HK1111230B - Pellicle storage container and method of manufacturing same - Google Patents

Description

Protective film assembly container and method for manufacturing same

Technical Field

The present invention relates to a container for a pellicle for lithography used as a dust-proof device in the production of articles such as semiconductor devices, printed circuit boards, and liquid crystal displays, and a method for producing the same.

Background

In the manufacture of semiconductor devices such as LSIs and articles such as liquid crystal displays, a semiconductor wafer or a glass substrate for liquid crystal is irradiated with light to produce a pattern, and if dust adheres to a photomask or a reticle (hereinafter simply referred to as a photomask) used in this case, the dust blocks light or refracts light, and the transferred pattern is damaged.

Therefore, these operations are usually performed in a clean room, and even so, it is difficult to keep the photomask clean frequently. Then, a method of attaching a pellicle as a dust-proof device to the surface of the photomask is adopted.

At this time, the foreign matter is not directly attached to the surface of the photomask but attached to the pellicle, and as long as the focus is aligned with the photomask pattern in the photolithography step, the foreign matter on the pellicle is out of focus, so that the foreign matter will not affect the transfer. However, although the closed space formed after the pellicle is attached to the photomask has an effect of preventing foreign matter from entering the inside from the outside, it is difficult to prevent the surface of the photomask from adhering to foreign matter if the foreign matter adheres to the pellicle itself and is inside the closed space. Therefore, in addition to the high cleanability of the pellicle itself, the pellicle container used for storage and transportation is strongly required to have the performance of maintaining the cleanability. Patent document 1 discloses a structure in which a pellicle is fixed in a pellicle container.

"patent document 1" registered utility model No. 3023612

Disclosure of Invention

Problems to be solved by the invention

As described above, the applicant strongly demanded that the pellicle film unit storing container has a function of maintaining the cleanness of the pellicle film unit when storing and transporting the pellicle film unit, and, for this reason, the cause of the formation of dust is first reduced as much as possible. The main causes of dusting are, for example: the material, the energization characteristic, the cleanliness of the parts constituting the pellicle assembly container, the contact between the pellicle assembly container and the pellicle, and the like. Therefore, it is necessary to consider various factors such as the material, strength, and electrical characteristics of the constituent material of the protective film module storage container and the method of fixing the protective film module.

A typical protective film module storage container is composed of a container body on which a protective film module is placed, and a lid body that covers and protects the protective film module and is fitted and locked to the container body at the peripheral edge portion thereof, wherein the lid body is made of resin and has transparency. Generally, a container having an outer size of about 200mm and housing a pellicle for semiconductor is formed by injection molding, and a large container having an outer size of about 500mm or more and housing a pellicle for liquid crystal is formed by sheet vacuum molding.

Recently, with the progress of the enlargement of the liquid crystal protective film module, the large protective film module having a size exceeding 1,000mm in the long side, or in the long side and the short side of the protective film module frame has become the mainstream of the large panel production. The large-sized protective film module container manufactured by vacuum forming of a sheet has a problem that the top surface of the cover body is bent by its own weight, and the bending becomes large to such an extent that the cover body cannot be disregarded with the trend of the large-sized protective film module container, and the cover body of the protective film module container comes into contact with the protective film during transportation.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a container for housing a pellicle for lithography, which can prevent a lid body of the container from contacting a housed pellicle during storage, transportation, housing, or removal, and can prevent contamination of the pellicle to maintain quality, and a method for manufacturing the container.

Means for solving the problems

In order to solve the above problems, the present inventors developed the following apparatus (1), and listed preferred embodiments (2), (3) and a manufacturing method (4).

(1) A container for housing a pellicle, comprising a container body on which a pellicle with a total of longer sides and shorter sides of more than 1,000mm is mounted, and a synthetic resin lid body for housing the pellicle and being in close contact with the container body at peripheral edges thereof, characterized in that:

the thickness of the lid body is less than 5mm, and the central part of the lid body has a sufficient convex curvature for maintaining a flat shape or an outward convex shape in a close state.

(2) The container for housing a pellicle according to (1), wherein the lid has a plate thickness of 1 to 4 mm.

(3) The container for housing a pellicle as described in (2), wherein the lid has a plate thickness of 2 to 3 mm.

(4) A method for manufacturing a container for housing a pellicle, the container comprising a container body on which a pellicle of which the total of long and short sides exceeds 1,000mm is mounted, and a lid body made of synthetic resin, the lid body housing the pellicle and being in close contact with the container body at peripheral edges thereof, the method comprising:

and a molding step of molding the sheet-like material for molding the lid body into a lid body having a thickness of 5mm or less by performing vacuum molding using a mold body having a convex surface.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the invention (1) described above, the cover of the container for housing a pellicle assembly does not contact the housed pellicle during storage, transportation, and operation, and the pellicle assembly can be prevented from being stained to maintain the quality.

The above effects are particularly remarkable in the case of the large-sized pellicle assembly defined in (2) and (3).

According to the manufacturing method of the above (4), the container for housing a pellicle of the present invention can be manufactured appropriately.

Drawings

FIG. 1 is a cross-sectional view showing one embodiment of a container for housing a pellicle according to the present invention;

FIG. 2 is a cross-sectional view showing another embodiment of a container for housing a pellicle of the present invention;

FIG. 3 is a sectional view showing an example of a vacuum forming mold for forming a lid body used in the present invention;

FIG. 4 is a prior art embodiment of a generic protective film assembly receptacle;

FIG. 5 is a prior art embodiment of a typical vacuum forming mold;

description of the main elements

1 Container body

2 cover body

3 protective film

4 protective film assembly frame

5 sheet Material

6 (vacuum forming) mould body

7 evacuation hole

8 protective film assembly

10 container for protective film assembly

Width of central part of W cover

Depth of recess of cover body horizontally formed at X central part due to self weight

Height of Y central part for offsetting X deformation

Detailed Description

The container for holding pellicle assemblies of the present invention is composed of a container body for holding pellicle assemblies and a cover body for covering the container body. The container body, which constitutes a container bottom plate or a tray, has a fixing means for allowing the peripheral edge of the container body to be closed and opened again with the peripheral edge of the lid body, and may have a means for fixing the pellicle assembly to the central portion of the container body completely or with a suitable degree of freedom of movement.

The cover body is an upper cover with a bulge part at the central part and is detachably arranged on the container body. When the container body and the cover body are combined into a whole, the cover body can form a containing space of the protective film assembly between the container body and the cover body under the state of not contacting with the protective film of the contained protective film assembly.

Here, the container body may be provided with a concentric groove for accommodating pellicle units of different sizes, and the pellicle units of different sizes may be placed in the groove corresponding to the frame size of the pellicle unit, thereby achieving a storage effect of suppressing the wobbling movement (see japanese unexamined patent publication No. 10-142772).

The protective film assembly container has a fixing means for bringing the peripheral edge portion of the container body and the peripheral edge portion of the lid body into close contact with each other.

Any device can be optionally selected as a fixing device for the container body and the lid body as long as the lid body can be freely attached and detached. An insertion mode may be used in which a projection provided on the peripheral edge portion of the lid body is inserted into a groove provided on the periphery of the container body. The container body and the lid body can be fixed by clamping both peripheral edges of the container body and the lid body by using an openable and closable clamp as another fixing means.

The synthetic resin constituting the container body and the lid body is not particularly limited, but a material which is easily molded (including heat distortion), easily subjected to antistatic treatment, and hardly thermally deformed is preferably used.

For example, the following may be used: acrylic colophony, polyethylene terephthalate colophony, Acrylonitrile-Butadiene-Styrene copolymer (ABS) colophony, polystyrene colophony, polycarbonate colophony, polyvinyl chloride colophony, polypropylene colophony, polyethylene colophony, propylene-ethylene-Styrene colophony and so on, as well as synthetic resin material for forming containers or containers. These resins are preferably subjected to antistatic treatment as described later.

In view of the light weight of the entire container for housing the pellicle, it is preferable to use a resin for the container body and the lid, and it is more preferable to use a synthetic resin. The thickness of the lid body is preferably small in consideration of weight reduction, but the thickness is small in consideration of the large bending deformation at the center of the top surface of the lid body, so that both the weight reduction and the reduction of the bending deformation are preferably satisfied. Generally, the cover should be made of a resin having a thickness of 5mm or less, preferably 1 to 4mm, more preferably 2 to 3 mm. In addition, it is preferable that the central portion of the top surface of the lid body is designed and formed in a shape protruding outward in advance to prevent the lid body from being bent and attached to the protective film due to its own weight during the molding process. As will be described in detail later.

The surface resistance values of the container body and the lid body are preferably set to 1X 10¹²Preferably, the ratio is not more than Ω/□. The surface resistance value is 1 × 10¹⁰Omega/□ or less, preferably 1X 10⁸Preferably below Ω/□. The surface resistance of the container body and/or the cover is set to 1 × 10¹²Antistatic property below omega/□The electric method is not particularly limited as long as it does not cause a problem of dust generation, and an appropriate method may be selected from among methods such as blending a hydrophilic polymer in a base polymer, blending a conductive material in a molding resin, applying a conductive film on the surface of a plate material before molding, and forming a conductive film on the surface of a container body or a lid body after molding. The conductive material blended in the molding resin includes a metal, a metal oxide, and a conductive polymer.

From the viewpoint of ease of production and production cost, it is preferable to use an antistatic-treated plastic. The antistatic treatment is, for example, a method of adding a conductive filler (carbon black, conductive fine fibers, metal fibers, etc.). Such as polycarbonate with carbon black added.

Other antistatic treatments, such as a treatment in which a hydrophilic polymer is dispersed in a base resin using a polymer alloy technique. The base resin comprises ABS resin, PMMA resin and HIPS resin, and the hydrophilic polymer comprises polyethylene glycol polyamide copolymer, polyethylene glycol methacrylate copolymer and ethylene oxide-epichlorohydrin copolymer. Manufacturers such as TORAY (stock), JSR (stock), Asahi chemical industry (stock), Wuyu chemical industry (stock) and the like have on the market antistatic resins prepared in the above manner.

As described above, the plastic with the conductive filler added or the resin in which the hydrophilic polymer is dispersed in the base resin can be used as a molding material for vacuum molding or injection molding of the container body and/or the lid.

The antistatic agents that can be incorporated into plastics in the present invention are described in horiba Shibata, entitled "antistatic agent", PLASTICS AGE (1993, 11 Yue., 134-145 pp.). The polymer alloy technique of dispersing a hydrophilic polymer in a base resin is described in "design of permanent antistatic material", PLASTICS AGE (1994, 4 th month, pages 104 to 109) and references thereof, which are commonly known in the chapter "meitian" and the chapter "prefecture".

The surface resistance value was measured in an environment at a temperature of 24 ℃ and a humidity of 50%. The measuring apparatus used a super-insulation meter SM-8205 manufactured by east asian electric wave industry (stock). The load voltage was rated at 1,000V. The measurement positions of the container body and the lid are located inside the container, and if the container body and the lid are rectangular, the measurement positions are located 50mm away from the measurement terminal with the intersection point (gate position) of the diagonal lines sandwiched therebetween.

The embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

Fig. 1 shows a pellicle assembly container according to an embodiment of the present invention. The cover body is in a close fit state, and the central part of the cover body is in an outward convex shape.

The pellicle unit container 10 is composed of a container body 1 and a lid body 2, and peripheral edge portions of the container body 1 and the lid body 2 can be tightly adhered to each other to form a sealed space in which the pellicle unit 8 is contained. The protective film component 8 is composed of a protective film 3 and a protective film component frame 4, and the protective film 3 is arranged on the protective film component frame 4 in an opening mode. As in the case of the conventional pellicle unit container, the container body 1 may be provided with a mounting table at a central portion thereof which is elevated in a first step for mounting the pellicle unit 8 thereon, and may be provided with a receiving portion (not shown) around the mounting table for preventing the pellicle unit 8 from moving away from the mounting table during transportation. Suitable means may be selected to seal the container body 1 and the lid body 2. This embodiment has a structure in which a projection provided on the peripheral edge of the lid body 2 is fitted and fixed (engaged and locked) into a groove provided on the peripheral edge of the container body 1, and the lid body 2 is covered and sealed on the container body 1 to form a sealed space for housing the pellicle assembly.

Fig. 2 shows another embodiment of the container for housing a pellicle according to the present invention. The lid is tightly adhered and the central part is kept almost flat. It is also the same as fig. 1, and in order that the lid body 2 does not bend and adhere to the protective film 3 due to its own weight during the molding process, the central portion of the top surface of the lid body 2 is designed in advance to have a convex shape. However, since the flat convex shape is formed to exactly offset the amount of bending caused by the weight of the container, the top surface of the cover 2 becomes flat when the container is horizontally placed.

Fig. 3 shows an example of a method of molding the lid body 2 used in the present invention. The present embodiment uses a molding method of vacuum forming the mold body 6. The lid body 2 is formed by bringing a resin sheet 5 into contact with a high-temperature mold body 6 and then forming a vacuum state through a vacuum hole 7. In the conventional method, the mold of the flat-shaped member such as the cover 2 of the container for receiving the pellicle is designed to be flat, and the cover 2 used in the present invention is designed to have a concave depth X (see fig. 4) due to its own weight calculated in advance, and the top surface of the mold body 6 is formed to be convex at a predetermined height Y.

Thus, the cover 2 can be used to prevent the cover 2 from being attached to the protective film 3 by being dented. It is pre-calculated how much the portion of the mold body 6 forming the top surface of the lid 2 is to be formed into a convex shape due to the bending X caused by its own weight, i.e., how large the height Y should be, which can be determined by factors such as the area, shape, material, thickness of the top surface, and the distance to the surface of the protective film.

In order to maintain the cap 2 in a flat state (shown in fig. 2) or in a convex shape (shown in fig. 1) in a sealed state where the internal and external air pressures of the container are equal, the height Y in fig. 3 varies depending on the material, thickness, area, aspect ratio, etc. of the molding material, for example, assuming that the width w of the central portion of the cap above the protective film 3 is 1,000mm, Y is generally in the following range:

0.001W≤Y≤0.2W

the width W is substantially equal to the diameter or the diagonal length of the pellicle.

In the manufacturing method of the present invention, if the projecting shape of the mold body is determined so as to satisfy the above-described relational expression, the container for housing a pellicle of the present invention can be appropriately manufactured.

Examples

Hereinafter, examples of the present invention will be described, but the present invention is not limited thereto.

The pellicle film assembly container 10 shown in fig. 1 and 2 was produced. The structure of the container 10 for housing pellicle is mainly composed of a container body 1 and a container cover 2, both of which are formed by vacuum forming method for ABS resin (surface resistance value 5 × 10) with antistatic property¹¹Omega/□) is molded.

In the protective film assembly storage container 10 of fig. 1, the top surface of the lid body 2 is designed to be convex even if it is bent by its own weight, so that the top surface does not adhere to the protective film 3.

The top surface of the cover 2 of the container 10 of fig. 2 is designed to have a gently convex shape to compensate for the amount of bending due to the weight of the top surface itself.

Fig. 3 shows a vacuum forming mold for manufacturing the lid body 2 of the present invention. The vacuum forming mold is mainly composed of a mold body 6 having a heat source, and vacuuming holes 7 for closely adhering the sheet 5 to the mold body 6.

When the container 10 for a pellicle of fig. 1 is manufactured, the height Y is set to a value such that the center of the top surface of the lid body is formed in a convex shape protruding upward by 5 to 10mm when the molded article is placed horizontally. In the production of the container 10 for housing a pellicle of fig. 2, the height Y is set so that the center of the top surface of the lid body becomes horizontal when the molded article is placed horizontally.

A silicone adhesive was applied as a protective film adhesive to one end surface of a protective film module frame 4 made of an aluminum alloy having an outer size of 782 × 474 × 6mm, and a silicone adhesive (trade name KR120, manufactured by shin-Etsu chemical industries) was applied as a photomask adhesive to the other end surface thereof, and the resultant was cured by heating, and then a fluorine-based polymer (trade name cytop, manufactured by Asahi glass (trade name)) was formed into a protective film 3 having a thickness of about 4 μm by spin coating, and the protective film module 8 was attached to the protective film module frame 4, and the module was stored in the protective film module storage containers 10, and was transported to and from Tokyo-Fugu, and the number of foreign matters on the protective film 3 before and after transportation was counted.

The pellicle film unit 8 was taken out from the pellicle film unit container 10 in a clean room of class 100, and the increased number of foreign matters on the surface of the pellicle film 3 was examined by irradiating light of 40 ten thousand luxes in a dark room, and it was found that there was no damage or an increase in foreign matters to the pellicle film 3 and that there was no deformation or damage to the parts constituting the pellicle film unit 8. Further, the charge amount of the pellicle film 3 after the transfer was measured by ION SYSTEM/MODEL775

-0.1kV。

Comparative example 1

As shown in fig. 4, the container for housing a pellicle assembly is manufactured without considering the bending due to the weight of the cover body 2 itself. The container body 1 and the lid body 2 are made of a material having a surface resistance value of 10¹⁸And omega/□ or higher. The container for housing a pellicle is manufactured by a vacuum forming mold having a generally horizontal top surface as shown in FIG. 5, and as a result, the center of the top surface of the lid body is bent downward when the molded article is placed horizontally, and the depth X of the recess is 13 mm.

A silicone adhesive was applied as a protective film adhesive to one end surface of a protective film module frame 4 made of an aluminum alloy having an outer size of 782 × 474 × 6mm, and a silicone adhesive (product name KR120, manufactured by shin-Etsu chemical industries) was applied as a photomask adhesive to the other end surface thereof, and the resultant was cured by heating, and then a fluorine-based polymer (product name cytop, manufactured by Asahi glass (trade name)) was formed into a protective film 3 having a thickness of about 4 μm by a spin coating method, and the protective film module was attached to the protective film module frame 4, thereby obtaining a protective film module, which was stored in the protective film module storage container, and was transported to and fro between Tokyo-Fugang, and the number of foreign matters on the protective film 3 before and after transportation was counted.

The pellicle was taken out from the pellicle housing container in a class 100 clean room, and the surface of the pellicle 3 was inspected in a dark room by irradiating light of 40 kilogrammes, and a contact mark having a diameter of about 25mm was found in the center of the pellicle 3, and numerous foreign matters of 10 μm or more were added around the contact mark. The charge amount of the protective film 3 after the transfer was measured to be-3.8 kV by ION SYSTEM/MODEL 775.

Claims (4)

1. A container for housing a pellicle, comprising a container body on which a pellicle with a total of longer sides and shorter sides of more than 1,000mm is mounted, and a synthetic resin lid body for housing the pellicle and being in close contact with the container body at peripheral edges thereof, characterized in that:

the cover body has a plate thickness of 5mm or less, and when the width of the central part of the cover body partitioned directly above the protective film positioned at the inner side of the protective film assembly frame is W and the maximum protruding amount of the central part of the cover body towards the upper outer side is Y, the cover body is bent and protruded towards the upper outer side in the range of Y being more than or equal to 0.001W and less than or equal to 0.2W, so that the central part of the cover body is kept in a flat state or an outward protruding shape in a sealing state.

2. The container for housing pellicle according to claim 1, wherein the lid has a plate thickness of 1 to 4 mm.

3. The container for housing a pellicle according to claim 2, wherein the lid has a plate thickness of 2 to 3 mm.

4. A method for manufacturing a container for housing a pellicle, the container comprising a container body on which a pellicle of which the total of long and short sides exceeds 1,000mm is mounted, and a lid body made of synthetic resin, the lid body housing the pellicle and being in close contact with the container body at peripheral edges thereof, the method comprising:

and a forming step of forming the sheet-like material for forming the lid body into a lid body having a thickness of 5mm or less by vacuum forming using a mold body having a convex surface, wherein when a width of a central portion of the lid body defined directly above the protective film positioned inside the protective film assembly frame is W and a maximum amount of projection of the central portion of the lid body to the upward outer side is Y, the lid body is bent and projected upward to the outer side within a range of 0.001W or more and 0.2W or less, and the central portion of the lid body is maintained in a flat or outwardly projected shape in a tightly adhered state.