JPH05281710A - Manufacture of pellicle - Google Patents

Abstract

PURPOSE:To obtain the process for manufacture of the pellicle which does not protrude to the outside of a frame, sticks at a specified coating width and thickness to a mask and sticks tightly to the mask without generating a clearance by sticking a tacky adhesive which is previously processed to a film shape to a pellicle frame. CONSTITUTION:This process for manufacture consists in previously processing the tacky adhesive to the film shape. The film shape refers to a planar, sheet, tape or film shape. The method for processing the tacky adhesive to the film shape is not particularly limited and includes, for example, a method of molding the tacky adhesive prior to curing having a flow property or plasticity to the prescribed film shape, then adequately curing the tacky adhesive by drying, cooling or light, heat or a chemical reaction by a reacting agent and a method of slicing the tacky adhesive cured to a solid form by means of a blade or metallic wire. The thickness of the tacky adhesive processed to the film shape is usually required to be merely set at the same thickness as the thickness at which the part to be adhered to the pellicle frame sticks to the pellicle after production.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a pellicle which is a protective dustproof body of a photomask and a reticle (hereinafter abbreviated as "mask") used in a lithography step in the production of a semiconductor integrated circuit, and more particularly to an adhesive. The present invention relates to a method of attaching an agent to a pellicle frame.

[0002]

2. Description of the Related Art In a semiconductor integrated circuit manufacturing process, a lithography process is a process of projecting a circuit pattern on a mask onto a silicon wafer coated with a photosensitive agent to form a fine circuit. It is an important process that affects.

At this time, if dust is present on the mask, the shadow of the dust is projected on the circuit, causing disconnection or short circuit of the circuit. In recent years, miniaturization of integrated circuits has progressed, and even fine dust causes defective products, so that dust management has become a problem.

Therefore, in order to protect and protect the mask from dust, a transparent plastic thin film cover called a pellicle has been proposed (Japanese Patent Publication No. 54-28716) and is used in an actual process.

The pellicle is generally made by attaching a transparent thin film (hereinafter referred to as "pellicle film") such as nitrocellulose to a frame (hereinafter referred to as "pellicle frame") made of aluminum or aluminum whose surface is anodized. Being manufactured.

As a method for attaching the pellicle to the mask, a double-sided tape or an adhesive is used (Japanese Patent Publication No.
No. 62261), a method of directly applying an adhesive to a pellicle frame (JP-A-1-48062), a method of using a hot-melt adhesive (JP-A-3-71134), etc. Therefore, an adhesive or an adhesive is used because it may generate dust (usually an adhesive is used, and these are hereinafter referred to as “adhesive”). The double-sided tape or pressure-sensitive adhesive is attached to the end surface of the pellicle frame at the time of manufacturing the pellicle, and when the pellicle is attached to the mask, it can be attached simply by pressure bonding.

Although a method of applying a pressure-sensitive adhesive to a pellicle frame has not been proposed so far, a method of applying a molten pressure-sensitive adhesive has been proposed as a method of applying a hot-melt pressure-sensitive adhesive. A method using an air gun, a screen printing method, a spray coating method (all of which are disclosed in JP-A-3-71134) have been proposed. Similar coating methods can be applied to other pressure-sensitive adhesives as long as they are in a liquid state, a viscous body, an emulsion, or the like.

[0008]

However, in any of the above methods, the applied shape, applied width, thickness and reproducibility of the applied pressure sensitive adhesive are not sufficient.

That is, when applying using a syringe or an air gun, it is difficult to make the application width and thickness of the adhesive constant or to apply the adhesive according to the frame shape, and the applied adhesive extends outside the pellicle frame. Therefore, the adhesive may adhere to the pattern of the mask. Further, in particular, a step is often generated at a portion where the start and end of application of the pressure-sensitive adhesive are joined together, and the adhesion is often incomplete when the adhesive is applied to the mask. In addition, since a sufficient thickness cannot be obtained by screen printing or spray coating, even when these are used, the adhesion to the mask is likely to be incomplete.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent the adhesive from sticking out of the pellicle frame and to adhere to the pellicle frame with a constant coating width and thickness. The object of the present invention is to provide a method for manufacturing a pellicle that does not form a gap when it is adhered to a mask.

[0011]

[Means for Solving the Problems] The inventors of the present invention have conducted various studies on a method of attaching an adhesive to a pellicle frame in order to solve the above-mentioned problems. As a result, after the adhesive is processed into a film, The inventors have found that the above problem can be solved by a method of attaching the pellicle frame, and have completed the present invention.

That is, the present invention relates to a method for manufacturing a pellicle in which an adhesive is attached to a pellicle frame, and in the step of attaching the adhesive to the pellicle frame, the film-shaped adhesive is attached to the pellicle frame in advance. And a method for producing a pellicle.

The present invention will be described in more detail below.

The material of the pellicle frame used in the present invention is not particularly limited. For example, in addition to aluminum which is the material of the ordinary pellicle frame or aluminum whose surface is anodized, a metal, an alloy other than aluminum, Examples include ceramics and resins. In addition, apply paint or resin on the surface of the pellicle frame,
It is also possible to use those which have been chemically or physically surface-treated with electroforming, plating or a surface-treating agent. Also, the shape or size of the pellicle frame is not particularly limited.

The pressure-sensitive adhesive used in the present invention is not particularly limited as long as it has a proper adhesive strength with the pellicle frame and the mask and has no fluidity at room temperature and normal pressure after solidification. For example, a solvent type, a solventless type, an emulsion type, a hot melt pressure sensitive adhesive, a liquid curable pressure sensitive adhesive or any other form of pressure sensitive adhesive can be used.

The material of the pressure-sensitive adhesive used in the present invention is not particularly limited as long as it has an appropriate pressure-sensitive adhesive force with respect to the mask and the pellicle frame. For example, acrylic-based, rubber-based, vinyl-based, silicone-based, Olefinic,
Examples thereof include polyesters, polyamides, polyurethanes, and copolymers thereof. In addition, a tackifier obtained by adding a tackifier or a filler, a softening agent, a plasticizer, an antioxidant, or an auxiliary material such as wax to the base polymer can also be used.

In the present invention, the pressure-sensitive adhesive is preliminarily processed into a film shape, and the film shape means a plate shape, a sheet shape, a tape shape or a film shape.

The method for processing the pressure-sensitive adhesive into a film is not particularly limited. For example, after the pressure-sensitive adhesive having fluidity or plasticity before curing is molded into a predetermined film shape, it is dried, cooled or exposed to light, A method of appropriately curing by heat or a chemical reaction by a reaction agent, a method of molding after curing such as slicing a solid cured adhesive with a blade or a wire, a solid adhesive in the case of a thermoplastic material Examples of the method include a method of heating and softening and molding at the same time, followed by hardening by cooling. If the pressure-sensitive adhesive has a large viscosity and does not flow even if it is not cured, but has plasticity, the curing operation is unnecessary.

In order to form a fluid or plastic pressure-sensitive adhesive into a film shape, it may be spread on a flat plate, may be sandwiched between two smooth surfaces, may be molded by pouring into a mold, A method of flatly spreading on a flat plate with a roller, spatula, blade, doctor blade, etc., spin coating method such as spin coating, dip coating method, method using roll coater, calender molding method, extrusion molding method, injection Examples include molding method.

The thickness of the pressure-sensitive adhesive processed into a film form may be set to be the same as the thickness of the pressure-sensitive adhesive adhered to the pellicle after manufacturing, in the portion bonded to the pellicle frame, but during or after manufacturing. When the thickness of the adhesive changes due to pressure, temperature, and other conditions, the thickness may be set in consideration of the change. The thickness of the adhesive attached to the pellicle frame is not particularly limited, but is preferably in the range of 0.05 mm to 3.0 mm in order to improve the adhesiveness with the mask.

The size of the adhesive processed into a film is
If the size is equal to or larger than the outer dimension of the pellicle frame, the adhesive can be attached to the pellicle frame seamlessly, so it is preferable that a gap does not easily occur when the pellicle is attached to the mask.
Even if the size of the pellicle frame is smaller than that of the pellicle frame, it is possible to attach the pellicle frame with care so as not to create a joint. Further, a part of the pressure-sensitive adhesive may be cut in order to prevent a pressure difference between the inside and outside of the pellicle from occurring.

In order to easily remove the cured adhesive from the mold or jig, and to prevent the adhesive from adhering to the blade or wire for slicing the solid adhesive, a smooth surface, a mold,
The surfaces of jigs such as rollers, spatulas, blades, doctor blades, and wires may be treated with a release agent or a release agent. The release agent or release agent is not particularly limited, and examples thereof include silicone-based or fluororesin-based release agents, which are preferable because they rarely migrate to the pressure-sensitive adhesive.

Before or after curing of the pressure-sensitive adhesive, or when or after processing into a film, covering one or both sides of the pressure-sensitive adhesive with release paper, release film, etc. It is preferable because it is prevented from adhering to fingertips and the like, and the adhesive is easily handled.
In addition, when the film-like pressure-sensitive adhesive is cut in accordance with the frame shape before being attached, the effect of protecting the pressure-sensitive adhesive from being deformed by an external force by attaching release paper or a release film is preferable. The release paper and the release film are not particularly limited as long as they have good releasability from the adhesive.

As a method of adjusting the size and shape of the adhesive to fit the pellicle frame, a film-shaped adhesive is attached to the pellicle frame and then a cutter, a scalpel, a needle, a wire, etc. (hereinafter referred to as "cutters"). (Abbreviated) etc. or a method of cutting the adhesive with a cutter and then attaching it to the pellicle frame. The cutters may be used as they are, but if they are treated with a release agent or release agent such as silicone-based, fluororesin-based, polyethylene glycol, wax, paraffin or surfactant, the cutters will stick to the adhesive. This is preferable because it prevents the occurrence of heat and improves workability. If it is a thermoplastic adhesive, a method of heating the cutters to cut the adhesive is also effective. To adjust the size and shape of the adhesive to fit the pellicle frame, use one side or both sides of the adhesive with release paper,
It is safe to cut with a cutter while still covered with a release film.

It is preferable to apply pressure to press the pellicle frame and the pressure-sensitive adhesive after the pressure-sensitive adhesive is attached to the pellicle frame, because the pressure-sensitive adhesive force between the pellicle frame and the pressure-sensitive adhesive is improved. The applied pressure is 0.01kg / c against the adhesive surface
The pressure is preferably m ² or more and 50 kg / cm ² or less, but in the case of a pressure-sensitive adhesive having a strong adhesive force, a pressure of less than 0.01 kg / cm ² can be used. If the pressure is more than 50 kg / cm ^{2, the} pressure-sensitive adhesive may be crushed and may stick out of the frame.

In the case of a thermoplastic pressure-sensitive adhesive, it is preferable that the pressure-sensitive adhesive is heated after the pressure-sensitive adhesive is attached to the pellicle frame because the adhesion between the pellicle frame and the pressure-sensitive adhesive is improved. It is effective to heat the heating temperature in the range of 30 degrees lower than the softening temperature to 120 degrees higher than the softening temperature. The heating time is adjusted depending on the heating temperature. If the temperature is lower than this, the effect of adhesion to the frame may be reduced because the pressure-sensitive adhesive does not soften, and if the temperature is higher than this, the pressure-sensitive adhesive is significantly deformed, which is not preferable. At this time, it is preferable to apply pressure to the pressure-sensitive adhesive so that the pressure-sensitive adhesive does not deform, because the adhesiveness is further improved.

If a flat plate or the like is pressed against the pressure-sensitive adhesive surface after the pressure-sensitive adhesive is attached, the flatness of the pressure-sensitive adhesive surface can be increased by
This is preferable because it improves the adhesion to the mask, but is usually unnecessary if the pressure-sensitive adhesive film has sufficient flatness.

[0028]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

Example 1 A polyisobutylene-based pressure-sensitive adhesive was dissolved in toluene, spread on a release film (a silicone-based release agent coated on a polyester film), and a release film was further placed on the release film. The adhesive was spread with a roller and the solvent was dried to obtain a film adhesive having a thickness of 0.7 mm. Peel off the release paper on one side, put a pellicle frame (aluminum-treated aluminum surface) on the adhesive, and
A pressure of kg / cm ² was applied for 1 hour to attach the adhesive to the pellicle frame. Next, the film adhesive was cut with a cutter knife along the shape of the pellicle frame. A pellicle was obtained by attaching a thin film of nitrocellulose to the end surface of the pellicle frame on which no pressure sensitive adhesive was attached, with an epoxy adhesive. The thickness of the adhesive was uniform, and the adhesive did not protrude outside the frame. Peel off the release paper and remove this pellicle at 5kg /
A pressure of cm ² was applied for 2 minutes and the mixture was attached to a quartz glass plate and left for 3 days, but the adhesiveness was good and no gap was generated.

The mask is usually made of quartz glass, but since the circuit pattern is drawn on one side by sputter chrome, the adhesion state between the mask and the adhesive when the pellicle is adhered to the mask is confirmed from the back side. Can not do it. Therefore, in this example, instead of the adhesion test with the quartz glass surface of the mask, an adhesion test with the quartz glass plate was performed, and the adhesion state of the adhesive was visually confirmed from the back side of the glass plate to which the pellicle was adhered. It was done.

Example 2 In the same manner as in Example 1, a film-like pressure-sensitive adhesive was prepared from a polyisobutylene-based pressure-sensitive adhesive. This was cut into the same size and shape as the pellicle frame with a cutter knife. The release film was peeled off, the pellicle frame was placed on the pressure-sensitive adhesive while carefully aligning it, and a pressure of 5 kg / cm ² was applied for 1 hour to adhere the pressure-sensitive adhesive to the pellicle frame. Next, a pellicle was prepared in the same manner as in Example 1. The thickness of the adhesive was uniform, and the adhesive did not protrude outside the frame. The release paper was peeled off, this pellicle was applied with a pressure of 5 kg / cm ² for 2 minutes, adhered to the quartz glass plate and left for 3 days, and the same method as in Example 1 was confirmed. I didn't.

Example 3 A polyethylene terephthalate release film was laid on the bottom of a tray, and an acrylic emulsion type pressure-sensitive adhesive was poured on the release film and dried to obtain a film-shaped pressure-sensitive adhesive having a thickness of 0.2 mm. Press the pellicle frame on top of this and press 5kg /
A pressure of cm ² was applied for 1 hour to attach the adhesive to the pellicle frame. Then, the adhesive was cut in the same manner as in Example 1 to prepare a pellicle. The thickness of the adhesive was uniform, and the adhesive did not protrude outside the frame. The release paper was peeled off, this pellicle was applied with a pressure of 5 kg / cm ² for 2 minutes, adhered to the quartz glass plate and left for 3 days, and the same method as in Example 1 was confirmed. I didn't.

Example 4 A hot-melt pressure-sensitive adhesive containing polyethylene as a base polymer was sandwiched between two polyethylene terephthalate release films and placed on a hot plate, which was then pressed with an iron plate to give a 0.5 mm thick film. A film adhesive was obtained. Then, a pellicle with an adhesive was prepared in the same manner as in Example 1. The thickness of the adhesive was uniform, and the adhesive did not protrude outside the frame. Peel off the release paper and add 5 kg of this pellicle
A pressure of / cm ² was applied for 2 minutes, the mixture was adhered to a quartz glass plate, left for 3 days, and confirmed by the same method as in Example 1. Adhesion was good and no gap was generated.

Example 5 Using a roll coater, polyethylene was coated with a base polymer hot melt adhesive on a release film made of polyethylene terephthalate to obtain a film adhesive having a thickness of 0.5 mm. Next, the film adhesive was cut in the same manner as in Example 1, and the pellicle film was attached to obtain a pellicle. The thickness of the adhesive was uniform, and the adhesive did not protrude outside the frame. Remove the release paper and remove this pellicle at 5kg / c
Apply a pressure of m ² for 2 minutes and attach it to a quartz glass plate.
When left for one day and confirmed by the same method as in Example 1, the adhesiveness was good and no gap was generated.

Example 6 The film-like pressure-sensitive adhesive obtained in Example 5 was punched with a mold to remove excess pressure-sensitive adhesive and processed into the same size and shape as the pellicle frame. Place the pellicle frame on this film adhesive while carefully aligning it with 5 kg / cm.
A pressure of ² was applied for 1 hour to attach the adhesive to the pellicle frame. Next, a pellicle was prepared in the same manner as in Example 1.
The thickness of the adhesive was uniform, and the adhesive did not protrude outside the frame. Peel off the release paper and remove this pellicle at 5 kg / cm ²
Was applied for 2 minutes to the quartz glass plate, left for 3 days, and confirmed by the same method as in Example 1,
Adhesion was good and no gap was generated.

Example 7 A pellicle prepared by the same method as in Examples 1 to 6 was used.
A pressure of 5 kg / cm ² was applied for 2 minutes on the sputtered chrome surface of the mask, and it was pasted, put in a desiccator and the air inside was gradually exhausted by a vacuum pump. The pellicle film bulged and the pellicle was adhered without gaps. It was confirmed.

Next, the same test was conducted again after leaving the mask with the pellicle attached for 3 days under normal pressure. In both cases, the pellicle film bulged and the pellicle adhered without gaps. confirmed.

Comparative Example 1 An olefinic hot melt adhesive was applied to a pellicle frame with an air gun [Hufner (Germany), piston type hand gun, nozzle system 1 mm]. Next, a pellicle was prepared in the same manner as in Example 1. The width and thickness of the pressure-sensitive adhesive were uneven, and many irregularities were found. There was also meandering, and sticking of the adhesive out of the pellicle frame was observed in many parts. This pellicle was attached to a quartz glass plate by applying a pressure of 5 kg / cm ² for 2 minutes, and many gaps were observed between the mask and the adhesive. Next, when the surface of the adhesive was heated on a hot plate at 100 ° C. for 10 seconds and attached again to the quartz glass plate and confirmed by the same method as in Example 1, there was no gap, but the entire circumference of the pellicle frame was found. Overhanging of the adhesive was seen throughout. In addition, a pellicle prepared by the same method was applied to the sputtered chromium surface of the mask at 5 kg / cm.
A pressure of ² was applied for 2 minutes for attachment, and a test was conducted by the same method as in Example 7. As a result, it was confirmed that the pellicle film did not swell at all and there was a gap between the adhesive layer and the mask. ..

Comparative Example 2 A polyisobutylene adhesive was dissolved in toluene and applied to a pellicle frame using a syringe. After drying, a pellicle was prepared in the same manner as in Example 1. The width and thickness of the pressure-sensitive adhesive were uneven, and many irregularities were found. There was also meandering, and sticking of the adhesive out of the pellicle frame was observed in many parts. A pressure of 5 kg / cm ² was applied for 2 minutes to the pellicle, which was attached to a quartz glass plate and confirmed by the same method as in Example 1. As a result, a large number of gaps were observed. In addition, a pellicle made by the same method was applied on the sputtered chromium surface of the mask 5k.
A pressure of g / cm ² was applied for 2 minutes for attachment, and a test was conducted in the same manner as in Example 7. The pellicle film did not swell at all, and there was a gap between the adhesive layer and the mask. confirmed.

[0040]

As is apparent from the above description, according to the method of the present invention, by sticking the film-shaped pressure-sensitive adhesive to the pellicle frame, the pressure-sensitive adhesive does not stick out of the pellicle frame, It has an effect that it is possible to manufacture a pellicle having a uniform width and a uniform thickness and having no gap between the mask and the mask when attached to the mask.

Claims (3)

[Claims] 1. A method for manufacturing a pellicle in which a pellicle film is attached to one end surface of a pellicle frame and an adhesive agent is attached to the opposite end surface thereof, and in the step of attaching the adhesive agent to the pellicle frame, the pellicle film is formed into a film in advance. A method of manufacturing a pellicle, which comprises applying the processed adhesive to a pellicle frame. 2. The method for producing a pellicle according to claim 1, wherein the film-shaped adhesive is attached to the pellicle frame, and then cut according to the shape of the pellicle frame. 3. The method for producing a pellicle according to claim 1, wherein the adhesive processed into a film shape is attached to the pellicle frame after being cut according to the shape of the pellicle frame.