JPH10239831A - Pellicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pellicle capable of keeping the uniform thickness of an adhesive layer for a long time and being easily and stably stuck to a reticle at the using time by using a material having specified or lower warpage as a liner. SOLUTION: In this pellicle, a pellicle film 2 is formed on the upper face of a square pellicle frame 1, an adhesive layer 3 for sticking a reticle is formed the lower end face, and a linear 4 is stuck to the lower face of the adhesive layer 3. The plastic film being a liner 4 is apt to have residual warpage due to a rolled state during storage. Thereby, a film having <=3mm warpage, especially <=1mm is used as a linear. By using the liner 4 with <=3mm warpage, production of air passage due to deformation of the adhesive layer 3 can be prevented when a reticle is stuck. Moreover, by controlling the warpage to <=1mm, deformation of the adhesive layer 3 can surely be prevented to satisfactorily stick the reticle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an LSI,
The present invention relates to a pellicle useful for an exposure method using light having a wavelength of substantially 500 nm or less, which is used as a foreign matter shield when manufacturing a semiconductor device such as an SI or a liquid crystal display panel.

[0002]

2. Description of the Related Art LS
In the manufacture of semiconductor devices such as I and VLSI or liquid crystal display panels, patterning is performed by irradiating light to a semiconductor wafer or a liquid crystal original plate, and an exposure original plate (hereinafter referred to as a reticle) used in this case. If foreign matter adheres to the surface, the foreign matter absorbs or bends the light, resulting in problems such as deformation of the transferred pattern, rough edges, and blackish white background. As a result, the dimensions, quality, appearance, and the like are impaired, and the performance and production yield of semiconductor devices, liquid crystal display panels, and the like are reduced.

[0003] Therefore, these operations are usually performed in a clean room, but it is difficult to keep the reticle clean even in the clean room. Therefore, a reticle is usually mounted with a pellicle that allows light for exposure to pass therethrough in order to prevent foreign matter.

When a pellicle is mounted, foreign matter does not directly adhere to the surface of the reticle but adheres to the pellicle. Therefore,
If exposure is performed while focusing on the reticle pattern, transfer can be performed irrespective of foreign matter on the pellicle.

Here, the pellicle is formed by attaching a transparent pellicle film made of nitrocellulose, cellulose acetate, or the like, which allows light to pass through well, to the upper end surface of a pellicle frame made of aluminum, stainless steel, polyethylene, or the like, and bonding it. On the end face, an adhesive layer for sticking a reticle made of a polybutene resin, a polyvinyl acetate resin, an acrylic resin, etc. for sticking to a reticle (hereinafter referred to as an adhesive layer).
Is formed, and a liner (release layer) for protecting the adhesive surface of the adhesive layer is applied to the lower end surface of the adhesive layer.

To attach such a pellicle to a reticle, the liner is peeled off, and the lower end surface of the pressure-sensitive adhesive layer in contact with the liner may be pressed in accordance with the fixed position of the reticle. In order to attach the reticle to a reticle on which a simple pattern is drawn, it is desirable that the bonding be performed with an attachment pressure as small as possible so as not to cause distortion in the reticle. In addition, it is essential that the pressure-sensitive adhesive layer adheres uniformly over the entire circumference of the pressure-sensitive adhesive layer, and that there is no air path serving as a ventilation source between the inside and outside of the pellicle frame. From this point,
The pressure-sensitive adhesive layer is formed to have a uniform thickness by using the pressure-sensitive adhesive having an appropriate softness as described above.

However, despite the fact that the pellicle immediately after manufacture has an adhesive layer having a uniform thickness, the adhesive layer may be deformed while being stored in the storage case, and is often used during use. Bad attachment due to air path. Such an air path mainly occurs at a corner of the pellicle frame. Therefore, a pellicle that can maintain an initial uniform thickness without deformation of the pressure-sensitive adhesive layer during storage and that can be stuck to a reticle with uniform contact without an air path is desired.

[0008] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a pellicle that can be maintained for a long period of time without changing the pressure-sensitive adhesive layer and has a uniform thickness immediately after production, and that can be easily and stably attached to a reticle at the time of use.

[0009]

Means for Solving the Problems and Embodiments of the Invention The present inventors have conducted intensive studies in order to achieve the above object, and as a result, the main cause of the deformation of the pressure-sensitive adhesive layer of the pellicle is the pressure-sensitive adhesive layer. The liner to be attached to is used by cutting a plastic film stored in a roll shape, and it is likely to have a curl easily and warpage remains. Therefore, even if this is stretched and pasted, it remains. It has been found that the stress acts to deform the adhesive layer.

That is, the liner is usually formed by applying a release agent to a plastic film represented by PET and cutting it into a pellicle frame shape (square frame shape). The plastic film forming the liner is a pellicle frame. Since the film is usually stored in a roll shape before being cut into a shape, the film has a curl, and even after the film is cut into a pellicle frame shape, warpage due to the curl tends to remain. Then, this is directly adhered to the pressure-sensitive adhesive layer, and when stored, that residual stress is applied to the pressure-sensitive adhesive layer to deform it, which is the cause of the above-described air path generation,
Further, when the liner is attached to the pressure-sensitive adhesive layer, the warping direction of the liner affects the air path generation at the above-mentioned corner portion, and in order to maintain a good pressure-sensitive adhesive layer shape until use, the liner flat surface is required. It was found that it was important to control the degree and direction of the liner warpage.

As a result of further study from this point, the use of a liner having a warpage of 3 mm or less, particularly 1 mm or less, makes it possible to hardly deform the pressure-sensitive adhesive layer even after storing the pellicle, and to achieve a uniform air path without any air path. It was found that a pellicle can be closely attached to a reticle. Also, in this case, when attaching the liner to the pressure-sensitive adhesive layer, a pellicle warped so that the corners are separated from the pressure-sensitive adhesive layer from the middle part of each side of the square frame-shaped liner, and this is adhered. It has been found that this is particularly advantageous in preventing an air path in a corner portion, and has led to the present invention.

Therefore, according to the present invention, a pellicle film is provided on an upper end surface of a pellicle frame, a reticle sticking adhesive layer is formed on a lower end surface, and a liner is peeled off on a lower end surface of the reticle sticking adhesive layer. In a pellicle that can be stuck, the amount of warpage of the liner is 3 mm or less, particularly 1 m.
m, and a pellicle characterized by using a thing having a square frame shape corresponding to the pressure-sensitive adhesive layer formed on the lower surface of the pellicle frame, and a liner at an intermediate portion of each side of the square frame. The present invention provides the pellicle in which a liner whose corner is warped so as to be separated from the pressure-sensitive adhesive layer is releasably attached to the pressure-sensitive adhesive layer.

In the present invention, the amount of warpage of the liner means the maximum height (mm) from the true plane when the liner is placed on the true plane. Therefore, even when the liner projects from the true plane at a plurality of places when placed on the true plane, the protrusion height of the largest protrusion is defined as the amount of warpage.

Hereinafter, the present invention will be described in more detail.
As shown in FIG. 1, the pellicle of the present invention has a pellicle film 2 stretched on an upper end surface of a rectangular frame-shaped pellicle frame 1 and a reticle adhesive layer 3 formed on a lower end surface thereof. The liner 4 is adhered to the lower end surface of the adhesive layer 3. In this case, the size of these members is the same as that of a normal pellicle, and the material can be the known material as described above. The liner is usually a plastic film such as polyethylene terephthalate (PET) coated on one or both sides with a release agent such as a silicone release agent.

In the present invention, a liner having a warpage of 3 mm or less, particularly 1 mm or less is used. By using a liner having a warpage of 3 mm or less, it is possible to prevent an air path at the time of attaching a reticle due to deformation of the pressure-sensitive adhesive layer, and to further prevent the deformation of the pressure-sensitive adhesive layer by setting it to 1 mm or less. Thus, it is possible to perform better attachment to the reticle.

Here, the liner having such a small amount of warpage is formed by pressing a plastic film forming the liner or cutting the plastic film into a liner shape and placing the liner on a hot plate so as to have a temperature higher than the glass transition temperature of the film material. Although there is a method of correcting warpage by heating, any method may be used as long as the damage to the liner release layer is small, and there is no particular limitation. However, since the residual stress does not disappear even if the warpage is temporarily corrected, even if the warp is temporarily corrected at the time of application with a vacuum chuck, electrostatic chuck, etc. Preferably, the object of the invention is not achieved and the straightening of the warp is substantially permanent.

When the liner is attached to the pressure-sensitive adhesive layer, as shown in FIG. 2, the corners of the rectangular frame-shaped liner 4 are separated from the pressure-sensitive adhesive layer 3 more than the center of each side. Warped liner, ie, liner 4 as described above.
Has a release layer 4b formed by applying a release agent to one surface of a plastic film 4a, and the release layer 4b is arranged on the pressure-sensitive adhesive layer 3 side and adhered to the pressure-sensitive adhesive layer 3. However, when the intermediate portion 4c of one side of the liner 4 is adhered to the pressure-sensitive adhesive layer 3, a liner is used in which the corners 4d and 4d are separated from the pressure-sensitive adhesive layer 3, and in the state of FIG. Adhering the corners 4d to the corners of the pressure-sensitive adhesive layer 3 is recommended because the air path at the corners can be reliably prevented and the liner can be stuck to the pressure-sensitive adhesive layer.

[0018]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, Comparative Examples and Reference Examples, but the present invention is not limited to the following Examples.

[Examples and Comparative Examples] An aluminum frame whose surface was anodized and had a height of 6.3 mm, an outer peripheral surface of 120 mm square and an inner peripheral surface of 110 mm square was prepared. A pellicle film is stretched on the upper end surface of the aluminum frame, and a silicone adhesive KR-120 (manufactured by Shin-Etsu Chemical Co., Ltd.) is applied on the lower end surface so as to form a 0.6 mm thick tape. The adhesive was cured at 30 ° C. for 30 minutes to form an adhesive layer. A liner obtained by applying a release agent to a PET film having the same shape as the end surface of the frame and having a thickness of 100 μm as described above with reference to FIG. 2 so that the warpage of the liner presses the pressure-sensitive adhesive at the center of the side. I got The pellicle was stored at room temperature for 3 months.

Thereafter, the liner was peeled off from the pellicle and attached on a reticle with a load of 20 kg for 1 minute, and the occurrence of an air path was evaluated according to the following criteria. Table 1 shows the results. Pasting result ○ Excellent (no air path, good pasting condition) △ Good (no air path, but part of the pasting part is incomplete) × defective (air path occurring)

[0021]

[Table 1] Note: The amount of warpage was measured using a laser displacement meter.

Reference Example A pellicle similar to that of the above embodiment was manufactured. In this case, the warpage of the liner is 5 ± 0.5 mm
Those with the liner warping applied in the direction of pressing the pressure-sensitive adhesive layer at the center of the side (Fig. 2), and those with the liner warpage pressed in the direction pressing the adhesive layer at the corner (Fig. 3) For, the sticking properties of those stored for three months in a storage case were compared. Table 2 shows the results. According to this result, no air path was generated at the corner in the case of, whereas air paths were generated in two places in the case of.

[0023]

[Table 2]

[0024]

According to the pellicle of the present invention, the pressure-sensitive adhesive layer for sticking the reticle can be stably maintained at a uniform thickness without deformation even when stored for a long period of time. Can be pasted on.

[Brief description of the drawings]

FIG. 1 is a perspective view of a pellicle showing one embodiment of the present invention.

FIG. 2 is a partial cross-sectional view illustrating a preferred example of a state in which a liner is adhered to an adhesive layer.

FIG. 3 is a partial cross-sectional view illustrating another example of a state in which a liner is attached to an adhesive layer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pellicle frame 2 pellicle film 3 adhesive layer 4 liner 4 a plastic film 4 b release layer 4 c side middle 4 d corner

Claims (3)

[Claims] 1. A pellicle film is stretched on an upper end surface of a pellicle frame, and a reticle sticking adhesive layer is formed on a lower end surface of the pellicle frame. A liner is detachably attached to a lower end surface of the reticle sticking adhesive layer. The pellicle according to claim 1, wherein the liner has a warpage of 3 mm or less. 2. The pellicle according to claim 1, wherein a liner having a warpage of 1 mm or less is used. 3. The liner has a square frame shape corresponding to the pressure-sensitive adhesive layer formed on the lower end surface of the pellicle frame, and a corner is separated from the pressure-sensitive adhesive layer with respect to a middle portion of each side of the square frame. 3. The pellicle according to claim 1, wherein the warped liner is releasably attached to the pressure-sensitive adhesive layer.