JP4970977B2 - Antireflection film forming composition and resist pattern forming method using the same - Google Patents

Description

  The present invention relates to an antireflective film forming composition for forming an antireflective film provided on a resist film, and a resist pattern forming method using such an antireflective film forming composition.

  As is well known, a semiconductor substrate is formed by laminating at least a dielectric layer (insulator layer) on a silicon wafer or the like. Then, by forming a patterned conductor layer (wiring layer) in the dielectric layer of the semiconductor substrate, a semiconductor wiring structure is configured.

  The formation of the wiring layer is performed as follows. First, a conductor layer is uniformly formed on the dielectric layer, and a resist film is formed on the conductor layer. The resist film is irradiated (exposed) with pattern light and developed to form a resist pattern, and the resist layer is used as a mask to pattern the conductor layer by etching to form a wiring layer. Then, after completely removing the resist film, a dielectric layer is further laminated on the conductor layer to form a wiring layer in the dielectric layer.

  In the process of forming the wiring layer, it has been known that a problem of standing wave effect due to multiple interference occurs when the resist film is exposed and patterned. That is, the phenomenon that the exposure light is transmitted through the resist film, the transmitted light is reflected on the lower layer surface, and a part of the reflected light is reflected on the resist upper surface is repeated in the resist film. Then, the single-wavelength irradiation light incident on the resist film formed on the substrate interferes with the reflected light from the substrate, causing variations in the amount of light energy absorbed in the thickness direction of the resist film. This variation affects the resist pattern dimension width obtained after development, resulting in a decrease in resist pattern dimension accuracy.

  This reduction in resist pattern dimensional accuracy is a serious problem, particularly when a fine pattern is formed on a substrate having a step, because the resist film thickness inevitably differs in the uneven portion of the step. Therefore, it is desired to develop a technique that eliminates the above-described interference action and does not reduce the resist pattern dimensional accuracy even in a fine pattern formed on a stepped substrate.

Therefore, conventionally, before forming a resist film on a semiconductor substrate, a method of forming an antireflection film having a property of absorbing exposure light on the substrate and forming a resist film on the antireflection film (for example, Patent Document 1 or the like) and a method of forming an antireflection film made of polysiloxane, polyvinyl alcohol, or the like on a resist film provided on a substrate (for example, Patent Documents 2 and 3).
U.S. Pat. No. 4,910,122 Japanese Examined Patent Publication No. 4-55323 JP-A-3-222409 JP 2005-157259 A

  However, the method of forming the antireflection film on the substrate has a drawback in that when the mask alignment is performed using light having the same wavelength as the exposure light, the mask alignment detection signal is weakened by the antireflection film and the mask alignment becomes difficult. There is. Further, it is necessary to transfer the resist pattern to the antireflection film with high accuracy, and after the transfer, the antireflection film must be removed by etching or the like without affecting the substrate. For this reason, the number of work steps increases, and it is not necessarily applicable to all substrate processing.

  On the other hand, the method of providing an antireflection film on a resist film provided on a substrate does not require a complicated process and is practical.

However, in the method of providing an antireflection film on a resist film provided on a substrate, C ₈ F ₁₇ SO ₃ H (PFOS) is currently used as a fluorosurfactant as a material for forming the antireflection film. ing. This substance is a designated chemical substance in Japan, and is also subject to the Important New Use Regulation (SNUR), which is a US ecological impact-related regulation, so there is a big problem in handling. Specifically, substances that fall under the SNUR regulations may pose unreasonable risks that may damage health or the environment. There is also a restriction on disposal. Therefore, instead of C ₈ F ₁₇ SO ₃ H (PFOS), it contains a fluorosurfactant that has no environmental problems and is easy to handle, and has the same effect as when C ₈ F ₁₇ SO ₃ H (PFOS) is used. There is a demand for a material for forming an antireflection film exhibiting the following.

  Therefore, Patent Document 4 discloses a resist upper layer film forming material containing at least a selectively soluble resin component provided on the resist film and a fluorine carbide compound that can be easily handled.

  However, although the resist upper layer film-forming material described in Patent Document 4 does not use PFOS as a fluorosurfactant, a precipitate is formed when such a fluorosurfactant is used in combination with a commonly used water-soluble film-forming component. There was a problem such as When precipitates are generated in the antireflection film, the resist film is not normally patterned, and improvement of such problems has been demanded.

  The present invention has been made in view of the problems as described above, and is an antireflection film-forming composition used when forming an antireflection film on a resist film, which is easy to handle, An object of the present invention is to provide a composition for forming an antireflection film that does not produce precipitates or the like after formation.

  In the composition for forming an antireflective film, the present inventors use a combination of a predetermined fluorosurfactant and a predetermined water-soluble film-forming component to remove precipitates and the like after the antireflective film is formed. It has been found that it does not occur, and the present invention has been completed.

［上記一般式（１）〜（４）において、ｍは１０〜１５の整数を表し、ｎは１〜５の整数を表し、ｏは２又は３を表し、ｐは２又は３を表し、Ｒ_ｆは水素原子、又は水素原子の一部若しくは全部がフッ素原子により置換されている炭素数１〜１６のアルキル基を表す。当該アルキル基は、水酸基、アルコキシアルキル基、カルボキシル基、又はアミノ基を有していてもよい。］

［上記一般式（５）において、Ｒ^１は水素原子又は炭素数１〜６のアルキル基若しくはヒドロキシアルキル基を表し、ｑは繰り返し単位数を表す。］ A first aspect of the present invention is an antireflective film forming composition for forming an antireflective film provided on a resist film, comprising at least a fluorosurfactant and a water-soluble film forming component. The fluorosurfactant is at least one selected from compounds represented by the following general formulas (1) to (4), and the water-soluble film-forming component is: An antireflection film-forming composition comprising at least the water-soluble resin represented by (5).

[In the general formulas (1) to (4), m represents an integer of 10 to 15, n represents an integer of 1 to 5, o represents 2 or 3, p represents 2 or 3, R _f represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms in which part or all of the hydrogen atoms are substituted with fluorine atoms. The alkyl group may have a hydroxyl group, an alkoxyalkyl group, a carboxyl group, or an amino group. ]

In above general formula (5), R ¹ represents a hydrogen atom or an alkyl or hydroxyalkyl group having 1 to 6 carbon atoms, q represents the number of repeating units. ]

  Moreover, the second aspect of the present invention is a method in which a resist film is formed on a substrate, and an antireflection film is formed on the resist film using the antireflection film forming composition of the present invention. The resist film is selectively irradiated with light through the film, subjected to heat treatment as necessary, and the antireflection film is removed before or during development of the resist film after irradiation. And a resist pattern forming method for obtaining a resist pattern.

  Since the composition for forming an antireflection film of the present invention does not contain a compound such as PFOS, it is easy to handle and does not adversely affect health and the environment. In addition, no deposits or the like are generated even after the antireflection film is formed, so that the resist film patterning is not adversely affected.

  Hereinafter, embodiments of the present invention will be described in detail.

<Antireflection film forming composition>
The composition for forming an antireflective film of the present invention is characterized by containing at least a predetermined fluorosurfactant and a predetermined water-soluble film forming component. Moreover, the composition for forming an antireflection film of the present invention may further contain a nitrogen-containing compound, or may contain a nonionic surfactant or an anionic surfactant.

［上記一般式（１）〜（４）において、ｍは１０〜１５の整数を表し、ｎは１〜５の整数を表し、ｏは２又は３を表し、ｐは２又は３を表し、Ｒ_ｆは水素原子、又は水素原子の一部若しくは全部がフッ素原子により置換されている炭素数１〜１６のアルキル基を表す。当該アルキル基は、水酸基、アルコキシアルキル基、カルボキシル基、又はアミノ基を有していてもよい。］ [Fluorosurfactant]
The fluorosurfactant used for the antireflection film-forming material of the present invention is at least one selected from compounds represented by the following general formulas (1) to (4).

[In the general formulas (1) to (4), m represents an integer of 10 to 15, n represents an integer of 1 to 5, o represents 2 or 3, p represents 2 or 3, R _f represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms in which part or all of the hydrogen atoms are substituted with fluorine atoms. The alkyl group may have a hydroxyl group, an alkoxyalkyl group, a carboxyl group, or an amino group. ]

Here, specifically as a fluorine-type surfactant represented by General formula (1), the compound represented by following Chemical formula (1a) is preferable.

Specifically, the fluorine-based surfactant represented by the general formula (2) is preferably a compound represented by the following chemical formula (2a) or (2b).

Specifically, the fluorine-based surfactant represented by the general formula (3) is preferably a compound represented by the following chemical formula (3a).

Specifically, the fluorine-based surfactant represented by the general formula (4) is preferably a compound represented by the following chemical formula (4a).

When these fluorosurfactants are used, the refractive index of the antireflection film is almost the same as that of the antireflection film using C ₈ F ₁₇ SO ₃ H (PFOS). It is good.

  As content of the said fluorosurfactant used for the composition for antireflection film formation, it is preferable that they are 0.1 mass% or more and 15.0 mass% or less, and 1.0 mass% or more and 3.0 mass%. % Or less is preferable. By containing the fluorosurfactant within the above content range, an antireflection film having excellent antireflection properties and coating properties can be obtained.

［上記一般式（５）において、Ｒ^１は水素原子又は炭素数１〜６のアルキル基若しくはヒドロキシアルキル基を表し、ｑは繰り返し単位数を表す。］ [Water-soluble film forming component]
The water-soluble film-forming component used in the composition for forming an antireflection film of the present invention contains a water-soluble resin represented by the following general formula (5).

In above general formula (5), R ¹ represents a hydrogen atom or an alkyl or hydroxyalkyl group having 1 to 6 carbon atoms, q represents the number of repeating units. ]

Here, as R ¹ , specifically, a methyl group, an ethyl group, and a hydroxyethyl group are preferable.

  By using the water-soluble resin represented by the general formula (5) as the water-soluble film forming component, no precipitates or the like are generated after the formation of the antireflection film even when used in combination with the above-mentioned fluorosurfactant. Therefore, a good resist pattern can be obtained without adversely affecting the patterning of the resist film.

  The water-soluble resin preferably has a mass average molecular weight of 1,000 to 1,000,000, and more preferably 10,000 to 500,000. By setting the mass average molecular weight of the water-soluble resin within the above range, the coating film stability can be improved.

  The composition for forming an antireflective film of the present invention may further contain a water-soluble resin usually used in the composition for forming an antireflective film as a water-soluble film forming component. Specifically, hydroxypropylmethylcellulose phthalate, hydroxypropylmethylcellulose acetate phthalate, hydroxypropylmethylcellulose acetate succinate, hydroxypropylmethylcellulose hexahydrophthalate, hydroxypropylmethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, cellulose acetate hexahydrophthalate, carboxymethylcellulose, Cellulose polymers such as ethyl cellulose and methyl cellulose; polyacrylamide, N, N-dimethylacrylamide, N, N-dimethylaminopropyl methacrylamide, N, N-dimethylaminopropyl acrylamide, N-methylacrylamide, diacetone acrylamide, N, N-dimethyl Acrylic acid polymers using monomers such as aminoethyl methacrylate, N, N-diethylaminoethyl methacrylate, N, N-dimethylaminoethyl acrylate, acryloylmorpholine, and acrylic acid; vinyl alcohols such as polyvinyl alcohol and polyvinylpyrrolidone And polymers; vinylpyrrolidone / acrylic acid copolymer; acrylamide / diacetone acrylamide copolymer; and the like. Among these, acrylic acid polymers and polyvinyl pyrrolidone are suitable.

  The content of the water-soluble resin other than the water-soluble resin represented by the general formula (5) is preferably 20% by mass or less, and preferably 10% by mass or less, with respect to the entire water-soluble film-forming component. Is more preferable.

  The concentration of the entire water-soluble film forming component used in the composition for forming an antireflection film is preferably 0.5% by mass or more and 10.0% by mass or less, and 1.0% by mass or more and 5.0% by mass. More preferably, it is as follows. By setting the concentration of the water-soluble film-forming component within the above range, the coating film stability can be improved.

[Nitrogen-containing compounds]
The composition for forming an antireflection film of the present invention may further contain a nitrogen-containing compound. Suitable nitrogen-containing compounds include, for example, quaternary ammonium hydroxides, alkanolamine compounds, and amino acid derivatives.

  The quaternary ammonium hydroxide includes tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltripropylammonium hydroxide, methyltributylammonium hydroxide. And choline and the like.

  Examples of alkanolamine compounds include 3-amino-1,2-propanediol, 2-amino-1,3-propanediol, triisopropanolamine, triethanolamine, and amino-2-methyl-1,3-propanediol. Can be mentioned.

  Amino acid derivatives include glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, tryptophan, methionine, serine, threonine, cysteine, tyrosine, asparagine, glutamine, aspartic acid, glutamic acid, lysine, arginine, histidine, 4-hydroxyproline. , Desmosine, γ-aminobutyric acid, β-cyanoalanine and the like.

  The above nitrogen-containing compounds may be used alone or in combination of two or more. Of these nitrogen-containing compounds, alkanolamine compounds are preferable, and 3-amino-1,2-propanediol and 2-amino-1,3-propanediol are more preferable.

[Surfactant]
The antireflection film-forming composition of the present invention may further contain a nonionic surfactant or an anionic surfactant in order to improve the coating property.

［上記一般式（６）において、Ｒ^２〜Ｒ^５は、それぞれ独立に炭素数１〜６の直鎖状又は分岐状のアルキル基を表し、Ｒ^６は炭素数２〜４の直鎖状又は分岐状のアルキレン鎖を表し、ｓ及びｔは、それぞれ独立に０〜３０の整数を表す。］ (Nonionic surfactant)
As a nonionic surfactant, the nonionic surfactant represented by General formula (6) can be mentioned, for example.

[In General Formula (6), R ^{2 to} R ⁵ each independently represents a linear or branched alkyl group having 1 to ⁶ carbon atoms, and R ⁶ is a linear or branched group having 2 to 4 carbon atoms, A branched alkylene chain is represented, and s and t each independently represent an integer of 0 to 30. ]

Here, as R < ² > -R < ⁵ >, a methyl group, an ethyl group, and an isopropyl group are preferable. R ⁶ is preferably an ethylene chain, a propylene chain, or a butylene chain. Furthermore, as s and t, integers of 0 to 16 are preferable.

  Specific examples of the nonionic surfactant represented by the general formula (6) include “Surfinol 104 series” and “Surfinol 400 series” manufactured by Air Products. Among these, “Surfinol 104 series” is preferable.

［上記一般式（７）において、Ｒ^７は炭素数７〜２０の直鎖状又は分岐状のアルキル基を表す。当該アルキル基は、水酸基、及び／又はカルボキシル基を有していてもよく、フェニレン基、及び／又は酸素原子によって中断されていてもよい。］ (Anionic surfactant)
As an anionic surfactant, the anionic surfactant represented by General formula (7) can be mentioned, for example.

In above general formula ^(7), R 7 represents a linear or branched alkyl group having 7 to 20 carbon atoms. The alkyl group may have a hydroxyl group and / or a carboxyl group, and may be interrupted by a phenylene group and / or an oxygen atom. ]

Here, as R ⁷ , a linear or branched alkyl group having 8 to 11 carbon atoms is preferable.

  Specific examples of the anionic surfactant represented by the general formula (7) include n-octane sulfonic acid, n-nonane sulfonic acid, n-decane sulfonic acid, and n-undecane sulfonic acid. it can. Among these, n-octanesulfonic acid, n-nonanesulfonic acid, and n-decanesulfonic acid are preferable.

［上記一般式（８）及び（９）において、Ｒ^８及びＲ^９はそれぞれ独立に炭素数１〜２０の直鎖状又は分岐状のアルキル基を表し、ｕ及びｖはそれぞれ独立に１〜５０の整数を表す。］ Moreover, as an anionic surfactant, the anionic surfactant represented by General formula (8) and General formula (9) can be mentioned.

[In the above general formulas (8) and (9), R ⁸ and R ⁹ each independently represent a linear or branched alkyl group having 1 to 20 carbon atoms, and u and v each independently represent 1 to 50. Represents an integer. ]

As R ⁸ and R ⁹ , a linear or branched alkyl group having 1 to 14 carbon atoms is preferable, and specifically, a methyl group, an ethyl group, and a propyl group are preferable. u and v are preferably integers of 3 to 30.

  Specific examples of the anionic surfactants represented by the general formulas (8) and (9) include Softanol 30, Softanol 50, Softanol 70, and Softanol 90 (all manufactured by Nippon Shokubai Co., Ltd.). it can. Among these, softanol 30, softanol 50, and softanol 70 are preferable.

(Surfactant addition amount)
The addition amount of these surfactants is preferably 100 mass ppm or more and 10000 mass ppm or less, and more preferably 500 mass ppm or more and 5000 mass ppm or less with respect to the entire composition for forming an antireflection film. preferable. By making the addition amount of the nonionic surfactant and the anionic surfactant within the above range, the coating property of the composition for forming an antireflection film can be enhanced.

[solvent]
The composition for forming an antireflective film of the present invention is usually used in the form of an aqueous solution, but the solubility of the fluorosurfactant can be improved by containing an alcohol organic solvent such as isopropyl alcohol or trifluoroalcohol. Since it improves and the uniformity of a coating film is improved, you may add an alcohol-type organic solvent as needed. The addition amount of the alcohol-based organic solvent is preferably selected in the range of 15% by mass or less with respect to the total amount of the solvent added to the composition for forming an antireflection film.

<Resist pattern formation method>
In the resist pattern forming method of the present invention, a resist film is formed on a substrate, an antireflection film is formed on the resist film using the antireflection film forming composition of the present invention, and the antireflection film is formed. The resist film is selectively irradiated with light, and if necessary, heat treatment is performed, and the resist film after the irradiation is subjected to the development treatment or before the development treatment, the antireflection film is removed, This is a resist pattern forming method for obtaining a resist pattern.

[Resist composition]
The resist composition that can be used in the resist pattern forming method of the present invention is not particularly limited, and can be arbitrarily selected from those commonly used. Any of a positive type and a negative type can be used arbitrarily, but in particular, those composed of a photosensitive substance and a film-forming substance and easily developed in an aqueous alkaline solution are preferably used.

  Particularly preferred resist compositions are positive and negative resist compositions having required characteristics that can be sufficiently adapted to ultrafine processing. Examples of the positive resist composition include those composed of a composition containing a quinonediazide photosensitive material and a film forming material. In addition, a chemically amplified resist composition whose alkali solubility is increased by the catalytic action of an acid generated by exposure can be given.

  The negative resist composition is not particularly limited, and conventionally known negative resist compositions can be used, but a crosslinking agent and an acid generator used as a negative resist composition for forming a fine pattern can be used. And a chemically amplified negative resist composition comprising the three components of the base polymer can be particularly preferably used.

[Formation of resist film and antireflection film]
In forming the resist film and the antireflection film, first, a resist composition is applied on a substrate of Si, Cu, Au, or the like by a spinner method, and heat treatment is performed to volatilize the solvent. Next, the antireflection film-forming composition of the present invention is applied onto the resist film by a spinner method, and heat treatment is performed to form an antireflection film on the resist film. In addition, the heat treatment at the time of forming the antireflection film is not necessarily required. When a good coating film having excellent uniformity can be obtained only by coating, it is not necessary to heat.

[Exposure / Development, etc.]
After the antireflection film is formed, the resist film is selectively irradiated with actinic rays such as ultraviolet rays and far ultraviolet rays (including excimer laser) through the antireflection film, and then heat treatment is performed as necessary. Then, a development process is performed to form a resist pattern on the substrate.

  The antireflection film has an optimum film thickness for effectively reducing the interference effect of actinic rays, and this optimum film thickness is λ / 4n (where λ is the wavelength of actinic rays used, and n is This is an odd multiple of the refractive index of the antireflection film. For example, an antireflection film having a refractive index of 1.41 is an odd multiple of 77 nm for ultraviolet rays (g-line), an odd multiple of 65 nm for ultraviolet rays (i-line), and a deep ultraviolet (excimer laser). On the other hand, an odd multiple of 44 nm is the optimum film thickness for actinic rays, and is preferably within a range of ± 5 nm of each optimum film thickness.

Further, it is preferable to form this antireflection film on a chemically amplified negative or positive resist film because it has an effect of improving the resist pattern shape in addition to the antireflection effect. Normally, a chemically amplified resist is subjected to the action of organic alkali vapors such as N-methyl-2-pyrrolidone, ammonia, pyridine, and triethylamine present in the atmosphere of a semiconductor production line, so that acid is insufficient on the resist film surface. Therefore, in the case of a negative resist, the upper end of the resist pattern tends to be rounded, and in the case of a positive resist, the resist pattern may be connected in a bowl shape. The effect of improving the shape of the resist pattern is to prevent such a phenomenon and obtain a rectangular resist pattern shape. As described above, the antireflection film can be suitably used as a protective film material for a chemically amplified resist film. Further, the antireflection film has a film stability as good as when C ₈ F ₁₇ SO ₃ H (PFOS) is used as the fluorosurfactant.

  The antireflection film may be removed at the same time as the development process of the resist film. However, in order to completely remove the antireflection film, it is preferable to remove the antireflection film before the development process. This peeling treatment can be performed, for example, by completely removing only the antireflection film by applying a solvent for dissolving and removing the antireflection film while rotating the silicon wafer with a spinner. As a solvent for removing the antireflection film, an aqueous solution containing a surfactant can be used.

  Hereinafter, the present invention will be described in detail with reference to examples. The present invention is not limited to the following examples.

<Example 1>
In a 5% isopropyl alcohol aqueous solution, 0.84 parts by mass of “GANTREZ” (AN-139 (trade name), manufactured by ISP) as a water-soluble film forming component and “EF-N441” (1, 1,2,2,3,3,4,4,4-nonafluoro-[(1,1,2,2,3,3,4,4,4-nonafluorobutyl) sulfonyl] -1-butanesulfonamide (Substance name, manufactured by Mitsubishi Materials Corporation) 1.68 parts by mass, 0.26 parts by mass of 3-amino-1,2-propanediol as a nitrogen-containing compound, “Softanol 30” (Nippon Catalyst) as a nonionic surfactant 0.05 parts by mass) was added to obtain a composition for forming an antireflection film.

<Example 2>
In a 5% isopropyl alcohol aqueous solution, 0.84 parts by mass of “GANTREZ” (AN-139 (trade name), manufactured by ISP) as a water-soluble film forming component and “EF-N331” (1, 1,2,2,3,3,3-heptafluoropropyl-N-[(1,1,2,2,3,3,3-heptafluoropropyl) sulfonyl] -1-propanesulfonamide (substance name) 1.68 parts by mass, manufactured by Mitsubishi Materials Corporation, 0.26 parts by mass of 3-amino-1,2-propanediol as a nitrogen-containing compound, and “Softanol 30” (manufactured by Nippon Shokubai Co., Ltd.) as a nonionic surfactant .05 parts by mass was added to obtain a composition for forming an antireflection film.

<Example 3>
In a 5% isopropyl alcohol aqueous solution, 0.84 parts by mass of “GANTREZ” (AN-139 (trade name), manufactured by ISP) as a water-soluble film forming component and “EF-N441” (1, 1,2,2,3,3,4,4,4-nonafluoro-[(1,1,2,2,3,3,4,4,4-nonafluorobutyl) sulfonyl] -1-butanesulfonamide (Substance name, manufactured by Mitsubishi Materials Corporation) 1.68 parts by mass, 0.26 parts by mass of 2-amino-1,3-propanediol as a nitrogen-containing compound, and “Softanol 30” (Nippon Catalyst) as a nonionic surfactant 0.05 parts by mass) was added to obtain a composition for forming an antireflection film.

<Example 4>
In pure water, 0.84 parts by mass of “GANTREZ” (AN-139 (trade name), manufactured by ISP) as a water-soluble film forming component, and “EF-N441” (1, 1, 2 as a fluorosurfactant) , 2,3,3,4,4,4-Nonafluoro-[(1,1,2,2,3,3,4,4,4-nonafluorobutyl) sulfonyl] -1-butanesulfonamide (substance name) ), Manufactured by Mitsubishi Materials Corporation) 1.68 parts by mass, 0.26 parts by mass of 3-amino-1,2-propanediol as a nitrogen-containing compound, and “Softanol 30” (manufactured by Nippon Shokubai Co., Ltd.) as a nonionic surfactant. 0.05 part by mass was added to obtain an antireflection film-forming composition.

<Comparative Example 1>
An antireflection film-forming composition was obtained in the same manner as in Example 1 except that 0.84 parts by mass of polyvinylpyrrolidone was used as the water-soluble film-forming component.

<Comparative example 2>
An antireflection film-forming composition was obtained in the same manner as in Example 3 except that 1.68 parts by mass of “EF-101” (PFOS, manufactured by Mitsubishi Materials Corporation) was used as the fluorosurfactant.

<Evaluation of the number of surface defects>
Using a spinner “DNS3” (Dainippon Screen Mfg. Co., Ltd.) on an 8-inch silicon wafer, the antireflection film-forming composition obtained in any of Examples 1 to 4 or Comparative Example 1 or 2 was used. It apply | coated and heat-processed at 60 degreeC for 60 second (s). The thickness of the antireflection film was 44 nm. About this laminated body, the number of defects in the wafer was measured with a pixel size of 1.25 μm using a surface defect observation apparatus “KLA-2132” (manufactured by KLA Tencor). The results are shown in Table 1.

  From Table 1, it can be seen that the antireflection film of Example 1 has fewer surface defects than the antireflection film of Comparative Example 1. From these results, it can be seen that the antireflection film formed by the composition for forming an antireflection film of the present invention produces little precipitates that adversely affect the patterning of the resist film.

<Evaluation of optical properties>
After applying “TDUR-P3435 (trade name)” (manufactured by Tokyo Ohka Kogyo Co., Ltd.) as a positive resist composition on an 8-inch silicon wafer using a spinner, heat treatment was performed at 90 ° C. for 60 minutes to obtain a film thickness. A 310 nm resist film was obtained. On this resist film, the composition for forming an antireflection film obtained in any of Examples 1 to 4 or Comparative Example 1 or 2 was applied using a spinner, and heat treatment was performed at 60 ° C. for 60 seconds. . The film thickness of the antireflection film was 44 nm.

  About the said laminated body, the refractive index (n value) and extinction coefficient (k value) in 193 nm, 248 nm, and 365 nm using a spectroscopic ellipsometer “Wbase32 (product name)” (manufactured by JA WOOLLAM JAPAN). ) Was measured. The results are shown in Table 1.

  From Table 2, in the laminate using the antireflection film forming composition of Example 3, the laminate using the antireflection film forming composition of Comparative Example 2 containing PFOS as a fluorosurfactant and It can be seen that the same refractive index and extinction coefficient are exhibited.

<Evaluation of resist pattern shape>
A laminate was produced using the antireflection film obtained in any one of Examples 1 to 4 or Comparative Example 1 or 2 in the same manner as in “Evaluation of optical properties”.

  Using a reduction projection exposure apparatus “NSR-S203B” (trade name, manufactured by Nikon Corporation), the above laminate was irradiated with a KrF excimer laser (248 nm) through a mask pattern, and heated on a hot plate at 90 ° C., 60 ° C. The baking process was performed for 2 seconds. Thereafter, it was washed with pure water for 6 seconds, developed using an aqueous solution of NMD-3 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. for 30 seconds, and then washed with pure water for 10 seconds to obtain a resist pattern. .

The 180 nm line pattern formed on the silicon wafer was observed with a scanning electron microscope (SEM), and the pattern shape of the resist pattern was evaluated. As a result, the antireflection film forming compositions of Examples 1 to 4 were used. It can be seen that the laminate exhibits the same characteristics even when compared with the laminate using the antireflection film-forming composition of Comparative Example 1 or 2.

Claims (8)

An antireflection film-forming composition for forming an antireflection film provided on a resist film,
It contains at least a fluorine-based surfactant and a water-soluble film-forming component,
The fluorosurfactant is at least one selected from compounds represented by the following general formula (2) or (3) :
The composition for anti-reflective film formation in which the said water-soluble film formation component contains at least water-soluble resin represented by following General formula (5).

In above general formula (2) or (3), n represents an integer of 1 to 5, o is to Table 2 or 3. ]

In above general formula (5), R ¹ represents a hydrogen atom or an alkyl or hydroxyalkyl group having 1 to 6 carbon atoms, q represents the number of repeating units. ]   The composition for forming an antireflection film according to claim 1, wherein the water-soluble resin has a mass average molecular weight of 1,000 to 1,000,000.   Furthermore, the composition for anti-reflective film formation of Claim 1 or 2 containing a nitrogen-containing compound.   The composition for forming an antireflection film according to claim 3, wherein the nitrogen-containing compound is 3-amino-1,2-propanediol and / or 2-amino-1,3-propanediol. Furthermore, the composition for anti-reflective film formation in any one of Claim 1 to 4 containing the nonionic surfactant represented by following General formula (6).

[In General Formula (6), R ^{2 to} R ⁵ each independently represents a linear or branched alkyl group having 1 to ⁶ carbon atoms, and R ⁶ is a linear or branched group having 2 to 4 carbon atoms, A branched alkylene chain is represented, and s and t each independently represent an integer of 0 to 30. ] Furthermore, the composition for anti-reflective film formation in any one of Claim 1 to 4 containing the anionic surfactant represented by following General formula (7).

In above general formula ^(7), R 7 represents a linear or branched alkyl group having 7 to 20 carbon atoms. The alkyl group may have a hydroxyl group and / or a carboxyl group, and may be interrupted by a phenylene group and / or an oxygen atom. ] Furthermore, the composition for anti-reflective film formation in any one of Claim 1 to 4 containing at least 1 type chosen from the anionic surfactant represented by following General formula (8) and (9).

[In the above general formulas (8) and (9), R ⁸ and R ⁹ each independently represent a linear or branched alkyl group having 1 to 20 carbon atoms, and u and v each independently represent 1 to 50. Represents an integer. ] A resist film is formed on the substrate,
On the resist film, an antireflection film is formed using the antireflection film-forming composition according to any one of claims 1 to 7,
The resist film is selectively irradiated with light through the antireflection film, and heat treatment is performed as necessary.
A resist pattern forming method for obtaining a resist pattern by removing the antireflection film before or during development of the resist film after irradiation.