alloys, ceramics (SiC, AlN, Al ₂ O ₃ etc.), a composite material of ceramics and metal ( Al-SiC, Al-AlN, Al-Al 2 O 3 , etc.), carbon steel, tool steel, stainless steel series, magnesium alloy, or a polycarbonate resin, a resin such as an acrylic resin, exhibits a substantially rectangular shape in plan view Yes. Since the pellicle 1 is attached to the mask via the adhesive layer, a material having high rigidity and relatively small weight is preferable, and materials such as aluminum, aluminum alloy, magnesium alloy, and resin are preferable. The pellicle frame 2 is configured by a plurality of divided members 20a to 20d and connecting members 21a to 21d described later.

The pellicle frame 2 has a pair of opposed long sides 2a and 2b and a pair of opposed short sides 2c and 2d shorter than the long sides 2a and 2b. In the pellicle frame 2, the long side 2a and the long side 2b are formed to have the same length, and the short side 2c and the short side 2d are formed to have the same length. The pellicle frame 2 has a rectangular opening 4. The opening area of the opening 4 is preferably 1000 cm ² or more, more preferably 3000 cm ² or more, more preferably 5000 cm ² or more and 35,000 ² or less.

  The pair of long sides 2a and 2b is formed of a column member having a width of, for example, 9.0 mm, and the length thereof is, for example, 800 mm. The pair of short sides 2c and 2d is made of a column member having a width of, for example, 7.0 mm, and the length thereof is, for example, 480 mm. That is, the width of the short sides 2c and 2d in plan view (top view) is narrower than the width of the long sides 2a and 2b. The curvature of the corner 5 of the pellicle frame 2 is, for example, R = 2 mm. In addition, the vertex when it is assumed that there is no curvature in the corner portion 5 is hereinafter simply referred to as “vertex”. Grooves 7 are provided along the longitudinal direction (side direction) on the side surface 6 of the pellicle frame 2.

  The width of each side 2a to 2d of the pellicle frame 2 is preferably as thin as possible from the viewpoint of securing an exposure area. However, if the width is too small, the pellicle frame 2 is stretched by the tension of the pellicle film 3 when the pellicle film 3 is expanded. There is a risk that the problem of bending will occur. Each side 2a to 2d can have a thickness of about 3 mm to 25 mm in order to obtain a width with consideration of rigidity with respect to the length of each side.

  Further, regarding the thickness of the pellicle frame body 2, the thinner the pellicle 1, the lighter and easier to handle the pellicle 1. However, if the pellicle film 3 is too thin, the pellicle frame body 2 will be bent by the tension of the pellicle film 3. Problems may arise. The thickness of the pellicle frame body 2 is preferably about 3.5 mm to 12 mm from the balance between the two according to the length of each side 2a to 2d.

  The pellicle film 3 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 preferably 10 μm or less and 0.1 μm or more, for example. The pellicle film 3 is spread on the upper edge surface 2 e so as to cover the opening 4 of the pellicle frame 2, and is attached to and supported by the pellicle frame 2.

  As an adhesive for adhering the pellicle film 3 to the upper edge surface 2e of the pellicle frame 2, for example, a fluorine-based polymer such as an acrylic resin adhesive, an epoxy resin adhesive, a silicone resin adhesive, or a fluorine-containing silicone adhesive is used. be able to.

  The adhesive material for sticking and supporting the pellicle film 3 is based on styrene ethylene butylene styrene, styrene ethylene propylene styrene, olefin-based hot melt adhesive material, silicone adhesive material, acrylic adhesive material, or foam. The adhesive tape used as the material can be used. The thickness of the pressure-sensitive adhesive layer is set within a range not exceeding the distance between the pellicle film 3 and the photomask in which the total thickness of the pellicle frame 2 and the thickness of the pressure-sensitive adhesive is defined. 01 mm or more is preferable.

  In addition, when the pellicle film 3 is attached to the photomask, if there is a space inside the adhesive layer, foreign matter may stay in the space. Therefore, when applying the pressure-sensitive adhesive to the lower edge surface of the pellicle frame 2, the pressure-sensitive adhesive layer is crushed and spread by the pressure applied when the pellicle 1 is attached to the photomask. It is preferable to apply to the inside of the opening 4 of the pellicle frame 2 so that the adhesive does not protrude into the opening 4. 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 pellicle frame 2, and is applied along each side 2a to 2d of the pellicle frame 2. It is preferable.

  As a protective film for protecting the adhesive material, a film made of polyethylene terephthalate resin or polyethylene resin can be used. Moreover, according to the adhesive force of an adhesive material, you may apply | coat a mold release agent, for example, a silicone type release agent, or a fluorine type release agent to the surface of a protective film. The thickness of the protective film is preferably, for example, 1 mm or less and 0.01 mm or more.

  Next, the pellicle frame 2 will be described in detail with reference to FIGS. 2 and 3. FIG. 3 is an enlarged perspective view showing a corner portion.

  The pellicle frame body 2 is a divided frame body composed of a plurality of frame members that form the periphery of the opening 4, and the divided members 20a and 20b that constitute each of the pair of long sides 2a and 2b, and a pair of short members. Dividing members 20c. Constituting each of the sides 2c, 2d. 20d and the corner member 5 and the connecting members 21a to 21d that connect the split members 20a and 20b and the split members 20c and 20d. That is, the pellicle frame body 2 includes one end of the divided members 20a and 20b and the divided members 20c. The one end part of 20d is connected so as to form a substantially right angle via the connecting members 21a to 21d, thereby forming a substantially rectangular shape. The pellicle frame body 2 has eight joint portions 22a to 22h along the circumferential direction of the frame body.

  The dividing member 20a and the dividing member 20b have substantially the same shape, and the dividing member 20c and the dividing member 20d have substantially the same shape. Further, the connecting members 21a to 21d that form the corner portions 5 each have an L shape, and all have substantially the same shape. The length of the divided members 20a and 20b is, for example, 700 mm, and the divided members 20c. The length of 20d is, for example, 380 mm. As for the length of connecting member 21a-21d, one side is 50 mm, for example. The distance between the joint portions 22a to 22h and the corner portion 5 closest to the joint portions 22a to 22h is the length of the long sides 2a and 2b or the short sides 2c and 2d provided with the joint portions 22a to 22h. Is set to 45% or less.

  When the pellicle frame 2 is based on the dividing member 20a, the dividing member 20a, the connecting member 21a, the dividing member 20d, the connecting member 21b, the dividing member 20b, and the connecting member 20a are connected in the clockwise direction with respect to the opening axis of the opening 4. The member 21c, the divided member 20c, and the connecting member 21d are connected in this order. In addition, in FIG. 2, although the junction parts 22a-22h are eight places, as a number of junction parts, what is necessary is just one place or more, Preferably it is 2-30 places, More preferably, it is 2-20 places, More preferably Are 4 to 15 places.

  Here, when there is one joint, it is possible to adjust at the joint without requiring flatness and dimensional accuracy as much as an integrated type without a joint when cutting from a single sheet-like base material. In addition, since it is possible to plastically deform one divided member to form a frame, it is possible to save the base material and reduce the cost. Furthermore, when the number of joints is two or more, it is more preferable because the flatness can be easily adjusted. By using two or more joint portions in this way, the processing accuracy of each part constituting the pellicle frame body 2 can be increased, and the integrated pellicle frame body is cut out from a single sheet-like base material. However, the flatness accuracy can be easily obtained, and the dimensional accuracy is increased.

  The above-mentioned joining parts 22a-22h are exhibiting a complicated shape (uneven shape), as shown in FIG. Specifically, for example, the joining portion 22f includes a convex portion 23 formed on the connecting member 21c and a concave portion 24 formed on the dividing member 20c. The convex portion 23 formed on the connecting member 21c has a substantially circular shape in plan view, and the width dimension d2 on the distal end side is larger than the width dimension d1 on the proximal end side. Correspondingly, the recess 24 formed in the split member 20c has a substantially circular shape in plan view. The joining portion 22f is joined by fitting with a convex portion 23 formed on the connecting member 21c and a concave portion 24 formed on the dividing member 20c. The joint portions 22a to 22e, 22g, and 22h have the same configuration.

  The shapes of the joint portions 22a to 22h may be shapes other than the above shapes. For example, as shown in FIG. 5A, a plurality of (here, two) convex portions 23a and 23b are formed on the connecting member 21a, and correspondingly, a plurality of concave portions 24a, 24b may be formed. Moreover, as shown in FIG.5 (b), the structure by which the convex part 23 and the recessed part 24 were each formed in the connection member 21a and the division member 20a may be sufficient.

  Moreover, as shown to Fig.6 (a) and (b), convex part 23a-23c and recessed part 24a-24c may exhibit substantially trapezoid shape in planar view. As a preferable shape of the joining portions 22a to 22h, a shape composed of a tenon and a groove, and a shape in which the entire outer peripheral surface (side surface) of the convex portion (tenon) 23 is covered by the inner peripheral surface of the concave portion (groove) 24 is preferable. That is, it is not a simple shape that just abuts the flat end faces 51a and 51b of the split members 50a and 50b as shown in FIG. 7, and it is only necessary that the bonding area is relatively larger than the simple shape. . In addition, when providing a junction part in the corner | angular part 5 vicinity, it is not limited to the structure which abuts an end surface along the circumferential direction of the pellicle frame 2, It is the structure which abuts the end surface of a division member on the side surface of a division member. There may be a configuration in which end surfaces inclined at the corner portion 5 are in contact with each other.

  The joint strength of the joint portions 22a to 22h is 10 kgf or more. The pellicle frame 2 bends inward when the pellicle film 3 is attached. At this time, when the bonding strength is 10 kgf or more, stress concentration is relieved, so that gaps, backlash, and the like are less likely to occur at the bonding portions 22a to 22h. Thereby, even if the pellicle frame body 2 is constituted by the divided members 20a to 20d and the connecting members 21a to 21d, the dimensions are stabilized. Further, the pellicle 1 is preferably less bent to the inside of the pellicle frame 2 when the pellicle film 3 is stretched. However, by setting the bonding strength of the bonding portions 22a to 22h to 10 kgf or more, the pellicle frame 2 Inward bending can be suppressed.

  This inward bending of the pellicle 1 is regulated to a predetermined amount by a mask manufacturer from the viewpoint of securing an effective exposure area of the pellicle 1. In the pellicle frame 2, it is necessary to set the amount of bending within the allowable range, but by setting the bonding strength to 10 kgf or more, the bending can be suppressed as described above, and the amount of bending is within the predetermined range. Can be set. Furthermore, when handling the pellicle 1 (operation such as movement), a jig is attached to the groove portion 7 of the pellicle frame body 2 to handle the pellicle 1 vertically and horizontally. If the inward deflection is large, the jig On the other hand, if the pellicle 1 is likely to fall off and is greatly bent outward, the pellicle 1 may be rubbed when attached to a jig, and foreign matter may be generated. In this respect, in the pellicle frame body 2, by setting the bonding strength at the bonding portions 22a to 22h to 10 kgf, it is possible to prevent the occurrence of foreign matter while preventing the pellicle 1 from falling.

  Further, the pellicle film 3 is attached to the pellicle frame 2 by applying a load to the pellicle frame 2, and this load varies from 10 kgf to 70 kgf depending on the apparatus. Therefore, it is necessary to take measures to prevent the joints 22a to 22h from being deformed by different loads depending on the apparatus. Further, when the shape of the pellicle frame body 2 is deviated from a predetermined dimension, the joint portions 22a to 22h are locally subjected to weighting in order to correct the size, and the joint portions 22a to 22h may be deformed. In order to solve these problems, the bonding strength of the bonding portions 22a to 22h is preferably 10 kgf or more, more preferably 15 kgf or more, and further preferably 25 kgf or more.

  As a joining method that achieves the joining strength of the joining parts 22a to 22h as described above and can be used from the exterior as the pellicle 1, the divided members 20a to 20d and the connecting members 21a to 21d are fitted or an adhesive is used. It is preferable to use it. When making it fit, the shape which provided the convex part in the edge part of joining, and the recessed part made to fit in the other edge part is preferable. Furthermore, a shape in which the root dimension (proximal end side dimension) of the convex portion is smaller than the maximum lateral dimension on the distal end side is more preferable because it is resistant to tension in the length direction.

  When an adhesive is used, it is suitable for various shapes of joints, and the rigidity can be further increased depending on the shape. The larger the adhesive application area is, the stronger the adhesive strength is. Therefore, it is preferable that the adhesive area is larger than the joining of the cross sections cut perpendicularly (simple joining). If it is not simple joining, joint strength can be made 10 kgf or more by using the above-mentioned joining together. In addition, the caulking crushes a part of the surface of the joint portion, but scratches occur, but a rigid surface, a mask adhesive, a film adhesive, or the like can be applied without any problem, and can be used. Further, by adopting a method such as fitting or bonding, there is no problem at all on the flatness of the joint portions 22a to 22h and the appearance as the pellicle 1.

  As welding methods other than the above-mentioned bonding, laser welding, shrink shrinkage, cold shrinkage, etc. can be considered, but although laser welding has high joining strength, unevenness occurs in the joint, so that only the joint is extremely flat. The properties deteriorate, and the appearance is not preferable. In addition, in the case of shrinkage, the appearance is good because extra pressure such as press is not required for fitting, but in the case of an aluminum alloy with high thermal conductivity, the effect of shrinkage cannot be expected and the joint strength is low. This is not preferable because of the possibility. A chilled swallow is not preferable because it has the same effect as a baked swallow. Therefore, the joining method of the joint is preferably a fitting or an adhesive for these reasons.

  Further, as shown in FIG. 8, a coating film P is formed as a surface treatment on the entire surface of the pellicle frame 2 having the above-described configuration. The coating film P that coats the surface of the pellicle frame 2 is formed of a coating material. 8 is a cross-sectional view taken along line VIII-VIII in FIG.

  Here, the coating material must be a material that can withstand the impact of the pellicle frame body 2 during the handling of the pellicle 1, the contact of the handling jig, and the transportation. In order to withstand contact and impact caused by the bending of the pellicle frame body 2, the coating material must be flexible. On the other hand, in order for the coating film P to withstand handling jigs and impacts during transportation, it is also necessary to have hardness. In other words, the physical properties of the coating material require properties that are contradictory to flexibility and hardness.

  Therefore, the coating material for forming the coating film P has a glass transition point of 50 ° C. or higher and 150 ° C. or lower, more preferably a glass transition point of 80 ° C. or higher and 140 ° C. or lower. The pencil hardness of the coating film P formed by applying a coating material is preferably B or more and 6H or less, and more preferably B or more and 5H or less. The coating material having such physical properties is preferably a coating type. The coating-type coating material referred to here is one in which coating is carried out in a liquid state, followed by heating, whereby polymerization proceeds and a coating film P is formed. As a method of coating the coating material in a liquid state, air spray, electrostatic coating, dip coating, and roll coating are desirable, and among these, an air spray method is preferable.

  After applying the coating material, heat treatment is performed. The heating temperature at this time is preferably 100 ° C. or higher. And an application | coating method and a heating temperature are adjusted so that it may be settled in the range of said glass transition point and pencil hardness at the temperature of 100 degreeC or more, and the optimal polymerization degree is selected. For the best coating, it is preferable to use an epoxy-based, acrylic-based, or fluorine-based material as the coating material, and more preferable to use acrylic-based and fluorine-based materials. Acrylic and fluorine materials are resistant to impacts due to external forces such as handling in the process, so there is little concern about peeling. Furthermore, it is most preferable to use a fluorine-based material that is resistant to shaving. The coating film P may be a single layer, and if it is a multilayer coating, the adhesion with the frame material can be improved.

  The pellicle frame 2 has a coating film P thickness of a predetermined portion (corner portion 5) of the long side 2a, 2b or short side 2c, 2d, and a thickness of about 20 times or less that of the other portion (center portion). It is preferable to do. Unreasonable force may be applied to the corners by attaching a handling jig or the like. Further, since the corner portion has high rigidity, it tends to be strongly attached to the mask. When the pellicle is peeled from the mask, a stronger force may be applied to the corner portion than near the center. At this time, if the coating film at the corners is 20 times or more thicker than the other parts, the adhesiveness is deteriorated, so that the coating film may be peeled off. Therefore, the thickness of the coating film P at the corner 5 is preferably 20 times or less that of the other part, more preferably 0.05 times to 20 times that of the other part. Further, the film thickness itself of the coating film P may be 5 μm to 100 μm. It is preferable that the portion to be subjected to this specific characteristic is the corner portion 5 of the pellicle frame body 2, and more preferably one corner portion 5 than the four corner portions 5, but the number is particularly limited. However, the effect becomes more conspicuous when the number is one or more.

  Then, the manufacturing method of the pellicle frame 2 is demonstrated. First, the divided members 20a to 20d and the connecting members 21a to 21d constituting the long sides 2a and 2b and the short sides 2c and 2d made of, for example, aluminum or an aluminum alloy are prepared. Next, the divided members 20a to 20d and the connecting members 21a to 21d are joined at the joining portions 22a to 22h to form a frame member. Subsequently, the above-described coating material is applied to the frame member by, for example, an air spray method. At this time, in the corner portion 5, the coating thickness is made thicker than other portions. Then, the frame member to which the coating material is applied is subjected to heat treatment, and the coating film P is formed on the surface of the frame member. Thus, the pellicle frame body 2 is formed. Thereafter, the pellicle film 3 is spread on the pellicle frame 2 to form the pellicle 1.

  As described above, in the pellicle frame body 2 of the pellicle 1, the glass transition point of the coating material is set to 50 ° C. or higher and 150 ° C. or lower in the coating of the divided frame body. Accordingly, even when the pellicle frame 2 is bent, the adhesion between the pellicle frame 2 and the coating material can be secured, and thus the coating film P can be prevented from peeling off. Moreover, since it has predetermined intensity | strength, the abrasion of the coating film P by a handling jig etc. can also be prevented. Therefore, generation | occurrence | production of damage, such as a crack of the coating film P, can be suppressed. Moreover, generation | occurrence | production of the outgas and foreign material resulting from peeling of the coating film P etc. can be prevented by suppressing the damage of the coating film P. As a result, haze can be suppressed. Moreover, since a large-scale apparatus is not required, cost can be reduced.

  The pellicle frame 2 of the pellicle 1 is formed by joining the divided members 20a to 20d and the connecting members 21a to 21d. In this embodiment, the joint strength at the joint portions 22a to 22h between the split members 20a to 20d and the connecting members 21a to 21d is set to 10 kgf or more. Therefore, even if it is a division | segmentation frame, while being able to suppress bending and distortion, rigidity can be ensured. Moreover, by setting it as the division | segmentation frame which consists of division member 20a-20d and connection member 21a-21d, a dimension can be adjusted easily and a manufacturing process can be simplified while being able to ensure a dimensional accuracy. Therefore, it is possible to easily obtain the same dimensional accuracy as that of the frame body having no joint portion. Therefore, when using the divided frame, rigidity and dimensional stability can be maintained without using a highly rigid member or the like for the joint portions 22a to 22h, and the yield can be improved. In particular, when the pellicle 1 is large, the configuration of this embodiment is more effective.

  Further, considering the anisotropy of the material, since the frame member having the same direction can be used, the anisotropy of the pellicle frame 2 as a whole is reduced. Since the residual stress and the anisotropy are thus reduced, the release due to stress strain or the like during the heating process in the manufacturing process of the pellicle 1 is reduced, and the dimension of the pellicle 1 is stabilized. For this reason, it is not necessary to perform a heat treatment or the like in advance in order to release the residual stress, and there is a manufacturing advantage that the number of processes is reduced. In addition, since the stress strain tends to open in the course of time, the divided frame body having a smaller residual stress can ensure dimensional stability even when stored for a long period of time.

  Moreover, in the surface treatment which applies an electrode to the pellicle frame 2, for example, alumite or electrodeposition coating, the electrode may not flow uniformly at the joint portions 22a to 22h. For this reason, coating is preferred from the viewpoint of problems such as pseudo foreign matter and appearance due to non-uniformity of the surface treatment or the like. In the case of anodizing, etc., a slight stress is applied when the electrode is applied, and there is no influence of the residual stress generated when the electrode is gripped. Furthermore, by using a coating material, unevenness in coating is reduced, and flatness can be maintained. In addition, since the coating material is often polymerized by applying heat, the heat treatment of aluminum can be performed at the same time, and the deformation of the dimensions due to the application of heat during the use of the pellicle can be prevented.

  Moreover, the pencil hardness of the coating film P is B or more and 6H or less. By setting it as such pencil hardness, the intensity | strength which can endure the impact during handling jigs and transportation can be ensured. Further, since the pellicle film 3 is stretched and supported on the pellicle frame 2, a general razor can be used in the process of cutting an excess portion of the pellicle film 3 because it has a predetermined strength. Thereby, it is not necessary to use special equipment and instruments in the manufacturing process, and an increase in facilities can be prevented.

  The coating material used for forming the coating film P is a coating type. Thus, by using a coating type coating material, a coating method such as air spray, electrostatic coating, dip coating, roll coating or the like can be used. Thereby, the coating film P can be formed uniformly and the flatness of the pellicle frame 2 can be ensured.

  The pellicle frame 2 is composed of a pair of opposing long sides 2a and 2b and a pair of opposing short sides 2c and 2d. At least one formed by the long sides 2a and 2b and the short sides 2c and 2d. The coating film P at one corner 5 has a thickness of 30 μm or more and 100 μm or less than the central part of the long sides 2a and 2b or the short sides 2c and 2d. According to such a configuration, it is possible to change the pasting accuracy when the pellicle 1 is pasted on the photomask.

  Then, the modification of the said embodiment is demonstrated. FIG. 9 is a top view of a pellicle frame according to a modification. As shown in FIG. 9, the pellicle frame 2A is different from the above-described pellicle frame 2 in the joining form, and is similar to the above-described pellicle frame 2 in that the coating film P is formed on the surface. The pellicle frame 2A is formed of divided members 30a and 30b that constitute the long sides 2Aa and 2Ab, and divided members 30c and 30d that constitute the short sides 2Ac and 2Ad. The long sides 2Aa, 2Ab, that is, the divided members 30a, 30b have the same length, and the short sides 2Ac, 2Ad, that is, the divided members 30c, 30d have the same length. The pellicle frame 2A is configured by joining the divided members 30a and 30b and the divided members 30c and 30d, and has four joint portions 31a to 31d. The structure of the joining parts 31a to 31d is the same as that of the joining parts 22a to 22h. The joint portions 31a to 31d may have other shapes.

  FIG. 10 is a top view of a pellicle frame according to a modification. As shown in FIG. 10, the pellicle frame 2B is different from the above-described pellicle frame 2 in the joining form, and is similar to the above-described pellicle frame 2 in that the coating film P is formed on the surface. The pellicle frame 2B is formed of divided members 40a to 40d that constitute the long sides 2Ba and 2Bb and divided members 40e to 40h that constitute the short sides 2Bc and 2Bd. The lengths of the divided members 40a to 40d constituting the long sides 2Ba and 2Bb are formed equal, and the lengths of the divided members 40e to 40h constituting the short sides 2Bc and 2Bd are formed equal. The pellicle frame 2B is configured by joining divided members 40a to 40d and divided members 40e to 40h, and has eight joint portions 41a to 41h. The structure of the junction parts 41a-41h is the same as the structure shown to Fig.5 (a). The joint portions 41a to 41h may have other shapes.

  Next, the present embodiment will be described more specifically with reference to examples and comparative examples. However, the present embodiment is not limited to the following examples unless it exceeds the gist.

[Example 1]
The material of the pellicle frame (the material of all the divided frames) was an aluminum alloy, and the thickness was 4.0 mm, the long side width was 6.0 mm, and the length was 430 mm. In addition, the short side had a width of 6.0 mm, a length of 300 mm, a groove was provided over the entire length of the side surface of the short side, the groove depth was 2 mm, and the groove height was 1.5 mm. The curvature of the corner was R = 2 mm. In other configurations, a pellicle frame was manufactured as shown in FIG. The length of the dividing member constituting the long side was 370 mm, and the length of the dividing member constituting the short side was 240 mm. As shown in FIG. 11, the joining portion has a stepped shape in which an end surface 61a having a step of the dividing member 60a and an end surface 61b having a step of the dividing member 60b are brought into contact with each other. Specific dimensions in FIG. 11 were 1.3 mm vertically from the lower surface, 10 mm in the longitudinal direction, 1.3 mm vertically, 10 mm in the longitudinal direction, and further 1.4 mm vertically, and an adhesive was used. Loctite 638 (manufactured by Henkel) was used as the adhesive.

  In addition, an acrylic resin is used for the coating material of the frame member, spray coating is performed so as not to cause coating unevenness and material sagging, and the glass transition point is 100 ° C. by heating at 140 ° C. for 30 minutes. A coating film having a pencil hardness of 2H was formed. Next, a styrene ethylene butylene styrene hot melt pressure sensitive adhesive having a thickness of 1.4 mm was applied to the pellicle frame along each side of the pellicle frame.

  Separately, a pellicle film of cellulose ester was formed on the substrate by spin coating, the pellicle film was adhered to a temporary frame, and then peeled off from the substrate. This temporary frame was made of aluminum. Then, in the pellicle frame body coated with the hot melt adhesive material, an acrylic film adhesive was applied to the opposite surface where the hot melt adhesive was not applied, and the pellicle film of the temporary frame was adhered and cured. . The excess film was cut to produce a pellicle, and the appearance was visually inspected to confirm that there was no problem. After the cutting, the pellicle frame body was bent inward, so after the shape was stabilized, the joint surface of the joint was visually confirmed. The results are shown in Table 1.

(Measurement method for dimensional stability measurement)
The measuring device was a laser displacement meter (LJ-G030 manufactured by Keyence). One regular square standard sample was prepared according to the outer dimensions of the frame. Separately, 5 samples were prepared for each example under the conditions of Examples and Comparative Examples, and compared with a regular square standard sample. If the most difference is 1.0 mm or more even in one sample out of 5 samples, “X”, if it is 0.5 mm or more and less than 1.0 mm, “△”, if it is less than 0.5 mm, “○” did.

(Joint strength test)
Next, a bonding strength test was performed. A sample of a 100 mm rod-shaped frame including a joint portion having the same shape as described above was produced. The joint part was a 50 mm position, which is a half of a 100 mm rod shape. Chucking is performed 10mm from the joint with the width direction facing the upper surface (chucking is in the range of 10mm to 30mm from the joint), and the opposite side of chucking is applied to a location 10mm from the joint It was measured. The measuring device was an Imada digital force gauge.

(Outgas evaluation)
A 10 cm rod shape was prepared as a sample and measured by GC-MS (manufactured by SUPELCO) by a heat desorption method. The conditions were a heating temperature of 50 ° C., a heating time of 60 minutes, an adsorbent Carbopack B + Carbosieve SIII, and a carrier gas (He).

(Handling properties)
The mounting operation was performed five times with a handling jig, and the shaving at the time of mounting was visually inspected with a condenser lamp. “◯” indicates that the result is good in all five times, and “X” indicates that there is a defect such as shaving even once.

[Example 2]
The pellicle frame had a long side width of 9.0 mm, a length of 800 mm, a short side width of 7.00 mm, a length of 480 mm, and a corner portion with a curvature of R = 0 mm. The length and depth of the other grooves and the thickness of the pellicle frame were the same as in Example 1. The pellicle frame was divided into four as shown in FIG. 9, the length of the divided frame material constituting the long side was 790 mm, and the length of the divided frame material constituting the short side was 480 mm. The joining portion has a shape shown in FIG. At the time of fitting, the maximum joint distance of each joint end face is 1.5 mm with respect to the above width, the maximum joint distance of each joint part inner surface is 2.0 mm, and the size of each face of the joint part is 0.02 mm. A crushing part (surplus part) was provided. And it fitted from the up-down direction, without using an adhesive agent.

  In addition, an epoxy-based resin is used for the coating material of the frame member, spray coating is performed so that coating unevenness and material sag do not occur, and the glass transition point is set to 80 ° C. by heating at 140 ° C. for 30 minutes. A coating film with a pencil hardness of H was formed and evaluated in the same manner as in Example 1. Further, a pellicle was produced in the same manner as in Example 1 except that the thickness of the hot melt adhesive material was 2.0 mm, and evaluation was performed in the same manner. The results are shown in Table 1. As a result of visual inspection of the joint, there was no problem in appearance.

[Example 3]
The pellicle frame has a long side width of 21.0 mm, a length of 2000 mm, a short side width of 19.5 mm, a length of 1800 mm, corners with a curvature of R = 0 mm, and a frame thickness of 6. It was set to 0 mm. The length and depth of the other grooves were the same as in Example 1. The pellicle frame was divided into eight parts as shown in FIG. 10, the length of the divided members constituting the long sides was set to 900 mm, and the length of the divided members constituting the short sides was set to 982 mm. The joining portion has a shape shown in FIG. The maximum joining distance of each joining end face is 2.1 mm with respect to the above width, the maximum joining distance of each joining part inner surface is 4.2 mm, and the surplus part is 0.025 mm. The mating was done.

  The coating material of the frame member is made of fluorine resin, spray coating is performed so that coating unevenness and material sag do not occur, and heating at 140 ° C for 30 minutes results in a glass transition point of 120 ° C and pencil hardness. A coating film with 5H was prepared and evaluated in the same manner as in Example 1. Further, a pellicle was produced in the same manner as in Example 1 except that the thickness of the hot melt adhesive material was 2.0 mm, and evaluation was performed in the same manner. The results are shown in Table 1. As a result of visual inspection of the joint, there was no problem in appearance.

[Comparative Example 1]
The pellicle frame was prepared by cutting out from one sheet-like base material having no joint. The width of the long side was 9.0 mm, the length was 800 mm, the width of the short side was 7.0 mm, and the length was 480 mm. The material was an aluminum alloy, and the thickness was 4.0 mm. On the side surface of the short side, a groove was provided over the entire length, the depth of the groove was 2 mm, and the height of the groove was 1.5 mm. In addition, the curvature of the corner portion was set to R = 2 mm, and then alumite treatment was performed. Otherwise, a pellicle was produced in the same manner as in Example 1, and the evaluation was performed in the same manner. The results are shown in Table 1. However, since there are no joints, no joint strength test was performed.

[Comparative Example 2]
The pellicle frame was prepared by cutting out from one sheet-like base material having no joint. The width of the long side was 9.0 mm, the length was 800 mm, the width of the short side was 7.0 mm, and the length was 480 mm. The material was an aluminum alloy, and the thickness was 4.0 mm. On the side surface of the short side, a groove was provided over the entire length, the depth of the groove was 2 mm, and the height of the groove was 1.5 mm. Further, the curvature of the corner portion was set to R = 2 mm, and coating was performed thereafter. The coating material is urethane resin, spray coating is performed so that uneven coating and material sag do not occur, and heating at 140 ° C for 30 minutes results in a glass transition point of 40 ° C and pencil hardness of 3B. A coated pellicle was produced in the same manner. Evaluation was performed in the same manner as in Example 1, and the results are shown in Table 1. However, since there are no joints, no joint strength test was performed.

[Comparative Example 3]
A pellicle frame and a pellicle were produced in the same manner as in Example 1 except that the surface treatment was anodized. Evaluation was performed in the same manner as in Example 1, and the results are shown in Table 1. Since anodized unevenness occurred and looked like a pseudo foreign material, the testability was poor.

  DESCRIPTION OF SYMBOLS 1 ... Pellicle, 2 ... Pellicle frame, 3 ... Pellicle film, 4 ... Opening part, 20a-20d ... Dividing member (frame member), 21a-21d ... Connection member (frame member), 22a-22h ... Joint part.

Claims (7)

A pellicle frame body that stretches and supports a pellicle film so as to cover an opening having a rectangular shape in plan view,
The periphery of the opening is formed by a frame member, and the frame member is joined by at least one joining portion,
A pellicle frame, wherein a glass transition point of a coating material for forming a coating film on the surface of the frame member is 50 ° C. or higher and 150 ° C. or lower.   The pellicle frame according to claim 1, wherein the pencil hardness of the coating film is B or more and 6H or less.   The pellicle frame according to claim 1 or 2, wherein the coating material is a coating type.   The pellicle frame according to any one of claims 1 to 3, wherein a main component of the coating material is epoxy, acrylic, or fluorine. The frame member is composed of a pair of opposing long sides and a pair of opposing short sides,
The thickness of the coating film of at least one corner formed by the long side and the short side is 20 times or less the thickness of the coating film of the central part of the long side or the short side. The pellicle frame according to any one of claims.   A pellicle comprising: the pellicle frame according to any one of claims 1 to 5; and a pellicle film stretched and supported so as to cover an opening of the pellicle frame. A method for manufacturing a pellicle frame that stretches and supports a pellicle film so as to cover an opening having a rectangular shape in plan view,
Preparing a frame member having a periphery of the opening and having at least one joint, and joining the joint of the frame member;
Applying a coating material having a glass transition point of 50 ° C. or higher and 150 ° C. or lower to the frame member to form a coating film;
And a step of heat-treating the coating film.

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