JP5496715B2 - Acrylic ester derivatives, polymer compounds and photoresist compositions - Google Patents

Description

  The present invention relates to an acrylate derivative, a method for producing the acrylate derivative, a polymer compound obtained by polymerizing a raw material containing the acrylate derivative, and a photoresist composition containing the polymer compound.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to radiation such as light and electron beams through a mask on which a predetermined pattern is formed. And performing a developing process to form a resist pattern having a predetermined shape on the resist film. A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the exposure light source is generally shortened in wavelength (increased energy). Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. Further, _{F 2} excimer laser of KrF excimer laser or ArF excimer laser than the short wavelength (high energy), an electron beam, is also studied, such as EUV (extreme ultraviolet) and X-ray is performed.

Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions. As a resist material satisfying such requirements, a chemically amplified resist composition containing a base material component whose solubility in an alkaline developer is changed by the action of an acid and an acid generator component that generates an acid upon exposure is used. It has been.
For example, as a positive chemically amplified resist composition, a composition containing a resin component (base resin) whose solubility in an alkaline developer is increased by the action of an acid and an acid generator component is generally used. Yes. When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the acid generator component in the exposed portion, and the resin component is alkali-developed by the action of the acid. The solubility in the solution increases, and the exposed portion becomes soluble in the alkaline developer.

  Currently, as a resist base resin used in ArF excimer laser lithography and the like, since it has excellent transparency near 193 nm, a resin (acrylic resin) having a structural unit derived from an acrylate derivative in its main chain, etc. Is commonly used, and a combination of an acrylate derivative having a methyladamantane ester as an acid labile group unit and an acrylate derivative having an ester of a lactone ring as a base adhesion unit has been proposed (for example, patents) Also, a combination with an acrylate derivative having 1,1-dioxide-tetrahydrothiophene has been proposed (for example, see Patent Document 2).

JP-A-9-90637 Special table 2008-521039 gazette

In the future, there is a demand for the development of new materials that can be used for lithography applications, as further progress in lithography technology and expansion of application fields are expected. One of the important issues in ArF lithography is reduction of line width roughness (LWR). LWR is a variation in the line width of the formed pattern, and one of the factors is swelling during development. In order to suppress pattern deformation due to this swelling, it is necessary that the polymer compound as the resist composition component is difficult to swell. However, a polymer compound prepared with a known combination of acrylic ester derivatives does not necessarily have a satisfactory level of performance.
The present invention has been made in view of the above circumstances, and is obtained by polymerizing an acrylic ester derivative useful as a raw material for a polymer compound having low swelling during development and a raw material containing the acrylic ester derivative. An object of the present invention is to provide a polymer compound, a photoresist composition having an improved LWR containing the polymer compound, and a method for producing the acrylate derivative.

  As a result of intensive studies, the inventors have invented an acrylate derivative having a specific sultone ring, and obtained a polymer compound obtained by polymerizing a raw material containing the acrylate derivative as a photoresist composition. As a result, it was found that swelling during development after exposure was suppressed and LWR was improved, and the present invention was completed.

That is, the present invention provides the following [1] to [5].
[1] The following general formula (1)

（式中、Ｒ^２、Ｒ^３およびＲ^４は、前記定義の通りである。）
で示されるアルコール誘導体（以下、アルコール誘導体（２）と称する。）をエステル化することを特徴とする、アクリル酸エステル誘導体（１）の製造方法。
［４］アクリル酸エステル誘導体（１）を含有する原料を重合することにより得られる高分子化合物（以下、高分子化合物（３）と称する。）。
［５］高分子化合物（３）を含有するフォトレジスト組成物。
［６］アルコール誘導体（２）のうち、Ｒ^２、Ｒ^３およびＲ^４が全て水素原子である組み合わせを除くアルコール誘導体（２）。 (In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group, and R ² , R ³ and R ⁴ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a carbon number. An acrylate derivative (hereinafter referred to as an acrylate derivative (1)).
[2] An acrylate derivative (1) wherein R ² and R ³ are hydrogen atoms and R ⁴ is a hydrogen atom or a methyl group.
[3] The following general formula (2)

(Wherein R ² , R ³ and R ⁴ are as defined above.)
A method for producing an acrylate derivative (1), which comprises esterifying an alcohol derivative (hereinafter referred to as alcohol derivative (2)).
[4] A polymer compound obtained by polymerizing a raw material containing the acrylate derivative (1) (hereinafter referred to as polymer compound (3)).
[5] A photoresist composition containing the polymer compound (3).
[6] Alcohol derivative (2) excluding the combination in which R ² , R ³ and R ⁴ are all hydrogen atoms among alcohol derivative (2).

  ADVANTAGE OF THE INVENTION According to this invention, the polymeric compound with small swelling at the time of image development after exposure can be provided, Furthermore, acrylic acid derivatives useful as a raw material of this polymeric compound, their manufacturing method, and LWR containing the said polymeric compound Can provide an improved photoresist composition.

[Acrylic acid ester derivative (1)]
In order to obtain a resist composition that forms a resist pattern with improved LWR, the acrylate derivative (1) of the present invention is useful.

R ¹ in the acrylate derivative (1) represents a hydrogen atom, a methyl group or a trifluoromethyl group. Among these, R ¹ is preferably a hydrogen atom or a methyl group.
R ² , R ³ and R ⁴ in the acrylate derivative (1) each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms.

The alkyl group having 1 to 6 carbon atoms independently represented by R ² , R ³ and R ⁴ may be linear or branched. For example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, Examples include n-butyl group, isobutyl group, s-butyl group, n-pentyl group, and n-hexyl group. Among these, from the viewpoint of obtaining a resist composition that forms a resist pattern having a good shape, an alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group is more preferable.
Examples of the cycloalkyl group having 3 to 6 carbon atoms which R ² , R ³ and R ⁴ each independently represent include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group.
Among the above, R ² and R ³ are preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably a hydrogen atom. R ⁴ is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably a hydrogen atom or a methyl group.

  Specific examples of the acrylate derivative (1) of the present invention are shown below, but are not particularly limited thereto.

[Production method of acrylic ester derivative (1)]
The acrylic ester derivative (1) of the present invention can be obtained by esterifying the alcohol derivative (2). Although there is no restriction | limiting in particular in the method of esterifying alcohol derivative (2), For example, the following method is mentioned.
Method 1: A method of reacting an acrylic acid halide with an alcohol derivative (2) in the presence of a base.
Method 2: A method in which acrylic anhydrides and alcohol derivative (2) are reacted in the presence of a base.
Method 3: A method of reacting acrylic acid and alcohol derivative (2).
Hereinafter, each of the methods 1 to 3 will be described in order.

(Method 1)
Specific examples of the acrylic acid halides used in Method 1 include acrylic acid chloride, methacrylic acid chloride, 2-trifluoromethylacrylic acid chloride, acrylic acid bromide, methacrylic acid bromide, and 2-trifluoromethylacrylic acid bromide. Can be mentioned. Among these, acrylic acid chloride, methacrylic acid chloride, and 2-trifluoromethylacrylic acid chloride are preferable from the viewpoint of availability.
The amount of acrylic acid halides used is preferably in the range of 1 to 10 moles relative to the alcohol derivative (2), and more preferably in the range of 1 to 5 moles from the viewpoint of ease of post-treatment.

Specific examples of the base used in Method 1 are not particularly limited as long as they neutralize the by-product acid. For example, pyridine, 2-methylpyridine, 2-methyl-5-ethylpyridine, 2,6- Nitrogen-containing heterocyclic aromatic compounds such as dimethylpyridine; amines such as triethylamine, triethylenetetramine, triethanolamine, piperazine, diazabicyclo [2.2.2] octane; bicarbonates of alkali metals such as sodium hydrogencarbonate, etc. Is mentioned. These may be used individually by 1 type, and 2 or more types may be mixed and used for them.
The amount of the base used is preferably in the range of 1 to 10 moles relative to the alcohol derivative (2), and more preferably in the range of 1 to 5 moles from the viewpoint of ease of post-treatment.

The reaction of Method 1 is carried out in the presence or absence of a solvent.
The solvent is not particularly limited as long as it does not inhibit the reaction. For example, saturated hydrocarbon solvents such as hexane, heptane, and cyclohexane; aromatic hydrocarbon solvents such as benzene, toluene, and xylene; such as methylene chloride, dichloroethane, and benzene chloride. Chlorinated hydrocarbon solvents; ether solvents such as diethyl ether, diisopropyl ether, tetrahydrofuran, and furan; nitrile solvents such as acetonitrile and benzonitrile; ester solvents such as methyl acetate, ethyl acetate, and propyl acetate; 2-butanone, 4-methyl- Examples thereof include ketone solvents such as 2-pentanone. A solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
When carried out in the presence of a solvent, the amount of the solvent used is preferably in the range of 0.5 to 100 times by mass with respect to the alcohol derivative (2), and from the viewpoint of ease of post-treatment, 0.5 to 20 A range of mass times is more preferable.

In the reaction of method 1, a polymerization inhibitor can be used to prevent polymerization.
Examples of the polymerization inhibitor include phenolic polymerization inhibitors such as hydroquinone and p-methoxyphenol; N, N′-diisopropyl-p-phenylenediamine, N, N′-di-2-naphthyl-p-phenylenediamine, N -Amine polymerization inhibitors such as phenyl-N '-(1,3-dimethylbutyl) -p-phenylenediamine; 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-acetamide And N-oxyl-based polymerization inhibitors such as -2,2,6,6-tetramethylpiperidine-N-oxyl. A polymerization inhibitor can be used alone or in combination of two or more. When a polymerization inhibitor is used, the amount used is not particularly limited and may be determined as appropriate.

Method 1 can also be carried out by adding an activator such as 4-dimethylaminopyridine.
The reaction temperature in Method 1 varies depending on the type of the alcohol derivative (2) and the acrylic halide, and whether or not an activator is used, but is generally in the range of −50 to 100 ° C., from the viewpoint of reaction rate and polymerization inhibition. A range of −30 to 80 ° C. is more preferable. The reaction pressure is not particularly limited, but it is usually preferable to carry out the reaction under normal pressure.
The reaction time in Method 1 varies depending on the type, amount used, reaction temperature, and the like of the base, the alcohol derivative (2) and the acrylic acid halide, but is preferably in the range of about 1 hour to 50 hours.
Method 1 is preferably carried out in an inert gas atmosphere such as nitrogen or argon.

  The method for carrying out method 1 is not particularly limited, but the reactor is charged with the alcohol derivative (2), a base, and optionally a solvent, a polymerization inhibitor, and an activator. A method of dropping acrylic acid halides at a temperature and a desired reaction pressure is preferred.

(Method 2)
Specific examples of the acrylic anhydrides used in Method 2 include acrylic anhydride, methacrylic anhydride, 2-trifluoromethyl acrylic anhydride, pivalic anhydride, pivalic anhydride, Examples include 2-trifluoromethylacrylic acid pivalic acid anhydride, acrylic acid methanesulfonic acid anhydride, methacrylic acid methanesulfonic acid anhydride, and 2-trifluoromethylacrylic acid methanesulfonic acid anhydride.
The amount of acrylic anhydrides used is preferably in the range of 1 to 10 moles relative to the alcohol derivative (2), and more preferably in the range of 1 to 5 moles from the viewpoint of ease of post-treatment.

  Examples of the base used in Method 2 include the same bases as those exemplified in Method 1. A base may be used individually by 1 type and may be used in mixture of 2 or more types. The amount of the base used is preferably in the range of 1 to 10 moles relative to the alcohol derivative (2), and more preferably in the range of 1 to 5 moles from the viewpoint of ease of post-treatment.

The reaction of Method 2 is carried out in the presence or absence of a solvent.
There is no restriction | limiting in particular as long as reaction is not inhibited, The same thing as the solvent illustrated by the method 1 is mentioned. A solvent may be used individually by 1 type and may be used in mixture of 2 or more types.
When carried out in the presence of a solvent, the amount of the solvent used is preferably in the range of 0.5 to 100 times by mass with respect to the alcohol derivative (2), and 0.5 to 20 mass from the viewpoint of ease of post-treatment. A range of double is more preferable.

  In the reaction of Method 2, a polymerization inhibitor can be used to prevent polymerization. Examples of the polymerization inhibitor include the same polymerization inhibitors as those exemplified in Method 1. A polymerization inhibitor can be used alone or in combination of two or more. When a polymerization inhibitor is used, the amount used is not particularly limited and may be determined as appropriate.

Method 2 can also be carried out by adding an activator such as 4-dimethylaminopyridine.
The reaction temperature in Method 2 varies depending on the types of the alcohol derivative (2) and acrylic anhydrides and whether or not an activator is used, but is generally preferably in the range of −50 to 100 ° C. From the reaction rate and polymerization inhibition, The range of 30-80 degreeC is more preferable. The reaction pressure is not particularly limited, but it is usually preferable to carry out the reaction under normal pressure.
The reaction time in Method 2 varies depending on the type and amount of the base, alcohol derivative (2) and acrylic anhydride, the reaction temperature, etc., but is preferably in the range of about 1 to 50 hours.
Method 2 is preferably carried out in an inert gas atmosphere such as nitrogen or argon.

(Method 3)
The acrylic acid used in Method 3 is acrylic acid, methacrylic acid or 2-trifluoromethyl acrylic acid. The amount of acrylic acid used is preferably in the range of 1 to 50 times mol with respect to the alcohol derivative (2), and more preferably in the range of 1 to 20 times mol from the viewpoint of ease of post-treatment.

  In Method 3, an acid catalyst is usually used. Examples of the acid catalyst include solid acid catalysts such as sulfuric acid, p-toluenesulfonic acid monohydrate, and acidic ion exchange resins. When using an acid catalyst other than the solid acid catalyst, the amount used is preferably in the range of 0.001 to 2 moles, more preferably in the range of 0.01 to 1 moles, relative to the alcohol derivative (2). . When a solid acid catalyst is used as the acid catalyst, the amount used may be appropriately set according to the amount used of the alcohol derivative (2).

  In the reaction of method 3, a polymerization inhibitor can be used to prevent polymerization. Examples of the polymerization inhibitor include the same polymerization inhibitors as those exemplified in Method 1. A polymerization inhibitor can be used alone or in combination of two or more. When a polymerization inhibitor is used, the amount used is not particularly limited and may be determined as appropriate.

The reaction temperature in Method 3 varies depending on the type of the alcohol derivative (2) and acrylic acid, but is generally preferably in the range of 30 to 150 ° C, more preferably in the range of 50 to 100 ° C. The reaction pressure is not particularly limited, but it is usually preferable to carry out the reaction under normal pressure.
The reaction time in Method 3 varies depending on the types and amounts of the base, alcohol derivative (2) and acrylic acids, the reaction temperature, etc., but is preferably in the range of about 1 hour to 50 hours.

  Since the reaction of Method 3 is an equilibrium reaction, it is preferable to carry out the reaction while removing by-product water from the reaction system in order to sufficiently proceed the reaction. As a method of removing water, for example, a method of removing water from a device such as a decanter using a solvent that forms an azeotrope with water such as hexane or toluene, or a water adsorbent such as molecular sieves is used. The method etc. are mentioned.

Separation and purification of the acrylate derivative (1) from the reaction mixture obtained in the above-mentioned method 1, 2 or 3 can be carried out by methods generally used for separation of organic compounds such as solvent extraction and distillation. Further, the purity can be improved by a method generally used for purification of organic compounds such as recrystallization, distillation, sublimation and the like.

  Although there is no restriction | limiting in particular in the manufacturing method of alcohol derivative (2) of this invention, as shown in the following chemical reaction formula, alcohol derivative (2) is passed from a corresponding epoxide derivative (4) via a sulfonic acid derivative (5). ) Can be manufactured. For example, epihydroxyhydrin and sodium bisulfite can be reacted to synthesize 2-hydroxy-1,3-propane sultone (see US Pat. No. 3,100,779).

（式中、Ｒ^２、Ｒ^３およびＲ^４は、前記定義の通りである。Ｘは、塩素原子、臭素原子またはヨウ素原子を表す。Mはナトリウム原子またはカリウム原子を表す。）

(In the formula, R ² , R ³ and R ⁴ are as defined above. X represents a chlorine atom, a bromine atom or an iodine atom. M represents a sodium atom or a potassium atom.)

[Polymer compound]
A polymer obtained by polymerizing the acrylic ester derivative (1) of the present invention alone or a copolymer obtained by copolymerizing the acrylic ester derivative (1) and another polymerizable compound (polymer compound (3)) ) Is useful as a polymer compound for photoresist compositions.
Specific examples of other polymerizable compounds (hereinafter referred to as copolymerization monomers) that can be copolymerized with the acrylate derivative (1) include compounds represented by the following chemical formulas. However, it is not particularly limited to these.

In the above formulas (I) to (XII), R ⁵ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ⁶ represents a polymerizable group. R ⁷ represents a hydrogen atom or —COOR ⁸ , and R ⁸ represents an alkyl group having 1 to 3 carbon atoms. R ⁹ represents an alkyl group.

In the comonomer, examples of the alkyl group having 1 to 3 carbon atoms that R ⁵ and R ⁸ each independently represent include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Examples of the alkyl group represented by R ⁹ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, and a t-butyl group. Examples of the polymerizable group represented by R ⁶ include an acryloyl group, a methacryloyl group, a vinyl group, and a crotonoyl group.

The polymer compound (3) can be produced by radical polymerization according to a conventional method. In particular, a method for synthesizing a polymer compound having a small molecular weight distribution includes living radical polymerization.
A general radical polymerization method includes a radical polymerization initiator and a solvent, and, if necessary, one or more kinds of acrylic ester derivatives (1) and, if necessary, one or more kinds of the above copolymerization monomers. Accordingly, the polymerization is carried out in the presence of a chain transfer agent.
The method for carrying out radical polymerization is not particularly limited, and conventional methods such as those used in the production of acrylic polymer compounds such as solution polymerization, emulsion polymerization, suspension polymerization and bulk polymerization can be used.

Examples of the radical polymerization initiator include hydroperoxide compounds such as t-butyl hydroperoxide and cumene hydroperoxide; di-t-butyl peroxide, t-butyl-α-cumyl peroxide, di-α-cumyl peroxide and the like. Dialkyl peroxide compounds; diacyl peroxide compounds such as benzoyl peroxide and diisobutyryl peroxide; and azo compounds such as 2,2′-azobisisobutyronitrile and dimethyl-2,2′-azobisisobutyrate.
The amount of the radical polymerization initiator used can be appropriately selected according to the polymerization conditions such as the acrylic ester derivative (1), copolymerization monomer, chain transfer agent, solvent used in the polymerization reaction, the amount of solvent used, and the polymerization temperature. Is the total amount of all polymerizable compounds [acrylic ester derivative (1) and comonomer, and so on. ] Usually, the range of 0.005 to 0.2 mol is preferable with respect to 1 mol, and the range of 0.01 to 0.15 mol is more preferable.

  Examples of the chain transfer agent include thiol compounds such as dodecanethiol, mercaptoethanol, mercaptopropanol, mercaptoacetic acid, and mercaptopropionic acid. When a chain transfer agent is used, the amount used is usually preferably in the range of 0.005 to 0.2 mol, more preferably in the range of 0.01 to 0.15 mol, per 1 mol of all polymerizable compounds. preferable.

The solvent is not particularly limited as long as the polymerization reaction is not inhibited. For example, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether propionate, ethylene Glycol ethers such as glycol monobutyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether; esters such as ethyl lactate, methyl 3-methoxypropionate, methyl acetate, ethyl acetate, propyl acetate; acetone, methyl ethyl ketone, methyl ipropyl ketone, methyl isobutyl Ketone, methyl amyl ketone, cyclopentanone, cyclohexano Ketones, such as diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, ethers such as 1,4-dioxane.
The usage-amount of a solvent is the range of 0.5-20 mass parts normally with respect to 1 mass part of all the polymeric compounds, and it is preferable that it is the range of 1-10 mass parts from a viewpoint of economical efficiency. .

The polymerization temperature is usually 40 to 150 ° C., and preferably 60 to 120 ° C. from the viewpoint of the stability of the polymer compound to be produced.
The time for the polymerization reaction varies depending on the polymerization conditions such as the acrylic ester derivative (1), the comonomer, the polymerization initiator, the type and amount of the solvent used, and the temperature of the polymerization reaction, but usually 30 minutes to 48 hours. The range of 1 hour to 24 hours is more preferable.

The polymer compound (3) thus obtained can be isolated by ordinary operations such as reprecipitation. The isolated polymer compound can be dried by vacuum drying or the like.
Examples of the solvent used in the reprecipitation operation include aliphatic hydrocarbons such as pentane and hexane; alicyclic hydrocarbons such as cyclohexane; aromatic hydrocarbons such as benzene and xylene; methylene chloride, chloroform, chlorobenzene, dichlorobenzene, and the like. Nitrogenated hydrocarbons such as nitromethane; Nitriles such as acetonitrile and benzonitrile; Ethers such as diethyl ether, diisopropyl ether, tetrahydrofuran and 1,4-dioxane; Ketones such as acetone and methyl ethyl ketone; Carboxyls such as acetic acid Acid; Esters such as ethyl acetate and butyl acetate; Carbonates such as dimethyl carbonate, diethyl carbonate, and ethylene carbonate; Methanol, ethanol, propanol, isopropyl alcohol Include water; alcohols such as butanol.

  The weight average molecular weight (Mw) of the resulting polymer compound (3) is not particularly limited, but is preferably in the range of 500 to 50000, more preferably in the range of 1000 to 30000. It is highly useful. The measurement of the weight average molecular weight (Mw) is as described in Examples.

  When the obtained polymer compound (3) is used as a polymer compound for a photoresist composition, the unit of the acrylic acid derivative (1) is 5 mol% to 80 mol%, preferably 10 to 60 mol%. Highly useful when included in proportions.

[Photoresist composition]
A photoresist composition is prepared by blending the polymer compound (3), an organic solvent and a photoacid generator, and, if necessary, a basic compound and additives. As the photoacid generator, a photoacid generator conventionally used for a chemically amplified resist can be used. Furthermore, a surfactant, a sensitizer, an antihalation agent, a shape improver, a storage stabilizer, an antifoaming agent, and the like can be added to the photoresist composition.
Hereinafter, the photoresist composition containing the polymer compound (3) will be described.

(solvent)
Solvents to be blended into the photoresist composition include, for example, propylene glycol monoethyl ether, propylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether propionate, ethylene glycol monobutyl ether, ethylene glycol Glycol ethers such as monobutyl ether acetate and diethylene glycol dimethyl ether; esters such as ethyl lactate, methyl 3-methoxypropionate, methyl acetate, ethyl acetate, and propyl acetate; acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclo Ketones such as pentanone and cyclohexanone Diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, ethers such as 1,4-dioxane. You may use these individually by 1 type or in mixture of 2 or more types.
The compounding quantity of a solvent is the range of 1-50 mass parts normally with respect to 1 mass part of high molecular compound (3), and it is preferable that it is the range of 2-25 mass parts.

(Photoacid generator)
There is no restriction | limiting in particular as a photo-acid generator, The photo-acid generator conventionally used for the chemically amplified resist can be used conventionally. Examples of the photoacid generator include nitrobenzyl derivatives such as 2-nitrobenzyl p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, and 2,4-dinitrobenzyl p-toluenesulfonate; Sulfonic acid esters such as 2,3-tris (methanesulfonyloxy) benzene, 1,2,3-tris (trifluoromethanesulfonyloxy) benzene, 1,2,3-tris (p-toluenesulfonyloxy) benzene; bis ( Benzenesulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (n-butyl) Sulfonyl) di Diazomethane derivatives such as zomethane; triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nanofluoro-n-butanesulfonate, trifluoromethanesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, tris (trifluoromethanesulfonate) (p-tert) -Butoxyphenyl) sulfonium, p-toluenesulfonic acid triphenylsulfonium, p-toluenesulfonic acid (p-tert-butoxyphenyl) diphenylsulfonium, p-toluenesulfonic acid tris (p-tert-butoxyphenyl) sulfonium, trifluoromethanesulfone Trinaphthylsulfonium acid, cyclohexylmethyl trifluoromethanesulfonate (2-oxocyclohexyl) sulfonium, Onium salts such as (2-norbornyl) methyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, 1,2'-naphthylcarbonylmethyltetrahydrothiophenium triflate; bis-O- (p-toluenesulfonyl) -α -Glyoxime derivatives such as dimethylglyoxime, bis-O- (n-butanesulfonyl) -α-dimethylglyoxime; N-hydroxysuccinimide methanesulfonate, N-hydroxysuccinimide trifluoromethanesulfonate, N-hydroxysuccinimide 1 -Propanesulfonic acid ester, N-hydroxyimide p-toluenesulfonic acid ester, N-hydroxynaphthalimide methanesulfonic acid ester, N-hydroxynaphthalimide benzenesulfonic acid ester Sulfonic acid ester derivatives of N-hydroxyimide compounds such as ter; 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxynaphthyl)- 4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2 -[2- (5-methyl-2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,5-dimethoxyphenyl) ethenyl]- And halogen-containing triazine compounds such as 4,6-bis (trichloromethyl) -1,3,5-triazine. You may use these individually by 1 type or in mixture of 2 or more types.
The compounding amount of the photoacid generator is usually in the range of 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer compound (3) from the viewpoint of ensuring the sensitivity and developability of the photoresist composition. It is preferable that it is in the range of 0.5 to 10 parts by mass.

(Basic compound)
In the photoresist composition, in order to improve the resolution by suppressing the acid diffusion rate in the photoresist film, an amount of a basic compound is added if necessary so that the characteristics of the photoresist composition of the present invention are not inhibited. Can be blended.
Examples of such basic compounds include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N- (1-adamantyl) acetamide, benzamide, N-acetyl. Ethanolamine, 1-acetyl-3-methylpiperidine, pyrrolidone, N-methylpyrrolidone, ε-caprolactam, δ-valerolactam, 2-pyrrolidinone, acrylamide, methacrylamide, t-butylacrylamide, methylenebisacrylamide, methylenebismethacrylamide Amides such as N-methylolacrylamide, N-methoxyacrylamide and diacetoneacrylamide; pyridine, 2-methylpyridine, 4-methylpyridine, nicotine, quinoline, Lysine, imidazole, 4-methylimidazole, benzimidazole, pyrazine, pyrazole, pyrrolidine, Nt-butoxycarbonylpyropidine, piperidine, tetrazole, morpholine, 4-methylmorpholine, piperazine, 1,4-diazabicyclo [2.2. 2] Examples include amines such as octane, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, and triethanolamine. You may use these individually by 1 type or in mixture of 2 or more types.
When blending a basic compound, the blending amount varies depending on the type of the basic compound used, but it is usually preferably in the range of 0.01 to 10 moles per mole of the photoacid generator. The range of 0.05 to 1 mol is more preferable.

(Surfactant)
In order to improve coatability, the photoresist composition of the present invention may further contain a surfactant in an amount that does not impair the characteristics of the photoresist composition of the present invention.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, and the like. You may use these individually by 1 type or in mixture of 2 or more types.
When the surfactant is blended, the blending amount is usually 2 parts by mass or less with respect to 100 parts by mass of the polymer compound (3).

(Other additives)
Further, the photoresist composition of the present invention has other properties such as a sensitizer, an antihalation agent, a shape improver, a storage stabilizer, an antifoaming agent, and the like. It can be blended in an amount that is not inhibited.

(Resist pattern formation method)
The resist pattern forming method includes a step of forming a resist film on a support using the photoresist composition, a step of exposing the resist film, and a step of developing the resist film to form a resist pattern. including.

The resist pattern can be formed, for example, as follows.
That is, first, the photoresist composition is coated on a support with a spinner or the like, and pre-baked at a temperature of 70 to 160 ° C. for 1 minute to 10 minutes, and this is subjected to, for example, an ArF excimer laser using an ArF exposure apparatus or the like. After selectively exposing light through a desired mask pattern, post-exposure baking is performed at a temperature of 70 to 160 ° C. for 1 to 5 minutes. Subsequently, this is developed using an alkaline developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide, preferably rinsed with pure water and dried to form a resist pattern. .
An organic or inorganic antireflection film can be provided between the substrate and the coating layer of the photoresist composition.
The wavelength used for exposure is not particularly limited. For example, ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray. The exposure can be performed using radiation such as. The photoresist composition of the present invention is particularly effective for an ArF excimer laser. The exposure dose is preferably in the range of 0.1 to 1000 mJ / cm ² .

(Immersion lithography)
Moreover, the photoresist composition which consists of a high molecular compound containing the acrylic ester derivative (1) of this invention can also be applied to immersion lithography. Immersion lithography is an exposure technique that increases resolution by injecting a liquid having a higher refractive index of light than the atmosphere between a projection lens of an exposure apparatus and a resist film. In ArF immersion lithography, pure water is used as the liquid. Specifically, pure water is injected between the pre-baked resist film and the projection lens for exposure, and when exposed by an ArF excimer laser having a wavelength of 193 nm, the radiation passing through the resist film has a wavelength of 135 nm, which is short. Since the wavelength is changed, high resolution can be obtained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by these examples. In addition, the measuring method of Mw and the calculation method of dispersion degree in each example are as follows.

(Measurement of Mw and Mn and calculation of dispersity)
The weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) using a differential refractometer as a detector and tetrahydrofuran (THF) as an eluent under the following conditions. It calculated | required as a conversion value by the calibration curve created with the standard polystyrene. Further, the dispersity (Mw / Mn) was determined by dividing the weight average molecular weight (Mn) by the number average molecular weight (Mn).
GPC measurement: TSK-gel SUPER HZM-H (trade name: 4.6 mm × 150 mm) and TSK-gel SUPER HZ2000 (trade name: Tosoh Corp., 4.6 mm × 150 mm) as columns ) Using one connected in series, measurement was performed under the conditions of a column temperature of 40 ° C., a differential refractometer temperature of 40 ° C., and an eluent flow rate of 0.35 mL / min.

Reference Synthesis Example Synthesis of 2-hydroxy-1,3-propane sultone In a 100 mL three-necked flask equipped with an electromagnetic stirrer and a thermometer, 10.6 g (102 mmol) of sodium hydrogen sulfite, 60.0 g of water, and epichloro The hydrin 9.24g (99.9mmol) was put, it stirred at 47-50 degreeC for 2.5 hours, and also it stirred at 95-100 degreeC for 3.0 hours. Water was distilled off from the reaction solution under reduced pressure, the produced white solid was filtered off, and 15.0 g of methanol was added to the obtained filtrate to produce white crystals. The crystals were filtered off and dried under reduced pressure at 40 ° C. for 1 hour to obtain 10.4 g of 2-hydroxy-1,3-propane sultone (white crystals, 75.0 mmol, yield 75.1%). It was.

<Example 1> Synthesis of 2-methacryloyloxy-1,3-propane sultone In a 50 mL three-necked flask equipped with an electromagnetic stirrer and a thermometer, 1.00 g of 2-hydroxy-1,3-propane sultone (7 .24 mmol), 0.013 g of p-methoxyphenol and 18.30 g of tetrahydrofuran were added and stirred at room temperature. While cooling with ice water, 1.18 g (11.25 mmol) of methacrylic acid chloride was added dropwise, and then 1.20 g (11.81 mmol) of triethylamine was added dropwise at an internal temperature of 4 to 6 ° C. After completion of dropping, the mixture was stirred at 4 ° C. for 1 hour and at 28 to 29 ° C. for 8 hours. 10.1 g of water was added dropwise at an internal temperature of 18 ° C. or lower, and the mixture was stirred for 30 minutes and then extracted 6 times with 20.0 g of ethyl acetate. The extracted all organic layers were combined, concentrated under reduced pressure, and the resulting concentrate was separated and purified by silica gel column chromatography (developing solution: ethyl acetate / methanol = 8/1 (v / v)) to give 2-methacryloyloxy. 0.52 g (white solid, 2.01 mmol, yield 27.8%) of -1,3-propane sultone was obtained.

¹ H-NMR (400 MHz, DMSO-d6, TMS, ppm) δ: 6.05 (1H, S), 5.68 (1H, s), 5.30-5.33 (1H, m), 4. 07 (1H, dd, J = 11.6, 2.8 Hz), 3.93 (1H, dd, J = 11.6, 6.4 Hz), 2.86 (1H, dd, J = 13.6, 8.4 Hz), 2.76 (1H, dd, J = 13.6, 4.4 Hz), 1.88 (3H, s)

<Example 2> Synthesis of 2-hydroxy-2-methyl-1,3-propane sultone In a 100-ml round bottom flask equipped with a magnetic stirrer, a condenser and a thermometer, 60.0 g of water and sodium bisulfite were added. 10.6 g (101.5 mmol) and 10.6 g (99.9 mmol) of methyl epichlorohydrin were added and heated to reflux for 2 hours. The obtained reaction liquid was transferred to a 200 mL eggplant flask, and 100 mL of ethanol was added to the concentrate obtained by concentration under reduced pressure, and the solid was filtered off. The filtrate was concentrated under reduced pressure, and 30 mL of methanol was added to the resulting concentrate and cooled to 0 ° C., whereby 10.2 g of 2-hydroxy-2-methyl-1,3-propane sultone (white solid, 66.9 mmol). Yield 67.0%).

¹ H-NMR (300 MHz, DMSO-d6, TMS, ppm) δ: 3.78 (1H, d, J = 10.4 Hz), 3.58 (1H, d, J = 10.4 Hz), 2.86 (1H, d, J = 13.8 Hz), 2.69 (1H, d, J = 13.8 Hz), 1.23 (3H, s)

<Example 3> Synthesis of 2-methacryloyloxy-2-methyl-1,3-propane sultone Into a 50 mL three-necked flask equipped with an electromagnetic stirrer and a thermometer, 2-hydroxy-2-methyl-1,3- Propane sultone 1.10 g (7.24 mmol), p-methoxyphenol 0.013 g and tetrahydrofuran 18.30 g were added and stirred at room temperature. While cooling with ice water, 1.18 g (11.25 mmol) of methacrylic acid chloride was added dropwise, and then 1.20 g (11.81 mmol) of triethylamine was added dropwise at an internal temperature of 0 to 2 ° C. After completion of dropping, the mixture was stirred at 2 ° C. for 1 hour and at 28 to 29 ° C. for 3 hours. 10.0 g of water was added dropwise at an internal temperature of 10 ° C. or lower, and the mixture was stirred for 30 minutes and then extracted 6 times with 20.0 g of ethyl acetate. The extracted all organic layers were combined, concentrated under reduced pressure, and the resulting concentrate was separated and purified by silica gel column chromatography (developing solution: ethyl acetate / methanol = 8/1 (v / v)) to give 2-methacryloyloxy. 0.27 g (white solid, 1.22 mmol, yield 16.9%) of 2-methyl-1,3-propane sultone was obtained.

¹ H-NMR (300 MHz, DMSO-d6, TMS, ppm) δ: 6.03 (1H, S), 5.65 (1H, s), 4.05 (1H, d, J = 10.3 Hz), 3.92 (1H, d, J = 10.3 Hz), 2.96 (1 H, d, J = 13.6 Hz), 2.84 (1 H, d, J = 13.6 Hz), 1.85 (3H , S), 1.30 (3H, s)

<Synthesis of polymer compound (3)>
The following polymer compounds were synthesized using monomers (1) to (4) represented by the following chemical formulas.

  The monomer (2) was synthesized according to the procedure described in Example 1 of Patent Document 2. Monomers (1), (3) and (4) were commercially available products.

<Example 4>
Synthesis of polymer compound (A)
Under a nitrogen atmosphere, 3.85 g (18.7 mmol) of 2-methacryloyloxy-1,3-propane sultone, monomer (4) 2 in a round bottom flask having an internal volume of 100 ml equipped with a magnetic stirrer, a condenser and a thermometer. .96 g (12.5 mmol), monomer (3) 4.39 g (18.7 mmol), methyl ethyl ketone 35.4 g and 2,2′-azobisisobutyronitrile 0.66 g (4.0 mmol) were charged at 80 ° C. The polymerization reaction was carried out for 4 hours. Next, the obtained reaction mixture was dropped into about 20-fold mass of methanol at room temperature while stirring to obtain a white precipitate. The precipitate was collected by filtration and dried under reduced pressure (26.7 Pa) at 50 ° C. for 10 hours to obtain 5.39 g of a polymer compound (A) comprising the following repeating units. When the obtained high molecular compound (A) was measured by GPC, it was Mw = 8800 and dispersion degree = 1.87.

<Example 5>
Synthesis of polymer compound (B)
In a 100 ml round bottom flask equipped with a magnetic stirrer, condenser and thermometer, in a nitrogen atmosphere, 4-methacryloyloxy-2-hydroxy-1,3-propane sultone 4.12 g (18.7 mmol), monomer (4) 2.96 g (12.5 mmol), monomer (3) 4.39 g (18.7 mmol), methyl ethyl ketone 35.4 g and 2,2′-azobisisobutyronitrile 0.66 g (4.0 mmol) The polymerization reaction was carried out at 80 ° C. for 4 hours. Next, the obtained reaction mixture was dropped into about 20-fold mass of methanol at room temperature while stirring to obtain a white precipitate. The precipitate was collected by filtration and dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 6.09 g of a polymer compound (B) comprising the following repeating units. When the obtained high molecular compound (B) was measured by GPC, it was Mw = 9500 and dispersity = 1.72.

<Comparative Synthesis Example 1>
Synthesis of polymer compound (C)
In a 100 ml round bottom flask equipped with a magnetic stirrer, a condenser and a thermometer, in a nitrogen atmosphere, 3.18 g (18.7 mmol) of monomer (1), 2.96 g (12.5 mmol) of monomer (4), Monomer (3) 4.39 g (18.7 mmol), methyl ethyl ketone 35.4 g and 2,2′-azobisisobutyronitrile 0.66 g (4.0 mmol) were charged, and a polymerization reaction was carried out at 80 ° C. for 4 hours. It was. Next, the obtained reaction mixture was dropped into about 20-fold mass of methanol at room temperature while stirring to obtain a white precipitate. The precipitate was collected by filtration and dried under reduced pressure (26.7 Pa) at 50 ° C. for 10 hours to obtain 6.06 g of a polymer compound (C) comprising the following repeating units. When the obtained high molecular compound (C) was analyzed by GPC, it was Mw = 10800 and dispersion degree = 1.72.

<Comparative Synthesis Example 2>
Synthesis of polymer compound (D)
In a 100-ml round bottom flask equipped with a magnetic stirrer, a condenser and a thermometer, in a nitrogen atmosphere, 3.82 g (18.7 mmol) of monomer (2), 2.96 g (12.5 mmol) of monomer (4), Monomer (3) 4.39 g (18.7 mmol), methyl ethyl ketone 35.4 g and 2,2′-azobisisobutyronitrile 0.66 g (4.0 mmol) were charged, and a polymerization reaction was carried out at 80 ° C. for 4 hours. It was. Next, the obtained reaction mixture was dropped into about 20-fold mass of methanol at room temperature while stirring to obtain a white precipitate. The precipitate was collected by filtration and dried at 50 ° C. under reduced pressure (26.7 Pa) for 10 hours to obtain 6.15 g of a polymer compound (D) composed of the following repeating units. When the obtained high molecular compound (D) was analyzed by GPC, it was Mw = 11200 and dispersion degree = 1.79.

<Examples 6 to 7 and Comparative Examples 1 and 2> Amount of swelling film thickness in a developer by the QCM method 100 masses of each of the polymer compounds A to D obtained in Examples 4 to 5 and Comparative Synthesis Examples 1 and 2 Parts, 3 parts by mass of TPS-109 (product name, component; nonafluoro-n-butanesulfonic acid triphenylsulfonium, manufactured by Midori Chemical Co., Ltd.) as a photoacid generator, propylene glycol monomethyl ether acetate / ethyl lactate = 1 / 1 (volume ratio) mixed solvent was mixed with each other to prepare four types of photoresist compositions having a polymer compound concentration of 12% by mass.
Each of the obtained photoresist compositions was filtered using a filter [made of tetrafluoroethylene resin (PTFE), pore size 0.2 μm], and then a 1-inch size quartz substrate having a gold electrode vacuum-deposited on the surface thereof. Each was applied by spin coating to form a photosensitive layer having a thickness of about 400 nm. The quartz substrate on which the photosensitive layer is formed is pre-baked on a hot plate at 110 ° C. for 90 seconds, and then exposed using an ArF excimer laser (wavelength: 193 nm) at an exposure amount of 100 mJ / cm ² , followed by 90 ° C. at 90 ° C. Post-exposure bake for seconds.
The quartz substrate was set in a quartz vibrator microbalance device “RQCM” (trade name; manufactured by Maxtek), and developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution for 120 seconds. After the change in frequency of the quartz substrate during development processing was monitored over time, the obtained change in frequency was converted into a change in film thickness, and the change in film thickness with respect to development time was plotted. The film thickness change once increased from the start of development and then turned to decrease, and the difference between the film thickness at the maximum point and the film thickness at 0 hours of development was calculated as the swollen film thickness. The results are shown in Table 1.

<Examples 8 to 9 and Comparative Examples 3 to 4> Two-beam interferometry exposure evaluation 100 parts by mass of each of the polymer compounds A to D obtained in Examples 4 to 5 or Comparative Synthesis Examples 1 to 2 and a photoacid As a generator, 3 parts by mass of TPS-109 (product name, component; nonafluoro-n-butanesulfonate triphenylsulfonium, manufactured by Midori Chemical Co., Ltd.), propylene glycol monomethyl ether acetate / ethyl lactate = 1/1 (volume ratio) Were mixed with each other to prepare four types of photoresist compositions having a polymer compound concentration of 12% by mass.
Each of the obtained photoresist compositions was filtered using a filter [made of tetrafluoroethylene resin (PTFE), pore size: 0.2 μm]. A cresol novolak resin (PS-6937 manufactured by Gunei Chemical Co., Ltd.) is coated with a 6% by weight propylene glycol monomethyl ether acetate solution by a spin coating method, and baked on a hot plate at 200 ° C. for 90 seconds to obtain a film thickness of about 100 nm. Each of the filtrates is applied by spin coating on a silicon wafer having a diameter of 10 cm on which an antireflection film (undercoat film) is formed, and prebaked on a hot plate at 130 ° C. for 90 seconds to have a thickness of about 400 nm. A film was formed.
This resist film was exposed by a two-beam interference method using an ArF excimer laser having a wavelength of 193 nm. Subsequently, the film was post-exposure baked at 130 ° C. for 90 seconds, and then developed with a 2.38% by mass-tetramethylammonium hydroxide aqueous solution for 60 seconds to form a 1: 1 line and space pattern. The developed wafer was cleaved and observed with a scanning electron microscope (SEM), and the pattern shape observation and line width variation (hereinafter referred to as LWR) at an exposure amount obtained by resolving a line and space with a line width of 100 nm at 1: 1. Measured). In the LWR, the line width is detected at a plurality of positions in the measurement monitor, and the dispersion (3σ) of variations in the detected positions is used as an index. The results are shown in Table 2.

  From Tables 1 and 2, in the case of the polymer compounds (A) to (B) containing the acrylate derivative (1) of the present invention in the repeating unit, the polymer not containing the acrylate derivative (1) in the repeating unit. Compared with the compounds (C) to (D), the amount of swollen film during the development process when producing a photoresist is very small and the LWR is improved, so that chemical amplification for semiconductor device production is achieved. It can be said that it is useful as a type resist.

  The acrylate derivative (1) obtained in the present invention is excellent as a lithographic property and is useful as a raw material for a polymer compound for a resist composition that forms a resist pattern having a good shape.

Claims (5)

The following general formula (1)

(In the formula, R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group, and R ² , R ³ and R ⁴ each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a carbon number. Represents 3 to 6 cycloalkyl groups.)
An acrylic ester derivative represented by The acrylic ester derivative according to claim 1, wherein R ² and R ³ are each a hydrogen atom, and R ⁴ is a hydrogen atom or a methyl group. The following general formula (2)

(In the formula, R ² , R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms.)
The alcohol derivative represented by the formula (1) is esterified:

(Wherein R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group). The high molecular compound obtained by superposing | polymerizing the raw material containing the acrylic ester derivative of Claim 1 or 2. A photoresist composition containing the polymer compound according to claim 4.