193nm top coating film for photoetching, and preparation method and application of 193nm top coating film

Abstract

The invention discloses a top coating film for 193nm photoetching as well as a preparation method and application of the top coating film. The top coating liquid comprises the following components in percentage by mass: 1-5% of a polymer and 95-99% of an organic solvent, the polymer is prepared by the following method. The preparation method of the polymer comprises the following steps: in the presence of an initiator, carrying out polymerization reaction on a monomer as shown in a formula (A), a monomer as shown in a formula (B) and a monomer as shown in a formula (C) in an organic solvent to obtain the polyacrylate polymer, in parts by weight, the content of the monomer shown in the formula (A) is 2 to 10 parts, the content of the monomer shown in the formula (B) is 1 to 6 parts, and the content of the monomer shown in the formula (C) is 1 to 3 parts; the top coating film is applied to ArF immersion photoetching, and the problems that the performance of photoresist is reduced and defects are increased can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to a topcoat film for 193nm photolithography, its preparation method and application. BACKGROUND

[0002] Photoresist is a key material in the photolithography process. In the photolithography projection, the patterns on the mask are projected on the photosensitive material, and through photochemical reaction, after baking and developing, the patterns are transferred on the photosensitive material. These patterns act as a barrier layer for the subsequent etching and ion implantation processes.

[0003] The photoresist can transfer the fine patterns on the mask to the substrate through the processes of coating, baking, exposure, development, etching, etc. The shorter the exposure wavelength, the higher the resolution of the photoresist. With the development of exposure wavelength from G line (436nm), I line (365nm), KrF (248nm), ArF (193nm), EUV (13.5nm), the structure of photoresist has also changed. In recent years, Moore's law continues to advance, and semiconductor processes have gradually improved. ArF immersion lithography has become the dominant lithography process for advanced processes, combined with multiple exposure processes, with a resolution of 45-7nm. ArF immersion lithography continues the ArF light source, increases the water medium (the refractive index of water is 1.44) between the photoresist and the lens of the lithography machine, increases the numerical aperture (NA) of the lithography machine, and improves the resolution and depth of focus of the photoresist.

[0004] During the immersion lithography process, there is interaction between the photoresist, the topcoat and the water. Component exchange occurs between the photoresist and the water (water penetrates into the photoresist causing swelling, and small molecules in the photoresist diffuse into the water), which leads to contamination and damage of the water and the lens of the lithography machine, degradation of the performance of the photoresist and an increase in defects. Increasing the hydrophobicity of the film-forming resin of the photoresist and the activation energy of the protecting group helps to inhibit the leaching of small molecules, but the effect is limited. Therefore, forming a water-resistant coating on the surface of the photoresist becomes an effective method for immersion lithography. SUMMARY

[0005] In view of the defects that the interaction between the photoresist, the topcoat and the water during the immersion lithography process leads to contamination and damage of the water and the lens of the lithography machine, and degradation of the performance of the photoresist, the present application provides a polyacrylate polymer, its preparation method and application. The 193nm photolithography topcoat film containing the polyacrylate polymer of the present application has any of the following advantages: better hydrophobicity, higher sliding angle, higher receding contact angle, and faster dissolution speed. In addition, the double-layer resin film containing the polyacrylate polymer of the present application has strong stability and excellent pattern resolution.

[0006] The present application provides a polyacrylate polymer, which is prepared by a preparation method comprising the following steps: polymerizing a monomer as shown in formula (A), a monomer as shown in formula (B), and a monomer as shown in formula (C) in an organic solvent in the presence of an initiator to obtain the polyacrylate polymer.

[0007] wherein the weight fraction of the monomer as shown in formula (A) is 2-10 parts, the weight fraction of the monomer as shown in formula (B) is 1-6 parts, and the weight fraction of the monomer as shown in formula (C) is 1-3 parts, by weight.

[0008]

[0009] In an embodiment of the present application, the weight fraction of the monomer as shown in formula (A) can be 2-10 parts (for example, 2 parts, 4 parts, 5 parts, 8 parts, or 10 parts), by weight.

[0010] In an embodiment of the present application, the weight fraction of the monomer as shown in formula (B) can be 1-6 parts (for example, 1 part, 1.5 parts, 2 parts, 4 parts, or 6 parts), by weight.

[0011] In an embodiment of the present application, the weight fraction of the monomer as shown in formula (C) can be 1-3 parts (for example, 1 part, 1.5 parts, 2 parts, 2.5 parts, or 3 parts), by weight.

[0012] In an embodiment of the present application, the weight average molecular weight (Mw) of the polyacrylate polymer is 7000-13000, preferably 7754, 8862, 9546, 10037, or 12261.

[0013] The organic solvent is a conventional organic solvent in the art. In an embodiment of the present application, the organic solvent is an alkyl ketone solvent, preferably methyl ethyl ketone.

[0014] In an embodiment of the present application, the weight fraction of the organic solvent can be 10-20 parts, preferably 15 parts, by weight.

[0015] The type and amount of the initiator are conventional in the art. In an embodiment of the present application, the initiator is azobisisobutyronitrile.

[0016] In an embodiment of the present application, the weight fraction of the initiator is 0.05-0.3 parts, preferably 0.1 part, by weight.

[0017] The temperature of the polymerization reaction is a conventional temperature for such a reaction in the art. In an embodiment of the present application, the temperature of the polymerization reaction is 60-90°C, such as 70°C.

[0018] In an embodiment of the present application, the time of the polymerization reaction in the polyacrylate polymer is 8-20 hours, such as 12 hours.

[0019] In an embodiment of the present application, the raw materials of the polymerization reaction are the monomer of formula (A) as described above, the monomer of formula (B) as described above, the monomer of formula (C) as described above, the organic solvent as described above, and the initiator as described above.

[0020] In an embodiment of the present application, the polymerization reaction in the polyacrylate polymer further comprises a post-treatment step, and the post-treatment step is preferably cooling, precipitation, and drying;

[0021] Preferably, in the post-treatment step, the organic solvent used in the precipitation is an alkane solvent, such as n-hexane.

[0022] Preferably, in the post-treatment step, the drying is vacuum drying, preferably 50°C vacuum drying for 24 hours.

[0023] In an embodiment of the present application, the polyacrylate polymer is polyacrylate polymers P1 to P5:

[0024] Polyacrylate polymer P1: the weight fraction of the monomer of formula (A) is 2 parts, the weight fraction of the monomer of formula (B) is 1 part, the weight fraction of the monomer of formula (C) is 1 part, the weight fraction of methyl ethyl ketone is 15 parts, and the weight fraction of azobisisobutyronitrile is 0.1 part; the weight average molecular weight of polyacrylate polymer P1 is 7754;

[0025] Polyacrylate polymer P2: the weight fraction of the monomer of formula (A) is 4 parts, the weight fraction of the monomer of formula (B) is 1.5 parts, the weight fraction of the monomer of formula (C) is 1.5 parts, the weight fraction of methyl ethyl ketone is 15 parts, and the weight fraction of azobisisobutyronitrile is 0.1 part; the weight average molecular weight of polyacrylate polymer P2 is 8862;

[0026] Polyacrylate polymer P3: the weight fraction of the monomer of formula (A) is 5 parts, the weight fraction of the monomer of formula (B) is 2 parts, the weight fraction of the monomer of formula (C) is 2 parts, the weight fraction of methyl ethyl ketone is 15 parts, and the weight fraction of azobisisobutyronitrile is 0.1 part; the weight average molecular weight of polyacrylate polymer P3 is 9546;

[0027] The polyacrylate polymer P4: the weight fraction of the monomer represented by formula (A) is 8 parts, the weight fraction of the monomer represented by formula (B) is 4 parts, the weight fraction of the monomer represented by formula (C) is 2.5 parts, the weight fraction of methyl ethyl ketone is 15 parts, and the weight fraction of azobisisobutyronitrile is 0.1 part; the weight average molecular weight of the polyacrylate polymer P4 is 10037;

[0028] The polyacrylate polymer P5: the weight fraction of the monomer represented by formula (A) is 10 parts, the weight fraction of the monomer represented by formula (B) is 6 parts, the weight fraction of the monomer represented by formula (C) is 3 parts, the weight fraction of methyl ethyl ketone is 15 parts, and the weight fraction of azobisisobutyronitrile is 0.1 part; the weight average molecular weight of the polyacrylate polymer P5 is 12261.

[0029] The application further provides a preparation method of the polyacrylate polymer, which comprises the following steps:

[0030] Polymerizing the monomer represented by formula (A), the monomer represented by formula (B), and the monomer represented by formula (C) in an organic solvent in the presence of an initiator to obtain the polyacrylate polymer;

[0031] The weight fraction of the monomer represented by formula (A) is 2-10 parts, the weight fraction of the monomer represented by formula (B) is 1-6 parts, and the weight fraction of the monomer represented by formula (C) is 1-3 parts.

[0032]

[0033] In the preparation method, the weight fractions of the monomers represented by formula (A) to (C), the preparation conditions, the solvent, and the initiator are the same as described above.

[0034] The application further provides a top layer coating liquid, which comprises the following components in mass fraction: 1-5% of the polyacrylate polymer and 95-99% of an organic solvent; % is the mass fraction percentage of each component in the total mass of the top layer coating liquid.

[0035] In an embodiment of the application, in the top layer coating liquid, the organic solvent is an alcohol solvent, preferably 4-methyl-2-pentanol.

[0036] In an embodiment of the application, in the top layer coating liquid, the mass fraction of the organic solvent is 96-99%, for example, 97%.

[0037] In an embodiment of the present application, the mass fraction of the polyacrylate polymer in the top coating liquid is 2-3%, for example, 3%.

[0038] In an embodiment of the present application, the top coating liquid consists of the polyacrylate polymer and the organic solvent, and the types and mass fractions of the polyacrylate polymer and the organic solvent are the same as described above.

[0039] The present application also provides a top coating film comprising the polyacrylate polymer described above.

[0040] In an embodiment of the present application, the top coating film is prepared by the following method: the preparation method of the top coating film comprises the following steps: coating the top coating liquid described above on the surface of a silicon wafer, and drying.

[0041] In an embodiment of the present application, the top coating liquid in the top coating film is preferably filtered by a membrane filter before coating; more preferably, the pore size of the membrane filter is 0.2 μm.

[0042] In an embodiment of the present application, the temperature for drying in the top coating film can be 50-120°C, preferably 80°C.

[0043] In an embodiment of the present application, the time for drying in the top coating film is 50-200 seconds, preferably 90 seconds.

[0044] In an embodiment of the present application, the coating method in the top coating film can be a conventional coating method in the art, for example, spin coating.

[0045] In an embodiment of the present application, the spin coating in the top coating film can be conventional, and preferably, a spinner is used for spin coating at a rotation speed of 1400-1600 rpm, for example, 1500 rpm.

[0046] The present application also provides a preparation method of the top coating film described above, which comprises the following steps: coating the top coating liquid described above on the surface of a silicon wafer, and drying.

[0047] The conditions and operations of the preparation method of the top coating film are the same as described above.

[0048] The present application also provides a double-layer resin film comprising a resist layer and the top coating film layer described above coated on the resist layer.

[0049] The resist film can be a conventional resist film in the art.

[0050] In an embodiment of the present application, the thickness of the double-layer resin film is 175-225 nm, for example, 200 nm.

[0051] In one embodiment of the present application, the top coating film layer has a thickness of 35-60 nm, for example 50 nm.

[0052] In one embodiment of the present application, the resist layer has a thickness of 140-165 nm, for example 150 nm.

[0053] In one embodiment of the present application, the double-layer resin film is composed of the resist layer as described above and the top coating film layer as described above.

[0054] The present application also provides a method for preparing the double-layer resin film as described above, which comprises the following steps: applying a resist solution to the surface of a substrate (silicon wafer) to obtain a resist layer; and applying a top coating solution to the resist layer to obtain the double-layer resin film.

[0055] In one embodiment of the present application, the method for preparing the double-layer resin film comprises the following steps: applying a resist solution to the surface of a silicon wafer and drying.

[0056] In one embodiment of the present application, the resist solution generally comprises a photoresist and a photo-acid generator, wherein the photoresist can be conventional in the art, preferably a positive photoresist, a negative photoresist or a negative tone development photoresist, more preferably a 193 nm positive photoresist (TOK, tai-6990PH).

[0057] In one embodiment of the present application, the photo-acid generator is triphenylsulfonium triflate, which is commercially available from Midori Kagaku Co. Ltd.

[0058] The present application also provides the use of the polyacrylate polymer as described above, the top coating film as described above or the double-layer resin film as described above in ArF immersion lithography.

[0059] The above preferred conditions can be combined in any manner, based on common general knowledge in the art, to obtain preferred embodiments of the present application.

[0060] The reagents and raw materials used in the present application are commercially available.

[0061] The positive progress of the present application is that the polyacrylate polymer provided by the present application can be used to prepare a top coating film with better hydrophobicity, higher sliding angle, higher receding contact angle and faster dissolution speed. In addition, the double-layer resin film containing the polyacrylate polymer of the present application has the advantages of strong stability and excellent pattern resolution. DETAILED DESCRIPTION

[0062] The present application will be further illustrated by the following examples, but the present application is not limited to the examples. The following examples are not specified conditions, the experimental method according to the conventional method and conditions, or according to the instructions for use.

[0063] Preparation method of Example 1

[0064] The gas in a glass flask was replaced with nitrogen three times, and then the monomers A, B, C, azobisisobutyronitrile, and methyl ethyl ketone in the table were added to the glass flask equipped with a condenser. The solution was warmed to 70°C under a nitrogen atmosphere, and stirred for 12 hours. After the reaction was terminated, it was poured into 50 parts of n-hexane and stirred to produce a precipitate, and the precipitate was filtered. The filter cake was dried at 50°C for 24 hours to obtain a white solid polymer, and the molecular weight was calculated by gel permeation chromatography (GPC, standard material: polystyrene).

[0065] polymer monomer a monomer b monomer c methyl ethyl ketone azobisisobutyronitrile M W ]]> P1 2g 1g 1 g 15g 0.1g 7754 P2 4g 1.5g 1.5g 15g 0.1g 8862 P3 5g 2g 2g 15g 0.1g 9546 P4 8g 4g 2.5g 15g 0.1g 10037 P5 10g 6g 3g 15g 0.1g 12261

[0066]

[0067] Preparation of top coat solution and production of top coat film of Example 2

[0068] Each 100 parts by mass (100 g) of the polyacrylate polymers P1 to P5 synthesized in Example 1 was dissolved with 900 parts by mass (900 g) of solvent 4-methyl-2-pentanol (MIBC), and the concentration was adjusted to 3 wt% with 4-methyl-2-pentanol to obtain a uniform and transparent top coat solution.

[0069] Each of the top coat solutions prepared above was filtered with a membrane filter (0.2 μm), and spin-coated onto a silicon wafer (size: 12-inch silicon wafer) using a spinner at a rotation number of 1,500 rpm, and dried on a hot plate at 80°C for 90 seconds to obtain a uniform top coat film of about 50 nm on the silicon wafer.

[0070] Test experiment of Example 3

[0071] Advancing contact angle / receding contact angle evaluation test

[0072] The advancing contact angle and the receding contact angle of a water droplet on the top coat film prepared in Example 2 were measured by the expansion / contraction method using a device CA-X manufactured by Shinto Scientific Instruments Co., Ltd. at 20°C (the results are shown in Table 1).

[0073] Alkaline developer solubility test

[0074] For the top coat film formed on a silicon wafer, the dissolution rate of the top coat film prepared in Example 2 in 2.38 mass% aqueous tetramethylammonium hydroxide solution (alkaline developer) was measured at 20°C using a resist development analyzer RDA-790 (manufactured by LithoTech Japan Corporation) (the results are shown in Table 1).

[0075] Production of resist / top coat double-layer resin film

[0076] After the resist solution (photoresist: tai-6990PH manufactured by TOK, photoacid generator (PAG): triphenylsulfonium triflate manufactured by Midori Kagaku Co., Ltd.) was spin-coated onto a silicon wafer using a spinner, the wafer was dried on a hot plate at 100°C for 90 seconds to form a resist film having a thickness of about 150 nm. After the resist film was spin-coated with the top coat solution filtered using a membrane filter (0.2 μm) using a spinner, the wafer was dried on a hot plate at 80°C for 90 seconds to form a double-layer resin film (double-layer film composed of a resist layer and a top coat layer) having a total thickness of about 200 nm.

[0077] For the double-layer resin film formed on a silicon wafer, the following water immersion treatment and exposure development test were performed.

[0078] Water immersion test

[0079] The 20 silicon wafers each having the double-layer resin film (double-layer film composed of a resist layer and a top coat layer) formed thereon were immersed in 20 mL of pure water at 20°C for 10 minutes, and the extractives were extracted, and the extract was measured by ion chromatography to confirm the presence or absence of the extractives (photoacid generator triphenylsulfonium triflate or its decomposition product). Except for the sample not using the top coat, no peak attributable to the photoacid generator or its decomposition product was detected. By providing the top coat, the dissolution of the resist components in water was suppressed (the results are shown in Table 1).

[0080] Exposure development (pattern formation) test

[0081] The double-layer resin film (double-layer film composed of a resist layer and a top coat layer) silicon wafer formed by prebaking at 80°C for 90 seconds was exposed at 193 nm through a photomask. While the exposed wafer was rotated, pure water was added dropwise for 2 minutes. Then, post-exposure baking was performed at 120°C for 60 seconds, and development was performed using an alkaline developer. As the alkaline developer, 2.38 mass% aqueous tetramethylammonium hydroxide solution was used, and the cross section of the obtained pattern was observed using a scanning electron microscope, and the pattern resolution was represented by the degree of deformation of the rectangle (the results are shown in Table 1).

[0082] The experimental results are shown in Table 1.

[0083] Table 1

[0084]

[0085] Conclusion: The top coat film prepared using the polyacrylate polymer P1-P5 has better hydrophobicity, higher sliding angle, higher receding contact angle, and faster dissolution speed. In addition, the double layer film prepared in the examples has strong stability and excellent pattern resolution. When the double layer resin film of the present application is immersed in pure water, no peak attributed to triphenylsulfonium triflate or its decomposition product is detected. It can be seen that by providing a top coat, the dissolution of the photoacid generator of the resist component in water is inhibited.

Claims

1. A topcoat coating liquid, characterized by, It comprises the following components by mass fraction: 1-5% of polyacrylate polymer and 95-99% of organic solvent; The polyacrylate polymer is prepared by a preparation method comprising the following steps: polymerizing monomer as shown in formula (A), monomer as shown in formula (B) and monomer as shown in formula (C) in an organic solvent in the presence of an initiator to obtain the polyacrylate polymer; The weight fraction of the monomer as shown in formula (A) is 2-10 parts, the weight fraction of the monomer as shown in formula (B) is 1-6 parts, and the weight fraction of the monomer as shown in formula (C) is 1-3 parts; 2. The topcoat fluid of claim 1, wherein It satisfies one or more of the following conditions: (1) In the top layer coating liquid, the organic solvent is an alcohol solvent, preferably 4-methyl-2-pentanol; (2) In the top layer coating liquid, the mass fraction of the polyacrylate polymer is 2-3%, for example 3%; (3) In the top layer coating liquid, the mass fraction of the organic solvent is 96-99%, for example 97%.

3. The topcoat fluid of claim 1, wherein (1) The weight fraction of the monomer as shown in formula (A) is 2-10 parts, for example 2 parts, 4 parts, 5 parts, 8 parts or 10 parts; (2) The weight fraction of the monomer as shown in formula (B) is 1-6 parts, for example 1 part, 1.5 parts, 2 parts, 4 parts or 6 parts; (3) The weight fraction of the monomer as shown in formula (C) is 1-3 parts, for example 1 part, 1.5 parts, 2 parts, 2.5 parts or 3 parts; (4) The weight average molecular weight of the polyacrylate polymer is 7000-13000, preferably 7754, 8862, 9546, 10037 or 12261. (1) In the polymerization reaction, the organic solvent is an alkyl ketone solvent, preferably methyl ethyl ketone; 4. The topcoat fluid of claim 1, wherein (2) In the polymerization reaction, the weight fraction of the organic solvent can be 10-20 parts, preferably 15 parts; (3) In the polymerization reaction, the initiator is azobisisobutyronitrile; (4) In the polymerization reaction, the weight fraction of the initiator is 0.05-0.3 parts, preferably 0.1 parts; (5) The temperature of the polymerization reaction is 60-90°C, for example 70°C; (6) The time of the polymerization reaction is 8-20 hours, for example 12 hours; (7) The raw materials of the polymerization reaction are the monomer as shown in formula (A), the monomer as shown in formula (B), the monomer as shown in formula (C), the initiator and the organic solvent; (8) The polymerization reaction can further comprise a post-treatment step: cooling, precipitation and drying; preferably, the organic solvent used in the precipitation is an alkane solvent, for example n-hexane; further preferably, in the post-treatment, the drying is vacuum drying, preferably 50°C vacuum drying for 24 hours; Preferably, in the top layer coating liquid, the polyacrylate polymer is polyacrylate polymer P1 to P5: ​ ​ Polyacrylate polymer P1: the weight fraction of the monomer represented by formula (A) is 2 parts, the weight fraction of the monomer represented by formula (B) is 1 part, the weight fraction of the monomer represented by formula (C) is 1 part, the weight fraction of methyl ethyl ketone is 15 parts, and the weight fraction of azobisisobutyronitrile is 0.1 part; the weight average molecular weight of polyacrylate polymer P1 is 7754; Polyacrylate polymer P2: the weight fraction of the monomer represented by formula (A) is 4 parts, the weight fraction of the monomer represented by formula (B) is 1.5 parts, the weight fraction of the monomer represented by formula (C) is 1.5 parts, the weight fraction of methyl ethyl ketone is 15 parts, and the weight fraction of azobisisobutyronitrile is 0.1 part; the weight average molecular weight of polyacrylate polymer P2 is 8862; Polyacrylate polymer P3: the weight fraction of the monomer represented by formula (A) is 5 parts, the weight fraction of the monomer represented by formula (B) is 2 parts, the weight fraction of the monomer represented by formula (C) is 2 parts, the weight fraction of methyl ethyl ketone is 15 parts, and the weight fraction of azobisisobutyronitrile is 0.1 part; the weight average molecular weight of polyacrylate polymer P3 is 9546; Polyacrylate polymer P4: the weight fraction of the monomer represented by formula (A) is 8 parts, the weight fraction of the monomer represented by formula (B) is 4 parts, the weight fraction of the monomer represented by formula (C) is 2.5 parts, the weight fraction of methyl ethyl ketone is 15 parts, and the weight fraction of azobisisobutyronitrile is 0.1 part; the weight average molecular weight of polyacrylate polymer P4 is 10037; Polyacrylate polymer P5: the weight fraction of the monomer represented by formula (A) is 10 parts, the weight fraction of the monomer represented by formula (B) is 6 parts, the weight fraction of the monomer represented by formula (C) is 3 parts, the weight fraction of methyl ethyl ketone is 15 parts, and the weight fraction of azobisisobutyronitrile is 0.1 part; the weight average molecular weight of polyacrylate polymer P5 is 12261.

5. The topcoat fluid of claim 1, wherein The top layer coating liquid is composed of the polyacrylate polymer and the organic solvent.

6. The topcoat fluid of claim 5, wherein The top layer coating liquid is composed of 3% of the polyacrylate polymer and 97% of 4-methyl-2-pentanol.

7. A top coat film characterized by, The components thereof include a polyacrylate polymer; the polyacrylate polymer is prepared by a method as follows; the preparation method of the polyacrylate polymer includes the following steps: in the presence of an initiator, a monomer represented by formula (A), a monomer represented by formula (B), and a monomer represented by formula (C) are subjected to a polymerization reaction in an organic solvent to obtain the polyacrylate polymer; The weight fraction of the monomer represented by formula (A) is 2-10 parts, the weight fraction of the monomer represented by formula (B) is 1-6 parts, and the weight fraction of the monomer represented by formula (C) is 1-3 parts; Preferably, the polyacrylate polymer is as claimed in any one of claims 2-5.

8. The topcoat film according to claim 7, wherein The top coating film is prepared by a method comprising the following steps: coating the top coating liquid according to any one of claims 1-5 on the surface of a silicon wafer, and drying; The top coating liquid is preferably filtered using a membrane filter before coating; more preferably, the membrane filter has a pore size of 0.2 μm; The drying temperature can be 50-120°C, preferably 80°C; The drying time can be 50-200 seconds, preferably 90 seconds; (4) The coating method is spin coating; (5) The spin coating is performed using a spinner at a rotation speed of 1400-1600 rpm, for example, at 1500 rpm.

9. A method for producing a top coat film, characterized by It comprises the following steps: coating the top coating liquid according to any one of claims 1-5 on the surface of a silicon wafer, and drying; Preferably, the operation and conditions of the preparation method are the same as those described in claim 8.

10. Use of the top coating film according to claim 7 in ArF immersion lithography.

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