JP2013020235A - Method for manufacturing pellicle support frame, pellicle support frame, and pellicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a pellicle support frame which is sufficiently blackened to be superior in light resistance even under irradiation of high energy light and is capable of suppressing the occurrence of haze, and to provide a pellicle support frame and a pellicle having these characteristics.SOLUTION: In the method for manufacturing a pellicle support frame including an optical thin film material and used as a pellicle, T6 thermal refined steel of an Al-Zn-Mg based alloy is annealed at temperatures of 100 to 400°C, and then, an alkaline aqueous solution including a citric acid is used to subject the T6 thermal refined steel to anodic oxidation treatment to blacken the T6 thermal refined steel by deposition of one or more elements selected from the group consisting of Ni, Co, Cu, Sn, Mn, and Fe due to electrolytic deposition. The pellicle support frame and the pellicle have Lvalues of 40 or less and contain a small amount of acid components.

Description

  The present invention relates to a method for manufacturing a pellicle support frame, a pellicle support frame, and a pellicle. More specifically, the pellicle support frame can reduce the occurrence of haze as much as possible and has excellent light resistance. The present invention relates to a method for manufacturing a pellicle support frame, a pellicle support frame, and a pellicle.

  Manufacturing of thin film transistors (TFTs) and color filters (CFs) used in semiconductor devices such as LSI and VLSI, liquid crystal display devices (LCDs), etc., includes a photolithography process using an exposure device. Usually, dust-proof means called a pellicle is used.

  In general, a pellicle is formed on one side of a support frame made of an aluminum material with a thickness of several millimeters having a shape matched to a photomask or a reticle, and a transparent high layer such as nitrocellulose, cellulose derivative, or fluoropolymer with a thickness of about 10 μm. A molecular film (optical thin film) is stretched and bonded to prevent foreign matter from adhering directly onto a photomask or reticle. In addition, even if foreign matter adheres to the pellicle, since these foreign matter do not form an image on the wafer coated with the photoresist, it is possible to prevent exposure patterns from being short-circuited or disconnected due to the image of the foreign matter. Yield can be improved.

In recent years, with the high integration of semiconductor devices and the like, drawing of a fine circuit pattern with a narrower line width has been required, and KrF excimer laser (wavelength 248 nm), ArF is also used for exposure light used in the photolithography process. Short wavelength light such as excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), etc. is mainly used. These short-wavelength exposure light sources have high output and high light energy, so if inorganic acid such as sulfuric acid or phosphoric acid remains on the anodized film on the surface of the aluminum material that forms the support frame, There is a problem in that a reaction product such as ammonium sulfate is produced by reacting with a basic substance such as ammonia present in the substrate, and this reaction product (haze) causes clouding on the pellicle and affects the pattern transfer image.

  Therefore, the content of inorganic acids such as sulfuric acid and phosphoric acid is reduced by forming an anodized film on the surface of the aluminum material by anodizing using an alkaline aqueous solution containing tartaric acid to obtain a support frame for the pellicle. And the method of preventing generation | occurrence | production of a haze as much as possible also under irradiation of high energy light is proposed (refer patent document 1).

  On the other hand, the support frame for the pellicle needs to be blackened after anodizing the aluminum material in order to prevent reflection of light from the light source and obtain a clear pattern transfer image. A method is known in which an organic dye or the like is infiltrated into a pore to make it black. However, when irradiated with light having a short wavelength and high energy, the organic dye may chemically change and cause a change in color tone or fading. Therefore, Ni, Co, or the like is electrolytically deposited in the pores of the anodized film. A method of blackening has been proposed (see Patent Document 2).

JP 2010-237282 A Japanese Patent No. 3361429

  As described above, since an optical thin film body is stuck to the support frame for pellicle and the state thereof is required to be maintained with high accuracy, JIS A7075 aluminum alloy is usually used. However, even if an Al—Zn—Mg based aluminum alloy such as JIS A7075 is anodized and subjected to electrolytic deposition as described in Patent Document 2, sufficient blackening cannot be achieved. I understand.

  Thus, as a result of intensive studies to solve this problem, the present inventors have further annealed the Al—Zn—Mg based aluminum alloy that has been subjected to T6 tempering treatment under predetermined conditions, so The present inventors have found that a support frame for a pellicle that is sufficiently blackened by electrolytic deposition can be obtained.

  Accordingly, an object of the present invention is to provide a method for manufacturing a support frame for a pellicle that is sufficiently blackened and has excellent light resistance even under irradiation with high energy light, and can suppress the occurrence of haze as much as possible. It is to provide.

  Another object of the present invention is to provide a pellicle support frame and pellicle having the above characteristics.

  That is, the present invention relates to a method for manufacturing a support frame for a pellicle that is used as a pellicle with an optical thin film body, and a T6 tempered material of an Al—Zn—Mg based aluminum alloy at a temperature of 100 to 400 ° C. After annealing, it is anodized using an alkaline aqueous solution containing citric acid, and one or more selected from the group consisting of Ni, Co, Cu, Sn, Mn and Fe are deposited by electrolytic deposition treatment. The method for manufacturing a support frame for a pellicle is characterized in that the support frame for pellicle is blackened.

The present invention also relates to a support frame for a pellicle obtained by the above method, which has an L ^* value of 40 or less and is immersed in pure water at 80 ° C. for 4 hours to measure the ion concentration eluted. In the ion elution test, the elution concentration in 100 ml of pure water per 100 cm ² of the support frame surface area is 0.2 ppm or less acetate ion, 0.06 ppm or less formate ion, 0.01 ppm or less oxalate ion, 0.01 ppm or less sulfate ion A support frame for a pellicle, characterized by having nitrate ions of 0.02 ppm or less, nitrite ions of 0.02 ppm or less, and chlorine ions of 0.02 ppm or less.

  Furthermore, the present invention is a pellicle comprising an optical thin film body on the pellicle support frame.

  In the present invention, a T6 tempered material of an Al—Zn—Mg-based aluminum alloy is used, and preferably a T6 tempered material of an Al—Zn—Mg—Cu-based aluminum alloy is used. Get. Al-Zn-Mg-based aluminum alloy has the strongest strength among aluminum alloys, and provides high dimensional accuracy and prevents deformation and scratches due to external force during use. It is suitable for obtaining a frame. Regarding this aluminum alloy, the chemical components other than the remaining Al are preferably 5.1 to 6.1% by mass of Zn, 2.1 to 2.9% by mass of Mg, and 1.2 to 2.0% by mass of Cu. Furthermore, in addition to Cr, Ti, and B, Fe, Si, Mn, V, Zr, and other elements may be included as impurities. A typical example of such a suitable aluminum alloy is JIS-defined A7075.

  The reason why the T6 tempered material of the Al—Zn—Mg based aluminum alloy is used is that strength is imparted by aging precipitation. That is, conventionally, when manufacturing a support frame for a pellicle, an ingot having a predetermined chemical composition is processed into a frame-like aluminum frame by extrusion or rolling, and subjected to a solution treatment, and then artificial age hardening is performed. A compound containing an alloy element is aged by treatment to impart strength. Accordingly, the T6 tempered material of Al—Zn—Mg aluminum alloy is also used in the present invention. In addition, the process for obtaining this T6 tempered material should just follow the tempering conditions of JISH0001.

In the present invention, the T6 tempered material of the Al—Zn—Mg based aluminum alloy is annealed at a temperature of 100 to 400 ° C., preferably 250 to 300 ° C. If the annealing temperature is less than 100 ° C., a sufficiently blackened support frame cannot be obtained even by the subsequent electrolytic deposition treatment. Conversely, if the annealing temperature exceeds 400 ° C., L ^* The value increases and proceeds in the direction of whitening. Moreover, about the time of annealing, it is good that it is 30 to 120 minutes, and while being able to advance blackening favorably, progress of whitening can be suppressed.

The reason why blackening can be achieved by annealing is not clear, but the alloy elements dissolved in the T6 refining treatment are precipitated again by this heat treatment, and precipitates such as MgZn ₂ contribute to blackening of the support frame. Think of things. This precipitate is taken into the anodic oxide film by anodizing treatment, and some of it is dissolved. However, if the amount of the precipitate increases, the coloring effect by electrolytic deposition is promoted, or the precipitate itself is light. It is presumed that it will appear black after absorbing the water. On the other hand, when the amount of precipitation is small, it is assumed that such an effect cannot be obtained sufficiently and looks bright. That is, if the annealing temperature is less than 100 ° C., the precipitation of the alloy elements is not sufficient. Conversely, if the annealing temperature exceeds 400 ° C., the precipitate becomes coarse and it is difficult to recognize the effect on the anodic oxide film as described above. Moreover, if the temperature becomes too high, the T6 tempered material may be softened.

Here, paying attention to MgZn ₂ that is one of the precipitates, in the present invention, annealing is performed so that the integrated diffraction intensity of MgZn ₂ in the T6 tempered material measured by the X-ray diffraction method becomes 40.0 or more. More preferably, annealing is preferably performed so that the integrated diffraction intensity of MgZn ₂ is 90.0 or more. By annealing so that the integrated diffraction intensity of MgZn ₂ in the T6 tempered material becomes 40.0 or more, the integrated diffraction intensity of MgZn ₂ measured by the X-ray diffraction method after field deposition treatment is 19. A pellicle support frame that is 5 or more and is preferably blackened can be obtained.

  After annealing the T6 tempered material, anodization is performed to form an anodized film on the surface. In the present invention, an alkaline aqueous solution containing citric acid is used as the electrolytic solution without using sulfuric acid which is the largest causative substance of haze.

  Here, citrates such as sodium citrate, potassium citrate, lithium citrate, and ammonium citrate can be suitably used as citric acid. The concentration of citric acid is preferably 20 to 300 g / L, and preferably 50 to 200 g / L. When the concentration of citric acid is lower than 20 g / L, an anodized film is hardly formed. On the other hand, when the concentration is higher than 300 g / L, citrate may be precipitated during anodization at a low temperature. Further, the pH of the alkaline aqueous solution containing citric acid is preferably 12.25 to 13.5, and more preferably 12.5 to 13.0. If the pH is lower than 12.25, the film formation rate is slow, making it difficult to blacken the support frame. Conversely, if the pH is higher than 13.5, the film dissolution rate is increased, and powder blowing may occur. is there.

  When an anodizing treatment is performed using an alkaline aqueous solution containing citric acid as an electrolytic solution, the bath temperature is preferably 0 to 15 ° C, and preferably 5 to 10 ° C. When the bath temperature is lower than 5 ° C, the film formation rate is slow and not efficient. On the other hand, when the bath temperature is higher than 15 ° C, the dissolution rate of the film is high, and it takes time for film formation, and there is a risk of powder blowing. There is. The anodizing voltage is preferably 5 to 100V, and more preferably 15 to 70V. If the voltage is lower than 5V, the film may be weakened. On the other hand, if the voltage is higher than 100V, the area of the pore is reduced, and blackening becomes difficult. Furthermore, the anodization treatment time is preferably 5 to 40 minutes, and preferably 7 to 20 minutes.

  An anodized film having a film thickness of 2 to 9 μm is preferably formed on the surface of the annealed T6 tempered material under these anodizing conditions including the concentration of citric acid and the pH of the alkaline aqueous solution. Is good. If the film thickness of the anodized film is smaller than 2 μm, it may not be sufficiently blackened in the subsequent electrolytic deposition treatment, and exposure light may be scattered. On the other hand, if it is larger than 9 μm, the amount of the acid component taken into the film may be excessive. In the present invention, by using an alkaline aqueous solution containing citric acid, the acid used is generally used as compared with the case where an anodized film is formed using an inorganic acid such as sulfuric acid (usually about 100 to 200 g / L). A predetermined anodic oxide film can be obtained while reducing the amount of.

  After forming the anodic oxide film, one or more selected from the group consisting of Ni, Co, Cu, Sn, Mn and Fe are deposited by electrolytic deposition treatment (secondary electrolysis), and the support frame Is colored black. These metals may be metal salts, oxides, or those present as colloidal particles, but preferably include Ni salts, Co salts, Cu salts, Sn salts, Mn salts, and Fe salts. It is preferable to use an electrolytic deposition bath to which one or more selected from the group is added. More preferable examples include an electrolytic deposition bath containing nickel sulfate and boric acid, an electrolytic deposition bath containing nickel acetate and boric acid, and the like. The electrolytic deposition bath may contain tartaric acid, magnesium oxide, acetic acid and the like for the purpose of preventing precipitation of eluted aluminum and adjusting pH.

  Further, the electrolytic deposition treatment can color the anodized film black according to the conditions of a bath temperature of 15 to 40 ° C., a voltage of 10 to 30 V, and a time of about 1 to 20 minutes. In this electrolytic deposition treatment, a voltage can be applied by a DC power supply or an AC power supply, and preliminary electrolysis may be performed at the start.

After blackening the anodized film by electrolytic deposition, it is preferable to perform sealing treatment. The conditions for the sealing treatment are not particularly limited, and a known method such as using water vapor or a sealing bath can be adopted. In particular, it is possible to contain acid components while eliminating the possibility of contamination with impurities. From the viewpoint of performing, sealing treatment with water vapor is desirable. Regarding the conditions for the sealing treatment with water vapor, for example, the treatment is performed for 12 to 60 minutes at a temperature of 105 to 130 ° C., a relative humidity of 90 to 100% (RH), and a pressure of 0.4 to 2.0 kg / cm ² G. Is good. In addition, after the sealing treatment, it is desirable to clean using, for example, pure water.

  In the present invention, prior to the anodizing treatment, the surface of the Al-Zn-Mg aluminum alloy T6 tempered material is roughened by mechanical means such as blasting or chemical means using an etching solution. Processing may be performed. By performing such roughening treatment in advance and performing anodizing treatment and electrolytic deposition treatment, the support frame becomes a low-reflective black that has been matted.

The support frame for a pellicle obtained by the present invention is sufficiently blackened in combination with the effect of annealing the T6 tempered material of an Al—Zn—Mg aluminum alloy, and has excellent light resistance. A pellicle support frame having an L ^* value of 40 or less, more preferably an L ^* value of 35 or less is obtained. At the same time, the pellicle support frame obtained by the present invention can exhibit the following characteristics in an ion elution test in which the ion concentration is measured by immersing in pure water at 80 ° C. for 4 hours.

That is, at an elution concentration in 100 ml of pure water per 100 cm ^{2 of} the support frame surface area, acetate ion (CH ₃ COO ⁻ ) is 0.2 ppm or less, preferably 0.1 ppm or less, and formate ion (HCOO ⁻ ) is 0. 0.06 ppm or less, preferably 0.03 ppm or less, oxalate ion (C ₂ O ₄ ²⁻ ) is 0.01 ppm or less, preferably less than 0.005 ppm (quantitative limit), and sulfate ion (SO ₄ ²⁻ ) Is 0.01 ppm or less, preferably less than 0.005 ppm (quantitative limit), nitrate ion (NO ₃ ⁻ ) is 0.02 ppm or less, preferably 0.01 ppm or less, and nitrite ion (NO ₂ ⁻ ). Is 0.02 ppm or less, preferably 0.01 ppm or less, and hydrochloric acid ion (Cl ⁻ ) is 0.02 ppm or less, preferably 0.01 ppm or less. These ions are considered to affect the generation of haze, and the haze generation was reduced as much as possible by controlling the elution amount of acetate ion, formate ion, sulfate ion, oxalic acid, and nitrous acid. A pellicle support frame can be obtained. The detection of eluted ions can be performed by ion chromatographic analysis, and detailed measurement conditions are as described in the examples.

The pellicle support frame obtained by the present invention can be used as a pellicle by attaching an optical thin film on one side thereof. There are no particular restrictions on the optical thin film body, and known materials can be used. For example, inorganic materials such as quartz, polymers such as nitrocellulose, polyethylene terephthalate, cellulose esters, polycarbonate, and polymethyl methacrylate are used. It can be illustrated. Further, the optical thin film body may be provided with an antireflection layer made of an inorganic material such as CaF ₂ or a polymer such as polystyrene or Teflon (registered trademark).

  On the other hand, the support frame end surface opposite to the surface on which the optical thin film body is provided is provided with an adhesive body for mounting the pellicle to the photomask or reticle. As the adhesive body, an adhesive material alone or a material in which an adhesive material is applied on both sides of an elastic substrate can be used. Here, examples of the adhesive material include acrylic, rubber-based, vinyl-based, epoxy-based, and silicone-based adhesives, and examples of the highly elastic material serving as a base material include rubber or foam. For example, butyl rubber, foamed polyurethane, foamed polyethylene and the like can be exemplified, but not limited thereto.

According to the present invention, it is possible to obtain a support frame for a pellicle that is sufficiently blackened and has a low acid component content, so that it has excellent light resistance even under irradiation with high energy light, and has a high haze. Generation can be suppressed as much as possible. Moreover, the pellicle support frame obtained by the present invention has high dimensional accuracy, is hardly scratched, has excellent durability, and has a low risk of dust generation. Therefore, when used as a pellicle, it is suitable for photolithography by high energy exposure such as KrF excimer laser, ArF excimer laser, F ₂ excimer laser, etc., and can be used reliably over a long period of time.

  Hereinafter, preferred embodiments of the present invention will be described based on examples and comparative examples.

[Confirmation experiment of blackening by annealing]
In order to confirm the effect of blackening by annealing, a hollow extruded material of JIS A7075 aluminum alloy (JIS A7075-T6) treated with tempering symbol T6 shown in JIS H0001 was heat-treated at the temperature and time shown in Table 1. The obtained samples were subjected to anodizing treatment and electrolytic deposition treatment to obtain an experimental surface-treated aluminum alloy material, and the L ^* value was measured.

In this experiment, the hollow extruded material of JIS A7075-T6 was heat-treated in the air under the conditions shown in Table 1, and then each sample was polished with emery # 600 in order to make the surface state the same. Subsequently, an alkaline aqueous solution (pH = 12.9) in which 50 g / L of sodium citrate dihydrate (Na ₃ (C ₆ H ₅ O ₇ ) · 2H ₂ O) and 4 g / L of sodium hydroxide are dissolved is electrolyzed. The solution was anodized under conditions of a bath temperature of 5 ° C., an electrolysis voltage of 70 V, and an amount of electricity of 7 C / cm ² . Furthermore, electroanalysis in which nickel (II) acetate tetrahydrate ((CH ₃ COO) ₂ Ni · 4H ₂ O) 100 g / L, boric acid 30 g / L, tartaric acid 3 g / L, and magnesium oxide 1 g / L were dissolved. Using a bath (pH = 5.4), constant voltage electrolysis at a bath temperature of 30 ° C. and an AC voltage of 13 V was performed for 6 minutes for electrolytic deposition treatment. Then, after performing sealing treatment for 30 minutes while generating steam at a relative humidity of 100% (RH) of 2.0 kg / cm ² G, temperature and 130 ° C, the brightness index L ^* value by Hunter's color difference formula is measured. did. The results are shown in Table 1.

As can be seen from the above results, it was confirmed that the heat treatment at 100 ° C. to 400 ° C. lowered (blackened) the L ^* value compared to the case of no treatment. In particular, the heat treatment at 200 ° C. to 400 ° C. has a lower L ^* value compared to the case of no treatment, and in particular, 250 ° C. × 60 minutes, 250 ° C. × 120 minutes, 300 ° C. × 30 minutes, and 300 ° C. In the case of x 60 minutes, it turned out that blackening can be remarkable.

In addition, in order to investigate the state of precipitation of MgZn ₂ by annealing of the above experimental surface-treated aluminum alloy material, after heat-treating the hollow extruded material of JIS A7075-T6 (surface without anodizing treatment and electrolytic deposition treatment) The state before the treatment) and the integrated diffraction intensity of the MgZn ₂ peak (diffraction angle 2θ = 19.7 °) were determined by the X-ray diffraction method. In addition, in order to confirm the state of precipitation of MgZn ₂ after the surface treatment subjected to anodizing treatment and electrolytic deposition treatment, the peak of MgZn ₂ (diffraction angle 2θ = 19.7 °) is similarly measured by X-ray diffraction. The integrated diffraction intensity was determined for. Table 2 shows a summary of the relationship between the obtained integrated diffraction intensity and the L ^* value of the experimental surface-treated aluminum alloy material obtained by subjecting the hollow extruded material to anodizing treatment and electrolytic deposition treatment. The X-ray diffraction was performed using a Ragaku X-ray diffractometer RAD-rR with a Bragg-Brentano optical system and a concentration method. Goniometer radius is 185mm, measurement type is 2θ / θ, tube is Kα of Cu, wavelength is 1.54056mm, monochromator is used, tube voltage is 50kV, tube current is 200mA, scanning range is 2θ = 10 ° ~ 70 °, axial feed rate is 1.0 ° / min, data sample width is 0.010 °, inner surface rotation of sample is 80 times / min, slit is diverging slit 1 °, scattering slit 1 °, light receiving slit 0.3 mm The measurement was performed using a scintillation detector under the conditions of a monochrome light receiving slit of 0.3 mm.

[Example 1]
The hollow extruded material of JIS A7075-T6 is cut and polished so that the outer dimensions of the support frame are 149 mm × 122 mm × height 5.8 mm and the support frame thickness is 2 mm, and processed into a frame material shape to form an aluminum frame. Prepared. This was annealed in the atmosphere at a heat treatment temperature of 250 ° C. and a heat treatment time of 120 minutes. Next, the surface of the annealed aluminum frame is shot blasted using stainless steel having an average diameter of about 100 μm, and sodium citrate dihydrate (Na ₃ (C ₆ H ₅ O ₇ ) · 2H ₂ O) 50 g An aluminum frame is used as an anode under the conditions of an alkaline aqueous solution (pH = 12.9) in which 4 g / L of sodium hydroxide is dissolved as an electrolyte, under conditions of a bath temperature of 5 ° C., an electrolysis voltage of 70 V, and an electric charge of 7 C / cm ^2. Oxidized. After washing with pure water, the anodic oxide film formed on the surface of the aluminum frame was confirmed with an eddy current film thickness meter (Fischer Instruments Co., Ltd.). The film thickness was 3.5 μm. It was.

Next, the anodized aluminum frame was added to nickel acetate (II) tetrahydrate ((CH ₃ COO) ₂ Ni · 4H ₂ O) 100 g / L, boric acid 30 g / L, tartaric acid 3 g / L, and magnesium oxide. Using an electrolytic deposition bath (pH = 5.4) in which 1 g / L is dissolved, constant voltage electrolysis at a bath temperature of 30 ° C. and a DC voltage of 13 V is performed for 6 minutes, and electrolytic deposition treatment (secondary electrolysis) is performed to obtain aluminum. Colored frame. After electrolytic deposition, the aluminum frame is put into a steam sealing device, and sealing is performed for 30 minutes while generating water vapor at a relative humidity of 100% (RH), 2.0 kg / cm ² G, and a temperature of 130 ° C., A pellicle support frame according to Example 1 was obtained. Table 3 summarizes some of the conditions employed in Example 1.

The pellicle support frame obtained above was measured for the brightness index L ^* value according to Hunter's color difference formula. The pellicle support frame was put in a polyethylene bag, sealed with 100 ml of pure water, and kept at 80 ° C. for 4 hours. The extracted water from which the components eluted from the support frame were extracted in this manner was set to a cell temperature of 35 ° C. and a column (IonPacAS11-HC) temperature of 40 ° C., and an ion chromatograph analyzer (Nippon Dionex Co., Ltd.) at 1.5 ml / min. Analysis was performed using ICS-2000). From this extracted water, acetate ion, formate ion, hydrochloric acid ion, nitrite ion, nitrate ion, sulfate ion and oxalate ion were detected, and the elution concentration in 100 ml of pure water per 100 cm ^{2 of} the support frame surface area was determined. These results are shown in Table 4. The quantitative limit (lower limit) of the ion chromatograph analyzer used in the examples is 0.005 ppm, and the analysis results shown in Table 4 indicate that neither sulfate ions nor oxalate ions were detected. .

[Example 2]
After processing up to electrolytic coloring as in Example 1, instead of water vapor sealing, the aluminum frame after electrolytic coloring was put into a solution containing 40 ml / L of Hanami Chemical Co., Ltd. Sealing X and sealed at 90 ° C. for 20 minutes. Thereafter, the pellicle support frame according to Example 2 was obtained by washing with pure water. Table 4 shows L ^* values of the pellicle support frame of Example 2 and extraction results.

[Example 3]
A pellicle support frame according to Example 3 was obtained in the same manner as in Example 1 except that the A7075-T6 material was heat-treated at 350 ° C. for 30 minutes. Table 4 shows the L ^* value of the obtained pellicle support frame and the extraction results.

[Comparative Example 1]
A support frame for a pellicle according to Comparative Example 1 was obtained in the same manner as in Example 1 except that annealing was not performed using A7075-T6 material. Table 4 shows the L ^* value of the obtained pellicle support frame and the extraction results.

[Comparative Example 2]
Comparative Example as in Example 2 except that the A7075-T6 material was anodized at 20 V and 10 C / cm ^{2 at} 20 V without annealing and using an A7075-T6 sulfuric acid electrolytic bath. A support frame for a pellicle according to No. 2 was obtained. Table 4 shows the L ^* value of the obtained pellicle support frame and the extraction results.

  The pellicle support frame and pellicle obtained by the present invention can be used in a photolithography process or the like in the manufacture of various semiconductor devices, liquid crystal display devices, etc., and in particular, even in a high energy exposure environment. Demonstrate.

Claims (11)

  A method for manufacturing a support frame for a pellicle that includes an optical thin film body and is used as a pellicle, comprising annealing a T6 tempered material of an Al—Zn—Mg-based aluminum alloy at a temperature of 100 to 400 ° C., and then citric acid And anodizing using an alkaline aqueous solution containing N, Co, Cu, Sn, Mn and Fe, and depositing one or more selected from the group consisting of Ni, Co, and blackening by electrolytic deposition treatment A method for manufacturing a pellicle support frame. Method for manufacturing a pellicle support frame according to claim 1, integrated diffraction intensity of MgZn ₂ in T6 tempered material was measured by X-ray diffractometry is annealed so that the 40.0 or more. The method for producing a support frame for a pellicle according to claim 1 or 2, wherein the integrated diffraction intensity of MgZn ₂ measured by an X-ray diffraction method after blackening by electric field deposition treatment is 19.5 or more.   The manufacturing method of the support frame for pellicles in any one of Claims 1-3 which anneals for 30 to 120 minutes.   The method for producing a support frame for a pellicle according to any one of claims 1 to 4, wherein the alkaline aqueous solution contains 20 to 300 g / L of citric acid and has a pH of 12.25 to 13.5.   The electrolytic deposition bath to which one or more selected from the group consisting of Ni salt, Co salt, Cu salt, Sn salt, Mn salt and Fe salt is added is used for the electrolytic deposition treatment. The manufacturing method of the support frame for pellicles in any one of -5.   The manufacturing method of the support frame for pellicles in any one of Claims 1-6 which roughens the surface of the T6 tempered material of an Al-Zn-Mg type aluminum alloy prior to an anodizing process.   The method for producing a support frame for a pellicle according to any one of claims 1 to 7, wherein the Al-Zn-Mg-based aluminum alloy is a JIS-defined A7075 aluminum alloy.   The manufacturing method of the support frame for pellicles in any one of Claims 1-8 which perform a sealing process with water vapor | steam after an electrolytic deposition process. A pellicle support frame obtained by the method according to any one of claims 1 to 9, wherein the L ^* value is 40 or less, and the ion concentration eluted by immersing in pure water at 80 ° C for 4 hours In the ion elution test for measuring the elution concentration, the elution concentration in 100 ml of pure water per 100 cm ² of the support frame surface area is 0.2 ppm or less acetate ion, 0.06 ppm or less formate ion, 0.01 ppm or less oxalate ion, 0 sulfate ion A support frame for a pellicle, which is 0.01 ppm or less, nitrate ion 0.02 ppm or less, nitrite ion 0.02 ppm or less, and chlorine ion 0.02 ppm or less.   A pellicle comprising the optical thin film body on the pellicle support frame according to claim 10.