JPH1020479A - Method for affixing pellicle to photomask - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for affixing a pellicle to a photomask by omitting the use of a linear having a possibility of generating foreign matter. SOLUTION: A tacky adhesive layer 2 is previously formed at the point to be affixed with a pellicle frame 3 of the photomask 1 and thereafter, the other end face 6 not formed with the tacky adhesive layer of the pellicle frame 3 is pressure welded onto the tacky adhesive layer 2 in the method for affixing the other end face of the pellicle frame 3 spread with a pellicle film 5 via the adhesive layer 4 at one end face to the photomask 1. Since the pellicle obtd. without using the liners is used, there is no generation of the foreign matter from the liners and the degradation in the performance by the foreign matter of the pellicle film is prevented and in addition, the material cost for the liners and the stages and costs for washing, blanking, inspecting, etc., of the liners are saved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for attaching a pellicle having a pellicle film stretched on one end face to a photomask.

[0002]

2. Description of the Related Art In recent years, the patterning of semiconductor devices has been miniaturized with the progress of high density and high integration, and even fine foreign substances adhering on a photomask may cause defects in a transfer pattern. In order to prevent foreign substances from adhering to the photomask, pellicles have been widely mounted on the photomask.

[0003] The pellicle is generally formed by attaching a pellicle film to one end of a pellicle frame made of metal or resin with an adhesive, and forming an adhesive layer on the other end of the pellicle frame. It has a structure in which the agent layer is protected by a release liner (also referred to as a separator).

[0004] This pellicle is used by peeling and removing a liner having a releasing property, and then pressing the exposed pressure-sensitive adhesive layer to a predetermined position of a photomask (also referred to as a reticle) to convert the pellicle into a photomask. Just fix it. On the other hand, when shipping the pellicle manufactured in this way, after confirming that the pellicle film is free from foreign matter, the pellicle is stored in a predetermined container, strictly packed so that foreign matter is not mixed, and packed.

[0005]

However, after transporting the pellicle to the destination, unpacking and unpacking the pellicle, taking out the pellicle and checking for the presence of foreign matter in the pellicle film, foreign matter may be generated.

It is considered that this is because foreign substances other than the pellicle film adhered to the pellicle film due to vibration or impact during transportation by truck, railroad, or airplane and during unloading and shipping.

[0007] Here, as a place where foreign matter may be present in addition to the pellicle film, the outer and inner surfaces of the pellicle frame and the liner surface used for protecting the pressure-sensitive adhesive layer can be considered. In particular, since the liner generally uses a plastic film coated with a release agent as a material, the liner is easily charged. As a result, fine particles easily adhere to the surface of the liner, and the fine particles may move to the pellicle film and become foreign matters. Furthermore, the liner is punched using a punching blade to match the shape of the frame,
Foreign matter is easily generated from the cross section of the punched portion.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method of attaching a pellicle to a photomask in which the use of a liner that may cause the generation of foreign matter is omitted.

[0009]

Means for Solving the Problems To achieve the above object, the present inventor has a method of attaching the other end of a pellicle frame having a pellicle film stretched on one end via an adhesive layer to a photomask. In the photomask, a pressure-sensitive adhesive layer is previously formed at a portion of the photomask to which the pellicle frame is to be adhered, and the other end face of the pellicle frame without the pressure-sensitive adhesive layer is pressure-bonded to the pressure-sensitive adhesive layer. To provide a method of attaching a pellicle to a pellicle.

According to the present invention, since the pressure-sensitive adhesive layer is formed in advance on the area on the photomask where the pellicle is to be adhered, it is not necessary to provide the pressure-sensitive adhesive layer on the other end surface of the pellicle frame on the pellicle itself. Therefore, according to the present invention, it is not necessary to use a liner for the purpose of protecting the pressure-sensitive adhesive layer usually formed on the other end surface of the pellicle frame. In addition to preventing the deterioration of performance due to foreign matter of the pellicle film, the cost of liner materials and the steps and costs of cleaning, punching, inspection, etc. of the liner can be reduced, which is very advantageous from the viewpoint of maintaining the pellicle cleanliness. In addition, it is industrially advantageous.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. In the method of attaching a pellicle to a photomask of the present invention, as shown in FIG. 1, an adhesive layer 2 is formed in advance on a region of a photomask 1 where an pellicle P is attached, and then the adhesive layer 2 is formed. A pellicle film 5 is stretched on one end face (upper end face) of the pellicle frame 3 via an adhesive layer 4, and the other end face 6 of the pellicle without an adhesive layer is formed on the other end face (lower end face) 6. And pressure-bonded to form an adhesive layer 2
A pellicle P is attached to the photomask 1 via

That is, the pellicle used in the present invention is shown in FIG.
As shown in (1), a pellicle film 5 is stretched on one end surface (upper end surface) of the pellicle frame 3 via an adhesive layer 4, and an adhesive layer is not formed on the other end surface (lower end surface) 6. is there. In the conventional pellicle, an adhesive layer is provided on the other end surface (lower end surface) 6, and this adhesive layer is protected by a liner.

Further, a photomask 1 used in the present invention
As shown in FIG. 3, it is necessary to previously form the pressure-sensitive adhesive layer 2 in a region of the photomask 1 where the pellicle is to be adhered.

Here, the material and shape of the photomask 1, the adhesive for forming the pellicle frame 3, the adhesive layer 4, and the material and shape of the pellicle film 5 can be known materials and shapes. For example, aluminum is generally used as the material of the pellicle frame, and glass such as synthetic quartz is generally used as the material of the photomask.

The pressure-sensitive adhesive used in the present invention is not particularly limited, and a general rubber-based pressure-sensitive adhesive or an acrylic pressure-sensitive adhesive can be used, but a silicone-based pressure-sensitive adhesive is used in terms of light resistance and chemical resistance. Is preferred.

Further, there is no particular limitation on the method of forming the pressure-sensitive adhesive layer on the area where the pellicle is to be adhered on the photomask, but it is preferable to apply the pressure-sensitive adhesive to a predetermined area while discharging a fixed amount of the pressure-sensitive adhesive. . The thickness of the pressure-sensitive adhesive layer can be a usual thickness, specifically 0.1 to 10 mm, preferably 0.2 to 0.6 mm.

The surface of the photomask to which the pellicle is adhered is usually the surface on which the pattern is formed, but the pellicle is also adhered to the opposite surface (the surface on which no pattern is formed). Is also good.

In this case, there is no particular limitation on the method of pressing the pellicle to the pressure-sensitive adhesive layer on the photomask, and it can be performed by a usual method.

Next, the present invention will be specifically described with reference to examples. [Example] The outer dimensions of the pellicle frame are 122 x 149 m.
m, an aluminum frame having a width of 2 mm and a height of 5.8 mm was used. A pellicle without a pressure-sensitive adhesive layer and a liner was produced on the other end while a fluoropolymer thin film was stretched as a pellicle film on one end of the frame via an adhesive.

Next, the pellicle is placed in a dedicated container and sealed to check the presence / absence of foreign matter due to the transport of the pellicle. After that, the pellicle is transported for 500 km by a truck, and the pellicle after the transport is taken out of the container. When the foreign matter on the film was measured using a condenser lamp in a dark room, no increase in the foreign matter was recognized.

On the other hand, a silicone-based pressure-sensitive adhesive (KR-120, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied using a dispenser to a region where the pellicle on the side of the photomask pattern is formed, and dried at 120 ° C. for 3 minutes. Let me be 2m wide
m, a pressure-sensitive adhesive layer having a thickness of 0.5 mm was formed.

Next, the pellicle subjected to the transportation test was placed at a predetermined position on the photomask, and a pressure of 30 kg was pressed for 3 minutes. As a result, it was confirmed that the pellicle and the photomask were uniformly adhered via the pressure-sensitive adhesive layer.

[0023]

According to the method of the present invention, since a pellicle without a liner is used, there is no generation of foreign matter from the liner. Therefore, the performance of the pellicle film due to foreign matter can be prevented from being reduced, and the raw material cost of the liner can be prevented. It is possible to omit processes and costs such as cleaning, punching and inspection of the pellicle and the liner, which is very advantageous from the viewpoint of maintaining the pellicle cleanliness and also industrially advantageous.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in which a pellicle is stuck on a photomask in carrying out the present invention.

FIG. 2 is a cross-sectional view of a pellicle frame before being attached on a photomask in the embodiment of the present invention.

FIG. 3 is a cross-sectional view of a photomask on which an adhesive layer has been formed in the practice of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photomask 2 Adhesive layer 3 Pellicle frame 4 Adhesive layer 5 Pellicle film 6 Pelicle frame other end without adhesive layer

Claims (1)

[Claims] 1. A method for attaching the other end of a pellicle frame having a pellicle film stretched on one end via an adhesive layer to a photomask, in which the pellicle frame of the photomask is pre-adhered to a portion where the pellicle frame is to be attached. A method for adhering a pellicle to a photomask, comprising: forming a pressure-sensitive adhesive layer; and bonding the other end surface of the pellicle frame without the pressure-sensitive adhesive layer to the pressure-sensitive adhesive layer.