JP2001222100A - Pellicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pellicle with an adhesive layer which exhibits superior retaining performance in the fixation of foreign matter such as dust and has light resistance to a short-wavelength light such as excimer light inside a pellicle frame. SOLUTION: The pellicle 1 has a pellicle frame 2, a pellicle film 3 stretched on the frame 2 and an adhesive layer 5 disposed on the inside of the frame 2. The adhesive layer 5 contains a perfluoro-polyether whose number average molecular weight is in the range of 1,000-15,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a pellicle,
In particular, the present invention relates to a pellicle having an adhesive layer having light resistance to short-wavelength light such as excimer light and having excellent dust resistance.

[0002]

2. Description of the Related Art In a photolithography process, a photomask or reticle (hereinafter referred to as a "mask") in which a circuit pattern is formed on a glass plate surface with a vapor-deposited film of chrome or the like is used. An operation of transferring the circuit pattern by exposure is performed. In this step, if the exposure is performed in a state where foreign matter such as dust adheres to the circuit pattern on the mask, the foreign matter is also transferred to the wafer and becomes a defective product wafer. In particular,
When exposure is performed by a stepper, there is a high possibility that all chips formed on the wafer become defective, and adhesion of foreign matter to the circuit pattern of the mask becomes a serious problem.
Pellicles have been developed to solve this problem, and various improvements have been made.

In general, a pellicle is a pellicle frame made of aluminum in which a transparent film made of nitrocellulose or the like is stretched on one side, and a double-sided tape is adhered to the other side to form a pellicle on a mask. It can be attached to. According to this, foreign matter can be prevented from entering from the outside, and even if foreign matter adheres to the film, no problem occurs because the image is transferred in an out-of-focus state at the time of exposure. However, if foreign matter such as dust adheres to the inside of the pellicle, the foreign matter may fall off after the pellicle is mounted. Further, the material on the surface of the pellicle frame may be partially disintegrated and fall off due to vibration or the like. It is not easy to prevent such dust generation inside the pellicle after the pellicle is mounted on the mask.

Therefore, in order to prevent dust from being generated from the inside of the film or the pellicle frame, an adhesive material or the like is previously applied to the inner surface of the pellicle frame to form a dust-proof film (Japanese Patent Laid-Open No. 64-64).
No. 48062), forming an adhesive substance layer on the inner surface of the pellicle film (Japanese Patent Application Laid-Open No. 1-120555), and applying an organic polymer or the like to the entire surface of the pellicle frame and performing smoothing treatment (Japanese Patent Application Laid-Open No. 6-301199; JP-A-7-43892
No.) etc. are known.

[0005] Applying an organic polymer or the like to the entire surface of the pellicle frame and performing a smoothing treatment is excellent in preventing dust from being generated from the pellicle frame, but is effective for dust floating in the pellicle. There is no. On the other hand, providing an adhesive layer inside the pellicle frame or film is excellent in preventing dust from being generated from the inside of the pellicle and fixing floating dust to prevent adhesion to the mask.

However, mask circuit patterns have been miniaturized year by year, and short-wavelength light such as excimer light has been used for exposure. Since short-wavelength light has high energy, acrylic-based adhesives, rubber-based adhesives, and silicone-based adhesives that have been conventionally used as adhesive materials for forming an adhesive layer are scorched, solidified, or fluidized. The adhesive layer is deteriorated, and the function of preventing dust generation and fixing floating matters is not sufficiently exhibited.

[0007]

SUMMARY OF THE INVENTION The present invention has been made from the above viewpoint, and a main object of the present invention is to exhibit excellent holding performance for fixing foreign substances such as dust, and to provide excimer light. An object of the present invention is to provide a pellicle having an adhesive layer having excellent light resistance to short-wavelength light inside the pellicle frame.

[0008]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a perfluoropolyether having a number average molecular weight in the range of 1,000 to 15,000 is provided inside a pellicle frame. By forming a pressure-sensitive adhesive layer containing a pellicle, it was found that a pellicle having a pressure-sensitive adhesive layer exhibiting excellent tackiness to dust and having excellent light resistance to excimer light was obtained, and completed the present invention. .

Therefore, according to the present invention, there is provided a pellicle having a pellicle frame, a pellicle film stretched over the pellicle frame, and an adhesive layer provided inside the pellicle frame. Having a number average molecular weight of 1000 to 1
A pellicle is provided comprising a perfluoropolyether in the range of 5000.

[0010] As described above, by using perfluoropolyether, excellent light resistance against short-wavelength light such as excimer light is exhibited, and the number average molecular weight is within the range of 1,000 to 15,000. By doing so, it becomes oily, and exhibits excellent adhesiveness to dusts for a long period of time.

Preferably, the perfluoropolyether has the following formula (1), (5) or (6)

_{Embedded image} X ¹ [X] _m1 OX ³ (1) (where X is one of a structural unit represented by the following formula (2) and a structural unit represented by the following formula (3)) A copolymer comprising a structural unit represented by the following formula (4) or a copolymer comprising a structural unit represented by the following formula (2) to (4):

Embedded image (Here, X ² represents an F atom or CF _3. )

Embedded image —OCF ₂ CF ₂ — (3)

Embedded image —OCF ₂ — (4), X ¹ and X ³ independently represent CF ₃ , C ₂ F ₅ or C ₃ F
₇ and m1 represents a positive integer. )

Embedded image (However, ^{X 4} represents a F atom, or CF _3, n4 represents a positive integer.)

Embedded image A perfluoropolyether represented by any one of F (CF ₂ CF ₂ CF ₂ O) _n5 CF ₂ CF ₃ (where n5 represents a positive integer).

X is a random copolymer in which the structural units represented by the formulas (2), (3) and (4) are connected irregularly, a copolymer in which the structural units are connected regularly, For example, alternating copolymers, such as formulas (2), (4), (2), (4),..., A block copolymer in which several structural units of the same type are connected, or a main chain May be a graft copolymer having a branched portion having a different type of structural unit.

Further, preferably, the perfluoropolyether is represented by the following formula (7):

Embedded image(However, X¹, X³Is independently CF₃, C₂F₅Also
Is C₃F₇And X ²Is an F atom or CF₃Represents
n1 and n2 are either 0 or a positive integer
And the other is a positive integer, and n3 and m1 are each
Represents a positive integer. Perfluoropolye represented by)
There is tell.

Preferably, the pressure-sensitive adhesive layer further contains a viscosity modifier, more preferably, the viscosity modifier is a fluororesin, and a ratio of the fluororesin (B) to the perfluoropolyether (A). (B / A)
Is 0.15 to 0.6 (weight ratio).

Preferably, the viscosity modifier is represented by the following formulas (8) to (10).

Embedded image

Embedded image

Embedded image Is a fluororesin having a number average molecular weight of 10,000 to 100,000 or a weight average molecular weight of 50,000 to 500,000.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view of a pellicle according to one embodiment of the present invention, and FIG. 2 is a side view of the pellicle according to one embodiment of the present invention. As shown in FIGS. 1 and 2, a pellicle 1 according to an embodiment of the present invention includes a pellicle frame 2, a pellicle film 3, an adhesive layer 4 for fixing the pellicle film 3 to the pellicle frame 2, and a pellicle frame. 2 has an adhesive layer 5 having a predetermined holding power.

As the pellicle frame 2 used in the embodiment of the present invention, any pellicle frame generally used can be used. As the pellicle frame 2,
For example, a pellicle frame made of aluminum alloy, stainless steel, polyethylene, black alumite-treated aluminum, or the like can be used. Further, the entire surface of these pellicle frames may be coated with an amorphous fluoropolymer or the like. In the present invention, among these, black alumite-treated aluminum can be suitably used.

As the thin film used as the pellicle film 3 in the embodiment of the present invention, any thin film generally used as a pellicle film can be used. Examples of the thin film used as the pellicle film 3 include those composed of, for example, nitrocellulose, ethyl cellulose, cellulose acetate, cellulose propionate, a pullulan compound, an amorphous fluoropolymer, and a silicone-modified polyvinyl alcohol. In particular, an amorphous fluoropolymer having sufficient resistance to excimer light can be preferably used.

The thin film used as the pellicle film is stretched, adhered and fixed to one opening of the pellicle frame 2, that is, one side surface on the light incident side via an adhesive layer 4. It is formed.

The pellicle 1 according to one embodiment of the present invention includes an adhesive layer 5 containing a perfluoropolyether having a number average molecular weight in the range of 1,000 to 15,000. Adhesive layer 5
Preferably has a specific perfluoropolyether represented by the above formula (1), (5) or (8), and more preferably, the perfluoropolyether and a fluororesin functioning as a viscosity modifier. And a sticky fluororesin composition comprising a mixture of

By forming the adhesive layer 5 in this manner, an adhesive layer having light resistance to short-wavelength light such as excimer light can be obtained. In addition, this adhesive layer 5
Has the following adsorption and retention performance for dusts.

Further, as shown in FIG. 2, by providing the adhesive layer 5 inside the pellicle frame 2, foreign substances such as dust floating in a space surrounded by the pellicle 1 and a mask (not shown) can be removed. An adhesive layer exhibiting an excellent holding performance for fixing to an adhesive layer and having light resistance even to short wavelength light such as excimer light can be obtained.

FIG. 3 is an explanatory view showing a test of the holding performance of the pressure-sensitive adhesive layer of the pellicle, and FIG. 4 shows a method (air blow method) for measuring a wind pressure generated from an air gun used for the test of the holding performance of the pressure-sensitive adhesive layer. FIG.

In this holding performance test, when the holding performance is tested, the wind pressure may be applied using an air gun 6 or the like. When the tip of the nozzle 62 is separated from the foreign matter 1 by a linear distance of 1 cm, the nozzle What is necessary is just to apply wind pressure by making 62 an angle of 45 degrees above the horizontal direction. The wind pressure is adjusted by using an air gun 6 having an inner diameter of the nozzle 62 of 0.65 mm, for example, at an original pressure of 0.6 kg / cm ² G from a distance of 1 cm vertically upward from the upper plate of the precision balance 8 to supply air. Blow into the upper plate of the precision balance (see Fig. 4)
Is equivalent to the pressure at which a weight display of about 1.3 g is made on the precision balance 8. The original pressure is 0.6 kg / cm ² G
To be precise, the pressure of the air emitted from the nozzle is 0.6 kg / cm ² G, but in practice, the pressure setting of the pressure reducer 61 may be set to 0.6 kg / cm ² G.

The "foreign matter" is assumed to be dust which is a problem in the pellicle, and in testing the holding performance, glass beads, polystyrene beads or the like may be used. Further, “do not scatter foreign matter” means that the foreign matter does not separate from the adhesive layer, and does not mean that the foreign matter scatters even if it moves on the adhesive layer.

The pellicle 1 according to one embodiment of the present invention includes an adhesive layer 5 containing a perfluoropolyether having a number average molecular weight in the range of 1,000 to 15,000, preferably in the range of 2,000 to 10,000. The adhesive layer 5 preferably has the following formulas (1), (5) and (6)

X ¹ [X] _m1 OX ³ (1) (where X is one of a structural unit represented by the following formula (2) and a structural unit represented by the following formula (3): A copolymer comprising a structural unit represented by the following formula (4) or a copolymer comprising a structural unit represented by the following formula (2) to (4):

Embedded image (Here, X ² represents an F atom or CF _3. )

Embedded image —OCF ₂ CF ₂ — (3)

Embedded image —OCF ₂ — (4), X ¹ and X ³ independently represent CF ₃ , C ₂ F ₅ or C ₃ F
₇ and m1 represents a positive integer. )

Embedded image (However, ^{X 4} represents a F atom, or CF _3, n4 represents a positive integer.)

Embedded image A specific perfluoropolyether represented by any of F (CF ₂ CF ₂ CF ₂ O) _n5 CF ₂ CF ₃ (where n5 represents a positive integer) The number average molecular weight is in the range of 1,000 to 15,000, preferably 2,000
It has a perfluoropolyether in the range of 10,000 to 10,000, and more preferably has an adhesive fluororesin composition comprising a mixture of the perfluoropolyether and a fluororesin which functions as a viscosity modifier. When the number average molecular weight of the perfluoropolyether is less than 1,000, there is a possibility that the thermal stability is insufficient or the volatilization occurs. On the other hand, if it exceeds 15,000, the adhesiveness tends to be poor. On the other hand, when it exceeds 15000, the compatibility with the fluororesin (B) is reduced, and the phase separation is easily caused. The number average molecular weight is measured with high precision by NMR.

In one embodiment of the present invention, the adhesive layer 5
Preferably, the number average molecular weight is 1000
A fluororesin composition composed of a mixture of a perfluoropolyether (A) and a fluororesin (B) in the range of 15,000 to 15,000 is used. In this case, the fluororesin (B) is used.
Of perfluoropolyether (A) and (B /
A weight ratio) is preferably 0.15 to 0.6, and more preferably 0.2 to 0.5. It is preferable to use a composition in this range from the viewpoints of adhesion retention of dust and prevention of dripping of the adhesive film.

The fluororesin (B) preferably used in one embodiment of the present invention contains fluorine in an amount of 12 to 80% by weight, particularly 28 to 75% by weight, most preferably 45 to 70% by weight. It is preferable from the viewpoint of light resistance that a fluorine resin is contained. Further, the fluororesin (B) has a high molecular weight sufficient to form a film, and generally has a molecular weight of 5 × 10 ³ or more in terms of number average molecular weight, and further from the viewpoint of compatibility with the perfluoropolyether (A). In particular, 1 × 10 ⁴ to 1 ×
10 ⁵ , or 5 × 10 ⁴ or more, especially 5 in terms of weight average molecular weight
It is good to be in the range of × 10 ^{5 to} 5 × 10 ⁶ . The number average molecular weight and the weight average molecular weight can be measured relatively accurately by the GPC method, particularly by using a light scattering detector (low-angle laser light scattering method) or the like.

The fluororesin (B) used should be capable of preventing the adhesive layer from sagging during temperature rise during storage or transportation, as well as during use.
Generally above 50 ° C., especially above 60 ° C., most preferably 75 ° C.
It preferably has a softening point of not less than ° C. Further, it is preferable that the fluororesin (B) is soluble in a solvent common to the perfluoropolyether (A) when coating the pellicle.

In terms of light resistance, film forming property and adhesion to the pellicle frame, the fluororesin (B) is made of tetrafluoroethylene and perfluoro (2,2) represented by the following formula (8).
-Dimethyl-1,3-dioxole) (PDD) (trade name: manufactured by Teflon AF DuPont),

Embedded image Alternatively, a copolymer of tetrafluoroethylene and 2,2,4-trifluoromethoxy-1,3-dioxole (TTD) represented by the following formula (9) (trade name: manufactured by Algoflon AD Ausimont),

Embedded image Alternatively, a perfluorobutenyl vinyl ether copolymer represented by the following formula (10) (trade name: CYTOP, manufactured by Asahi Glass Co., Ltd.)

Embedded image Can be suitably used.

Adhesive layer 5 used in one embodiment of the present invention
It is preferable that the compound generally shows tackiness in a temperature range of -10 ° C to 50 ° C. This tackiness can be confirmed by the test method described above. This is exactly the same for the adhesiveness after light irradiation.

The pressure-sensitive adhesive layer 5 according to one embodiment of the present invention only needs to be provided with a thickness capable of holding dust and the like.
Although the thickness is not particularly limited, it is generally 1 μm.
m to 1 mm, especially 3 μm to 100 μm, most preferably 3 μm
It is preferable that the film is provided with a film thickness of μm to 20 μm.

Next, a method for manufacturing a pellicle according to an embodiment of the present invention will be described. The pellicle 1 according to one embodiment of the present invention can be manufactured by forming the adhesive layer 5 inside the pellicle frame 2 and then stretching the pellicle film 3 on one side of the pellicle frame 2 on the light incident side. it can.

In order to form the adhesive layer 5, for example, first, a coating containing a mixture of a specific perfluoropolyether represented by any of the above formulas (1), (5) and (6) and a fluororesin is used. Make a solution. The concentration of the coating solution in a solvent capable of dissolving the fluororesin and the perfluoropolyether varies depending on the composition of the resin and the type of coating, but is usually 5 to 80% by weight, preferably 10 to 10% by weight.
It is prepared so as to be about 70% by weight.

As such a solvent, for example, perfluoro (2-butyltetrahydrofuran), perfluoro (2-propyltetrahydrofuran), perfluorotripropylamine, perfluorotributylamine, perfluorononane, perfluorooctane, perfluoro —N-isopropylmorpholine and the like.

In order to apply the obtained coating solution to the inside of the pellicle frame, any coating means known per se can be used, for example, a spray coating method, a dipping coating method, a brush coating method, a spatula coating method. , A roller coating method, a casting coating method and the like can be used. In the case of the casting method, for example,
The droplets placed on the frame can be spread by a jig and uniformly applied. Finally, the coating liquid applied on the frame is dried to form an adhesive layer.

After the adhesive layer 5 is formed, a pellicle thin film is stretched on one side of the pellicle frame 2 on the light incident side to obtain the pellicle 1 according to one embodiment of the present invention. Stretching may be performed according to a normal method, and the thin film may be fixed by forming the adhesive layer 4 with a commonly used adhesive.

As the adhesive, an adhesive known per se,
For example, a cellulose derivative, a chlorinated polypropylene, a polyamide adhesive, a fluororesin adhesive, an acrylic adhesive, an epoxy resin, a polyimide contact agent and the like are used.

The present invention will be further described in the following examples, but the present invention is not limited to the following examples.

[0041]

EXAMPLES (Examples 1 to 6) DuPont was used as a fluororesin.
Product name marketed by the company: Teflon AF 1601
(Weight average molecular weight: about 200,000 to 220,000) was used. Also, as a perfluoropolyether, Au
available from _{simont KK, CF 3 - [(} O-CF (CF
_{3) -CF 2) n - (} O-CF 2) m] represented by -O-CF ₃ (n, m are integers), trade name: Fomblin YHVA
C140 / 13 (number average molecular weight: about 7000, kinematic viscosity at 20 ° C .: 1400 ± 200 cst, vapor pressure at 20 ° C .: 5 × 10 ⁻¹³ Torr or less) was used.
The mixing ratio (B / A) of the fluororesin (B) and the perfluoropolyether (A) is 1/2, 1/3, 1/5, 1/1.
0, 1/15 (wt / wt) or perfluoropolyether alone (B / A = 0/1) is applied to a pellicle frame, and a foreign matter holding force measurement method shown below (impact method) , Air blow method) to determine the foreign matter holding force value. The impact method and the air blow method are described in Example 7.
The same applies to Comparative Examples 1 to 12. At this time, the mixing method of the fluororesin and the perfluoropolyether is as follows. First, the fluororesin Teflon AF1601 is dissolved in a fluorine solvent perfluoro (2-butenyltetrahydrofuran), and the Fomblin YHVAC 140/13 is added to the Teflon AF1601 solid content. It was added so as to have a predetermined compounding ratio. Using a stirrer, they were sufficiently stirred and mixed so that each solution became uniform. In addition, it adjusted so that the quantity of a fluorine solvent might be 20 weight%. The fluororesin composition thus adjusted is applied to a pellicle frame, dried,
Inspection was performed by the following foreign matter holding force measurement method.

(Method of Measuring Foreign Material Retaining Force) Impact method: Standard particles (glass) having a particle size of 350 to 500 μm
Is attached using horse hair, and gently smashed several times against a hard table,
Check for a drop. Air blow method (see FIG. 3): standard particles (polystyrene) having a particle diameter of 66 μm are attached using horse hair, and from an angle of 45 °, a distance of 1 cm and an air gun at an air gun pressure of 0.1 to 2 mm. The particles were blown in a range of 0.0 kg / cm ² G for 10 seconds to check the movement of the particles, and the maximum value of the air source pressure when there was no movement of 1 mm or more during blowing was defined as the foreign matter holding force. Table 1 shows the results.

[0043]

[Table 1]

Here, the air blow portion waving refers to a phenomenon in which the surface of the adhesive layer changes shape so as to wavy by air blow. According to Table 1, all of the examples have excellent foreign matter holding power, but among them, those of Examples 1 to 3 and the fluororesin (B)
And the perfluoropolyether (A) compounding ratio (B /
A) Those having a (weight ratio) of 0.2 to 0.5 are particularly excellent in the impact method, in which there is no dropping, the foreign matter holding force in the air blow method is large, and the air blow portion has no waving. It shows the characteristic.

Example 7 As a fluororesin, DuPo was used.
Brand name commercially available from nt Co .: Teflon AF160
1 fluororesin (weight average molecular weight: about 200,000 to 220,000)
It was used. Also, as perfluoropolyether,
Is commercially available from _{Ausimont KK, CF 3 - [(} O-CF (C
_{F 3) -CF 2) n -} (O-CF 2) m] represented by -O-CF ₃ (n, m are integers), trade name: Fomblin YHV
AC18 / 8 (number average molecular weight: about 3000, kinematic viscosity at 20 ° C .: 180 ± 20 cst, vapor pressure at 20 ° C .: 2 × 10 ⁻⁸ Torr or less) was used. The compounding ratio (B / A) of the fluororesin (B) and the perfluoropolyether (A) was set to 1/3 (wt / wt), and the other points were the same as those in Examples 1 to 6. The retention values were determined. After applying the fluororesin composition of the mixed resin to the pellicle frame, the adhesive layer dried at room temperature for 1 hour at a room temperature has a foreign matter holding power of 1.5 kg / cm ² G, measured by an air blow method.
Met. The wavy phenomenon of the applied adhesive layer was slight and no problem.

Example 8 In the same manner as in Example 7, the fluororesin composition was applied to a pellicle frame, and then applied at 100 ° C.
After 1 hour of treatment under the condition of 200 mmHg, the foreign matter holding power measured by the air blow method when left at room temperature for 1 hour was 1.5 kg / cm ² G. Also in this case, the waving phenomenon of the applied adhesive layer was slight and there was no problem. After the solvent is completely removed in this way, it is generally considered that the foreign matter holding power is reduced. However, in the present embodiment, there is no change in the foreign matter holding power, and excellent characteristics are obtained over time. It shows that it shows.

Example 9 Using the same fluororesin composition used in Example 7, the light resistance was examined by the following laser irradiation method. Irradiation dose (J / cm ² ) not irradiated, 500, 1000, 1500, 3000 (J / c
m ² ), and the foreign matter holding force was examined by the same impact method and air blow method as in Examples 1 to 6. In any case, no fall of the foreign matter by the impact method was observed.
In addition, the foreign matter holding force by the air blow method is 1.5
There was no change at kg / cm ² G, indicating that the fluororesin composition of this example had light resistance.

(Laser Irradiation Method) A fluororesin composition is applied to an aluminum frame piece and irradiated with ArF laser (wavelength:
193 nm ArF laser irradiation device: L5837 manufactured by Hamamatsu Photonics). Energy density: 1 mJ / cm ² , frequency: 100H
z, irradiation atmosphere: air

Examples 10 to 12 Using the same fluororesin compositions used in Examples 1 to 3, the light resistance was examined in the same manner as in Example 9. As a result, 3000 J / c
After the laser irradiation of m ² , no fall of the foreign matter by the impact method was observed in any case, and the foreign matter holding force by the air blow method was the same as that shown in Table 1 and did not change. As described above, the fluororesin compositions described in Examples 1 to 3 were prepared by using the laser with the ratio of fluororesin (B) / perfluoropolyether (A) in the range of B / A = 1/2 to 1/5. Even after irradiation, it has been found that particularly excellent foreign matter holding power is maintained, and that it has excellent light resistance.

<Comparative Example 1> Low CTFE (chlorotrifluoroethylene) polymer used in a conventional pellicle
(Trade name: Daifoil # 100, manufactured by Daikin Industries, Ltd.) and THV (vinylidene fluoride, tetrafluoroethylene,
Hexafluoropropylene copolymer) resin (trade name: TH
A 30: 1 (weight ratio) mixed pressure-sensitive adhesive layer (V200, manufactured by Sumitomo 3M) was applied to the inner wall of the pellicle frame, and the light resistance was examined in the same manner as in Example 9. As a result, before the laser irradiation, no drop of the standard particles was observed by the impact method, but 100 J / cm
After the ArF laser beam irradiation of No. ² , it was found that the standard particles dropped only by tilting the pellicle frame without performing the impact method. When the ArF laser beam irradiation part was observed, it was confirmed that a part of the adhesive layer had disappeared and the background of the Al pellicle frame was exposed. From these results, it was found that the conventional adhesive layer did not have light resistance to laser irradiation of 100 J / cm ² .

[0051]

According to the present invention, an excellent holding performance for fixing foreign matters such as dust floating in a space surrounded by a pellicle and a mask, and a short wavelength light such as excimer light can be obtained. A pellicle having an adhesive layer having excellent light resistance inside the pellicle frame can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of a pellicle according to an embodiment of the present invention.

FIG. 2 is a sectional view of a pellicle according to an embodiment of the present invention.

FIG. 3 is an explanatory view showing a test of a holding performance of an adhesive layer of a pellicle according to an embodiment of the present invention.

FIG. 4 is an explanatory view showing a method of measuring a wind pressure emitted from an air gun used for a test of a holding performance of an adhesive layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Pellicle 2 ... Pellicle frame 3 ... Pellicle film 4 ... Adhesive layer 5 ... Adhesive layer

Claims (6)

[Claims] 1. A pellicle comprising a pellicle frame, a pellicle film stretched over the pellicle frame, and an adhesive layer provided inside the pellicle frame, wherein the adhesive layer has a number average molecular weight of 1,000. A pellicle comprising a perfluoropolyether in the range of １５15000. 2. The method of claim 1, wherein the perfluoropolyether is represented by the following formula (1), (5) or (6): X ¹ [X] _m1 OX ³ (1) A copolymer comprising one of the structural unit represented by 2) and the structural unit represented by the following formula (3) and a structural unit represented by the following formula (4), or the following formula (2) A copolymer comprising structural units represented by formulas (1) to (4): (Here, X ² represents an F atom or CF _3. ) (3) —OCF ₂ CF ₂ — (3) —OCF ₂ — (4), X ¹ and X ³ are independently _{CF 3,} C 2 _{F 5} or _C 3 F
₇ and m1 represents a positive integer. ) (However, X ⁴ represents an F atom or CF ₃ and n 4 represents a positive integer.) F (CF ₂ CF ₂ CF ₂ O) _n5 CF ₂ CF ₃ (6) 2. The pellicle according to claim 1, wherein n5 is a positive integer. 3. The method according to claim 1, wherein the perfluoropolyether has the following formula:
(7)(However, X¹, X³Is independently CF₃, C₂F₅Also
Is C₃F₇And X ²Is an F atom or CF₃Represents
n1 and n2 are either 0 or a positive integer
And the other is a positive integer, and n3 and m1 are each
Represents a positive integer. Perfluoropolye represented by)
The pellicle according to claim 2, wherein the pellicle has a tellurium. 4. The pellicle according to claim 1, wherein the pressure-sensitive adhesive layer further contains a viscosity modifier. 5. The method according to claim 1, wherein the viscosity modifier is a fluororesin, and the ratio (B / A) of the fluororesin (B) to the perfluoropolyether (A) is 0.15 to 0.6 (weight ratio). The pellicle according to claim 4, wherein the pellicle is provided. 6. The method of claim 1, wherein the viscosity modifier is represented by the following formulas (8) to (1).
0) Embedded image Embedded image The pellicle according to claim 4 or 5, wherein the pellicle is a fluororesin having a number average molecular weight of 10,000 to 100,000 or a weight average molecular weight of 50,000 to 500,000 represented by any of the above.