JP2855045B2 - Pellicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pellicle, in particular, an LS.
I, practically 500nm, used as a dust proof when manufacturing semiconductor devices such as LSI and liquid crystal display panels
The present invention relates to a pellicle in an exposure method using the following light.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices such as LSIs and VLSIs or liquid crystal display panels, a semiconductor wafer or a liquid crystal master is irradiated with light to form a pattern. If dust adheres, the dust absorbs light or bends the light, so the transferred pattern will be deformed, the edges will be rough, and the white background will be stained black, In addition, there is a problem in that the quality, appearance, and the like are impaired, and the performance and manufacturing yield of semiconductor devices and liquid crystal display panels are reduced. For this reason, these operations are usually performed in a clean room. However, it is difficult to keep the exposure master clean even in this clean room. A pellicle that adheres to the pellicle is often adhered.

[0003] In this case, the dust does not directly adhere to the surface of the exposure master, but adheres to the pellicle. Therefore, if the focus is set on the pattern of the exposure master during lithography,
Dust on the pellicle is irrelevant to the transfer, but this pellicle film is usually made of a transparent pellicle film made of nitrocellulose, cellulose acetate, modified polyvinyl alcohol, fluoropolymer, etc. A good solvent for the pellicle film is applied to the upper part of a pellicle frame made of polyethylene or the like and air-dried (see JP-A-58-219,023) or bonded with an adhesive such as an acrylic resin or an epoxy resin ( (See U.S. Pat. No. 4,861,402 and JP-B-63-27,707.) Further, an adhesive layer composed of a polybutene resin, a polyvinyl acetate resin, an acrylic resin, etc., for mounting an exposure master on a lower portion of a pellicle frame. , And a release layer (separator) for the purpose of protecting the adhesive layer.

[0004] The pellicle is usually formed by attaching a pellicle film to one end of a pellicle frame made of metal or resin with an adhesive, forming an adhesive layer on the other end surface of the pellicle frame, and releasing the adhesive layer. It is a structure protected by a sheet-like material (referred to as a separator) having releasability. When this pellicle is used, the sheet-like material (separator) having releasability is peeled off and removed, and then the exposed adhesive layer is exposed. The pellicle is fixed to a photomask by pressing the pellicle to a predetermined position of a photomask (also referred to as a reticle). When manufacturing and shipping the pellicle, after confirming that there is no abnormality in the pellicle film, the pellicle is fixed. Are stored in a predetermined container, and strictly packed and packed so that foreign matter is not mixed.

[0005]

However, when this pellicle is transported to its destination, the packaging and unpacking are unpacked, the pellicle is taken out, and the presence or absence of foreign matter in the pellicle film is confirmed. In addition, there is a problem that foreign matter is easily generated even when the pellicle is taken out of the container. This is thought to be due to vibrations and impacts during transportation by truck, railroad, or airplane, and during loading and unloading, which causes foreign substances that existed outside the pellicle film to adhere to the pellicle film. As a place where foreign matter is latent, there is a generally used plastic release sheet-like material (hereinafter referred to as a plastic separator). Since the plastic separator is an insulator, static electricity is easily generated. Has a disadvantage that the specific gravity is less than 1.0 and the cleaning in pure water is difficult.

[0006]

[Summary of the present invention such disadvantages relates to a pellicle which solves the drawbacks, it is only from the separator conductive metal foil for adhesive for fixing to the pellicle of the mask substrate It is characterized by becoming.

That is, the present inventors have conducted various studies on a method for preventing foreign matter from adhering to a pellicle. As a result, if the separator used for the pellicle is made of a conductive material, generation of static electricity can be prevented. Therefore, it was found that the adhesion of the foreign matter to the pellicle was prevented, and thus the foreign matter from the separator was not attached to the pellicle, and the research on the type of the constituent material of the separator was advanced. The present invention was completed by confirming that the metal foil would have a smooth surface and would not be easily damaged by ultrasonic cleaning. This is described in more detail below.

[0008]

According to the present invention, since static electricity separator is not generated here prevents the adhesion of foreign matter, the pellicle film from the separator in the results, there is no adhesion of foreign matter into the pellicle frame.

[0009] Periku Le of the present invention, a mask based on a pellicle
It is known insulating material separator for adhesive prior to fixed to the plate, for example, foreign matter by static electricity and made of plastic is of was easy to adhere, comprising the separator of only the conductive metal foil In this case, this substance comes into contact with other substances, and if it is rubbed, no static electricity is generated here. It does not adhere to the pellicle film, pellicle frame or the like during transportation or the like and contaminate it.

The separator of the present invention is a conductive metal foil which has a smooth surface, is not easily damaged by ultrasonic cleaning or the like, and is easy to clean.

Examples of the metal foil include a copper foil, an aluminum foil, and a stainless steel foil. As a result of a transport test, it has been confirmed that all of the metal foils are free of foreign matter. It has the property of rusting more easily than foil, and if rust occurs during use, it may become a foreign substance.Therefore, it has strong corrosion resistance, does not change the surface state, and remains clean It is most preferable to use a stainless steel foil capable of maintaining the state. The shape of the separator in the present invention may be a pellicle frame punched out, which may be a square or a circle punched out of the pellicle frame outer dimensions. In the case of this quadrangular or circular separator, it is preferable to provide an adhesive layer in an area other than the area that comes into contact with the adhesive layer of the pellicle frame because foreign substances scattered from the frame inner wall or the like can be fixed by this adhesive layer. .

[0012]

Next, examples of the present invention and comparative examples will be described. Examples 1 to 3 and Comparative Example 1 A pellicle film having a thickness of 8,150 mm, made of an amorphous fluorine-based polymer, Cytop (trade name, manufactured by Asahi Glass Co., Ltd.), having a frame size of 120 × 98 mm, A duralumin pellicle frame with a 2mm wide and 5.8mm thick surface anodized,
An adhesive, polybutene, SV-7,000 [trade name of Nippon Oil Co., Ltd.] is applied to a thickness of about 0.5 mm and adhered.

Embedded image Was applied so that the thickness became 0.5 μm.

Then, a separator made of a copper foil (Example 1), an aluminum foil (Example 2), a stainless steel foil (Example 3) and a polyethylene terephthalate film (Comparative Example 1) is bonded to produce a pellicle. After the transportation test, the pellicle container was transported by air between Tokyo and Fukuoka, and the increase in foreign matter adhering to the pellicle film after the completion of the transportation test was measured by a 300,000 Lux condenser lamp in a 0.5 Lux dark room. When illuminated and observed, the results as shown in the following Table 1 were obtained, and those of Examples 1 to 3 using conductive metal foil as a separator and insulating plastics materials were used. A clear difference was produced in the case of Comparative Example 1, and it was confirmed that the example of the example was superior to the comparative example in that the increase in foreign substances was suppressed.

[0014]

[Table 1]

[0015]

According to the present invention eliminates the adsorption of foreign matter by static electricity, therefore with eliminating foreign substances adhering to the pellicle membrane from the separator, since the easy cleaning with ultrasonic cleaning, further deposition of foreign matter Disappears.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Aihiko Nagata 2-13-1 Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd.Precision Functional Materials Laboratory (72) Inventor Sakae Kawaguchi Isobe, Annaka-shi, Gunma 2-13-1 Shin-Etsu Chemical Co., Ltd.Precision Functional Materials Research Laboratory (72) Inventor Shu Kashida 2-13-1 Isobe, Annaka-shi, Gunma Prefecture Shin-Etsu Chemical Co., Ltd.Precision Functional Materials Research Laboratory (72 Inventor Yoshihiro Kubota 2-13-1 Isobe, Annaka-shi, Gunma Shin-Etsu Chemical Co., Ltd.Precision Functional Materials Laboratory (56) References JP-A-1-246546 (JP, A) JP-A1-246547 (JP, A) JP-A-4-204446 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03F 1/14

Claims (1)

(57) [Claims] 1. A pellicle characterized in that the separator for the pressure-sensitive adhesive for fixation to the pellicle of the mask substrate is made of only a conductive metal foil.