JP7575202B2 - Pellicle case, tray and method for holding a pellicle - Google Patents

Description

The present invention relates to a pellicle case, a tray, and a method for holding a pellicle.

In the manufacturing process of large-scale integrated circuits (LSIs), etc., pellicles are used to protect photomasks from dust. A pellicle generally has a pellicle frame, a pellicle film, which is a transparent thin film, arranged on one end of the pellicle frame, and an adhesive layer arranged on the other end of the pellicle frame (the side opposite the pellicle film) for attaching it to the photomask.

The pellicle can be held in a pellicle case. For example, the method described in Patent Document 1 is known as a method for holding a pellicle in a pellicle case. In this method, a protective film (hereinafter sometimes referred to as a "liner") is attached to the adhesive layer of the pellicle, and the pellicle is then placed in the pellicle case, and a portion of the liner is fixed to the pellicle case with adhesive tape. When the pellicle is removed from the pellicle case, the liner is peeled off from the adhesive layer of the pellicle, and is left in the pellicle case by the adhesive tape.

JP 2007-017811 A

As described above, in the method described in Patent Document 1, when the pellicle is removed from the pellicle case, the liner is peeled off from the adhesive layer of the pellicle, and the liner is left in the pellicle case by the adhesive tape. Here, the inventors have noted that, depending on various circumstances, there are not only cases where it is desirable to remove the pellicle while leaving the liner in the pellicle case, but also cases where it is desirable to remove the liner and pellicle from the pellicle case (removing the pellicle together with the liner).

However, when storing a pellicle in a tray with adhesive tape, it takes time to store it because there are many places where the tape needs to be applied. If it takes a long time to store it, there is a risk of foreign matter adhering to it.

In addition, with the method described in Patent Document 1, it is difficult to remove the pellicle together with the liner from the pellicle case. In relation to this, in the method described in Patent Document 1, it is possible to peel off the tape that attaches part of the liner to the pellicle case before removing the pellicle. However, in this case, peeling off the adhesive tape may cause the adhesive components of the adhesive tape to scatter, and the scattered adhesive components may contaminate the pellicle membrane.

The present invention has been proposed in light of these circumstances, and the object of the present invention is to provide a pellicle case, a tray, and a method for holding a pellicle, which can hold a pellicle in an appropriate manner during storage and transportation, and which can also remove the pellicle from the pellicle case when removing it.

The present inventors have conducted extensive research to solve the above problems, and have found that by providing releasability to a portion of the tray that comes into contact with the adhesive layer and specifying the peel strength between the portion and the adhesive layer, it is possible to achieve both reliable adhesive strength during storage and transportation and suitable peeling when the tray is removed, thereby completing the present invention.
That is, the present invention is as follows.
[1] A pellicle container comprising: a frame having a long side length of 500 mm to 2000 mm and a short side length of 300 mm to 1800 mm; a pellicle arranged on one end surface side of the frame, the pellicle having an adhesive layer comprising at least one adhesive selected from the group consisting of an acrylic adhesive, a rubber adhesive, a vinyl adhesive, an epoxy adhesive, and a silicone adhesive and having a thickness of 0.8 mm to 2.5 mm; and a pellicle case containing the pellicle,
A tray for placing the pellicle is provided,
At least a portion of the tray that comes into contact with the adhesive layer has releasability,
The pellicle storage item is characterized in that the peel strength when the portion is brought into contact with the adhesive layer (the peel strength when the adhesive layer has a size of 4.5 mm x 30 mm and a thickness of 1.2 mm) is 0.1 to 1.5 kgf .
[2] A pellicle container comprising: a frame having a long side length of 500 mm to 2000 mm and a short side length of 300 mm to 1800 mm; a pellicle arranged on one end surface side of the frame, the pellicle having an adhesive layer comprising at least one adhesive selected from the group consisting of an acrylic adhesive, a rubber adhesive, a vinyl adhesive, an epoxy adhesive, and a silicone adhesive and having a thickness of 0.8 mm to 2.5 mm; and a pellicle case containing the pellicle,
A tray for placing the pellicle is provided,
At least a portion of the tray that comes into contact with the adhesive layer has releasability,
The part contains at least one selected from the group consisting of a silicone compound, a fluorine-based compound, and a urethane-based compound.
[3]
The pellicle storage item described in [1] or [2], wherein the tray has a tray body, and the portion is a release layer arranged on at least the surface of the tray body that comes into contact with the adhesive layer.
[4]
The pellicle storage item described in [3], wherein the release layer is formed by coating on at least one surface of the tray body.
[5]
The pellicle case further includes a cover for covering the tray,
The cover is
A pellicle storage item described in any of [1] to [4], which is provided with an abutment portion that abuts against at least a portion of the frame of the pellicle placed on the tray when the tray is covered with the cover.
[6]
The pellicle case is
The pellicle storage item described in any one of [1] to [5] further comprises a pin holding mechanism for inserting and fixing a pin into a non-through pin insertion hole provided on a side of the frame of the pellicle placed on the tray.

The present invention provides a pellicle case, tray, and method for holding a pellicle, which allows a pellicle to be appropriately held in the pellicle case during storage and transportation, and allows the pellicle to be appropriately removed from the pellicle case when removed.

FIG. 1 illustrates an embodiment of a pellicle. FIG. 2 is a diagram showing an embodiment of a pellicle case. FIG. 1 is a cross-sectional view showing a state in which a pellicle is placed on a tray. FIG. 13 is a top view showing the state in which the pellicle is stored in the tray. FIG. 2 is a cross-sectional view showing a state in which a pellicle is stored in a pellicle case. FIG. 13 is a diagram showing another embodiment of the pellicle case. Diagram explaining the method for measuring peel strength FIG. 13 is a diagram showing another embodiment of the pellicle case.

The following describes the form for carrying out the present invention (hereinafter abbreviated as "embodiment") with reference to the drawings. The present invention is not limited to the following embodiment, and can be practiced with various modifications within the scope of the gist. In each drawing, the same components are given the same reference numerals, and duplicate explanations may be omitted.

[First embodiment]
An overview of the pellicle according to this embodiment will be described below: Fig. 1(a) is a top view showing the pellicle, and Fig. 1(b) is a vertical cross-sectional view.
In the following description, the upper side in each figure will be referred to as "top" and the lower side as "bottom".

<Pellicle>
The pellicle 1 is a structure that provides dust protection for a photomask in photolithography etc. The pellicle 1 includes a pellicle frame 2, a pellicle film 3, and an adhesive layer 4.

The pellicle frame 2 can have any shape that allows the pellicle film 3 to be stretched over the pellicle frame 2. For example, when viewed from the front of the frame, the frame can have an outer shape such as a rectangle, a polygon, a circle, or an ellipse. The rectangle can be a square, a rectangle, or the like, and can have both right-angled corners and roughly rectangular shapes with rounded corners (Figure 1). The polygon can be a triangle, a trapezoid, a parallelogram, a pentagon, a hexagon, or the like.

The size of the pellicle frame 2 and its opening can be determined according to the size of the photomask. When the pellicle frame 2 is rectangular in shape consisting of a pair of long sides and a pair of short sides when viewed from the front, the long side length can be 500 mm to 2000 mm, the short side length can be 300 mm to 1800 mm, the widths of the long and short sides can be 4.0 mm to 20.0 mm, and/or the frame height can be 2.0 mm to 8.0 mm.

As shown in FIG. 1, the pellicle frame 2 has an edge portion. The edge portion can have a rod-shaped edge member that extends linearly. A pair of edge members can be arranged parallel to each other with a gap therebetween, and similarly, another pair of edge members can be arranged parallel to each other with a gap therebetween. The ends of the two contacting edge members can be connected so that they form approximately a right angle with each other.

The pellicle frame 2 and its edge members can be formed from known materials such as, for example, aluminum; aluminum alloys (e.g., 5000 series, 6000 series, 7000 series, etc.); steel; stainless steel; magnesium alloys; ceramics (e.g., SiC, AlN, Al ₂ O ₃ , etc.); composite materials of ceramics and metals (e.g., Al-SiC, Al-AlN, Al-Al ₂ O _3, etc.); engineering plastics such as PE, PA, PC, PEEK, etc.; fiber composite materials such as GFRP, CFRP, etc.; or combinations thereof.

The pellicle film 3 is a transparent thin film formed from nitrocellulose, a cellulose derivative, a fluoropolymer, or the like. The pellicle film 3 has a thickness of 10 μm or less, and is formed so as to sufficiently transmit the light emitted by the light source in photolithography. As shown in FIG. 1(b), the pellicle film 3 is adhered and fixed to one end side of the pellicle frame 2 with an adhesive (not shown), and covers the pellicle frame 2.

As shown in FIG. 1(b), an adhesive layer 4 is arranged on the other end side of the pellicle frame 2 (the side opposite the pellicle film of the pellicle frame) to attach the pellicle 1 to the photomask. This adhesive layer 4 also has the function of holding the pellicle 1 in the pellicle case 10.

The adhesive layer 4 is composed of an adhesive such as an acrylic, rubber, vinyl, epoxy, or silicone adhesive, and more preferably is made of an acrylic, rubber, or silicone adhesive. The thickness of the adhesive layer 4 is preferably, for example, 0.8 mm to 2.5 mm.

The pellicle 1 configured as described above can be transported and stored while held in the pellicle case 10.

<Pellicle case>
(Configuration of pellicle case)
An overview of the pellicle case according to this embodiment will be described with reference to FIG.
Fig. 2 is a vertical cross-sectional view showing an example of a pellicle case. Figs. 3 and 4 are views showing a state in which a pellicle is held on a tray of the pellicle case, with Fig. 3 being a vertical cross-sectional view and Fig. 4 being a top view. Fig. 5 is a cross-sectional view showing a state in which a pellicle is held in the pellicle case.

A pellicle case 10 for storing a pellicle includes a tray 20 for placing the pellicle 1 thereon, and at least a portion of the tray 20 that comes into contact with an adhesive layer 4 provided on the pellicle 1 has releasability. The peel strength between the portion and the adhesive layer 4 is 0.05 to 2.5 kgf.
This allows the pellicle 1 to be suitably held in the pellicle case 10 or tray 20, while allowing the pellicle 1 to be suitably removed from the pellicle case 10 or tray 20.

In this embodiment, the tray 20 comprises a tray body 21 and a release layer 23 disposed on at least the surface of the tray body 21 that comes into contact with the adhesive layer 4 of the pellicle 1.

As shown in FIG. 2, the pellicle case 10 further has a cover 30 for covering the tray 20. The tray 20 can have an area in the center for placing the pellicle 1, and an area around the periphery for fitting with the cover 30.

The tray body 21 and cover 30 are made of resin materials such as polyethylene terephthalate, acrylonitrile butadiene styrene, acrylic, polycarbonate, and polyvinyl chloride.

The thickness of the tray 20 and cover 30 is preferably a value sufficient to protect the pellicle 1 from vibrations and shocks that may occur during transportation or storage of the pellicle 1, and is preferably, for example, 2.0 to 10.0 mm.
The planar shape and size of the tray 20 and cover 30 are determined appropriately according to the shape and size of the pellicle 1 to be held.

The tray body 21 has a fixing surface 21a for holding the pellicle 1, and a fitting portion 24 having an uneven shape is formed on the periphery of the fixing surface 21a. The fixing surface 21a means the outermost surface of the tray body 21 on which the pellicle is placed. The tray 20 in FIG. 2 has a configuration in which a release layer 23 is formed on one surface (fixing surface 21a) of the tray body 21.

When the cover 30 is fitted to the tray 20, it has a ceiling surface 31 that is approximately parallel to the fixing surface 21a of the tray 20, and a slope 32 that is continuous with the ceiling surface 31 around the periphery of the ceiling surface 31. In addition, a fitting portion 33 having an uneven shape is formed on the periphery of the cover 30. The fitting portion 33 formed on the periphery of the cover 30 and the fitting portion 24 formed on the periphery of the tray 20 can be fitted together.

When the cover 30 and the tray 20 are fitted together, a space 11 for accommodating the pellicle 1 is formed between the cover 30 and the tray 20 (see Figure 5).

A number of positioning pins 22 protruding from the fixed surface 21a are arranged around the periphery of the fixed surface 21a. The positioning pins 22 are arranged along the outer shape of the pellicle 1 to be placed on the fixed surface 21a. The positioning pins 22 also have a tapered shape with a smaller diameter the further away from the fixed surface 21a. Therefore, when the pellicle 1 is placed on the tray 20, the adhesive layer 4 of the pellicle 1 can be attached to the release layer 23 while being guided by these positioning pins 22. The position of the pellicle 1 can also be determined by these positioning pins 22 (see FIG. 4).

In this embodiment, a release layer 23 is formed on the surface of the tray body 21 that comes into contact with the adhesive layer 4 provided on the lower end surface of the pellicle frame 2, i.e., the fixing surface 21a. The peel strength between the release layer 23 and the adhesive layer 4 of the pellicle 1 is 0.05 to 2.5 kgf. This allows the pellicle 1 to be suitably held in the pellicle case 10 or the tray 20, and on the other hand, allows the pellicle 1 to be suitably removed from the pellicle case 10 or the tray 20.

The release layer 23 preferably contains at least one selected from the group consisting of silicone compounds, fluorine-based compounds, and urethane-based compounds, and more preferably contains a silicone-based compound. This makes it easier to hold the pellicle 1 in the pellicle case 10 or tray 20 and also makes it easier to remove the pellicle 1 from the pellicle case 10 or tray 20.

The release layer 23 may be formed at least on the surface of the tray body 21 in a portion that comes into contact with the adhesive layer 4 provided on the pellicle frame 2. For example, in the example shown in FIG. 2, the release layer 23 is formed on the entire surface of one side (fixing surface 21a) of the tray body 21, but the release layer 23 may be formed on the entire surface including both sides of the tray body 21, as shown in FIG. 6.

The thickness of the release layer 23 is, for example, preferably 1.0 to 40.0 μm, more preferably 1.2 to 30.0 μm, and even more preferably 1.5 to 20.0 μm.

The peel strength between the release layer 23 and the adhesive layer 4 is preferably 1.5 kgf or less, more preferably 1.0 kgf or less, and even more preferably 0.8 kgf or less. This makes it easier to hold the pellicle 1 in the pellicle case 10 or tray 20 and also makes it easier to remove the pellicle 1 from the pellicle case 10 or tray 20.

The peel strength between the release layer 23 and the adhesive layer 4 is preferably 0.05 kgf or more, more preferably 0.1 kgf or more, and even more preferably 0.2 kgf. This allows the pellicle 1 to be securely held in the pellicle case 10 or tray 20, while allowing the pellicle 1 to be conveniently removed from the pellicle case 10 or tray 20.

The peel strength between the release layer 23 and the adhesive layer 4 can be set within the above range by appropriately selecting the combination of the material constituting the release layer 23 and the material constituting the adhesive layer 4.

Moreover, the peel strength between the release layer 23 and the adhesive layer 4 can be controlled by adjusting the film thickness of the release layer 23 .
For example, as the thickness of the release layer 23 increases, the peel strength tends to increase, whereas as the thickness of the release layer 23 decreases, the peel strength tends to decrease.

By partially thinning (or thickening) the film thickness of the release layer 23, it may be possible to partially vary the peel strength between the release layer 23 and the adhesive layer 4. Even if the peel strength is varied, movement of the pellicle during transportation can be suitably prevented as long as it is within the range of the adhesive layer according to this embodiment. On the other hand, by varying the peel strength, it becomes easier to trigger a peel between the liner and the adhesive layer when removing the pellicle, making it easier to remove the pellicle.

(Method of measuring peel strength)
In this embodiment, the "peel strength between the release layer and the adhesive layer" can be measured as follows.
FIG. 7 is a diagram for explaining a method for measuring "the peel strength between the release layer and the adhesive layer" in this specification.
The release layer is an example of a "site in contact with the adhesive layer", and this measurement method is also applied to the second embodiment described later.

The fabricated pellicle is cut (edge member: 11 mm x length x 30 mm y length x 4 mm z length, adhesive layer: 4.5 mm x length x 30 mm y length x 1.2 mm z length) to obtain a pellicle piece as a test piece. The adhesive layer side of the pellicle piece is placed in contact with and left at rest on a sample piece plate (50 mm x length x 100 mm y length x 7 mm z length) coated with a release layer, and a weight of 1 kgf is placed on top of the pellicle piece for 10 seconds. The weight is then removed and left for 10 minutes.

The tensile test is carried out using an autograph (Shimadzu Corporation, model "AGS-X 500N") as the measuring device. The sample piece plate is fixed, and the side of the frame of the pellicle piece is clamped by the fixing jig of the measuring device. The fixing jig is pulled vertically from the sample piece plate at a pulling speed of 5 mm/min, and the tensile strength when the pellicle piece is completely separated from the sample piece plate can be used as the "peel strength between the release layer and the adhesive layer." All of these tests can be carried out at room temperature (25°C).

(Method of forming release layer)
The release layer 23 can be formed by coating a coating liquid for a release layer on the surface of the tray body 21. By coating, the release layer 23 can be easily and reliably formed on the tray 20.
In addition, the coating in this embodiment includes not only a method of applying a coating liquid for a release layer to the surface of the tray body 21, but also a method of immersing (dipping) the tray body 21 in the coating liquid for a release layer.

The coating liquid for the release layer can be obtained, for example, by diluting it to an optimal concentration with an optimal solvent. The coating method is preferably air spray, electrostatic coating, dip coating, or roll coating, and among these, the air spray method is preferred.

(Storage of pellicle in pellicle case)
3 and 4 are diagrams showing a state in which a pellicle is stored in a pellicle case. In the storage space 11 of the pellicle case 10, the pellicle 1 is placed on the fixing surface 21a in the center of the tray 20. At this time, the adhesive layer 4 of the pellicle 1 is attached to the release layer 23 of the tray 20. In this way, the pellicle 1 is held in the tray 20.

As shown in FIG. 5, the tray 20 on which the pellicle 1 is placed can be covered with a cover 30. This makes it easier to prevent dust from adhering to the pellicle 1 and also makes it easier to protect the pellicle 1 from vibrations and shocks during transportation and storage.

When the cover 30 covers the tray 20, a portion of the inclined surface 32 forms an abutment portion 32a that abuts against at least a portion of the pellicle frame 2 of the pellicle 1 placed on the tray 20. By covering the tray 20 with the cover 30, the abutment portion 32a can press the pellicle 1 against the tray 20, thereby more reliably preventing the pellicle 1 from moving within the pellicle case 10 during transport.

Furthermore, it is preferable to provide a non-through pin insertion hole on the side of the pellicle frame 2 of the pellicle 1, and to fix the pellicle 1 placed on the tray 20 of the pellicle case 10 by inserting a pin into this pin insertion hole. This more reliably prevents the pellicle 1 from moving within the pellicle case 10 due to vibrations during transportation, etc.

When the pellicle 1 is removed from the pellicle case 10, particularly when the user grasps and lifts the pellicle, an end portion where peeling begins is first formed between the adhesive layer 4 of the pellicle 1 and the release layer 23 on the tray 20 side, the area peeled off from the release layer 23 expands, and finally the entire pellicle 1 can be completely peeled off from the release layer 23.

In particular, when the pellicle 1 is grasped and lifted by a machine, the position of the pellicle 1 or the tray 20 can be fixed by the machine while the unfixed component is moved away from the release layer 23 in the direction in which they face each other, allowing the adhesive layer 4 on the pellicle 1 side to be peeled off almost all at once from the release layer 23.

[Second embodiment]
An outline of a second embodiment of a pellicle case will be described with reference to the drawings.
FIG. 8 is a vertical cross-sectional view showing an example of a pellicle case of the present embodiment.
In the following description, differences from the first embodiment will be mainly described, and descriptions of common parts will be omitted.

In the pellicle case described above, the release layer 23 was formed on the surface of the tray body 21 in the tray 20, but in the pellicle case of this embodiment, the release layer is formed integrally with the tray body 21 in the tray 20, that is, the tray body 21 itself has releasability.
In the pellicle case of this embodiment, at least the portion of the tray 20 (tray body 21) that comes into contact with the adhesive layer 4 has releasability, and the peel strength between the portion and the adhesive layer 4 is 0.05 to 2.5 kgf.

The peel strength between the tray 20 and the adhesive layer 4 is preferably 1.5 kgf or less, more preferably 1.0 kgf or less, and even more preferably 0.8 kgf or less. This makes it easier to hold the pellicle 1 in the pellicle case 10 or tray 20 and also makes it easier to remove the pellicle 1 from the pellicle case 10 or tray 20.

Furthermore, the peel strength between the tray 20 and the adhesive layer 4 is preferably 0.05 kgf or more, more preferably 0.1 kgf or more, and even more preferably 0.2 kgf or more. This allows the pellicle 1 to be securely held in the pellicle case 10 or the tray 20, while allowing the pellicle 1 to be conveniently removed from the pellicle case 10 or the tray 20.

The tray 20 (tray body 21) preferably contains at least one selected from the group consisting of silicone compounds, fluorine-based compounds, and urethane-based compounds, and more preferably contains a silicone-based compound. This makes it easier to hold the pellicle 1 in the pellicle case 10 or tray 20 and easier to remove the pellicle 1 from the pellicle case 10 or tray 20.

The tray body 21 may also be formed containing resin materials such as polyethylene terephthalate, acrylonitrile butadiene styrene, acrylic, polycarbonate, polyvinyl chloride, etc. This provides the tray body 21 with the strength to protect the pellicle 1 from vibrations and shocks that may occur when the pellicle 1 is transported or stored.

From the above viewpoints, it is preferable that the thickness of the tray 20 (tray body 21) is, for example, 2.0 to 10.0 mm.

The above describes an embodiment of the present invention, but the present invention is not limited to this and can be modified as appropriate without departing from the spirit of the invention.

By using the pellicle case according to the present invention, the pellicle can be appropriately held in the pellicle case or tray during storage and transportation, and the pellicle can be appropriately removed from the pellicle case when it is removed, so that the pellicle case can be widely used as a case for transporting and storing pellicles.

1: Pellicle 2: Pellicle frame 3: Pellicle film 4: Adhesive layer 10: Pellicle case 11: Storage space 20: Tray 21: Tray body 21a: Fixing surface 22: Positioning pin 23: Release layer 24: Fitting portion 30: Cover 31: Ceiling surface 32: Slope 32a: Contact portion 33: Fitting portion

Claims (6)

A pellicle container comprising: a frame having a long side length of 500 mm to 2000 mm and a short side length of 300 mm to 1800 mm; a pellicle arranged on one end surface side of the frame, the pellicle having an adhesive layer comprising at least one adhesive selected from the group consisting of an acrylic adhesive, a rubber adhesive, a vinyl adhesive, an epoxy adhesive, and a silicone adhesive, and having a thickness of 0.8 mm to 2.5 mm; and a pellicle case containing the pellicle,
A tray for placing the pellicle is provided,
At least a portion of the tray that comes into contact with the adhesive layer has releasability,
The pellicle storage item is characterized in that the peel strength when the portion is brought into contact with the adhesive layer (the peel strength when the adhesive layer has a size of 4.5 mm x 30 mm and a thickness of 1.2 mm) is 0.1 to 1.5 kgf . A pellicle container comprising: a frame having a long side length of 500 mm to 2000 mm and a short side length of 300 mm to 1800 mm; a pellicle arranged on one end surface side of the frame, the pellicle having an adhesive layer comprising at least one adhesive selected from the group consisting of an acrylic adhesive, a rubber adhesive, a vinyl adhesive, an epoxy adhesive, and a silicone adhesive, and having a thickness of 0.8 mm to 2.5 mm; and a pellicle case containing the pellicle,
A tray for placing the pellicle is provided,
At least a portion of the tray that comes into contact with the adhesive layer has releasability,
The part contains at least one selected from the group consisting of a silicone compound, a fluorine-based compound, and a urethane-based compound. The pellicle storage item according to claim 1 or 2, wherein the tray has a tray body, and the portion is a release layer disposed on at least the surface of the tray body that comes into contact with the adhesive layer. The pellicle storage item according to claim 3, wherein the release layer is formed by coating on at least one surface of the tray body. The pellicle case further includes a cover for covering the tray,
The cover is
The pellicle storage item according to any one of claims 1 to 4, further comprising an abutment portion that abuts against at least a portion of the frame of the pellicle placed on the tray when the tray is covered with the cover. The pellicle case is
A pellicle storage item as described in any one of claims 1 to 5, further comprising a pin holding mechanism for inserting and fixing a pin into a non-through pin insertion hole provided on a side of the frame of the pellicle placed on the tray.

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