JP3797753B2 - Pellicle storage structure and storage method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pellicle housing structure and a housing method for preventing foreign matter from adhering to a photomask or a reticle used in a lithography process when manufacturing an LSI or the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in the manufacture of semiconductor circuit patterns and the like, it has been practiced to prevent foreign matter from adhering to a photomask or reticle using a dust-proof means generally called a pellicle (for example, Japanese Patent Publication No. 54-28718). ). The pellicle is a transparent polymer film (hereinafter referred to as a pellicle) such as nitrocellulose or cellulose derivative having a thickness of about 10 μm or less on the upper edge surface of a frame of about several millimeters thick having a shape matched to the shape of a photomask or reticle. The adhesive film is spread and adhered, and an adhesive material is applied to the lower edge surface of the frame body, and a protective film is adhered to the adhesive material with a predetermined adhesive force.
[0003]
The pressure-sensitive adhesive is for fixing the pellicle to a photomask or reticle, and the protective film is used to maintain the adhesive strength of the pressure-sensitive adhesive until the pressure-sensitive adhesive is used for that purpose. It protects the adhesive surface. When transporting this pellicle from the manufacturer to the user, in order to prevent foreign matter from adhering to the pellicle film or the like, or to prevent the pellicle from being damaged, the pellicle is stored in a case consisting of a tray and a lid, Further, it is generally stored in a dust-proof bag or the like and transported.
[0004]
Conventionally, the pellicle case having the above-described structure is stored as shown in FIGS. That is, in the figure, the pellicle film 52 is bonded to one upper edge surface of the frame body 51 in a stretched (pinched) state, and the other surface (lower edge surface) of the frame body 51 has an appropriate thickness. The adhesive material 53 is provided, and a protective film 54 is attached to the lower surface of the adhesive material 53 to form a pellicle. The pellicle is placed so that the protective film 54 is in contact with the installation surface 55 a which is a flat surface of the tray 55.
[0005]
The pellicle placed on the installation surface 55 a of the tray 55 is restrained from moving left and right by a protruding post 55 b provided on the tray 55, and covers the lid 56 from above. It was stored in the case by fixing four corners with 55. As a result, the pellicle was restrained by being surrounded by the inclined surface 56a of the lid 56, the post 55b, and the installation surface 55a, and stored in the case.
[0006]
[Problems to be solved by the invention]
However, as described above, the pellicle is transported in a storage state constrained by the inclined surface 56a of the case lid 56, the post 55b, and the installation surface 55a. However, it cannot be avoided that the pellicle is subjected to some vibration or impact during transportation. . When there is a large gap between the pellicle and the inclined surface 56a of the case lid 56 in the conventional restraint state of the pellicle, the pellicle collides with the case lid 56 due to vibration and impact during transportation. Due to strong rubbing, it sometimes wears and generates dust. In such a case, there has been a problem of losing the most important function of delivering the pellicle to the user without foreign matter.
[0007]
On the other hand, when the gap between the pellicle and the case is eliminated, that is, when the inclined surface 56a is in contact with the frame 51 (or the end of the pellicle film 52) in advance, mutual contact is also achieved. It is known from experience that the inner surface of the inclined surface 56a or the end of the pellicle film 52 is worn by the pressure to generate foreign matter.
[0008]
Therefore, the most preferable method in such a pellicle storage structure is to take a very small gap between the pellicle and the inclined surface 56a of the lid 56 of the case. Specifically, when the pellicle is placed on the tray 55, the lid 56 is covered, and the lid 56 and the tray 55 are fixed to each other with the clip 57, 0.1 to between the slope 56 a and the upper end of the frame body 1. In this structure, a gap of about 0.3 mm is provided.
[0009]
Inventor's experiments have confirmed that such a clearance can withstand a certain amount of vibration and impact. However, in this case as well, there was a problem of generating dust when subjected to a large impact. Furthermore, it is necessary to provide a means for reducing the impact applied to the case or pellicle by a packing method (for example, using a large amount of a soft foam material having a high impact effect), or a transportation means with less vibration and impact is required. In order to secure an appropriate gap between the lid 56 and the pellicle, it is necessary to form the tray 55 and the lid 56 with high accuracy. However, many of these means have a problem that it is extremely difficult to guarantee that no dust is generated in principle.
[0010]
The present invention is a completely new technology developed in view of the above-mentioned many problems. In particular, when storing the pellicle in the case, the pellicle is temporarily attached to the installation surface of the case tray with a predetermined adhesive force. Therefore, the pellicle is restrained in the case, thereby providing a completely new technology that can sufficiently withstand vibration and shock during transportation.
[0011]
[Means for Solving the Problems]
In view of the above-mentioned many problems, the present inventor can solve the above-mentioned problems by fixing the pellicle to the tray of the case for storing the pellicle by conducting many years of research and various experiments. I found However, after the pellicle stored in the case reaches the user side, the user must be able to easily remove the pellicle from the case. I realized that I had to fully consider it.
[0012]
That is, when fixing the pellicle to the tray, it was invented that the user temporarily attached temporarily by adhering or sticking with a predetermined adhesive force that allows the user to easily remove the pellicle from the tray.
[0013]
As described above, temporarily attaching the pellicle to the tray with a predetermined adhesive force is reasonable, for example, to make the pellicle and the tray have a bonding strength when vibration or impact is applied during transportation. It is. In the inventor's experiment, there is data that a case in which a moderate amount of cushioning material is packed, an acceleration of about 5G to 10G is applied to the case during normal land transportation. Therefore, an adhesive force of about 10 times the weight of the pellicle is considered appropriate for obtaining a realistic effect.
[0014]
However, in principle, any small adhesive force is resistant to impact and has the effect of reducing the strength of rubbing between the pellicle and the lid. Therefore, it is not necessary to set the lower limit of the adhesive force in the present invention, but in order to make the effects of the present invention clearer and to make it possible to clearly discriminate the implementation of the present invention, the lower limit of the adhesive force or the adhesive force. Is set as follows.
[0015]
That is, although there are some aspects that are difficult to define with respect to the adhesive force or the adhesive force, in the present invention, when a certain load is applied to the bonded portion and the film does not completely peel for more than 1 second, the adhesive force exceeds the certain load. Define that there is. The lower limit of the adhesive force based on this definition can be about the weight of the pellicle.
[0016]
On the other hand, it is difficult to determine the upper limit of the adhesive force because conditions vary depending on the method of taking out the pellicle from the case. That is, for example, if the tray is simply placed on a flat surface with its weight left, and the pellicle placed on the tray is taken out, the adhesive force between the pellicle and the tray needs to be less than the weight of the tray. Otherwise, the tray will be lifted when it is lifted to remove the pellicle.
[0017]
However, in recent years, there are an increasing number of methods in which a user takes out a pellicle from a tray using an automatic sticking machine. In this case, since the tray is fixed by the suction pad, the pellicle can be detached from the tray even with a stronger adhesive force. As described above, the upper limit of the adhesive force between the pellicle and the tray has a room for selection depending on the method of fixing the tray when the pellicle is taken out, and should be appropriately selected depending on the situation. Of course, it is not necessary to say that the minimum necessary adhesive strength is practically preferable.
[0018]
The pellicle storage structure according to the present invention has been invented to solve many conventional problems as described above. The overall structure of the invention is summarized as follows. And a pellicle film adhered to the upper edge surface of the frame, an adhesive applied to the lower edge of the frame, and an adhesive adhered to the lower edge of the frame to protect the adhesive In a structure in which a pellicle made of a protective film is housed in a case made of a tray lid, the protective film of the pellicle is temporarily attached to the tray with a predetermined adhesive force. It is a storage structure.
[0019]
In the pellicle storage structure of the present invention, as described above, the pellicle protective film is temporarily attached to the tray with a predetermined adhesive force when the pellicle is stored in the case including the tray and the lid. It can be restrained directly to the tray via the adhesive force of this, and when transporting the pellicle, it can prevent the pellicle from hitting the case strongly due to vibration and impact, and dust can be prevented from being generated .
[0020]
The gist of the second invention of the pellicle storage structure according to the present invention is to support the weight of the pellicle that is weaker than the adhesive force between the protective film and the frame body when temporarily attaching the protective film of the pellicle to the tray. The pellicle storage structure according to the first aspect of the present invention is characterized in that the pellicle is temporarily attached with an adhesive strength that can be reduced.
[0021]
In the second invention, as described above, when temporarily attaching the protective film located on the lowermost surface of the pellicle to the tray, the weight of the pellicle weaker than the adhesive force between the protective film and the frame can be supported. Since it is temporarily attached to the tray with a certain degree of adhesive force, the pellicle temporarily attached to the tray can be easily peeled off from the tray with a very weak force.
[0022]
The pellicle storage method according to the present invention is also a technique that fundamentally improves many conventional problems, similar to the above-described pellicle storage structure, and the gist of the invention is that the frame and the frame A pellicle comprising a pellicle film adhered to the upper edge surface, an adhesive material applied to the lower edge surface of the frame body, and a protective film adhered to the lower edge surface of the frame body to protect the adhesive material In the method of storing in a case comprising a tray and a lid, an adhesive or adhesive having a predetermined adhesive force on the lower surface of the protective film or the installation surface of the tray adhered to the lower edge surface of the pellicle frame Then, the protective film is adhered to the tray with a predetermined adhesive force, and the pellicle is temporarily attached to the tray.
[0023]
In the above-described storage method of the present invention, an adhesive material or adhesive material having a predetermined adhesive force is applied to the lower surface of the protective film adhered to the lower edge surface of the pellicle frame, and the protective film is applied. Since the pellicle is temporarily attached to the tray, the pellicle can be temporarily and precisely attached to a predetermined position of the tray in the case, and thereby the pellicle can be restrained in a stable state via the tray.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the pellicle storage structure and storage method according to the present invention will be specifically described with reference to the drawings. FIG. 1 is a longitudinal sectional view showing the pellicle storage structure according to the present invention, and FIG. It is a longitudinal cross-sectional enlarged explanatory drawing of the state which expanded the part.
[0025]
1 and 2, the pellicle is applied to the frame 1, the pellicle film 2 bonded to the upper edge of the frame 1, and the lower edge of the frame 1, as already described in detail. The adhesive material 3 is attached, and a protective film 4 adhered to the adhesive material 3 to protect the adhesive material 3. In the above embodiment, the adhesive material 3 is applied to the lower edge surface of the frame 1, but the adhesive material 3 formed in advance in a layered form is simply laminated on the lower edge surface of the frame 1. It is only necessary to apply the adhesive (however, in this specification, including such a case, it is simply referred to as “apply”).
[0026]
How is the pellicle configured as described above effective in storing the pellicle in the case made up of the tray 5 and the lid 6 and where the pellicle should be specifically bonded to the tray 5? As a whole, the following is considered.
[0027]
That is, a portion where the pellicle and the tray 5 may contact each other is between the frame body 1 and the plurality of posts 5b supporting the frame body 1 from the surroundings, or the protective film 4 and the tray 5 It can be considered between the post 5b or between the protective film 4 and the installation surface 5a of the pellicle.
[0028]
Of course, in addition to this, the tray 5 can be positively provided with a structure in contact with the pellicle, and the tray 5 and the frame body 1 can be connected with an adhesive tape, for example. However, in general, the pellicle is stored, transported, and taken out from the tray 5 as shown in FIG. 1, and the pellicle is placed most stably on the tray 5 with the pellicle placed on the tray 5 as shown in FIG. Can be fixed on the tray 5 by a structure in which the protective film 4 and the installation surface 5a are adhered to each other by an adhesive (or adhesive) 8. In the figure, 7 is a clip for fixing the corner portions of the tray 5 and the lid 6.
[0029]
In this case, when the pellicle is taken out from the tray 5, the adhesive force between the protective film 4 and the tray 5 is such that the protective film 4 can be taken out while being fixed to the pressure-sensitive adhesive 3 as usual. 4 and the adhesive material 3 should be weaker than the adhesive force.
[0030]
As described above, when the adhesive material 8 is provided between the protective film 4 and the installation surface 5 a, the adhesive force between the adhesive material 3 and the protective film 4, and between the protective film 4 and the adhesive material 8. In order to adjust the balance between the adhesive force and the adhesive force between the adhesive material 8 and the installation surface 5a, it is effective to select the material of the adhesive material 3, the protective film 4, the adhesive material 8 and the installation surface 5a. It is. In order to interpose this adhesive material 8 between the protective film 4 and the tray 5, it is possible to apply the adhesive material 8 to either the protective film 4 or the tray 5 in advance.
[0031]
In the present invention, these materials are not particularly limited, but in general, the pressure-sensitive adhesive material 3 is a rubber-based, acrylic-based, or acrylic-based material from the viewpoint of adhesion to a reticle or mask material and releasability. Select adhesive material such as silicone. As the material of the installation surface 5a, that is, the tray 5, from the viewpoint of moldability and antistatic property, for example, an acrylic resin imparted with antistatic properties, or a plastic such as ABS resin is generally used.
[0032]
Therefore, in order to adjust the balance of the adhesive force, it is preferable to select the material of the protective film 4 and the material of the adhesive material 8. As the protective film 4, a film such as polyethylene or polyester can be used. These materials may be used alone, but the adhesive force can be controlled by forming a film of silicone or the like on one or both sides of the film.
[0033]
In particular, the silicone-treated polyester film can change the adhesive strength between the front and back sides depending on the type of silicone, and the degree of design freedom can be obtained. For the adhesive material 8, a rubber-based, acrylic-based, or silicon-based adhesive material is appropriately selected from the viewpoint of adhesive strength and dust generation.
[0034]
Specific embodiments of the pellicle storage structure and the storage method thereof according to the present invention will be described in detail as follows.
[0035]
[Example 1]
In FIGS. 1 and 2, a pellicle composed of a frame 1, a pellicle film 2, an adhesive material 3, and a protective film 4 is applied to an area corresponding to the protective film 4 on the installation surface 5a with an acrylic latex adhesive material 8 applied thereto. The protective film 4 was temporarily attached to the installation surface 5a, whereby the pellicle was adhered and fixed to the tray 5, and the pellicle was restrained to the tray 5 and stored in the case.
[0036]
At this time, a gap of about 0.3 mm was secured between the upper end of the pellicle and the slope 6a of the lid 6. A drop test was carried out in a packaged state in which 10 cases of such storage cases were stacked, and a cushioning material generally called an air cap was arranged around the case and stored in a cardboard box. As a result of performing a drop test from a height of 1 m ten times, rubbing between the pellicle and the lid 6 and generation of dust based on rubbing were not recognized at all.
[0037]
In this embodiment, the acrylic latex-based adhesive material 8 was applied in a spot manner, not in an application that adheres (adheres) over the entire circumference of the protective film 4. The adhesive strength at this time was 8 times or more and 15 times or less the weight of the pellicle in the above definition. The pellicle could be easily removed from the tray 5 by hand with the tray 5 sucked and fixed from the lower surface with an air suction pad.
[0038]
[Comparative Example 1]
In contrast to the above-described Example 1, in Comparative Example 1, the acrylic latex adhesive 8 was not interposed between the protective film 4 and the tray 5, and the protective film 5 was placed in the tray 5 in the same manner as in the conventional storage method. The drop test was performed in the same packaging state as in Example 1 described above. As a result, rubbing was observed on all 10 pellicles, and dust generation was observed in half of them. The impact value in this drop test was a maximum impact value of 50 G in the corrugated cardboard box, which is an outer box, and a maximum of 10 G in the case containing the pellicle. (Using a shock sensor manufactured by Fuji Film Co., Ltd.).
[0039]
【The invention's effect】
Since the pellicle storage structure and the storage method thereof according to the present invention have the above-described configuration and operation, they have the following great effects.
[0040]
In the present invention, when the pellicle is housed in the case made of the tray and the lid, the pellicle is temporarily attached to the tray with a pellicle protective film and a predetermined adhesive force. It is possible to prevent strong contact with the case.
[0041]
Accordingly, it is possible to prevent the pellicle from striking against the case to cause rubbing and damaging the pellicle itself, or generating small dust due to strong rubbing between the pellicle and the case, and this dust from adhering to the pellicle.
[0042]
In the present invention, since the pellicle protective film is adhered to the tray with a predetermined adhesive force, the pellicle can be easily removed from the tray. In particular, when temporarily attaching the pellicle to the tray, if the pellicle is temporarily attached to the tray with an adhesive force that can support the weight of the pellicle that is weaker than the adhesive force between the protective film and the frame, the pellicle must be weakly applied from the tray. Can be easily removed.
[0043]
Since the overall configuration of the present invention is extremely simple as described above, it can be easily implemented without using any special means, and therefore can be efficiently implemented at low cost. It has a great effect such that it can be provided safely and inexpensively to the user without impairing the function.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a pellicle storage structure according to the present invention.
2 is an enlarged explanatory view of a longitudinal section of a main part of FIG.
FIG. 3 is a longitudinal cross-sectional explanatory view showing an example of storing a pellicle of a conventional example.
4 is an enlarged explanatory view of a longitudinal section in a state in which a main part of FIG. 3 is enlarged.
5 is an explanatory plan view of a main part showing a pellicle storage state in FIG. 3; FIG.
[Explanation of symbols]
1 Frame 2 Pellicle film 3 Adhesive material 4 Protective film 5 Tray 5a Installation surface
5b Post 6 Lid
6a Slope 7 Clip 8 Adhesive
51 Frame 52 Pellicle membrane
53 Adhesive 54 Protective film
55 Tray 56 Lid
57 clips

Claims (3)

A frame, a pellicle film bonded to the upper edge of the frame, an adhesive applied to the lower edge of the frame, and an adhesive to the lower edge of the frame to protect the adhesive In the structure in which the pellicle made of the protective film is housed in a case made of a tray and a lid, the protective film of the pellicle is directly attached to the tray with a predetermined adhesive force. Pellicle storage structure. When temporarily attaching the protective film of the pellicle to the tray, the pellicle is temporarily attached with an adhesive force capable of supporting the weight of the pellicle that is weaker than the adhesive force between the protective film and the frame. The pellicle storage structure according to claim 1. A frame, a pellicle film bonded to the upper edge of the frame, an adhesive applied to the lower edge of the frame, and an adhesive to the lower edge of the frame to protect the adhesive In a method of storing a pellicle made of a protective film in a case made of a tray and a lid, a predetermined adhesive force is applied between the protective film and the tray adhered to the lower edge surface of the frame of the pellicle. A method for storing a pellicle, comprising: interposing an adhesive material or a pressure-sensitive adhesive material having the protective film, adhering the protective film to the tray with a predetermined adhesive force, and temporarily attaching the pellicle to the tray.

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