JPH06186732A - Adhesive pellicle film and pellilcle - Google Patents

Abstract

PURPOSE:To provide an adhesive pellicle film excellent in adhesiveness and light transmissivity and having excellent light resistance even to light having such short wavelength as 360-450nm. CONSTITUTION:An adhesive material layer made of fluorine-contg. poly-(meth) acrylate is formed on one side of a transparent thin film of fatty acid ester of cellulose. The poly(meth)acrylate is a copolymer of 20-80mol% monomer (A) represented by a formula CH2=C(R<1>)-COOR<2> (where R<1> is H or methyl and R<2> is straight chain fluoroalkyl) with 80-20mol% monomer (B) represented by a formula CH2=C(R<3>)-COOR<4> (where R<3> is H or methyl and R<4> is branched fluoroalkyl) and has 0.10-0.35dl/g intrinsic viscosity (eta) measured in m-xylene hexafluoride at 60 deg.C. The objective adhesive pellicle film for exposure with light having such short wavelength as 360-450nm is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photolithography process in the production of semiconductor elements such as IC and LSI and in the production of liquid crystal display elements (hereinafter referred to as the production of semiconductor elements).
The present invention relates to an adhesive pellicle film and a pellicle for short-wavelength light exposure having a wavelength of 360 to 450 nm for preventing foreign matters such as dust from adhering to a photomask, a reticle, or the like (hereinafter, simply referred to as a mask) used in.

[0002]

2. Description of the Related Art In a photolithography process, a mask or the like having a circuit pattern formed on a glass plate surface by a vapor deposition film of chromium or the like is used to transfer the circuit pattern onto a resist-coated silicon wafer. There is. In this step, when exposure is performed with foreign matter such as dust attached to the circuit pattern on the mask or the like, the foreign matter is also transferred onto the wafer, resulting in a defective product. In particular, when the exposure is performed by a stepper, there is a high possibility that all chips formed on the wafer will be defective, and adhesion of foreign matter to a circuit pattern such as a mask is a serious problem.

In order to solve this problem, a pellicle for a dustproof body is used in which a transparent light-transmissive film is arranged on one or both surfaces of a mask substrate at appropriate intervals. This pellicle is generally made by stretching a transparent light-transmitting pellicle film on one side of a pellicle frame, which serves as a holding frame made of aluminum. It can be installed. By using this pellicle, it is possible to prevent foreign matter from entering from the outside, and even if foreign matter adheres to the pellicle film, it will not be transferred onto the wafer, improving the yield during manufacturing of semiconductor devices and the like. To do.

However, the foreign matter that has already adhered to the inside of the pellicle film or the pellicle frame cannot be removed any longer after the pellicle is attached to the mask or the like. Therefore, when using such a pellicle, a pellicle provided with an adhesive film on the inner side surface of the pellicle frame is proposed in order to prevent foreign matter attached to the inside of the pellicle from dropping on a mask or the like and hindering exposure. (JP-A-60-57841).

However, as described above (JP-A-60-57841).
No.) uses double-sided adhesive tape on the adhesive surface of the pellicle frame and mask, so foreign matter such as dust is generated from the foam tape that is the base material of the double-sided adhesive tape, and this becomes a pollution source. . Therefore, JP-A 1-480
No. 62 proposes a pellicle that does not use a double-sided adhesive tape on the adhesive surface. However, even if these methods are used, foreign matter attached to the inner surface of the pellicle film may fall onto a mask or the like due to impact during use, which may cause defective LSI manufacturing.

On the other hand, the pellicle film is used as a dust-proof film at the time of exposure, and since a high light transmittance is required, adhesion of foreign matter is extremely disliked, and a material having a low foreign matter adhesion property is used. Conventionally, as a material for such a pellicle film, a polyvinyl butyral-based polymer (JP-A-59-16) is used.
4356, JP-A-59-206406, JP-A-63.
-68840, JP-A-63-138352, JP-A-63-163461, JP-A-63-163462,
JP-A-63-163463), cellulose-acetate-butyrate-based polymer (JP-A-61-106243).
No.), a cyanoethyl cellulose-based polymer (JP-A-61-
130346), alkyl cellulose polymers (JP-A-62-59955), nitrocellulose, cellulose propionate (JP-A-3-259258) and the like. As a pellicle film, a pellicle film in which an antireflection layer is laminated on a transparent thin film made of these materials has also been proposed (for example, JP-A-60-237450).
No.).

Whether the pellicle film is a single layer of the above-mentioned material or a laminated anti-reflection layer, a material having a non-sticky surface is used to prevent foreign matter from adhering. is necessary. However,
Although foreign matter does not easily adhere to the pellicle film made of such a non-sticky material on the surface, if the foreign matter is accidentally adhered, the adhered foreign matter is likely to drop, which hinders exposure.

To solve these problems, liquid fluorocarbon or silicon oil is applied to one surface of the transparent thin film (Japanese Patent Laid-Open No. 63-15250), or an adhesive fluorine-containing poly (meth) acrylate is used. A method for forming a polymer (JP-A-1-120555, JP-A-3-259258) has been proposed.

However, when these pellicle films are used for exposure with short-wavelength light having a wavelength of 360 to 450 nm, the energy of the light is high and the films may be destroyed. As described above, the conventional pellicle film is not always satisfactory in light resistance in the short wavelength region of the exposure wavelength of 360 to 450 nm.

[0010]

DISCLOSURE OF THE INVENTION An object of the present invention is to solve the above problems by providing excellent adhesiveness and light transmittance,
Moreover, the wavelength 3 has excellent light resistance against short wavelength light.
An object is to provide an adhesive pellicle film (hereinafter sometimes simply referred to as a pellicle film) for short wavelength light exposure of 60 to 450 nm. Still another object of the present invention is to have the above-mentioned pellicle film, and even if a foreign substance accidentally adheres to this pellicle film, the foreign substance can be adhered to the adhesive substance layer to prevent the foreign substance from falling onto a mask or the like. To provide a pellicle.

[0011]

The present invention is a pellicle comprising the following pellicle film and the pellicle film and a pellicle frame. (1) On one surface of the transparent thin film of fatty acid ester of cellulose, the general formula [1]

[Chemical 3] (In the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear fluoroalkyl group.) At least 1
Seed monomer (A) and general formula [2]

[Chemical 4] (In the formula, R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents a branched fluoroalkyl group.) A copolymer with at least one monomer (B) The monomer (A) component ratio is 20 to 80 mol%,
The constituent component ratio of the monomer (B) is 80 to 20 mol%, and the intrinsic viscosity [η] measured in meta-xylene hexafluoride at 60 ° C. is 0.10 to 0.35 dl / g.
Which is characterized in that an adhesive substance layer made of fluorine-containing poly (meth) acrylate is formed.
Adhesive pellicle film for short wavelength light exposure of ~ 450 nm. (2) The adhesive pellicle film as described in (1) above, wherein the intrinsic viscosity [η] of the copolymer is more than 0.20 dl / g and 0.35 dl / g or less. (3) The ratio of the constituent components of the monomer (A) in the copolymer is 2
The adhesive pellicle film as described in (1) or (2) above, wherein the content of the constituent component of the monomer (B) is more than 55 mol% and less than 80 mol% and more than 0 mol% to less than 45 mol%. . (4) The ratio of the constituent components of the monomer (A) in the copolymer is 7
The adhesive pellicle film according to the above (1) or (2), which is more than 5 mol% and 80 mol% or less, and the ratio of the constituent components of the monomer (B) is 20 mol% or more and less than 25 mol%. . (5) A pellicle comprising the adhesive pellicle film according to any one of (1) to (4) and a pellicle frame.

In the present invention, a transparent thin film made of a fatty acid ester of cellulose is used as the transparent thin film forming the main body of the pellicle film. This transparent fatty acid ester thin film of cellulose has an average light transmittance at a wavelength of 360 to 450 nm used for exposure (the same number of peaks and troughs of interference waves of light transmittance occurring between irradiation wavelengths are averaged. The value is high and the properties required for a pellicle film such as film-forming properties are excellent, and the light resistance to light having a short wavelength of 360 to 450 nm is excellent.

Specific examples of the fatty acid ester of cellulose include cellulose acetate, cellulose propionate, cellulose butyrate and cellulose valerate. Of these, cellulose propionate is preferred.

As the material of the transparent thin film, nitrocellulose, alkyl cellulose, etc., which have been conventionally used, are 450 to
Although it is suitable for exposure with light having a wavelength of 600 nm, light resistance is poor in a short wavelength region adopted for exposure in the present invention, and film breakage may occur.
It is not suitable for exposure to short wavelength light of 50 nm.

The transparent thin film can be produced from a solution containing a fatty acid ester of cellulose by a rotary film forming method, and the film thickness is selected so that the transmittance is high with respect to the wavelength used.
For example, it is usually 1.4 to 1.6 μm for simultaneously increasing the transmittances of the exposure wavelengths of 436 nm and 405 nm, and 1.2 to 1.4 μm for simultaneously increasing the transmittances of the 436 nm and 365 nm rays. To be selected.

In the present invention, as an adhesive substance, at least one monomer (A) represented by the above general formula [1],
Fluorine-containing poly (meth) acrylate which is a copolymer with at least one kind of monomer (B) represented by the general formula [2] is used.

The fluorine-containing poly (meth) acrylate used in the present invention has a high light transmittance and is excellent in adhesiveness, and even if foreign matter is attached, it is retained as it is and is hard to drop.
In addition, the refractive index is less than that of the transparent thin film, and it also has an antireflection effect. Further, the fluorine-containing poly (meth) acrylate does not deteriorate even when exposed to light having a short wavelength of 360 to 450 nm, and has excellent light resistance. Then, by coating a transparent thin film composed of a fatty acid ester of cellulose with this fluorinated poly (meth) acrylate, the light resistance of the fatty acid ester of cellulose is remarkably improved,
As a whole, excellent light resistance to short-wavelength light having a wavelength of 360 to 450 nm is obtained. Therefore, by forming an adhesive substance layer made of such a fluorinated poly (meth) acrylate on one surface of the transparent thin film made of the fatty acid ester of cellulose, an adhesive having excellent light resistance in the short wavelength region can be obtained. A pellicle film having a hydrophilic property is obtained.

Next, the fluorine-containing poly (meth) acrylate will be described in detail. R in the general formula [1]
² is a linear fluoroalkyl group having 2 to 1 carbon atoms
4 is preferable. In particular,

Embedded image —CH ₂ CF ₃ , —CH ₂ C ₂ F ₅ , —CH ₂ C
_{3 F 7, -CH 2 C 4} F 9, -CH 2 C 5 F 11, -CH 2 C 7 F
_{15, -CH 2 C 8 F 17} , -CH 2 C 9 F 19, -CH 2 C 10 F
_{21, -CH 2 CH 2 CF 3} , -CH 2 CH 2 C 2 F 5, -CH 2
_{CH 2 C 3 F 7, -CH} 2 CH 2 C 4 F 9, -CH 2 CH 2 C 5 F
_{11, -CH 2 CH 2 C 7} F 15, -CH 2 CH 2 C 8 F 17, -C
_{H 2 CH 2 C 9 F 19} , -CH 2 CH 2 C 10 F 21, -CH 2 (C
_{F 2) 2 H, -CH 2} (CF 2) 4 H, -CH 2 (CF 2)
₆ H, -CH ₂ (CF ₂ ) ₈ H, -CH ₂ (CF ₂ ) ₁₀ H,-
_{CH 2 CF 2 CHFCF 3, -CH} 2 CF 2 CHF (CF 2)
₆ H etc. can be illustrated. A linear fluoroalkyl group containing ether oxygen is inferior in light resistance to light having a short wavelength of 360 to 450 nm, and is not suitable for use in the present invention.

Further, R ⁴ in the general formula [2] is a branched fluoroalkyl group, preferably a branched fluoroalkyl group having 3 to 14 carbon atoms. In particular,

[Chemical 6] Can be exemplified.

Particularly preferred R ⁴ among these is

[Chemical 7] Can be exemplified. Such R ⁴ is derived from a dimer or trimer of hexafluoropropylene. A branched fluoroalkyl group containing ether oxygen has a molecular weight of 360 to
It is not suitable for use in the present invention because it has poor light resistance to light having a short wavelength of 450 nm.

The proportion of the monomer (A) in the fluorine-containing poly (meth) acrylate used in the present invention is 20 to 80 mol%, and the proportion of the monomer (B) is 8%.
It is 0 to 20 mol%. In addition to these monomers, other monomers may be contained within the range not impairing the object of the present invention. Constituent ratio of monomer (A) is 20 mol%
Or more and less than 45 mol% and the constituent component ratio of the monomer (B) is more than 55 mol% and 80 mol% or less, the constituent component ratio of the monomer (A) in the copolymer is 75 mol%. % And 80 mol% or less,
Even when the ratio of the constituents of the monomer (B) is 20 mol% or more and less than 25 mol%, an adhesive substance layer having excellent light resistance to short wavelength light, adhesiveness and light transmittance is formed.

The intrinsic viscosity [η] of the fluorine-containing poly (meth) acrylate measured in meta-xylene hexafluoride at 60 ° C. is 0.10 to 0.35 dl / g. Intrinsic viscosity greater than 0.20 dl / g, 0.35
Even if it is dl / g or less, an adhesive substance layer having excellent light resistance to short wavelength light, adhesiveness and light transmittance is formed.

The fluorine content of the fluorine-containing poly (meth) acrylate is preferably 50% by weight or more. When the fluorine content is in this range, it is transparent and has a high average light transmittance, and color unevenness and whitening due to disturbance between layers do not occur.

The production method for producing the fluorine-containing poly (meth) acrylate used in the present invention is not particularly limited, and any method can be adopted as long as a polymer having the above-mentioned constituent ratios and physical properties can be obtained. However, a method of copolymerizing a monomer component in the presence of a radical initiator can be preferably used.

As the radical initiator, various known ones can be used. Specifically, azo compounds such as azobis (isobutyronitrile) and dimethylazoisobutyrate; benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert.
-Butyl peroxide, 2,5-dimethyl-2,5-di (peroxybenzoate) hexyne-3,1,4-bis (tert-butylperoxyisopropyl) benzene, lauroyl peroxide, dilauroyl peroxide, tert-butyl peracetate, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3,2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, tert-butylperbenzoate, tert-butylper Phenylacetate,
Examples thereof include organic peroxides or organic peresters such as tert-butyl perisobutyrate, tert-butyl per-sec-octoate, tert-butyl perpivalate, cumyl perpivalate, and tert-butyl perdiethyl acetate. Among these, azobis (isobutyronitrile) is preferable.

The copolymerization reaction may use a solvent or may be carried out without a solvent. Examples of the solvent include hexafluorobenzene, benzotrifluoride, trifluoromethylanisole, xylene hexafluoride and the like.

The copolymerization reaction is carried out by adding the radical initiator in an amount of 0.05 to 10.0 mol%, preferably 0.1 to 5.0 mol% based on the total number of moles of the monomers. desirable. The reaction temperature is 20 to 150 ° C., preferably 40 to 100 ° C., and the reaction time is 1 to 40 hours, preferably 5 to 28 hours. The copolymerization reaction is preferably carried out in an inert gas atmosphere (for example, nitrogen, argon, etc.). By performing the reaction under the above reaction conditions, particularly by adding the radical initiator in the above range, the polymer having the intrinsic viscosity [η] can be easily obtained.

Since the fluorine-containing poly (meth) acrylate used in the present invention also has an antireflection function, it is not necessary to form another antireflection layer, but a high refractive index substance layer is provided to enhance the antireflection effect. You may form an adhesive substance layer on the formed. The adhesive substance layer is formed on one surface of the transparent thin film which is the main body by the adhesive substance, and the film thickness at that time is 1 / 4n (n is the refractive index) of the wavelength of the light used. preferable.

An antireflection layer can be formed on the other surface of the transparent thin film, which is the main body of the pellicle film, as in the conventional case. In this case, as the antireflection layer, a non-adhesive fluorine-based polymer or silicon-based polymer which has been conventionally used for the antireflection layer can be used. The non-adhesive fluorine-based polymer includes a polymer of perfluorooctylethyl (meth) acrylate, a copolymer of tetrafluoroethylene and vinylidene chloride, and a ternary copolymer of tetrafluoroethylene, vinylidene chloride and hexafluoropropylene. Examples include coalescing.
Further, in order to improve the antireflection effect, these non-adhesive substance layers may be formed on the high refractive index substance layer.

Next, in the method for producing a pellicle film having an adhesive substance layer, the case where the adhesive substance layer made of fluorine-containing poly (meth) acrylate is formed on the transparent fatty acid ester thin film of cellulose as the main body will be described. . First, a solution containing a fatty acid ester of cellulose is supplied onto a smooth substrate such as glass, and a transparent thin film of a fatty acid ester of cellulose is formed by a rotary film forming method. The fatty acid ester of cellulose is dissolved in a good solvent, and if necessary, a solution obtained by purification such as filtration is used. As the solvent, ketones such as methyl ethyl ketone, methyl isobutyl ketone, and acetone; lower fatty acid esters such as butyl acetate and isobutyl acetate; mixtures of these ketones or esters with alcohols such as isopropyl alcohol are used.

The thickness of the transparent thin film to be formed can be appropriately changed by changing the viscosity of the solution and the rotation speed of the substrate. The fatty acid ester transparent thin film of cellulose formed on the substrate is dried by means of irradiation with hot air or an infrared lamp to remove the residual solvent.

Then, a solution containing the above-mentioned fluorinated poly (meth) acrylate is supplied onto the transparent fatty acid ester thin film of cellulose, and the fluorinated poly (meth) is formed by the rotary film forming method as in the formation of the transparent fatty acid ester thin film of cellulose. An adhesive material layer made of acrylate is formed. On this occasion,
As the solvent for dissolving the fluorine-containing poly (meth) acrylate, aromatic halogen compounds, fluoroalkylated alcohols, hexafluoropropylene oligomers, fluorinated cyclic ether compounds and the like are used.

Specifically,

[Chemical 8] And the like. Among these, metaxylene hexafluoride, pentafluoropropanol, benzotrifluoride and the like are particularly preferable.

By using these specific solvents, a solution containing a fluorinated poly (meth) acrylate having a good spin film-forming property can be obtained, and a fluorinated poly (meth) acrylate can be obtained.
When forming the adhesive substance layer made of acrylate, it is possible to prevent adverse effects such as dissolution or swelling of the cellulose propionate transparent thin film as the base layer. The film thickness of the adhesive substance layer is the same as the transparent fatty acid ester thin film of cellulose,
It can be controlled by appropriately changing the viscosity of the solution and the rotation speed of the substrate.

On the other hand, in the case of producing a pellicle film having an adhesive substance layer on one side and a non-adhesive substance layer on the other side,
The transparent thin film having an adhesive substance layer on one side obtained above was peeled from the substrate and attached to a temporary frame. For example, tetrafluoroethylene /
Solution in which vinylidene chloride / hexafluoropropylene terpolymer (for example, 50/29/21 weight ratio) is dissolved in a solvent such as perfluoro-2-methyl-1-oxy-3-thiacyclohexane-3,3-dioxide. Can be applied to form an antireflection layer composed of a non-adhesive substance layer by a rotary film forming method.

In order to produce a pellicle film having a five-layer structure consisting of an adhesive substance layer / high refractive index substance layer / transparent thin film / high refractive index substance layer / non-adhesive substance layer, a transparent thin film is first prepared in the same manner as described above. Is formed, a high-refractive-index substance solution for forming a high-refractive-index substance layer is supplied on this to form a film by a rotary film-forming method, and then an adhesive substance layer is further formed thereon in the same manner as described above. To do. Next, the film thus obtained is peeled from the substrate and attached to a temporary frame, and the high refractive index substance solution for forming the high refractive index substance layer is supplied to the other surface of the transparent thin film and rotated. It can be carried out by forming a film by a film forming method and then forming a non-adhesive substance layer thereon in the same manner as described above.

As a method for continuously producing a pellicle film having an adhesive substance layer and a non-adhesive substance layer,
A solution containing fluorine-containing poly (meth) acrylate (provided that the solvent is not particularly limited to the above-mentioned solvent, and can dissolve the fluorine-containing poly (meth) acrylate) is supplied onto a smooth substrate such as glass. A fluorine-containing poly (meth) acrylate thin film is formed by a rotary film forming method, and dried by means of irradiation with hot air or an infrared lamp to remove the residual solvent. Then, after performing the same operation as above on this thin film to form a transparent thin film of fatty acid ester of cellulose, further supply a solution containing tetrafluoroethylene / vinylidene chloride / hexafluoropropylene terpolymer, etc., A non-adhesive substance layer is formed by a rotary film forming method, and a pellicle film having a three-layer structure can be manufactured.

In order to continuously produce a pellicle film having a five-layer structure consisting of an adhesive substance layer / high refractive index substance layer / transparent thin film / high refractive index substance layer / non-adhesive substance layer, a smooth substrate such as glass is used. After forming the adhesive substance layer by performing the same operation as above, after supplying a high refractive index substance solution for forming a high refractive index substance layer on it to form a film by a rotary film forming method, Further, the same operation as described above is performed thereon to form a transparent thin film of fatty acid ester of cellulose. Subsequently, in order to form a high-refractive index substance layer on the fatty acid ester transparent thin film of cellulose, a high-refractive index substance solution is supplied to form a film by a rotary film forming method, and then the same operation as described above is further performed thereon. It can be carried out by forming a non-adhesive substance layer.

Next, the pellicle film having the adhesive substance layer formed on the substrate is peeled off from the substrate for use as a pellicle. In this case, for example, by applying a cellophane tape or a frame-shaped jig coated with an adhesive to the outermost layer of the laminated film formed on the substrate, that is, the edge of the film surface in contact with the outside air, the cellophane tape or the frame-shaped jig is adhered. The jig can be peeled off directly from the substrate by lifting it from one end by hand or mechanical means. At this time, since the interlayer adhesive force between the fatty acid ester layer of cellulose and the fluorinated poly (meth) acrylate layer is large, the film is peeled off without separation, and the pellicle film thus obtained is attached to the pellicle frame to form a pellicle. It is formed.

When a pellicle film is attached to the pellicle frame,
The pellicle film is attached so that the adhesive substance layer of the pellicle film is on the side of the pellicle frame. That is, when used as a pellicle, the pellicle film is attached to the pellicle frame so that the surface of the mask or the like faces the surface of the adhesive substance layer.

The pellicle frame is not particularly limited, and a conventionally used alumite treated aluminum frame or the like can be used, and other materials may be used. The pellicle frame may have any shape such as a circle or a square. It is also preferable to apply an adhesive or the like to the pellicle frame to prevent foreign matter from falling onto the mask or the like.

The pellicle manufactured in this manner is used as a dust-proof cover at the time of exposure by superimposing it on a mask or the like as in the conventional one. When manufacturing the pellicle, foreign matter such as dust is manufactured so as not to adhere thereto, but the foreign matter brought in by mistake adheres to the adhesive substance layer and does not fall onto the mask or the like. The foreign matter attached to the non-adhesive substance layer of the pellicle is removed by air blow or the like, and the foreign matter attached to the adhesive substance layer is about 50 μm or less if it does not drop onto the mask etc. while being attached to the adhesive substance layer. Since the object does not form an image on the transfer surface, it is not transferred and does not cause defective LSI manufacturing.

[0043]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partial sectional view showing a pellicle according to an embodiment. In the figure, reference numeral 1 is a pellicle, and a pellicle film 3 is stretched on one side surface of a pellicle frame 2. Here, the pellicle film 3 is a transparent thin film 4 made of a fatty acid ester of cellulose.
The adhesive substance layer 5 made of a fluorine-containing poly (meth) acrylate is laminated on one surface and the non-adhesive substance layer 6 is laminated on the other surface, and the adhesive substance layer 5 comes to the pellicle frame 2 side. Is stretched. Pellicle frame 2 of pellicle film 3
The adhesive substance layer 5 formed on the side and the non-adhesive substance layer 6 formed on the opposite side are also used as an antireflection layer. An adhesive 7 is also applied to the inner surface of the pecryl frame 2, and the pellicle frame 2 is attached to an adherend 8 such as a mask by an adhesive.
Is glued to.

The pellicle 1 having the above structure is used as a dustproof cover during exposure. At this time, the foreign matter attached to the non-adhesive substance layer 6 is removed by air blow or the like, but the foreign matter attached to the adhesive substance layer 5 does not drop as it is and does not interfere with the exposure. Even when exposed to light having a short wavelength of 360 to 450 nm, no film breakage occurs.

Example 1 A perfluorooctylethyl acrylate (CH ₂ = CHCOOC ₂ H ₄ C ₈ F ₁₇ , hereinafter F) was placed in a 200 ml reactor equipped with a stirring blade, a condenser and a bubbling tube.
13.5 g (26 mmol) of OEA), CH ₂ ═CHCOOCH ₂ CF (CF having a branched fluoroalkyl group synthesized from a dimer of hexafluoropropylene)
₃ ) CHFCF (CF ₃ ) ₂ (hereinafter abbreviated as HFP-DA) 40.1 g (104 mmol) and azobis (isobutyronitrile) as an initiator (hereinafter abbreviated as AIBN)
After charging 0.64 g (3.9 mmol) and bubbling 8.5 liters of nitrogen gas per hour through a bubbling tube for 2 hours, the mixture was reacted at 60 ° C. for 8 hours in a nitrogen atmosphere.

Next, 700 ml of methanol at -30 ° C. was put into a mixer, the reaction solution was slowly added under strong rotation to precipitate a polymer, and after discharging the liquid part, 700 ml of methanol at -30 ° C. was added again and vigorously stirred. To wash the polymer. The precipitated and washed polymer was dried under reduced pressure of 100 mmHg at 100 ° C. for 16 hours to obtain 49.5 g of an elastic transparent polymer.

The fluoropolymer thus obtained was measured by ¹³ C-NMR (in a CDCl ₃ solvent).
The composition ratio is FOEA 25 mol%, HFP-DA
It was 75 mol%. Also, the intrinsic viscosity [η] is 60 ° C.
As a result of measurement in meta-xylene hexafluoride of
It was 0.16 dl / g.

Next, as the three solutions used for film formation, a 6% by weight solution of methyl propionate in methyl ethyl ketone for a fatty acid ester film of cellulose and 5% by weight of the above-obtained fluoropolymer for an adhesive layer. % Meta-xylene hexafluoride solution and 1.2 wt% polyperfluorooctylethyl methacrylate meta-xylene hexafluoride solution were prepared for the non-adhesive layer.

A solution containing cellulose propionate was first dropped on the substrate by the rotary film forming method, and the solution was rotated at 1000 rpm for 60 seconds to form a film, followed by drying at 120 ° C. for 1 minute. Subsequently, a solution containing a fluoropolymer was dropped on this film and rotated at 680 rpm for 30 seconds to form an adhesive substance layer.

A transparent thin film of cellulose propionate having an adhesive substance layer was peeled from the substrate and attached to a temporary frame, and then a solution containing polyperfluorooctylethylmethacrylate was dropped on the other surface by a rotary film forming method. , 600
The non-adhesive material layer was formed by rotating at rpm for 30 seconds.

The pellicle film thus obtained was attached to the pellicle frame so that the adhesive substance layer was on the side of the pellicle frame to prepare a pellicle. The adhesive strength test and the foreign matter retention test of the adhesive substance layer were performed by the following methods. The results are shown in Table 1. In addition, FIG. 2 shows the light transmittance with respect to the wavelength with which this pellicle film is irradiated.

1) Adhesion Test When the pellicle film is attached to the pellicle frame, contrary to the above, the pellicle frame is attached so that the adhesive substance layer is on the opposite side of the pellicle frame to obtain a pellicle. A test piece was obtained by sticking to the plate. The adhesive force of the adhesive substance layer of this test body was measured using the adhesive force measuring device shown in FIG.

The adhesive force measuring device 9 can press and hold the holding jig 11 against the pellicle film 3 by moving the Instron 10 up and down.
The strain gauge 12 is configured so that the load can be read. The material of the holding jig 11 that comes in contact with the pellicle film 3 is stainless steel SUS304, and the contact surface is R-shaped and polished as shown in FIG. To measure the adhesive strength, Instron 1
0 is pressed down at a constant speed of 5 mm / min, and the pressing jig 11 is pressed against the surface of the pellicle film 3 with a load of 7.5 g for 1 minute.
After that, the Instron 10 is pulled up at a constant speed of 5 mm / min, and the load at the moment when the holding jig 11 is separated from the surface of the pellicle film 3 is read by the strain gauge 12. Pellicle membrane 3
Since the contact area of the holding jig 11 is 0.22 cm ² , the adhesive force is calculated by the following equation. Adhesive force (g / cm ² ) = [load of strong gauge 11 (g) / contact area (0.22 cm ² )]

The specific measuring method is as follows. The pellicle 1 on which the pellicle film 3 is stretched is attached to the adherend 8 such that the adhesive substance layer 5 is on the opposite side of the pellicle frame 2. Push down the Instron 10 at a constant speed of 5 mm / min,
Hold the presser tool 11 on the surface of the pellicle film 3 with a load of 7.5 g.
Press for minutes. The Instron 10 is pulled up at a constant speed of 5 mm / min. The load at the moment when the holding jig 11 is separated from the surface of the pellicle film 3 is read. Wipe the holding jig 11 with acetone. Repeat the above procedure to obtain the average value three times.

2) Foreign Material Retention Test Foreign matter of 5 to 10 μm was added to the adhesive material layer of the pellicle attached so that the adhesive material layer was on the side of the pellicle frame.
Attach two pieces and attach to a quartz substrate. This is dropped three times from a height of 5 cm, and the number of foreign particles that have dropped onto the quartz substrate and the number of foreign particles that have moved from the position where it was attached before the drop are totaled and counted as the number of moving foreign particles. Prior to the 1) adhesive strength test and 2) foreign matter retention test, it was confirmed that a film having a constant film thickness was obtained when the rotation speed of the spinner during film formation by the rotary film formation method was kept constant.

Examples 2 to 7 and Comparative Examples 1 to 4 The procedure of Example 1 was repeated except that the fluoropolymers shown in Table 1 were used instead of the fluoropolymers of Example 1. The results are shown in Table 1.

[0057]

[Table 1]

[0058]

As described above, according to the present invention, one of the transparent fatty acid ester transparent thin films of cellulose is provided with a fluorine-containing poly (meth) having a specific composition and a specific intrinsic viscosity [η].
By forming the adhesive material layer made of acrylate, the adhesiveness and light transmittance are excellent, and the wavelength of 360
An adhesive pellicle film for exposure to short wavelength light having a wavelength of 360 to 450 nm, which has excellent light resistance to light having a short wavelength of to 450 nm, can be obtained. Further, by stretching the pellicle film on the pellicle frame, even if a foreign substance accidentally adheres to the pellicle film, a pellicle can be obtained which can prevent the foreign substance from falling onto the mask etc. by attaching the foreign substance to the adhesive substance layer. To be

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a pellicle of an embodiment.

FIG. 2 is a graph showing the light transmittance of the pellicle film of Example 1.

FIG. 3 is a cross-sectional view showing an adhesive force measuring device.

FIG. 4 is a sectional view showing a holding jig.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pellicle 2 Pellicle frame 3 Pellicle film 4 Transparent thin film 5 Adhesive substance layer 6 Non-adhesive substance layer 7 Adhesive 8 Adhesive force measuring device 10 Instron 11 Holding jig 12 Strain gauge

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location C09J 133/14 JDE 7921-4J H01L 21/027 (72) Inventor Minoru Fujita Waki-cho, Kuga-gun, Yamaguchi Prefecture 6-1-2 Waki Mitsui Petrochemical Industry Co., Ltd.

Claims (5)

[Claims] 1. On one surface of a transparent thin film of a fatty acid ester of cellulose, a compound of the general formula [1] (In the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear fluoroalkyl group.) At least 1
With a monomer (A) of the general formula [2] (In the formula, R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents a branched fluoroalkyl group.) A copolymer with at least one monomer (B) The monomer (A) component ratio is 20 to 80 mol%,
The constituent component ratio of the monomer (B) is 80 to 20 mol%, and the intrinsic viscosity [η] measured in meta-xylene hexafluoride at 60 ° C. is 0.10 to 0.35 dl / g.
Which is characterized in that an adhesive substance layer made of fluorine-containing poly (meth) acrylate is formed.
Adhesive pellicle film for short wavelength light exposure of ~ 450 nm. 2. The intrinsic viscosity [η] of the copolymer is 0.20d.
The adhesive pellicle film according to claim 1, wherein the adhesive pellicle film has a content of more than 1 / g and not more than 0.35 dl / g. 3. The proportion of the constituent component of the monomer (A) in the copolymer is 20 mol% or more and less than 45 mol%, and the proportion of the constituent component of the monomer (B) is more than 55 mol% and not more than 80 mol%. The adhesive pellicle film according to claim 1 or 2, wherein 4. The monomer (A) component ratio in the copolymer is more than 75 mol% and 80 mol% or less, and the monomer (B) component ratio is 20 mol% or more and less than 25 mol%. The adhesive pellicle film according to claim 1 or 2, wherein 5. A pellicle comprising the adhesive pellicle film according to any one of claims 1 to 4 and a pellicle frame.