KR20120111997A - Pellicle film, manufacturing method thereof, and pellicle with pellicle film attached - Google Patents

Abstract

PURPOSE: A pellicle film, a manufacturing method of the same, and a pellicle with the same are provided to improve exposure quality and throughput by being used under higher exposure intensity. CONSTITUTION: A pellicle film(15) for a pellicle which is used for a lithography process irradiating ultraviolet rays of a wavelength range between 350nm and 450 nm. The pellicle film includes an ultraviolet ray absorbent layer(22) on at least the surface of a raw pellicle film toward exposure light source. An anti-reflective layer is further arranged on the ultraviolet ray absorbent layer. A binding resin for the ultraviolet ray absorbent layer is a silicon resin.

Description

PELLICLE FILM, MANUFACTURING METHOD THEREOF, AND PELLICLE WITH PELLICLE FILM ATTACHED}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pellicle used as a dust barrier when manufacturing a semiconductor device, an IC package, a printed board, a liquid crystal display, or an organic EL display, and more particularly, an i-ray (365 nm) and an h-ray 405 as exposure light sources. Pellicle film used in a lithography process using ultraviolet light including any one of nm) and g-rays (436 nm) or a composite thereof, a method for producing the same, and a pellicle having the film attached thereto.

In the manufacture of semiconductors such as LSI and ultra-LSI, circuit boards such as IC packages, printed boards, liquid crystal displays, and organic EL displays, a photoresist is provided on the surface of a semiconductor wafer, a package substrate or a display plate. Lithography is performed by irradiating light through a photomask having a pattern and developing it to produce a pattern. However, if dust adheres to the photomask or reticle (hereinafter simply referred to as photomask) used at this time, the dust Because the light absorbs or refracts the light, the transferred pattern is deformed, the edges are cracked, the base is black, and the size, quality and appearance of the final product are damaged. There was problem to be.

Thus, these operations are usually performed in a clean room, but it is still difficult to keep the photomask clean at all times. Therefore, exposure is performed after a pellicle is affixed on the photomask surface as a dust cover. In this case, foreign matter does not adhere directly to the surface of the photomask, but adheres to the pellicle. When the focus is aligned on the photomask pattern during lithography, the foreign matter on the pellicle becomes irrelevant to transfer.

Generally, a pellicle is produced by attaching or adhering a transparent pellicle film that transmits light well to an upper surface of a pellicle frame made of aluminum, stainless steel, engineering plastic, or the like. In addition, the lower end of the pellicle frame is a pressure-sensitive adhesive layer made of polybutene resin, polyvinyl acetate resin, acrylic resin, hot melt pressure-sensitive adhesive, silicone resin or the like for mounting on a photomask, and, if necessary, for the purpose of protecting the pressure-sensitive adhesive layer. One release layer (separator) is provided.

Further, in the state where the pellicle is attached to the photomask, a small hole for adjusting the air pressure is provided in a part of the pellicle frame for the purpose of eliminating the pressure difference between the space enclosed inside the pellicle and the outside. In order to prevent the intrusion of the foreign material carried in by air, a filter may be provided.

As the pellicle film, an optimum material is selected and used corresponding to the light source used for exposure. For example, when using an ArF laser (193 nm) or KrF laser (248 nm), the fluorine resin which has sufficient transmittance and light resistance with respect to the light of this wavelength is used (patent document 1).

On the other hand, in the case of exposure using i-line (365 nm), h-line (405 nm), and g-line (436 nm), cellulose-based resins such as nitrocellulose, ethyl cellulose and cellulose propionate, polyvinyl acetal resin and cyclo It is possible to use olefin resin etc. (patent document 2, 3, 4). In general, a high pressure mercury lamp or an ultra high pressure mercury lamp is used for these light sources.

The high pressure mercury lamp and the ultrahigh pressure mercury lamp have a broad wavelength characteristic having several peaks between 254 nm and 577 nm. Among them, in the light-emitting amount and the light energy, i-line (365 nm) having the highest intensity, followed by g-line (436-nm) and h-line (405-nm), are preferably used for lithography, and rarely 313 nm. In some cases, light may be used. In addition, in particular, when processing throughput, such as a display manufacture use, places importance on all, the light up to 365 nm-436 nm may be used instead of a specific wavelength alone.

Since the above-mentioned fluorine resin has almost no absorption even in short wavelengths, and can be used for wavelengths of KrF lasers and ArF lasers having high energy at short wavelengths, the wavelengths of i-rays and g-rays, which are lower energy, of course, can be used without any problem. Can be. However, a fluorine resin has the drawback that the cost is very high. Therefore, in general, in the wavelength region of the i-g-g line, in consideration of various characteristics as the pellicle film material, a cellulose resin or the like which is easy to use is often used.

Patent Document 1: Japanese Patent Laid-Open Publication No. 03-39963 Patent Document 2: Japanese Patent Laid-Open Publication No. 01-100549 Patent Document 3: Japanese Patent Laid-Open Publication No. 01-172430 Patent Document 4: Japanese Patent Laid-Open No. 2010-152308 In recent years, in the lithography process, in order to draw a circuit with a finer line width, higher exposure intensity has been calculated | required for the purpose of improving productivity. When the exposure intensity is increased, deterioration by ultraviolet rays of the pellicle film is promoted, and problems such as a decrease in the film thickness, a decrease in the transmittance, and the generation of haze occur. Specifically, the part which was shielded by the chromium (Cr) layer of the photomask does not change at all because the ultraviolet ray does not reach, but in the part without the Cr layer (the part where the pattern is drawn), the ultraviolet ray is directly on the surface of the pellicle film. Because it is irradiated, the membrane of this part is damaged. As described above, when a high-pressure mercury lamp or an ultra-high pressure mercury lamp is used for the exposure light source, the light generated from these light sources includes not only i-line, h-ray, and g-ray used for exposure, but also light having a wavelength other than that. For example, short wavelength light, such as 254 nm, 302 nm, and 313 nm, is contained. Since these short wavelength light, especially 254 nm light is higher energy than the binding energy of the molecule | numerator which comprises a pellicle film | membrane, such as a cellulose resin, the bond is cut | disconnected. Since the molecules whose bonds are cleaved are decomposed and vaporized, the surface of the pellicle film is cut off and the film thickness is reduced. When the film thickness of the pellicle is partially reduced, the optical path length becomes nonuniform, which is not optically desirable, and the surface is roughened to scatter light, so that the transmittance may be lowered. In addition, the film strength decreases, and in more severe cases, the tension applied to the pellicle film becomes uneven, and wrinkles may occur on the surface of the pellicle film. In order to prevent such a problem, what is necessary is just to remove the light of short wavelength which is not used for patterning, such as 254 nm, 302 nm, 313 nm, among the light which arises from an exposure light source. As the method, the filter which removes only these short wavelength light, the mirror which reflects the light other than these short wavelength light, etc. are inserted in the optical path from an exposure light source to a photomask, for example. In addition, you may add the layer which has a filter function similarly to the side which is not the pattern surface of a photomask. These filter functions are applied to methods, such as vapor deposition and sputtering, for the inorganic material which absorbs in the short wavelength area | regions, such as TiO2, ZnO2, CeO2, for example on the opposite side to the pattern surface of a filter substrate, such as quartz glass, or photomask itself. It can obtain by making it adhere. However, this processing cost is not necessarily inexpensive, and since these materials have a high refractive index and a large reflection, there is a problem that the intensity of light used for exposure decreases. Therefore, the correspondence on the pellicle side, rather than the correspondence on the exposure machine and the photomask side, has been demanded. However, it is very difficult to impart the inorganic material onto the pellicle film. This is because it is necessary to store the pellicle film in the vacuum chamber at the time of vapor deposition or sputtering, but large amounts of foreign matter adhere to the pellicle film because large air flows in and out of the vacuum chamber during decompression and recovery to atmospheric pressure. to be. However, the pellicle film cannot be cleaned differently from a glass substrate or the like. Therefore, when foreign matter adheres to the pellicle film for which very high cleanliness is required, the defect immediately becomes defective. For this reason, until now, the pellicle film which consists of inexpensive cellulose resin was used, and the pellicle film which was excellent in the durability with respect to the short wavelength light did not exist. Therefore, it is unavoidable to adopt the method of adding a pellicle film before a problem arises.

Accordingly, a first object of the present invention is to provide an inexpensive pellicle film having high resistance to short wavelength ultraviolet rays such as 254 nm and 313 nm, which is suitable for exposure using i-rays, h-rays, and g-rays.

It is a second object of the present invention to provide a method for producing a low-cost, durable pellicle film used in a lithography process by ultraviolet light in a wavelength range of 350 nm to 450 nm.

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

The said various objective of this invention is a pellicle film for a pellicle used in the lithography process which irradiates an ultraviolet-ray of 350 nm-450 nm wavelength range, The said pellicle film | membrane is an ultraviolet-ray on the surface of the exposure light source side at least in the raw material pellicle film | membrane. An ultraviolet absorbing layer having an absorbing layer, wherein the ultraviolet absorbing layer has an average transmittance of 90% or more for ultraviolet rays in the wavelength region of 350 nm to 450 nm, and an average transmittance of 50% or less for ultraviolet rays in a wavelength region of 200 nm to 300 nm. It was achieved by the pellicle using the pellicle film, its manufacturing method, and the pellicle film characterized by the above-mentioned.

In this invention, it is preferable to further have an antireflection layer on the said ultraviolet absorber layer. Moreover, it is preferable that the said ultraviolet absorber layer is comprised by silicone resin, and it is preferable that the refractive index of an ultraviolet absorber layer is 1.50 or less.

Although the pellicle film of this invention uses the same inexpensive materials as conventionally, such as a cellulose resin, a polyvinyl acetal resin, and a cycloolefin resin, the pellicle film | membrane does not provide the light of 300 nm or less component which exists as an unnecessary component in exposure light. Since the resistance is high, the light resistance is significantly superior to that of the conventional pellicle film. Therefore, it becomes possible to use even higher exposure intensity, and the improvement of exposure quality and the improvement of the throughput are achieved. In addition, since the decrease in the film thickness during use is small, it is possible to prevent troubles such as generation of wrinkles and dark areas, and to maintain the exposure quality for a long time.

1 is a cross-sectional view showing the basic structure of the pellicle of the present invention.
2 is a cross-sectional view of a pellicle film of the present invention having an ultraviolet absorbing layer.
3 is a cross-sectional view of the pellicle film of the present invention further having an antireflection layer in addition to the ultraviolet absorbing layer.
4 is a schematic perspective view of a pellicle of the present invention.

Although the material of the raw material pellicle film which comprises the pellicle film of this invention can be suitably selected from a well-known thing, Cellulose resins, such as nitrocellulose, ethyl cellulose, a cellulose acetate, a cellulose propionate, a cellulose acetate propionate, and polyvinyl The same inexpensive materials as conventional ones, such as acetal resin and cycloolefin resin, can be used. These materials have sufficient resistance in the 350 nm to 450 nm wavelength region used for patterning, but have low resistance to light of short wavelength components of 300 nm or less that exist as unnecessary components in the exposure light, and thus deterioration proceeds. . In this invention, since the arrival of the said short wavelength component to the raw material pellicle film is inhibited by the ultraviolet absorption layer provided in the incidence side surface of a pellicle film | membrane, light resistance is greatly improved.

In particular, the ultraviolet absorbing layer needs to have an average transmittance of 90% or more with respect to ultraviolet rays in a wavelength region of 350 nm to 450 nm, and an average transmittance of 50% or less with ultraviolet rays in a wavelength region of 200 nm to 300 nm. Although the material of such an ultraviolet absorbing layer can be suitably selected from a well-known thing, Especially in this invention, it is preferable to comprise an ultraviolet absorbing layer with a silicone resin. By using a silicone resin as an ultraviolet absorbing layer, unlike an inorganic material, since it can apply | coat and form into a film in the solution melt | dissolved in the solvent, it is possible to manufacture the pellicle film of this invention similarly to the case of manufacturing a normal pellicle film | membrane. In this way, a clean pellicle film of the present invention with less foreign matter can be obtained. Moreover, since silicone resin is excellent in light resistance, there exists an advantage that even if it absorbs an ultraviolet-ray, the degree of deterioration is few.

It is preferable to further provide an antireflection layer in addition to the ultraviolet absorbing layer in the pellicle film of the present invention. The antireflection layer may be prepared in consideration of the material, the film thickness, and the position to be provided according to the refractive index of the ultraviolet absorption layer to be provided. The antireflection layer may be provided in the outermost layer on the incident side of the pellicle film, the outermost layer on the exit side, or both sides thereof. However, depending on the combination of refractive indices, the antireflection layer may be provided in the middle of the ultraviolet absorber layer and the raw material pellicle film. In addition, the material of an antireflection layer is not limited to one type, Combining several things, You may make an antireflection layer into a multilayered structure.

Moreover, in this invention, the refractive index of the said ultraviolet absorbing layer can be 1.50 or less, and can also have a function as an antireflection layer with an ultraviolet absorbing ability.

In the pellicle film of the present invention, the material pellicle film constituting the pellicle film of the present invention, an ultraviolet absorber layer and an antireflection layer, is applied to any one of the material solutions serving as the outermost layer on the film formation substrate, and dried and solidified, and then dried. On the solidified layer, the steps of applying, drying, and solidifying the constituent materials of the respective layers are repeated in the same order, in the order of the desired film structure, and finally, the entire pellicle film formed on the film formation substrate is laminated. It is preferable to manufacture by peeling from a film-forming board | substrate. According to this method, the pellicle film of this invention which has an ultraviolet absorbing layer with little adhesion of a foreign material can be obtained similarly to the manufacturing method of a normal pellicle film.

Since the pellicle film of the present invention has an ultraviolet absorbing layer for absorbing ultraviolet rays in the wavelength range of 200 nm to 300 nm, which is the main cause of deterioration of the raw material pellicle film on the exposure light source side of the pellicle film, the pellicle film does not use an expensive fluorine resin as the raw material pellicle film. Even if it is, it becomes a pellicle film excellent in light resistance. In particular, as described above, when the silicone resin is used as the ultraviolet absorbing layer, since it becomes possible to dissolve in a solvent and apply the ultraviolet absorbing layer, it is preferable to manufacture the pellicle film of the present invention by the same means as in the case of manufacturing a normal pellicle film. It becomes possible to obtain the clean pellicle film | membrane excellent in durability and few foreign substances at low cost.

1 is a cross-sectional view showing the outline of a pellicle of the present invention. In the figure, reference numeral 15 is a pellicle film of the present invention, and is attached with an appropriate tension to the pellicle frame 11 via the adhesive layer 13. Reference numeral 12 denotes an adhesive layer for sticking the pellicle to the photomask during use, and reference numeral 14 denotes a separator for protecting the adhesive layer until use.

FIG. 2 is an enlarged cross-sectional view of a pellicle film A portion in FIG. 1. Reference numeral 21 is a raw material pellicle film, and 22 is an ultraviolet absorber layer. FIG. 3 is an enlarged cross-sectional view of the pellicle film A portion in FIG. 1 similarly to FIG. 2, but in the case of the embodiment having the antireflection layer 23 in addition to the ultraviolet absorbing layer 22.

The pellicle of this invention can be used as a pellicle in all the lithography which uses the ultraviolet-ray of the wavelength range of 350 nm-450 nm, and the use wavelength, use, size, etc. are not restrict | limited. The material of the pellicle frame 11 to which the pellicle film of the present invention is applied can be appropriately selected from materials used for known pellicle frames, such as engineering plastics, steel, stainless steel, aluminum alloys, titanium and alloys thereof, and CFRP.

The material of the raw material pellicle film 21 used for the pellicle film 15 of the present invention can be appropriately selected from known pellicle film materials, and an expensive material having excellent light resistance to light of 350 nm or less, such as a fluorine resin In the present invention, cellulose resins such as nitrocellulose, ethyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate propionate, polyvinyl acetal resin, cycloolefin resin and the like are inexpensive. It is suitably used.

The material of the ultraviolet absorbing layer 22 used for this invention is 90% or more of the average transmittance | permeability with respect to the ultraviolet-ray in the wavelength range of 350 nm-450 nm in the state apply | coated to the pellicle film, and the wavelength of 200 nm-300 nm. It is preferable that it is comprised from the organic substance whose average transmittance | permeability with respect to the ultraviolet-ray of an area | region is 50% or less, and it needs to be a material which does not produce the problem of deterioration and dust generation especially by irradiation of an ultraviolet-ray. In view of the above, in the present invention, as described above, it is preferable to use a silicone resin having high transparency, excellent transmittance, and excellent light resistance even under short-wavelength ultraviolet irradiation. Moreover, since silicone resin before hardening is melt | dissolved in organic solvents, such as toluene and xylene, since it can apply | coat and make into a film form, it is stable fit.

As said silicone resin used by this invention, the straight silicone resin which introduce | transduced the methyl group and the phenyl group, or the organic modified silicone resin which introduce | transduced polyether, epoxy, amine, carbonyl group, aralkyl group, fluoroalkyl group, etc. is preferable. In this invention, what is necessary is just to examine from both surfaces of an optical characteristic and a mechanical characteristic among these, and to select the thing of a desired characteristic. Moreover, as a form of resin, forms, such as resin and rubber | gum which are solid and have desired film strength and flexibility, are preferable. In the present invention, the curing mechanism of these silicone resins and rubbers is not particularly limited, and any of heat curing type, two-component curing type and addition reaction type may be used.

In the present invention, the pellicle film 15 of the present invention is disposed so that the light of exposure 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 which also serves as the antireflection film 23, the ultraviolet absorbing layer 22 may be provided on the emission side so as to overlap (not shown).

In the present invention, as shown in FIG. 3, in addition to the ultraviolet absorbing layer 22, an 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 film 21 on the opposite side to the surface on which the ultraviolet absorption layer 22 is provided, but instead of or on the ultraviolet absorption layer 22. An antireflection layer may be further provided. In addition, depending on the refractive index of the ultraviolet absorbing layer 22, it is also possible to provide an antireflection layer in the middle of the ultraviolet absorbing layer 22 and the raw material pellicle film 21. The pellicle film 15 of this invention contains all these aspects.

The material of the antireflection layer can be appropriately selected from known materials having a refractive index lower than that of the adjacent layers. For example, when providing in the surface of the raw material pellicle film | membrane which consists of general cellulose resin, since the refractive index of a cellulose resin is about 1.5, the fluorine-type resin whose refractive index is about 1.3-1.35 can be used suitably. In addition, what is necessary is just to design a film thickness, the number of layers, etc. suitably according to a well-known technique according to the material to be used.

For this reason, when the refractive index of the ultraviolet absorbing layer 22 is 1.5 or less, the ultraviolet absorbing layer 22 can also function as an antireflection layer. Accordingly, the antireflection layer itself may be omitted, and as in the embodiment shown in FIG. 3, an antireflection layer is added, and from the incident side of the light, to the three layers of the ultraviolet absorption layer (and antireflection layer) → raw material pellicle film → antireflection layer You may be. In this configuration, although the number of film formations is large, it is disadvantageous in terms of cost, but the effect of excellent light resistance and high transmittance can be obtained. In particular, silicone resins developed for optical applications often have a refractive index of 1.40 to 1.50 and can be suitably used.

In addition, the film thickness of the ultraviolet absorbing layer 22 should be determined with an emphasis on ultraviolet ray transmitting characteristics than in the case of the film thickness design of the antireflection layer. From the wavelength-light transmittance characteristics of the raw materials, the average light transmittance in the range of 350 nm to 450 nm is 90% or more, preferably 200 nm to 300 nm, so as to be as high as possible. In the range of the wavelength region, it is necessary to consider the average light transmittance to be 50% or less, and determine the film thickness of the ultraviolet absorbing layer 22.

Next, the manufacturing method of the pellicle film of this invention is demonstrated in detail.

Basically, the pellicle film of this invention can be obtained by apply | coating and forming into a film the material solution of an ultraviolet absorbing layer on the surface of the raw material pellicle film formed on the smooth substrate. Referring to the case where the three-layer structure of the ultraviolet absorbing layer-raw material pellicle film-antireflection film, which is the embodiment shown in FIG. 3, is described, first, ultraviolet rays on a smoothly polished substrate such as soda glass, quartz glass, silicon wafer, etc. The solution of the absorber is applied and dried in accordance with known means such as spin coating, slit and spin, and slit coating, and solidified to obtain the ultraviolet absorbing layer 22. The film thickness is designed and determined from the transmittance. Next, a solution of the raw material pellicle film material is applied onto the formed ultraviolet absorbing layer 22 according to the optical design, and dried and solidified to obtain the raw material pellicle film 21. In the same manner, a solution of the antireflection material is applied onto the raw material pellicle film, dried and solidified, and an antireflection layer 23 is further provided on the formed raw material pellicle film.

Each said film-forming may be performed according to the structural design of the pellicle film of this invention, and is not limited at all. Here, although the aspect which formed the ultraviolet absorbing layer into the base was demonstrated, you may make an antireflection layer into a lower layer, and form a raw material pellicle film on the upper layer, and may further form an ultraviolet absorbing layer on this raw material pellicle film. Although this order may employ | adopt the reverse order of normal order for the convenience of a process, it is preferable to make the layer with high peelability from a film-forming board | substrate into the lowest layer (= film-forming board | substrate side). In addition, you may perform the surface treatment which improves peelability on the film-forming board surface as needed.

As described above, after obtaining the pellicle film 15 of the present invention that has been solidified on the film formation substrate, a frame-like release jig (not shown) having the same appearance as the substrate appearance is adhered, and when the film is slowly pulled up and peeled off, the ultraviolet rays The pellicle film of this invention which has an absorption layer can be obtained.

Moreover, the pellicle of this invention can be obtained when the pellicle film of this invention obtained in this way is adhere | attached on the pellicle frame provided with the contact bonding layer.

Hereinafter, although an Example further demonstrates this invention, this invention is not limited at all by this.

Example 1

A pellicle frame 41 made of A5052 aluminum alloy having a shape as shown in FIG. 4 was manufactured by machining. The shape of this pellicle frame 41 is a rectangle whose outer dimensions are 1146 × 1392 mm and the inner dimensions of each part are 1124 × 1370 mm, the thickness is 5.8 mm, and the shape of each part is inside. This R2 and the outside were R6. Further, the long side is provided with recessed holes 43 having a diameter of 2.5 mm and a depth of 2 mm in four parts for handling, and the grooves 42 having a height of 2 mm and a depth of 3 mm are formed in two parts of the short side and the long side. Prepared. Moreover, the ventilation hole 46 of diameter 1.5mm was provided in 8 parts in both long sides.

This pellicle frame was brought into a clean room of class 10, washed well with a surfactant and pure water, and dried. Subsequently, a silicone adhesive (all brand name KR3700, manufactured by Shin-Etsu Chemical Co., Ltd.) as a pellicle film adhesive layer 45 on one end face of the pellicle frame and a mask adhesive layer 44 on the other end face of toluene. It diluted with and apply | coated using the air pressurized dispenser, and it heated and hardened | cured. Subsequently, the filter 47 was attached so as to cover the vent hole 46 on the side of the pellicle frame 41. Finally, a 150-micrometer-thick PET film with a release agent applied to the surface is cut and manufactured in the same shape as a pellicle frame by a cutting plotter, and a mask adhesive layer protective separator (not shown) is attached to complete the frame portion. I was.

Separately, the raw material pellicle film material solution obtained by diluting cellulose propionate (manufactured by Sigma-Aldrich) with butyl acetate was subjected to a slit coat method on a film substrate made of smoothly polished quartz having a thickness of 1200 x 1500 mm x 17 mm. Applied. The coating amount at this time was set so that the film thickness after drying might be 4.0 micrometers. After standing still for 1 hour, the solvent was naturally dried to some extent, and then heated to 130 ° C. with an IR lamp (not shown) to form a raw material pellicle film.

Next, on this raw material pellicle film, addition curing type silicone rubber (brand name KER-2500, Shin-Etsu Chemical Co., Ltd.) A, B liquid is mixed well as an ultraviolet absorbing layer, and after adjusting a viscosity with toluene, a slit coat is carried out. It was applied according to the law. At this time, the film thickness was adjusted to 1 micrometer after drying. Thereafter, the mixture was left to stand horizontally for 2 hours to smooth the surface, and toluene used for dilution was evaporated, and further heated at 100 ° C for 1 hour using an IR lamp, followed by heating at 150 ° C for 5 hours, and completely reacted and cured. I was. The refractive index of this ultraviolet absorbing layer was 1.41. The whole was cooled to room temperature, the frame-type stainless steel peeling jig of the same form as the board | substrate exterior was adhere | attached on an ultraviolet absorbing layer, and it pulled up slowly with static elimination, and obtained the pellicle film of this invention as a peeling film.

Subsequently, the ultraviolet absorbing layer is disposed so as to face the pellicle film adhesive layer side, the pellicle film 48 of the present invention having the ultraviolet absorbing layer is adhered to the adhesive layer 45 of the pellicle frame 41, and the pellicle frame 41 is provided. The unnecessary film around was cut and removed with the cutter knife, and the pellicle 40 of this invention was completed.

About the obtained pellicle of the present invention, the light transmittance of the pellicle film was measured using a transmittance measuring instrument (manufactured by Otsuka Denshi Co., Ltd.), and the average transmittance was 95.2% in the entire wavelength range of 350 nm to 450 nm. It was. On the other hand, in the wavelength range of 200 nm-300 nm, the average value of the transmittance | permeability was about 48%.

Moreover, about the obtained pellicle of this invention, the high pressure mercury lamp was irradiated and the light resistance was confirmed. A high-pressure mercury lamp (manufactured by Ushio Denki Co., Ltd.) is disposed so that light passes in the order of the ultraviolet absorbing layer to the pellicle film, and the ultraviolet light having a light intensity of 5000 mW / cm 2 is irradiated to the surface of the pellicle film, and thus the light transmittance in the wavelength range. , Change in film thickness and appearance were confirmed. As a result, even when the cumulative energy was tested up to 600,000 J, no change was observed in the light transmittance, the film thickness, and the appearance of the irradiated portion.

[Example 2]

In the same manner as in Example 1, a pellicle frame made of an A5052 aluminum alloy having an outer dimension of 280 × 280, an inner dimension of 270 × 270, and a height of 4.8 mm was prepared and washed well with a surfactant and pure water in a Class 10 clean room. And completely dried. Then, the pellicle film of this invention is made to adhere | attach the pellicle film of a silicone adhesive (brand name: X-40-3004A, Shin-Etsu Chemical Co., Ltd. product) to the cross section of the other side as an adhesive layer for sticking to a photomask on one end surface. A silicone pressure sensitive adhesive (trade name: KR3700, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied as the adhesive for the coating, and the resultant was heated in an oven and cured. Subsequently, the separator which apply | coated fluorine modified silicone to the 150-micrometer-thick PET film was cut | disconnected to the frame shape of the form substantially the same as the frame external dimension, and adhere | attached on the said adhesion layer.

Next, the surface was smoothed and diluted with a fluorine-based solvent (trade name: EF-L174, manufactured by Mitsubishima Material Co., Ltd.) using a 350 x 350 x 8 mm quartz substrate that was well cleaned. A brand name: Saitop, Asahi Glass Co., Ltd.) was apply | coated on the quartz substrate by the spin coat method. The film thickness at this time was adjusted so that it might become 0.07 micrometer after drying. After application, the film formation substrate was kept horizontal, dried until the solvent was not flowing, and then heated to 180 ° C. by a hot plate to completely remove the solvent.

Next, cellulose propionate (manufactured by Sigma-Aldrich) was diluted with butyl acetate and coated on the fluorine resin layer by spin coating. The film thickness at this time was adjusted so that it might become 4 micrometers only by the cellulose resin layer after drying. At this time, after application, the film-forming substrate was kept horizontal, dried until the solvent did not flow, and then heated to 130 ° C. by a hot plate to completely remove the solvent.

Next, as a UV absorbing layer, A liquid and B liquid of organic modified silicone resin (brand name: SCR1011, Shin-Etsu Chemical Co., Ltd. product) were mixed well, and what adjusted the viscosity with toluene was apply | coated by the spin coat method. . At this time, the film thickness was adjusted to 1 micrometer after drying. Thereafter, the surface was left standing horizontally for 2 hours, the surface was leveled, and the diluted toluene was evaporated, and further heated at 70 ° C for 1 hour using the IR lamp, followed by heating at 150 ° C for 5 hours, and completely reacted and cured. In addition, the refractive index of this ultraviolet absorbing layer was about 1.5.

After hardening an ultraviolet-ray absorbing layer, the whole was cooled to room temperature, the aluminum alloy frame of the same form as the board | substrate external appearance was bonded, and it peeled slowly, destaticizing, and obtained the pellicle film of this invention. The ultraviolet absorbing layer of the obtained pellicle film of the present invention was adhered to the adhesive layer toward the adhesive layer, and the pellicle film of the present invention was cut off with a cutter knife to obtain the pellicle of the present invention. About the pellicle film of this pellicle, the light transmittance was measured using the transmittance measuring instrument (made by Otsuka Denshi Co., Ltd.). The average transmittance in the wavelength range of 350 nm-450 nm is 95.0%, 200 nm-300 It was about 35% about the wavelength range of nm.

[Comparative Example]

A pellicle was produced using the same pellicle frame as used in Example 1. As the pellicle film used at this time, a single-layer film having a thickness of 4 µm made of only cellulose propionate used in Example 1 was used. The manufacturing method of this pellicle film was the same as that of Example 1 except only the process of forming a ultraviolet absorbing layer.

About this pellicle, the light transmittance of the pellicle film was measured using the transmittance measuring instrument (made by Otsuka Denshi Co., Ltd.), and the average transmittance in the wavelength range of 350 nm-450 nm was 95.0%. As a result of performing a light irradiation test on this pellicle under the same conditions as in the case of Example 1, when the cumulative energy became 600,000 J, a thin cloudy circular trace of radiation occurred on the irradiation part. In addition, about 2% of the transmittance | permeability was shown by the average transmittance in the wavelength range of 350 nm-450 nm, and when the film thickness was computed from the measurement spectrum, the film thickness reduction of about 40 nm was confirmed.

The pellicle film of the present invention significantly improves light resistance in lithography using an ultraviolet ray having a wavelength of 350 nm to 450 nm, despite the use of an inexpensive film material such as cellulose resin. Do.

11 pellicle frame 12 adhesive layer
13 Adhesive Layer 14 Separator
15 The pellicle film of the present invention with an ultraviolet absorbing layer
21 Raw material pellicle film 22 UV absorbing layer
23 Antireflective Layer 40 Pellicle of the Invention
41 pellicle frame 42 groove
43 depression hole 44 adhesive layer
45 Adhesive Layer 46 Ventilation Holes
47 filters
48 The pellicle film of this invention adhering the ultraviolet absorption layer

Claims (7)

A pellicle film for pellicles used in a lithography step of irradiating ultraviolet light in a wavelength region of 350 nm to 450 nm, wherein the pellicle film has an ultraviolet absorbing layer on at least the surface of an exposure light source side of the raw material pellicle film, and the ultraviolet absorbing layer is The average transmittance in the wavelength range of 90 nm or more with respect to the ultraviolet ray in the wavelength range of 350 nm to 450 nm, and the transmittance for the ultraviolet ray in the range of 200 nm to 300 nm are 50% or less as an average of the wavelength range. A pellicle membrane characterized by the above-mentioned. The pellicle film according to claim 1, further comprising an antireflection layer on the ultraviolet absorbing layer. The pellicle film according to claim 1 or 2, wherein the bonding resin constituting the ultraviolet absorbing layer is a silicone resin. The pellicle film according to claim 1 or 2, wherein a refractive index of the ultraviolet absorbing layer is 1.50 or less. As a manufacturing method of the pellicle film which has an ultraviolet absorber and an antireflection layer which peels the said film-forming board | substrate after providing three layers of a raw material pellicle film, an ultraviolet absorber layer, and an antireflection layer in arbitrary order on a film-forming board | substrate sequentially, Each layer is formed sequentially by apply | coating the material solution corresponding to each layer, and then drying and solidifying this, The manufacturing method of the pellicle film which has an ultraviolet-ray absorption layer and an antireflection layer. A pellicle formed by pasting a pellicle film produced by the method for producing a pellicle film according to claim 5 to a pellicle frame. A pellicle comprising the pellicle film according to claim 1 or 2 attached to a pellicle frame.

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