JP2011186327A - Frame body for large pellicle, and large pellicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a frame body for a large pellicle, which has high handleability and is capable of suppressing the occurrence of an air path at the time of using. <P>SOLUTION: A frame body 2 for a large pellicle stretches and supports a large pellicle film so as to cover an opening, and a frame section forming the peripheral edge of the opening 4 comprises junctions in at least three places along an axial direction of the frame section. Since the pellicle frame body has the junctions in at least three places, each of divided frame body portions functions as a reinforcing member, and deflection of the frame body can be reduced synergistically. Rigidity of the entire pellicle frame body is enhanced as a result and deflection is suppressed, so that a large pellicle hardly comes off a handling jig in spite of changes in position to various directions when the large pellicle is fixed to the handling jig and is inspected. Because of further enhancement of rigidity, pasting accuracy is high and is maintained when the large pellicle is pasted to a photomask or the like, so that an air path hardly occurs. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is used when 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 the 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.
For example, Patent Document 1 proposes a large pellicle applicable to a large photomask.
Patent Document 2 also proposes a frame that uses a frame and a reinforcing material having a larger elastic coefficient than that of the frame in order to cope with bending and distortion of the large pellicle frame.
Separately, Patent Document 3 discloses a pellicle frame used for ultraviolet light exposure of 200 nm or less used in exposure that requires high resolution, and does not affect the accuracy of mask flatness. It has also been proposed to use a frame obtained by joining two or more types of materials having different elastic moduli in the thickness direction of the frame.

JP 2001-109135 A JP 2006-284927 A JP 2009-063740 A

By the way, the pellicle frame is often cut out from one sheet-like base material by punching. This is based on the viewpoint of ensuring the flatness of the pellicle. However, depending on the flatness of the base material, a base material that cannot be used appears. Moreover, it is not easy to obtain the accuracy of the flatness of the frame body as the size of the base material that can be used increases, and the manufacturing process is time-consuming. As a result, the productivity is lowered and the cost of the frame is increased.
In addition, when the size is increased, the frame body may bend or distort due to various factors such as the weight of the frame body itself, the tension of the pellicle film, and the stress caused by the temperature change. Such bending or distortion is not preferable from the viewpoint of the handling property of the pellicle frame or the pellicle. Further, when such a pellicle is bent or distorted, an air path may be generated between the pellicle frame and the photomask. On the other hand, the method of increasing the rigidity of the pellicle frame by increasing the cross-sectional area of the frame is not preferable in view of the effective exposure area and the like.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a frame for a large pellicle that has good handling properties and can suppress the generation of an air path during use.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that a frame for a large pellicle having a specific structure can solve the above problems, and have completed the present invention.

That is, the large pellicle frame of the present invention is a large pellicle frame that extends and supports the large pellicle film so as to cover the opening having a rectangular shape in plan view, and the frame that forms the periphery of the opening Is a frame for a large pellicle having three or more joints along the axial direction of the frame.
Since the pellicle frame has three or more joint portions, each of the divided frame portions serves as a reinforcing member, and the flexure of the frame can be reduced synergistically. In other words, the overall rigidity of the pellicle frame will be increased, and bending can be suppressed. For example, when a large pellicle is fixed to a handling jig and inspection is performed, the pellicle can be handled in various directions. Hard to fall off the jig. Furthermore, since the rigidity is further increased, the accuracy of application is good when the image is applied to a photomask or the like, and the accuracy is maintained, so that an air path hardly occurs.
Furthermore, by forming the frame body with a plurality of members, it is possible to cut out a portion with good flatness of the base material, and the flatness of the frame body after joining is also improved. It is also possible to produce a large frame from a small base material, which has the advantage of cost reduction.
Conventionally, the pellicle frame has been often cut out from a single sheet-like base material based on the viewpoint of ensuring the flatness of the pellicle. The present invention has been made against such technical common sense and has the excellent effects as described above.

In addition, the frame portion includes a pair of opposing side portions and another pair of side portions arranged in series via the pair of side portions and the top portion, and at least one of the joint portions and the joint It is preferable that the distance between the top portion at the closest distance to the portion is 45% or less of the length of the side portion on which the joint portion is provided.
By doing in this way, it becomes possible to prevent the bending of a frame body more. That is, the rigidity of the corner portion can be further increased by arranging the joint portion in the vicinity of the corner portion.
From the same viewpoint, two of the joints are provided via a common top, and the distance between the top and the joint is the length of the side where the joint is provided. It is preferably 45% or less.

  ADVANTAGE OF THE INVENTION According to this invention, the handling property is favorable and the frame for large pellicles which can suppress generation | occurrence | production of an air path at the time of use is provided.

It is a perspective view showing an embodiment of a large pellicle. It is the schematic which looked at the frame for large pellicles from the top. It is a schematic perspective view which shows the top part of the frame for large pellicles. It is a schematic perspective view which shows the shape of the junction part in Example 2. FIG.

  Hereinafter, the best mode for carrying out the present invention (hereinafter abbreviated as “this embodiment”) will be described in detail. In addition, this invention is not limited to this following Embodiment, It can implement by changing variously within the range of the summary.

  FIG. 1 is a perspective view showing a large pellicle according to an embodiment of the present invention. The large pellicle 1 includes a large pellicle frame 2 and a large pellicle film 3 bonded to the upper edge surface 2 e of the large pellicle frame 2. 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 is made of, for example, aluminum, aluminum alloys (5000 series, 6000 series, 7000 series, etc.), iron and iron alloys, ceramics (SiC, AlN, Al2O3, etc.), a composite material of ceramics and metal (Al -SiC, Al-AlN, Al- Al 2 O 3 , etc.), carbon steel, tool steel, made of stainless series or the like, and has a plan view, a substantially rectangular shape.
Although the large pellicle frame 2 is composed of a plurality of members as described later, it is preferable that at least a pair of members via the joint portion is formed of a material having the same elastic modulus.

The large pellicle frame 2 is composed of a pair of long sides 2a and 2b and a pair of short sides 2c and 2d shorter than the long sides 2a and 2b, and has a rectangular opening 4. ing. 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, more preferably 10000 cm ² or more, particularly preferably 18000Cm ² or more, and most preferably at 23000Cm ² or more Yes, and the upper limit is preferably 35000 cm ² or less.

The pair of long sides 2a and 2b is formed of a column member having a width of, for example, 16.5 mm, and the length thereof is, for example, 1750 mm. The pair of short sides 2c and 2d is formed of a column member having a width of, for example, 18.5 mm, and the length thereof is, for example, 1550 mm. That is, the width of the short sides 2c and 2d in plan view (viewed from above) is wider than the width of the long sides 2a and 2b. The curvature of the top 5 of the large pellicle frame 2 is R = 20 mm. In addition, the vertex when it assumes that the curvature does not exist in the top part 5 is only described as "vertex" below.
Further, a groove portion 7 is provided along the longitudinal direction (side direction) on the side surface 6 of the large pellicle frame body 2.

  The large 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 large pellicle film 3 is spread on the upper edge surface 2 e so as to cover the opening 4 of the large pellicle frame 2, and is attached to and supported by the 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, the large pellicle frame 2 will be described with reference to FIG. FIG. 2 is a schematic view of the large pellicle frame 2 used in the large pellicle shown in FIG. 1 as viewed from above.
In the large pellicle frame 2, the frame portion constituting the peripheral portion of the opening 4 includes divided frame bodies 21 a and 21 b constituting the pair of long sides 2 a and 2 b, and both axial ends of the divided frame bodies 21 a and 21 b. The divided frame bodies 21e, 21h, 21f, and 21g, which are connected to each other through the joint portion and respectively form the four top portions 5 of the large pellicle frame body 2, and the divided frame bodies 21e, 21h, 21f, and 21g. Are formed from divided frame bodies 21c and 21d that bridge the open ends of the two via a joint portion. That is, the large pellicle frame body 2 has eight joint portions along the axial direction of the frame portion constituting the peripheral edge portion of the opening 4.
In FIG. 2, the large pellicle frame body 2 has a divided frame body 21a, a divided frame body 21d, a divided frame body 21f in a clockwise direction with the divided frame body 21a as a base point and the opening axis of the opening 4 as a reference. The divided frame body 21b, the divided frame body 21g, the divided frame body 21c, the divided frame body 21h, and the divided frame body 21a are connected in this order.
Here, the number of joint locations may be three or more, but is preferably 3 to 30 locations, more preferably 3 to 25 locations, and even more preferably 3 to 20 locations.

In the large 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.
Moreover, the shape of the division | segmentation frame 21a and the division | segmentation frame 21b is substantially the same, the shape of the division | segmentation frame 21c and the division | segmentation frame 21d is substantially the same, Furthermore, the division | segmentation frame which forms the top part 5, respectively. The shapes of the bodies 21e, 21h, 21f, and 21g are substantially the same.

The distance between at least one of the joint portions and the top portion closest to the joint portion is preferably 45% or less, more preferably 35% or less of the length of the side portion on which the joint portion is provided. The lower limit is more preferably 25% or less, and the lower limit is preferably 0% or more, more preferably 5% or more. Here, it is more preferable that two of the joint portions are provided via a common top portion, and the distance between the top portion and the joint portion is within the above range.
The long side length Le is defined as the maximum distance in the long side axis direction at the opposing short side, and the short side length Ls is defined as the maximum distance in the short side axis direction at the opposing long side. Is done.
Further, the distance Lp between the junction and the apex at the closest distance to the junction is defined as the distance between the apex and the point farthest from the center of the opening 4 on the end face of the divided frame forming the apex. Is done.

Specifically, in FIG. 2, the length of the divided frame bodies 21a and 21b is, for example, 875 mm, and the length of the divided frame bodies 21c, 21d is, for example, 775 mm. Therefore, Lp is, for example, 25% of the length of Le, and Lp is, for example, 25% of the length of Ls.
The length of the divided frame is defined as the maximum length along the circumferential direction of the frame (frame portion axial direction) between both end faces of the divided frame.

FIG. 3 is a schematic perspective view showing the top of the large pellicle frame 2. The top portion 5 of the large pellicle frame 2 includes, for example, a divided frame 21b constituting a part of the long side 2b, a divided frame 21d constituting a part of the short side 2d, and substantially perpendicular directions thereof. It is formed from the division | segmentation frame 21f provided in a row.
Here, convex portions are respectively formed on the end surface of the divided frame body 21b and the end surface of the divided frame body 21d, and concave portions corresponding to the shape of the convex portions are formed on both end surfaces of the divided frame body 21f. The convex portions are in close contact with the concave portions, and the respective members are continuously provided. Note that an adhesive or the like can be appropriately sandwiched between the contact surfaces.

  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. In the case of a frame in which the length of each side 2a to 2d is 1400 mm or more, the width of each side 2a to 2d is preferably 13 mm to 30 mm, more preferably 15 mm to 27 mm, and particularly preferably 19.5 mm to 25 mm. It is preferable that

  Further, the smaller the thickness of the pellicle frame 2 is, the smaller the pellicle 1 becomes lighter and easier to handle. Problems may arise. In the case of the pellicle frame 2 having a length of each side 2a to 2d of 1400 mm or more, the thickness of the pellicle frame 2 is preferably 4.5 mm to 12 mm, more preferably 6.0 mm to 10 mm, and particularly preferably from the balance of both Is preferably 7.2 mm to 9 mm.

The present invention is not limited to the embodiment described above. For example, in the above embodiment, the shapes of the divided frame bodies are aligned to some extent, but the shapes of the divided frame bodies may be different from each other. In the above-described embodiment, eight joint portions are provided, but four joint portions may be provided. In this case, for example, the divided frame bodies 21c, 21h, and 21g can be formed as one divided frame body, and the divided frame bodies 21e, 21d, and 21f can be formed as one divided frame body.
Also, the joining method at the joint is not particularly limited, and an adhesive may be used in addition to adhesive bonding, or screwing may be used.

  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 as long as the gist thereof is not exceeded.

[Example 1]
The material of the large pellicle frame (the material of all the divided frames) was an aluminum alloy, the thickness was 6.5 mm, and the long sides were 16.5 mm wide and 1750 mm long. The short side had a width of 18.5 mm and a length of 1550 mm, and was provided with a groove over the entire length of the short side. The depth of the groove was 5 mm and the height of the groove was 2 mm. Moreover, the curvature of the top was 20 mm. Otherwise, a large pellicle frame was formed as shown in FIG. The length of the division members 21a and 21b was 875 mm, and the length of the division members 21c and 21d was 775 mm. Therefore, Lp was 25% of the length of Le, and Lp was 25% of the length of Ls.

The large pellicle frame was set up vertically with respect to the ground so that the short side was in the vertical direction and the long side was in the horizontal direction with respect to the ground, and then a handling jig was mounted from the vertical direction. The handling jig is composed of a handle portion that is gripped by an operator and a holding portion that is connected to the handle portion and holds a large pellicle, and the holding portion has a U-shape. The holding portion is composed of a pair of engaging portions that are inserted into and engaged with grooves formed on the short side of the pellicle frame body, and a support portion that connects the handle portion and supports the long side. . The engaging portion is a long member having a thickness equivalent to the width of the groove portion formed on the short side. The length of the member engaging portion is 700 mm, and the width of the engaging portion is 33 mm. The distance between the pair of engaging portions is 1742 mm. The support portion is a long member having a thickness equivalent to the long side of the pellicle frame, and the length of the support portion is 1752 mm.
Next, the position was changed so that the large pellicle frame was horizontal with the handling jig mounted, and the position was returned to the vertical direction. Such an operation was performed 10 times. As a result, the result was that the large pellicle frame of the present embodiment did not come off the handling jig.

Next, a styrene ethylene butylene styrene-based hot melt adhesive is used as an adhesive for this large pellicle frame, and the pellicle has a thickness of 1.8 mm, a coating width of 6 mm, and an interval of 2 mm from the opening. It applied along each side of the frame.
And in the clean room, it stuck on the blue plate glass instead of the photomask. The large pellicle frame was affixed by the width of the large pellicle frame along a straight line connecting the tops of the corners of each side using a bonding apparatus. As a result, the entire surface of the adhesive layer could be pressed, and the adhesive layer could be pressed uniformly. Further, a large pellicle frame was attached as it was and left in a vertical state for one month, but no air pass or the like was generated.

[Example 2]
A plane in which the width of the long side is 9 mm, the length of the long side is 780 mm, the width of the short side is 7 mm, the length of the short side is 470 mm, and the shape of the joint is from the inner peripheral vertex to the outer peripheral vertex of the frame A frame for a large pellicle was formed in the same manner as in Example 1 except that the shape was changed. FIG. 4 is a schematic perspective view showing the shape of the joint portion in the second embodiment. In this case, Lp is 0% of the length of Le, and Lp is 0% of the length of Ls.
When the presence or absence of the occurrence of an air path was evaluated in the same manner as in Example 1, no air path or the like was generated.

[Comparative Example 1]
A frame for a large pellicle was formed in the same manner as in Example 1 except that no joint was provided.
When the large pellicle frame was checked for handleability in the same manner as in Example 1, the result was that it was detached from the handling jig twice.
Moreover, when the presence or absence of the air path was confirmed in the same manner as in Example 1, it was visually confirmed that the air path was generated at several places in the central portion of the long side.

[Comparative Example 2]
A frame for a large pellicle was formed in the same manner as in Comparative Example 1 except that a joint was provided at the center position in the side direction of the pair of long sides (that is, two joints were provided).
When the presence or absence of an air path was confirmed in the same manner as in Example 1 for this large pellicle frame, it was visually confirmed that there were air paths at several locations in the central portion of the long side.

  As is clear from the results described above, the large pellicle frame of the present embodiment has excellent rigidity, can realize a large pellicle that is excellent in handling properties and hardly generates an air path.

  The present invention can be suitably used particularly in the field of large pellicles where handling is a problem.

DESCRIPTION OF SYMBOLS 1 ... Large pellicle, 2 ... Large pellicle frame body, 2a, 2b ... Long side, 2c, 2d ... Short side, 21a, 21b, 21c, 21d, 21e, 21f, 21g, 21h, 21b ',
21d '... divided frame, 3 ... large pellicle film, 4 ... opening, 6 ... side, 7 ... groove.

Claims (7)

A frame for a large pellicle that extends and supports a large pellicle film so as to cover an opening having a rectangular shape in plan view,
The frame forming the periphery of the opening is a large pellicle frame having three or more joints along the axial direction of the frame. The frame part is composed of a pair of opposing side parts, and another pair of side parts provided continuously through the pair of side parts and the top part,
2. The large size according to claim 1, wherein a distance between at least one of the joint portions and a top portion closest to the joint portion is 45% or less of a length of a side portion on which the joint portion is provided. Pellicle frame.   Two of the joints are provided via a common top, and the distance between the top and the joint is 45% or less of the length of the side where the joint is provided. 2. A frame for a large pellicle according to 2.   The large pellicle according to any one of claims 1 to 3, wherein the frame portion includes a pair of opposing long side portions, and a pair of short side portions provided in series via the pair of long side portions and the top portion. Frame body.   The said frame part is divided | segmented into a some division | segmentation frame body via the said junction part, and at least a pair of division | segmentation frame body via a common junction part is formed with the raw material which has the same elastic modulus. A frame for a large pellicle according to any one of -4.   The frame for a large pellicle according to claim 5, wherein the plurality of divided frame bodies are all formed of a material having the same elastic modulus.   A large pellicle comprising the large pellicle frame according to any one of claims 1 to 6 and a large pellicle film stretched and supported so as to cover an opening of the large pellicle frame.

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