TWI446104B - Pellicle film, method of manufacturing the same, and pellicle sticking the film - Google Patents

Description

Dustproof film, method of manufacturing the same, and pellicle assembly to which the film is attached

The present invention relates to a pellicle for use as a dustproof material in the manufacture of a semiconductor device, an IC package, a printed substrate, a liquid crystal display, or an organic EL display, and more particularly to an i-line (365 nm), h-line (405 nm). Or any of g lines (436 nm) or ultraviolet rays obtained by combining them as a pellicle film used in the photolithography step of an exposure light source, a method for producing the same, and a pellicle film module to which the film is attached.

LSI (Large Scale Integration), semiconductors such as super LSI, circuit boards such as IC packages and printed boards, and semiconductor wafers, package substrates, or displays for manufacturing liquid crystal displays and organic EL displays. A photoresist is provided on the surface of the original plate, and then light is irradiated thereto by a patterned mask to develop a pattern. The photomask or reticle (hereinafter, referred to as a reticle) used at this time is attached with dust, which absorbs light or bends light, and thus has the following problems: transfer The pattern is deformed or the edges of the pattern are blurred. In addition, the substrate becomes black and dirty, and the size, quality, and appearance of the final product are damaged.

Therefore, these operations are usually performed in a clean room, but even so, it is difficult to keep the reticle clean from time to time. Therefore, the pellicle is attached to the surface of the photomask as a dustproof material before exposure. In this case, the foreign matter does not directly adhere to the surface of the reticle, but is attached to the Guard On the dust film assembly, as long as the focus is placed on the pattern of the reticle during photolithography, the foreign matter on the pellicle assembly is irrelevant to the transfer.

In general, a pellicle film is produced by attaching a transparent pellicle film that transmits light well or subsequently to an upper end surface of a pellicle frame including aluminum, stainless steel, and engineering plastics. Further, at the lower end of the pellicle frame, an adhesive layer including a polybutene resin, a polyvinyl acetate resin, an acrylic resin, a hot-melt adhesive, an anthrone resin, or the like for mounting the photomask is provided, and if necessary A release layer (release sheet) for protecting the adhesive layer is provided.

In addition, in a state in which the pellicle is attached to the reticle, a small hole for adjusting the air pressure is provided in a part of the pellicle frame in order to prevent passage of a space between the space enclosed by the pellicle and the outside of the pellicle assembly. The foreign matter brought in by the moving air of the small hole is sometimes provided with a filter.

As the pellicle film, it is necessary to select an optimum material corresponding to the light source used for exposure. For example, when an ArF laser (193 nm) or a KrF laser (248 nm) is used, a fluorine-based resin having sufficient transmittance and light resistance to light of the wavelength is used (Patent Document 1).

In addition, when exposure is performed using i-line (365 nm), h-line (405 nm), and g-line (436 nm), a cellulose resin such as nitrocellulose, ethyl cellulose, or cellulose propionate can be used for polymerization. A vinyl acetal resin, a cycloolefin resin, etc. (patent document 2, patent document 3, and patent document 4). Among these light sources, high pressure mercury lamps or ultra high pressure mercury lamps are generally used.

The high pressure mercury lamp and the ultrahigh pressure mercury lamp have a characteristic of having a wide wavelength of several peaks between 254 nm and 577 nm. Among them, from the viewpoint of the amount of luminescence and the light energy, the highest intensity i-line (365 nm) can be used well in the photolithography, and then the g-line (436 nm) and the h-line (405 nm) light, and occasionally Light of 313 nm was used. Further, in the case where the output of the display is particularly important for the production of the display, the light of the specific wave is not used alone, and for example, all of the light of 365 nm to 436 nm is used.

The fluororesin described above has almost no absorption at short wavelengths, and it is possible to use wavelengths of short-wavelength and high-energy KrF lasers and ArF lasers. Therefore, even wavelengths such as i-line and g-line which are lower than their energy are used. no problem. However, fluororesin has the disadvantage of being extremely expensive. Therefore, in general, in the wavelength range of the i-line to the g-line, various types of characteristics of the dust-proof film material are considered, and a cellulose resin which is easy to use is often used.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 03-39963

[Patent Document 2] Japanese Patent Special Opening 01-100549

[Patent Document 3] Japanese Patent Laid-Open No. 01-172430

[Patent Document 4] Japanese Patent Laid-Open No. 2010-152308

In recent years, in the photolithography step, in order to draw a circuit having a finer line width and to improve productivity, higher exposure intensity is required. When the exposure intensity is increased, the deterioration of the ultraviolet ray of the pellicle film is promoted, and the film thickness is reduced, the transmittance is lowered, and haze is generated. Specifically, the portion of the chrome (Cr) layer of the photomask is shielded from light by purple The outer line, so there is no change, but in the portion where the Cr layer is not present (the portion in which the pattern is drawn), the surface of the pellicle film is directly irradiated with ultraviolet rays, and the film of the portion is damaged.

As described above, in the case of using a high-pressure mercury lamp or an ultra-high pressure mercury lamp, the light generated from these light sources includes not only i-line, h-line, g-line for exposure, but also light of other wavelengths. The latter includes short-wavelength light of 254 nm, 302 nm, 313 nm, and the like. These short-wavelength light, particularly 254 nm light, has a higher energy than the bonding energy of a molecule constituting a dust-proof film such as a cellulose resin, and thus the bond is cut. The molecules whose bonds are cut are decomposed and vaporized, so that the surface of the pellicle is scraped and the film thickness is reduced.

When the film thickness of the partial pellicle film is reduced, the optical path length becomes uneven, and besides being optically poor, the surface becomes uneven and light is scattered, so that the transmittance is also lowered. Further, the film strength is reduced, and in the case of further seriousness, the tension on the pellicle film becomes uneven, and wrinkles may occur on the surface of the pellicle film.

In order to prevent such a problem, light of a short wavelength which is not used for patterning such as 254 nm, 302 nm, or 313 nm may be removed from the light generated from the exposure light source. As a method, for example, a filter that removes only these short-wavelength light or a mirror that reflects light other than the short-wavelength light is inserted into the optical path from the exposure light source to the reticle. . Further, a layer having the same filter function may be added to the side of the pattern surface without the mask. These filter functions can be obtained by, for example, TiO ₂ , ZnO ₂ , CeO ₂ or the like having absorption in the short wavelength range on the opposite side of the pattern surface of the filter substrate such as quartz glass or the reticle itself. The material is adhered by a method such as vapor deposition or sputtering. However, such processing costs are not necessarily inexpensive, and since these materials have a high refractive index and a large reflection, there is a disadvantage that the intensity of light used for exposure is lowered. Therefore, the correspondence is not made on the side of the exposure machine or the reticle, but on the side of the pellicle.

However, it is extremely difficult to impart the above-mentioned inorganic material to the pellicle. The reason for this is that the vapor-proof film must be stored in the vacuum chamber during vapor deposition or sputtering, but a large amount of air is introduced into the vacuum chamber during decompression and return to atmospheric pressure, so that a large amount of foreign matter adheres to the dust-proof film. . However, the pellicle film is different from the glass substrate and the like, and cannot be washed. Therefore, in the case where foreign matter adheres to the pellicle film which requires extremely high cleanliness, it immediately becomes defective.

For the above reasons, a pellicle film which is excellent in durability against short-wavelength light using a pellicle film including an inexpensive cellulose resin has not been hitherto. Therefore, this method of replacing the pellicle film has to be used before the problem occurs.

Therefore, a first object of the present invention is to provide a pellicle having high resistance and low cost to short-wavelength ultraviolet rays of 254 nm or 313 nm suitable for exposure using i-line, h-line, and g-line.

A second object of the present invention is to provide a method for producing a pellicle film which is inexpensive and excellent in durability used in the photolithography step of ultraviolet rays in the wavelength range of 350 nm to 450 nm.

Further, a third object of the present invention is to provide an inexpensive pellicle module which can be used in the photolithography step of ultraviolet rays in the wavelength range of 350 nm to 450 nm.

The above objects of the present invention are achieved by a pellicle film, a method of manufacturing the same, and a pellicle film assembly using the pellicle film. The pellicle film is a pellicle for a pellicle film assembly used in a photolithography step of irradiating ultraviolet rays in a wavelength range of 350 nm to 450 nm, characterized in that the pellicle film is on the surface of at least the exposure light source side of the raw material pellicle film. The ultraviolet absorbing layer has an average transmittance of ultraviolet rays in the wavelength range of 350 nm to 450 nm of 90% or more, and an average transmittance of ultraviolet rays in the wavelength range of 200 nm to 300 nm of 50% or less. In the present invention, it is preferred to further have an antireflection layer on the ultraviolet absorbing layer. Further, the ultraviolet absorbing layer is preferably made of an fluorenone resin, and the refractive index of the ultraviolet absorbing layer is preferably 1.50 or less.

In the pellicle film of the present invention, a commercially available inexpensive material such as a cellulose resin, a polyvinyl acetal resin or a cycloolefin resin is used, but 300 nm or less which is an unnecessary component during exposure is used. Since the component has high light resistance, it is superior to the conventional dustproof film in that the light resistance is greatly improved. Therefore, a higher exposure intensity can be used, so that an improvement in exposure quality and an increase in yield can be achieved. Further, since the decrease in the film thickness during use is small, problems such as occurrence of wrinkles or blurring can be prevented, and the exposure quality can be maintained for a long period of time.

The material of the raw material pellicle constituting the pellicle film of the present invention can be appropriately selected from known materials, but nitrocellulose, ethyl cellulose, cellulose acetate, and cellulose propionate can be used. And a cellulose resin such as cellulose acetate propionate, a commercially available inexpensive material such as a polyvinyl acetal resin or a cycloolefin resin. These materials have sufficient resistance in the wavelength range of 350 nm to 450 nm used for patterning, but have low resistance to light of a short-wavelength component of 300 nm or less which is present as an unnecessary component in exposure, thereby resulting in The deterioration is fast. In the present invention, the ultraviolet absorbing layer provided on the incident side surface of the pellicle film can prevent the short-wavelength component from reaching the raw material pellicle film, and thus the light resistance is greatly improved.

In particular, the ultraviolet ray absorbing layer has an average transmittance of 90% or more for ultraviolet rays in a wavelength range of 350 nm to 450 nm, and an average transmittance of 50% or less for ultraviolet rays in a wavelength range of 200 nm to 300 nm. The material of such an ultraviolet absorbing layer can be suitably selected from known ones. In the present invention, it is particularly preferred to constitute an ultraviolet absorbing layer with an fluorenone resin. When the fluorenone resin is used as the ultraviolet ray absorbing layer, unlike the inorganic material, the film can be formed into a film in a solution dissolved in a solvent. Therefore, the dust-proof film of the present invention can be produced in the same manner as in the case of a general production of a dust-proof film. . Thereby, the cleaned pellicle film of the present invention having less foreign matter can be obtained. Further, since the anthrone resin is excellent in light resistance, it has an advantage that the degree of deterioration is extremely small even if ultraviolet rays are absorbed.

In the pellicle film of the present invention, it is preferably in addition to the ultraviolet absorbing layer. Further, an antireflection layer is further provided. The antireflection layer may be provided in consideration of the material, the film thickness, and the position to be imparted according to the refractive index of the ultraviolet absorbing layer to be applied. The antireflection layer may be provided on the outermost layer of the pellicle film on the incident side, the outermost layer on the exit side, or the outermost layer on both sides, but may be provided between the ultraviolet absorbing layer and the raw material pellicle film in accordance with a combination of refractive indexes. Further, the material of the antireflection layer is not limited to one type, and the antireflection layer may have a multilayer structure in a plurality of combinations.

Further, in the present invention, the refractive index of the ultraviolet absorbing layer is set to 1.50 or less, and it is possible to have an ultraviolet absorbing ability and a function as an antireflection layer.

The dust-proof film of the present invention is preferably produced by coating a material solution which is the outermost layer on the film-forming substrate among the raw material dust-proof film, the ultraviolet absorbing layer, and the anti-reflection layer which constitute the dust-proof film of the present invention. After drying and solidifying, the same step is repeatedly performed on the dried and solidified layer in the order of the desired film structure, and the constituent materials of the respective layers are sequentially coated, dried, and cured, and finally, The entire pellicle film on which the laminate is formed on the film formation substrate may be peeled off from the film formation substrate. According to this method, the dust-proof film of the present invention having a small amount of adhesion of foreign matter and having an ultraviolet absorbing layer can be obtained in the same manner as the method for producing a conventional dust-proof film.

The dust-proof film of the present invention has an ultraviolet absorbing layer that absorbs ultraviolet rays in a wavelength range of 200 nm to 300 nm (the main cause of deterioration of the raw material dust-proof film on the exposure light source side of the pellicle film), so that it is not used as a raw material without using expensive fluororesin as a raw material. The film can also be a dust-proof film excellent in light resistance. Especially as described above, using an anthrone resin as the ultraviolet absorption In the case of the layer, since the ultraviolet absorbing layer can be applied by dissolving in a solvent, the pellicle film of the present invention can be produced in the same manner as in the case of generally manufacturing a pellicle film, and the durability can be improved inexpensively and the foreign matter is small. Clean dustproof film.

Fig. 1 is a cross-sectional view showing the outer shape of a pellicle according to the present invention. Reference numeral 15 in the drawing is a dust-proof film of the present invention, which is attached to the pellicle frame 11 by applying an appropriate tension to the pellicle frame 11 through the adhesive layer 13. Reference numeral 12 is an adhesive layer for attaching the pellicle to the reticle when in use, and 14 is a release sheet for protecting the adhesive layer before use.

Fig. 2 is an enlarged cross-sectional view showing a portion A of the pellicle film of Fig. 1. Reference numeral 21 is a raw material dustproof film, and reference numeral 22 is an ultraviolet absorbing layer. Fig. 3 is an enlarged cross-sectional view showing a portion A of the pellicle film of Fig. 1, which is the same as Fig. 2, but has an embodiment of the antireflection layer 23 except for the ultraviolet absorbing layer 22.

The pellicle according to the present invention can be used as a pellicle in all photolithography of ultraviolet rays in the wavelength range of 350 nm to 450 nm, and the wavelength, use, size, and the like are not limited. The material of the pellicle frame 11 to which the pellicle of the present invention is attached may be known from engineering plastics, steel, stainless steel, aluminum alloy, titanium and alloys thereof, CFRP (Carbon Fiber Reinforced Polymer/Plastic), and the like. The material used for the pellicle frame is suitably selected.

The material of the raw material pellicle film 21 used in the pellicle film 15 of the present invention can be appropriately selected from known pellicle materials, or A high-priced material excellent in light resistance to light of 350 nm or less, such as a fluorine-based resin, is used, but in the present invention, nitrocellulose, ethyl cellulose, cellulose acetate, cellulose propionate, and cellulose acetate propionate are used. The cellulose resin, the polyvinyl acetal resin, the cycloolefin resin, and the like are inexpensive, and therefore can be suitably used.

The material of the ultraviolet absorbing layer 22 used in the present invention is preferably such that, in the state in which the pellicle film is applied, the average transmittance of ultraviolet rays in the wavelength range of 350 nm to 450 nm is 90% or more, and the wavelength is 200 nm to 300 nm. The range of ultraviolet rays has an average transmittance of 50% or less, and in particular, it is a material that does not cause deterioration or dust generation under ultraviolet light irradiation. From the above, in the present invention, as described above, it is preferable to use an fluorenone resin which is excellent in light resistance and high in transmittance, and which is excellent in transmittance and short-wavelength ultraviolet rays. Further, since the fluorenone resin before curing can be dissolved in an organic solvent such as toluene or xylene, it is easy to apply and form a film.

The above fluorenone resin used in the present invention is preferably a linear fluorenone resin into which a methyl group or a phenyl group is introduced, or an organic modification in which a polyether, an epoxy group, an amine group, a carbonyl group, an aralkyl group, a fluoroalkyl group or the like is introduced.矽 ketone resin and the like. In the present invention, in consideration of both optical properties and mechanical properties, it is only necessary to select a material having desired properties from the fluorenone resins. Further, as a form of the resin, a form of a resin or a rubber having a desired film strength and flexibility is preferable. In the present invention, the curing mechanism of the fluorenone resin or the rubber is not particularly limited, and may be any of a heat curing type, a two-liquid curing type, and an addition reaction type.

In the present invention, the dust-proof film 15 of the present invention is disposed such that the exposed light passes through the ultraviolet absorbing layer 22 before reaching the raw material pellicle film 21, that is, the ultraviolet absorbing layer is located on the incident side of the light. However, in the case of the ultraviolet absorbing layer having the antireflection layer 23, the ultraviolet absorbing layer 22 may be further provided on the emission side (not shown).

In the present invention, as shown in FIG. 3, in addition to the ultraviolet absorbing layer 22, the antireflection layer 23 may be further provided. In the embodiment of Fig. 3, the anti-reflection layer 23 is provided on the surface of the raw material pellicle 21 opposite to the surface on which the ultraviolet absorbing layer 22 is provided, but an anti-reflection layer may be further provided on the ultraviolet absorbing layer 22. Instead of or in addition to the above, an anti-reflection layer is further provided on the ultraviolet absorbing layer 22. Further, depending on the refractive index of the ultraviolet absorbing layer 22, an antireflection layer may be provided between the ultraviolet absorbing layer 22 and the raw material dustproof film 21. The pellicle film 15 of the present invention includes all of these modes.

The material of the antireflection layer can be suitably selected from known materials having a refractive index lower than that of the adjacent layers. For example, in the case of being provided on the surface of the raw material dust-proof film including a general cellulose resin, the refractive index of the cellulose resin is about 1.5, and therefore a fluorine-based resin having a refractive index of about 1.3 to 1.35 can be suitably used. Further, the film thickness, the number of layers, and the like may be appropriately designed according to the materials to be used and according to a known technique.

For the above reasons, if the refractive index of the ultraviolet absorbing layer 22 is 1.5 or less, the ultraviolet absorbing layer 22 can function as an antireflection layer, and thus the antireflection layer can be omitted, as shown in FIG. In the same way, in addition to the anti-reflection layer, it is ultraviolet from the incident side of the light. Line absorbing layer (and anti-reflective layer) → raw material dust-proof film → three layers of the anti-reflective layer. In this configuration, the number of film formations is large, which is disadvantageous in terms of cost, but an effect of excellent light resistance and high transmittance can be obtained. In particular, the fluorenone resin developed for optical use has a refractive index of 1.40 to 1.50, and can be suitably used.

Further, the film thickness of the ultraviolet absorbing layer 22 is determined not only by the thickness of the antireflection layer but also by the ultraviolet ray transmission property. From the wavelength-light transmittance characteristics of the raw material, the average light transmittance in the wavelength range of 350 nm to 450 nm is 90% or more, preferably as high as possible, and must be in the wavelength range of 200 nm to 300 nm. In consideration of the average light transmittance in the range of 50% or less, the film thickness of the ultraviolet absorbing layer 22 is determined.

Hereinafter, a method of producing the pellicle film of the present invention will be described in detail.

The pellicle film of the present invention can be obtained by substantially forming a film of a material of the ultraviolet absorbing layer coated on the surface of the raw material pellicle film formed on the smooth substrate. In the case of the three-layer structure of the ultraviolet absorbing layer-material pellicle-antireflection layer of the embodiment shown in FIG. 3, first, a smooth-polished substrate such as soda glass, quartz glass, or ruthenium wafer is used. The solution of the ultraviolet absorbing material is applied by a known means such as a spin coating method, a slit and spin method, or a slit coating method, dried, and cured to obtain an ultraviolet absorbing layer 22. The film thickness is determined by the design of the transmittance. Next, a solution of the raw material pellicle material is applied to the film-formed ultraviolet absorbing layer 22 by optical design, and dried and solidified to obtain a raw material pellicle film 21. Similarly The solution of the reflective material is applied onto the raw material dustproof film to be dried and solidified, and the antireflection layer 23 is further provided on the raw material dustproof film formed as described above.

The various film formations described above may be carried out in accordance with the structural design of the pellicle film of the present invention, without any limitation. Here, the film formation method of the ultraviolet absorbing layer of the base will be described. However, the antireflection layer may be the lowermost layer, the upper layer may be formed into a film of the raw material, and the film of the ultraviolet absorbing layer may be formed on the raw material dustproof film. This order may be reversed depending on the state of the step, but it is preferable to use a layer having high peeling property with the film formation substrate as the lowermost layer (= film formation substrate side). Further, a surface treatment for improving the peeling property may be performed on the surface of the film formation substrate as needed.

As described above, the cured pellicle film 15 of the present invention is obtained on the film formation substrate, and then adhered to a frame-shaped peeling jig (not shown) having the same outer shape as the outer shape of the substrate, and is slowly pulled up and peeled off. Thus, the pellicle film of the present invention having an ultraviolet absorbing layer can be obtained.

Further, the dust-proof film of the present invention can be obtained by attaching the dust-proof film of the present invention thus obtained to the pellicle frame to which the adhesive layer is applied.

Hereinafter, the present invention will be further described by way of examples, but the invention is not limited thereto.

[Example 1]

The A5052 aluminum alloy pellicle frame 41 of the shape shown in Fig. 4 was produced by machining. The pellicle frame 41 has a shape in which the outer dimensions of the corner portions are 1146 mm x 1392 mm, the inner dimensions of the corner portions are 1124 mm x 1370 mm, and the thickness is 5.8 mm. The inside of the shape is R2 and the outside is R6. Further, four jig holes 43 having a diameter of 2.5 mm and a depth of 2 mm were provided on the long side for processing, and grooves 42 having a height of 2 mm and a depth of 3 mm were provided at two places on the short side and the long side. Further, eight vent holes 46 having a diameter of 1.5 mm were provided on the two long sides.

The pellicle frame is transported to a Class 10 clean room, which is well washed with a surfactant and pure water and allowed to dry. Then, an anthracene sulphide layer is disposed on one end surface of the pellicle frame as a pellicle film adhesion layer 45, and an oxime ketone adhesive (trade name is KR3700, manufactured by Shin-Etsu Chemical Co., Ltd.) is diluted on the other end surface by toluene. The film is applied as a mask adhesive layer 44 by an air pressure type dispenser, and is heated and hardened. Then, the filter 47 is attached so as to cover the vent hole 46 on the side surface of the pellicle frame 41. Finally, a release agent was applied to the surface, and a PET film having a thickness of 150 μm was cut into a shape similar to that of the pellicle frame by a cutting plotter, and a release sheet for protecting the adhesive layer of the mask was attached. (not shown), so the frame is partially completed.

In addition, a raw material dust-proof film material solution obtained by diluting cellulose propionate (manufactured by Sigma-Aldrich) with butyl acetate on a film-formed substrate made of 1200 mm × 1500 mm × 17 mm thick, was coated with a slit. The coating method is applied. The coating amount at this time was set so that the film thickness after drying became 4.0 micrometer. This was allowed to stand for 1 hour, and the solvent was naturally dried to some extent, and then heated to 130 ° C by an IR lamp (not shown) to form a raw material dust-proof film.

Then, on the raw material pellicle film, an addition hardening type is carried out. Ketone rubber (trade name: KER-2500, manufactured by Shin-Etsu Chemical Co., Ltd.) A liquid and B liquid were well mixed, and the viscosity was adjusted with toluene, and then applied as a UV absorbing layer by a slit coating method. At this time, the film thickness was adjusted so that the film thickness after drying became 1 μm. Thereafter, the surface was allowed to stand horizontally for 2 hours to smooth the surface, and the toluene used for the dilution was evaporated, further heated by an IR lamp at 100 ° C for 1 hour, and then heated at 150 ° C for 5 hours to completely react. And hardened. The ultraviolet absorbing layer had a refractive index of 1.41. The frame-shaped stainless steel peeling jig which has the same shape as the outer shape of the substrate is then cooled to the ultraviolet absorbing layer, and is slowly pulled up while removing electricity to obtain a release film as the pellicle film of the present invention.

Then, the ultraviolet absorbing layer is disposed toward the back side of the pellicle film, and the pellicle film 48 of the present invention having the ultraviolet absorbing layer is placed on the adhesive layer 45 of the pellicle frame 41 as described above, and the pellicle frame is placed. The unnecessary film around the 41 is cut and removed with a cutter, and the pellicle assembly 40 of the present invention is completed.

In the obtained pellicle film of the present invention, the light transmittance of the pellicle film was measured using a transmittance measuring machine (manufactured by Otsuka Electronics Co., Ltd.), and as a result, an average of 95.2% of the entire wavelength range of 350 nm to 450 nm was transmitted. rate. On the other hand, in the wavelength range of 200 nm to 300 nm, the average value of the transmittance is about 48%.

Further, the obtained pellicle of the present invention was irradiated with a high-pressure mercury lamp to confirm light resistance. The high-pressure mercury lamp (manufactured by Oxtail Motor Co., Ltd.) is arranged such that the light passes through the ultraviolet absorbing layer → the pellicle film, and the surface of the pellicle film is irradiated with ultraviolet light having a light intensity of 5000 mW/cm ² so that the light in the above wavelength range The transmittance, the change in film thickness, and the appearance were confirmed. As a result, even when the experiment was carried out until the cumulative energy was 600,000 J, no change was observed in the light transmittance, the film thickness, and the appearance of the irradiated portion.

[Embodiment 2]

An A5052 aluminum alloy pellicle frame having an outer dimension of 280 mm × 280 mm, an inner dimension of 270 mm × 280 mm, and a height of 4.8 mm was produced in the same manner as in Example 1. The surfactant was cleaned in a clean room of 10 stages using a surfactant and pure water. Wash and let it dry completely. Thereafter, an anthrone adhesive (trade name: X-40-3004A, manufactured by Shin-Etsu Chemical Co., Ltd.) was used as an adhesive layer for attaching to the photomask on one end surface, and an anthrone adhesive was coated on the other end surface. (trade name: KR3700, manufactured by Shin-Etsu Chemical Co., Ltd.) As an adhesive for adhering the pellicle film of the present invention, it is cured by oven heating. Then, a release sheet obtained by applying a fluorine-modified fluorenone to a PET film having a thickness of 150 μm was cut into a frame shape having substantially the same shape as the outer dimension of the frame, and attached to the adhesive layer.

Then, a quartz substrate of 350 mm x 350 mm x 8 mm thick which was smooth-polished and well-cleaned was used, and a fluorine-based solvent (trade name: EF-L174, manufactured by Mitsubishi Materials Co., Ltd.) was spin-coated. A diluted fluororesin (trade name: CYTOP, manufactured by Asahi Glass Co., Ltd.) was applied onto a quartz substrate. The film thickness at this time was adjusted so that it would become 0.07 micrometer after drying. After the application, the film-forming substrate was dried while the solvent was hard to flow while being horizontal, and then heated to 180 ° C with a hot plate to completely remove the solvent.

Next, cellulose propionate (manufactured by Sigma-Aldrich) was treated with butyl acetate. The ester was diluted and coated on the upper surface of the above fluororesin layer by a spin coating method. The film thickness at this time was adjusted so that the cellulose resin layer after drying became 4 micrometers. After the application, the film-forming substrate was also kept horizontal until the solvent was hard to flow, and then heated to 130 ° C with a hot plate to completely remove the solvent.

Next, the liquid A and the liquid B of the organically modified fluorenone resin (trade name: SCR1011, manufactured by Shin-Etsu Chemical Co., Ltd.) were well mixed, and a solution obtained by adjusting the viscosity with toluene by a spin coating method was applied. Comes as an ultraviolet absorbing layer. At this time, the film thickness was adjusted so as to become 1 μm after drying. Thereafter, the mixture was allowed to stand horizontally for 2 hours while the surface was leveled, and the diluted toluene was evaporated, and further heated at 70 ° C for 1 hour using an IR lamp, and then heated at 150 ° C for 5 hours to complete it. It hardens by reaction. Further, the ultraviolet absorbing layer has a refractive index of about 1.5.

After the ultraviolet ray absorbing layer is cured, the whole is cooled to room temperature, and then an aluminum alloy frame having the same shape as the outer shape of the substrate is gradually peeled off while being electrically removed to obtain a dust-proof film of the present invention. The ultraviolet absorbing layer of the obtained pellicle film of the present invention is applied to the adhesive layer in the adhesive layer, and the pellicle film on the outer side of the frame is cut and removed by the dicing blade to obtain the pellicle film of the present invention. The light-transmitting rate of the pellicle film of the pellicle film was measured using a transmittance measuring machine (manufactured by Otsuka Electronics Co., Ltd.), and as a result, the average transmittance in the wavelength range of 350 nm to 450 nm was 95.0%, and the wavelength range of 200 nm to 300 nm was approximately It is 35%.

[Comparative example]

Use the same protection as the pellicle frame used in Example 1. A dust film assembly frame for making a dustproof film assembly. As the pellicle film used at this time, a single layer film having a thickness of 4 μm including only the cellulose propionate used in the above Example 1 was used. The method for producing the pellicle film is the same as that of the first embodiment except that the step of forming only the ultraviolet absorbing layer is omitted.

In the pellicle film assembly, the light transmittance of the pellicle film was measured using a transmittance measuring machine (manufactured by Otsuka Electronics Co., Ltd.), and as a result, the average transmittance in the wavelength range of 350 nm to 450 nm was 95.0%. In the same manner as in the case of Example 1, the pellicle was subjected to a light irradiation test, and as a result, when the cumulative energy was 600,000 J, a thin, opaque circular irradiation mark was generated in the irradiation portion. Further, regarding the transmittance, an average transmittance in the wavelength range of 350 nm to 450 nm was observed to be about 2%, and the film thickness was calculated from the measurement spectrum. As a result, it was confirmed that the film thickness of about 40 nm was reduced.

[Industry use possibility]

In the light-shielding film of the present invention, in the use of a film material such as a cellulose resin, a light-resistant film of ultraviolet light having a wavelength of 350 nm to 450 nm is used, and the light resistance is greatly improved. Therefore, the present invention is extremely meaningful in the industry. .

11‧‧‧Plastic membrane assembly frame

12‧‧‧Adhesive layer

13‧‧‧Next layer

14‧‧‧ peeling film

15‧‧‧The pell film of the invention

21‧‧‧Material dustproof film

22‧‧‧UV absorbing layer

23‧‧‧Anti-reflective layer

40‧‧‧The pell film assembly of the present invention

41‧‧‧Plastic membrane assembly frame

42‧‧‧ditch

43‧‧‧Jig hole

44‧‧‧Adhesive layer

45‧‧‧Next layer

46‧‧‧Ventinel

47‧‧‧Filter

48‧‧‧Plastic film of the invention having an ultraviolet absorbing layer

Fig. 1 is a cross-sectional view showing the basic structure of a pellicle according to the present invention.

2 is a cross-sectional view of a pellicle film of the present invention having an ultraviolet absorbing layer.

Fig. 3 is a cross-sectional view showing a pellicle film of the present invention having an antireflection layer in addition to the ultraviolet absorbing layer.

Fig. 4 is a schematic perspective view of a pellicle according to the present invention.

15‧‧‧The pell film of the invention

21‧‧‧Material dustproof film

22‧‧‧UV absorbing layer

Claims (6)

A pellicle film which is a pellicle for a pellicle film assembly used in a photolithography step of irradiating ultraviolet rays in a wavelength range of 350 nm to 450 nm, characterized in that the pellicle film is on the surface of at least the exposure light source side of the raw material pellicle film. An ultraviolet absorbing layer composed of an fluorenone resin; the ultraviolet absorbing layer having an average transmittance of 90% or more in the wavelength range of ultraviolet rays in a wavelength range of 350 nm to 450 nm; and the ultraviolet absorbing layer For ultraviolet rays of 200 nm to 300 nm, the average transmittance in this wavelength range is 50% or less. The pellicle film of claim 1, wherein the anti-reflection layer is further provided on the ultraviolet absorbing layer. The pellicle according to the first or second aspect of the invention, wherein the ultraviolet absorbing layer has a refractive index of 1.50 or less. A method for producing a dust-proof film having an ultraviolet absorbing layer and an anti-reflection layer, wherein three layers of a raw material dust-proof film, an ultraviolet absorbing layer made of an fluorenone resin, and an anti-reflection layer are sequentially disposed on a film formation substrate in an arbitrary order Thereafter, the film-forming substrate is peeled off, and each of the layers is formed by applying a material solution corresponding to each layer, drying and solidifying the layers. A pellicle assembly characterized by being dust-proof by the method of claim 4 The film is attached to the frame of the pellicle. A pellicle film according to any one of claims 1 to 3, which is attached to a pellicle frame.