JP2013227269A - Acrylic ester derivative - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide novel acrylic ester derivatives having excellent lithography properties such as LWR (Line Width Roughness) to achieve high resolution when used as one of the constituent units of a polymer compound to be contained in a photoresist composition.SOLUTION: Acrylic ester derivatives are represented by general formula (1). In the formula, Ris a hydrogen atom or a 1-5C alkyl group; Ris a hydrogen atom, a 1-5C alkyl group, or a 1-5C halogenated alkyl group; X is a 1-5C alkylene group which may include an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom.

Description

  The present invention relates to an acrylate derivative. More specifically, the present invention relates to an acrylate derivative having both an acetal skeleton and a norbornane sultone skeleton.

In recent years, in the field of electronic device manufacturing typified by integrated circuit element manufacturing, there has been an increasing demand for higher integration of devices, and therefore, a photolithography technique for forming a fine pattern is required.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. 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. In addition, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.
Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions.
As a resist material satisfying such requirements, a chemically amplified resist containing a base material component whose solubility in an alkaline developer is changed by the action of an acid and an acid generator that generates an acid upon exposure is used. . Resin (base resin) is mainly used as the base component of the chemically amplified resist.
For example, a positive chemically amplified resist contains, as a base resin, a resin whose solubility in an alkaline developer is increased by the action of an acid. When a resist pattern is formed, an acid is generated from an acid generator by exposure. The solubility of the base resin in an alkaline developer is increased by the action of the acid (see, for example, Patent Document 1).
Moreover, as a negative chemically amplified resist, a base resin that contains a possible resin (alkali-soluble resin) in an alkaline developer and further contains a crosslinking agent is generally used. In such a resist composition, when an acid is generated from an acid generator upon exposure at the time of forming a resist pattern, the base resin and the crosslinking agent react due to the action of the acid, and the solubility of the base resin in an alkaline developer decreases. (For example, refer nonpatent literature 1 and 2.).
Currently, as a resist base resin used in ArF excimer laser lithography and the like, a resin having a structural unit derived from (meth) acrylic acid ester in the main chain (acrylic resin) is excellent in transparency near a wavelength of 193 nm. Resin) is mainly used.
Further, as a polymer compound for a photoresist composition, a polymer compound formed from a structural unit having a norbornane lactone skeleton or a norbornane sultone skeleton through a linking group from an acryloyloxy group has also been proposed (Patent Literature). 2 and 3).

JP 2003-241385 A JP 2001-188346 A International Publication No. 2010/001913

SPIE Advances in Resist Technology and Processing XIV, Vol. 3333, p. 417-424 (1998) SPIE Advances in Resist technology and Processing XIX, Vol. 4690, p. 94-100 (2002)

In the future, development of new materials that can be used for lithography applications is demanded as further advancement of lithography technology and expansion of application fields are expected. As pattern miniaturization progresses, a photoresist material is desired that has improved various lithography properties such as resolution and line width roughness (LWR) and pattern shape more than ever. . Therefore, the development itself of a new compound (monomer) that can be a structural unit of a polymer compound to be contained in a photoresist composition is important.
Accordingly, an object of the present invention is to provide a novel acrylate derivative that is excellent in lithographic properties such as LWR and can have high resolution when used as one of the structural units of a polymer compound contained in a photoresist composition. There is.

The present invention relates to the following [1] to [3].
[1] The following general formula (1)

（式中、Ｒ^１は、水素原子または炭素数１〜５のアルキル基を表し、Ｒ^２は、水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を表す。Ｘは、酸素原子若しくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子を表す。）

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ² represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom.)

An acrylic ester derivative represented by the formula [hereinafter referred to as an acrylic ester derivative (1). ].
[2] The acrylate derivative of the above [1], wherein R ¹ is a hydrogen atom in the general formula (1).
[3] The acrylate ester derivative of the above [1] or [2], wherein, in the general formula (1), X is a methylene group, an ethylene group or an oxygen atom.

  The photoresist composition using the polymer compound obtained by polymerizing the raw material containing the acrylic ester derivative (1) of the present invention is excellent in transparency around 193 nm. Further, since the photoresist composition has an appropriate alkali solubility and the dissolution rate can be controlled, the photoresist pattern swells and collapses (the photoresist pattern collapses during development due to the effect of capillary action). , And the LWR is improved as compared with the prior art, so that a high-resolution photoresist pattern can be formed.

  When the acrylic ester derivative (1) of the present invention is one of the constituent units of a polymer compound contained in the photoresist composition, it is excellent in lithography characteristics such as LWR and high resolution can be obtained. Hereinafter, the acrylic ester derivative (1) will be described in detail.

[Acrylate ester derivative (1)]
The acrylic ester derivative (1) of the present invention is represented by the following general formula (1).

（式中、Ｒ^１は、水素原子または炭素数１〜５のアルキル基を表し、Ｒ^２は、水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基を表す。Ｘは、酸素原子若しくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子を表す。）

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ² represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom.)

In the general formula (1), examples of the alkyl group having 1 to 5 carbon atoms represented by R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, t- A butyl group, n-pentyl group, isopentyl group, s-pentyl group, t-pentyl group and the like can be mentioned. Among these, from the viewpoint of the polarity of the acrylate derivative (1), an alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group is more preferable.
Examples of the halogenated alkyl group having 1 to 5 carbon atoms represented by R ² include a group in which part or all of the alkyl group having 1 to 5 carbon atoms is substituted with a halogen atom such as a fluorine atom. The halogen atom is preferably a fluorine atom, and the halogenated alkyl group is preferably a trifluoromethyl group.
R ¹ is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, from the viewpoint of improving the LWR and obtaining a high-resolution photoresist pattern. R ² is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a methyl group.

In the general formula (1), examples of the alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom represented by X include a methylene group, an ethane-1,2-diyl group (ethylene group), and propane. -1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group and other alkylene groups having 1 to 5 carbon atoms; 2-oxaethane-1 , 2-diyl group, 2-oxapropane-1,3-diyl group, 3-oxapentane-1,5-diyl group and the like, an alkylene group containing 1 to 5 carbon atoms, such as 2-thioethane-1, C1-C5 alkylene groups containing sulfur atoms, such as 2-diyl group, 2-thiopropane-1,3-diyl group, 3-thiopentane-1,5-diyl group, are mentioned.
Among them, X is preferably a methylene group, an ethylene group, or an oxygen atom, more preferably a methylene group, from the viewpoint of improving the LWR and obtaining a high-resolution photoresist pattern.

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) with another polymerizable compound is a photoresist composition. It is useful as a polymer compound for products (especially positive photoresist compositions). By using a photoresist composition containing the polymer compound, there is an effect that a LWR is small and a resist pattern having a good shape can be formed (high resolution can be obtained). The reason why such an effect is obtained is estimated as follows.
The structural unit derived from the acrylate derivative (1) in the polymer compound has the following acetal structure:

（Ｒ^１は前記定義の通りである。）

(R ¹ is as defined above.)

Therefore, it is easily dissociated by the action of an acid, and the dissociation efficiency of the acid dissociable, dissolution inhibiting group is improved. Thereby, it is considered that the difference in solubility (dissolution contrast) between the unexposed portion and the exposed portion in the alkaline developer becomes larger than that of the conventional positive resist composition, and high resolution can be obtained.
Furthermore, since the polymer compound contains a norbornane sultone skeleton, it has a bulky structure as compared with the conventional acetal type acid dissociable, dissolution inhibiting group, so that pattern collapse and film loss are suppressed, and a photo of a good shape is obtained. It is considered that a resist pattern is easily formed. As one of the factors for obtaining a good photoresist pattern shape, it is possible to suppress the diffusion of the acid remaining after exposure or acid treatment by having a cyclic group containing —SO ₂ — which is a polar group. Since the affinity with the developer is improved in the development process, it is presumed that the lithography properties such as LWR are improved.
For the above reasons, it is assumed that the improvement of the lithography characteristics such as LWR and the high resolution have been achieved. In addition, a compound in which a cyclic group containing —SO ₂ — is directly bonded to an acryloyloxy group and a compound in which a cyclic group containing —SO ₂ — is bonded to an acryloyloxy group via a long linking group are known. However, the acrylate derivative (1) of the present invention has a better result in lithography properties such as LWR and resolution than those, and this indicates that the acetal structure and the —SO ₂ — The combination with a cyclic group containing is shown to be important.

(Method for producing acrylic ester derivative (1))
As shown below, the acrylic ester derivative (1) of the present invention is produced by reacting, for example, an alcohol derivative (3) and an aldehyde compound (4) in the presence of an acid to produce an alkyl ether compound (2). Next, it can be produced by esterifying the alkyl ether compound (2) (second step).

（式中、Ｒ^１、Ｒ^２およびＸは、前記定義の通りである。Ｙは、塩素原子、臭素原子またはヨウ素原子を表す。）

(In the formula, R ¹ , R ² and X are as defined above. Y represents a chlorine atom, a bromine atom or an iodine atom.)

(First step)
Although the specific example of the alcohol derivative (3) which can be used as a raw material at a 1st process is shown below, it is not specifically limited to these.

  There is no restriction | limiting in particular about the manufacturing method of alcohol derivative (3) used at a 1st process, It can manufacture by a well-known method. For example, it can be produced by hydrolyzing norbornenesulfonyl chloride, which can be produced from 2-chloroethanesulfonyl chloride and cyclopentadiene, to be converted into a sulfonic acid derivative and then treated with an oxidizing agent (see International Publication No. 2010/026974). ).

Examples of the aldehyde compound (4) used as a raw material in the first step include formaldehyde, acetaldehyde, propionaldehyde, isobutyraldehyde, and pivalaldehyde. Of these, formaldehyde, propionaldehyde, and isobutyraldehyde are preferable, and formaldehyde is more preferable, from the viewpoint of improving the LWR and obtaining a high-resolution photoresist pattern. In addition, it is preferable to use paraformaldehyde which is a precursor as formaldehyde.
The amount of the aldehyde compound (4) used is preferably 0.7 to 10 mol, more preferably 1 to 10 mol, further preferably 1.2 to 5 mol, relative to 1 mol of the alcohol derivative (3). 4 to 2 mol is particularly preferred.

Examples of the acid used in the first step include hydrogen halide gases such as hydrogen chloride gas and hydrogen iodide gas; hydrohalic acids such as hydrochloric acid, hydrobromic acid and hydroiodic acid; Examples thereof include inorganic acids such as nitric acid or aqueous solutions thereof; organic acids such as methanesulfonic acid, p-toluenesulfonic acid, and trichloroacetic acid. In addition, since there exists a possibility that presence of water may suppress progress of reaction, it is preferable to use what is not aqueous solution as an acid. Among these, hydrogen halide gas is preferable from the viewpoint of the reactivity between the alcohol derivative (3) and the aldehyde compound (4), and hydrogen chloride gas is more preferable from the viewpoint of the stability of the generated alkyl ether compound (2). . That is, Y in the general formula (2) is preferably a chlorine atom. When Y is a chlorine atom, the alkyl ether compound (2) can be easily produced, and the acrylic ester derivative (1) described later can be easily produced.
As for the usage-amount of an acid, 1-30 mol is preferable with respect to 1 mol of alcohol derivatives (3), 3-15 mol is more preferable, It is still more preferable to add until the loss | disappearance of an alcohol derivative (3) is confirmed. . The disappearance of the alcohol derivative (3) can be easily confirmed by gas chromatography.

The first step is usually performed in the presence of a solvent. The solvent is not particularly limited as long as it does not inhibit the reaction, and examples thereof include aliphatic hydrocarbons such as pentane, hexane, heptane, and octane; aromatic hydrocarbons such as toluene, xylene, and cymene; methylene chloride, dichloroethane, chloroform, four Halogenated hydrocarbons such as carbon chloride; ethers such as tetrahydrofuran and diisopropyl ether. Of these, dichloromethane, 1,2-dichloroethane, and chloroform are preferable, and dichloromethane is more preferable. A solvent may be used individually by 1 type and may use 2 or more types together. Of these, halogenated hydrocarbons are preferable, and methylene chloride is more preferable.
The amount of the solvent used is preferably 2 parts by mass or more, more preferably 4 to 30 parts by mass, and further 9 to 20 parts by mass with respect to 1 part by mass of the alcohol derivative (3). preferable.

The reaction temperature in the first step varies depending on the type of alcohol derivative (3), aldehyde compound (4), acid or solvent used, etc., but usually from the viewpoint of solubility of raw materials and acids, it is preferably -20 to 20. 30 ° C., more preferably −10 to 10 ° C., still more preferably −10 to 5 ° C. Although there is no restriction | limiting in particular in the reaction pressure of a 1st process, It is simple and preferable to implement under a normal pressure.
There is no restriction | limiting in particular in the reaction time of a 1st process. Usually, it is preferable to react until the disappearance of the alcohol derivative (3) is confirmed.

There is no restriction | limiting in particular in the reaction operation method in a 1st process. There is no restriction | limiting in particular also in the addition methods and order of a raw material, an acid, a solvent, etc., It can add in arbitrary methods and order. As a specific reaction operation method, for example, a method in which an alcohol derivative (3), a solvent and an aldehyde compound (4) are charged in a batch reactor and an acid is added to the obtained mixed solution at a predetermined temperature is preferable. In addition, when using hydrogen halide gas as an acid, the method of blowing this gas into a liquid mixture is employ | adopted preferably.
The first step is preferably carried out in the absence of water. However, it is not necessary to perform dehydration treatment on the raw material or solvent, or to bring the reaction system into an inert gas atmosphere such as nitrogen gas. The reaction can proceed.

  Separation and purification of the alkyl ether compound (2) from the reaction mixture obtained in the first step can be performed by a method generally used for separation and purification of organic compounds. For example, after completion of the reaction, the alkyl ether compound (2) can be separated by concentrating the organic layer, and the concentrated solution may be used as it is in the second step, or, if necessary, recrystallization, distillation, silica gel column chromatography. You may use the high purity alkyl ether compound (2) obtained by refine | purifying by a graphic etc. for a 2nd process.

  Although the specific example of the alkyl ether compound (2) obtained by a 1st process is shown below, it is not specifically limited to these.

(Second step)
Although there is no restriction | limiting in particular in the method of esterification of a 2nd process, For example, the alkyl ether compound (2) obtained at the 1st process, and following General formula (5)

（式中、Ｒ^２は、前記定義の通りである。）

(In the formula, R ² is as defined above.)

A method of reacting an acrylic acid compound represented by formula (hereinafter referred to as acrylic acid compound (5)), preferably in the presence of a base.

  Specific examples of the acrylic acid compound (5) used in the second step include acrylic acid, methacrylic acid, 2- (trifluoromethyl) acrylic acid, and the like. The amount of the acrylic acid compound (5) used is preferably 0.7 to 20 mol with respect to 1 mol of the alkyl ether compound (2) from the viewpoint of economy and ease of post-treatment, More preferably, it is -5 mol, and it is further more preferable that it is 1-5 mol.

Examples of the base that can be used in the second step include alkali metal hydrides such as sodium hydride and potassium hydride; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkali metals such as sodium carbonate and potassium carbonate. Carbonates; tertiary amines such as triethylamine, tributylamine, 4-dimethylaminopyridine; and nitrogen-containing heterocyclic compounds such as pyridine. Among these, weak bases are preferable, tertiary amines and nitrogen-containing heterocyclic compounds are more preferable, tertiary amines are further preferable, and triethylamine is particularly preferable.
In the case of using a base, the amount used is preferably 0.7 to 5 mol with respect to 1 mol of the alkyl ether compound (2) from the viewpoints of economy and ease of post-treatment. More preferably, it is -3 mol, and it is further more preferable that it is 1-3 mol.

The second step can be performed in the presence or absence of a polymerization inhibitor. The polymerization inhibitor is not particularly limited as long as it does not inhibit the reaction. For example, quinone compounds such as hydroquinone, benzoquinone and tolquinone; 2,6-di-tert-butylphenol, 2,4-di-tert-butylphenol, 2 -Alkylphenol compounds such as -tert-butyl-4,6-dimethylphenol, p-tert-butylcatechol, 4-methoxyphenol; amine compounds such as phenothiazine. A polymerization inhibitor may be used individually by 1 type, and may use 2 or more types together. Among these, alkylphenol compounds are preferable, and 4-methoxyphenol is more preferable.
When using a polymerization inhibitor, the amount used is preferably 5% by mass or less, more preferably 1% by mass or less, and further preferably 0.5% by mass or less, based on the total mass of the reaction mixture including the solvent.

The second step is usually performed in the presence of a solvent. The solvent is not particularly limited as long as it does not inhibit the reaction. For example, aliphatic hydrocarbons such as hexane, heptane, and octane; aromatic hydrocarbons such as toluene, xylene, and cymene; halogenated carbons such as methylene chloride and dichloroethane. Hydrogen; ethers such as tetrahydrofuran and diisopropyl ether; amides such as dimethylformamide. These solvents may be used alone or in combination of two or more. Of these, aromatic hydrocarbons and halogenated hydrocarbons are preferable, and toluene and methylene chloride are more preferable.
It is preferable that the usage-amount of a solvent is 0.1-20 mass parts with respect to 1 mass part of alkyl ether compounds (2) from a viewpoint of economical efficiency and the ease of post-processing, and 0.1-10 masses. More preferably, it is a part.

  The reaction temperature in the second step varies depending on the type of alkyl ether compound (2), acrylic acid compound (5), base, polymerization inhibitor and solvent used, but is preferably -50 to 100 ° C. From the viewpoint of inhibiting the polymerization of the acrylic acid compound (5) and the acrylic ester derivative (1) and from the viewpoint of solubility in a solvent such as raw materials and bases, −10 to 50 ° C. is more preferable. More preferably, it is 10-15 degreeC, and it is especially preferable that it is 0-10 degreeC. Although there is no restriction | limiting in particular in the reaction pressure of a 2nd process, It is simple and preferable to implement under a normal pressure.

  The reaction time in the second step varies depending on the type of alkyl ether compound (2), acrylic acid compound (5), base, polymerization inhibitor and solvent used, but usually 0.5 hours to 48 hours. Preferably, 1 hour to 24 hours are more preferable.

The second step is preferably carried out in the absence of water, but the reaction can be carried out sufficiently even without subjecting the raw materials and solvent to a dehydration treatment or an inert gas atmosphere such as nitrogen gas in the reaction system. Can be advanced.
Conversely, in the second step, the reaction can be stopped by adding water. The usage-amount of water should just be 1 mol or more with respect to 1 mol of excess bases. If the amount used is small, the excess base cannot be completely decomposed and a by-product may be produced.

  There is no restriction | limiting in particular in the reaction operation method in a 2nd process. Moreover, there is no restriction | limiting in particular in addition method and order, such as an alkyl ether compound (2), an acrylic acid type compound (5), a polymerization inhibitor, and a solvent, It can add in arbitrary methods and order. As a specific reaction operation method, for example, a batch reactor is charged with an alkyl ether compound (2), an acrylic acid compound (5) and, if desired, a solvent and a polymerization inhibitor. A method of adding a base at a predetermined temperature (dropping if necessary) is preferred.

Separation and purification of the acrylate derivative (1) from the reaction mixture obtained in the second step can be carried out by methods generally used for separation and purification of organic compounds. For example, after completion of the reaction, the reaction mixture is neutralized, extracted with an organic solvent, and the resulting organic layer can be concentrated to separate the acrylate derivative (1). As needed, it can refine | purify by recrystallization, distillation, silica gel column chromatography, etc., and can obtain a highly purified acrylic ester derivative (1).
The acrylic ester derivative (1) can be suitably used as a raw material for a polymer compound for a photoresist composition, regardless of whether it is a single enantiomer or a mixture of enantiomers.

  Specific examples of the acrylic ester derivative (1) are shown below, but are not particularly limited thereto.

≪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) with another polymerizable compound is a photoresist composition. It is useful as a polymer compound for physical use.
The polymer compound has a structural unit (a0) represented by the following general formula (a0).

（式中、Ｒ^１、Ｒ^２およびＸは、前記定義の通りである。）

(Wherein R ¹ , R ² and X are as defined above.)

Specific examples of the structural unit (a0) are shown below. In the following formulas, R ² is preferably a hydrogen atom, a methyl group or a trifluoromethyl group.

The polymer compound contains the structural unit (a0) based on the acrylate derivative (1) in an amount of more than 0 mol% and 100 mol%, from the viewpoint of improving the LWR and obtaining a high-resolution photoresist pattern. Preferably it contains 5-80 mol%, More preferably, it is 10-70 mol%, More preferably, it contains 10-50 mol%.
Specific examples of other polymerizable compounds (hereinafter referred to as copolymerization monomers) that can be copolymerized with the acrylate derivative (1) include, for example, compounds represented by the following chemical formulas. However, it is not limited to these.

In the above formulas (I) to (X), R ³ represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a cyclic hydrocarbon group having 3 to 10 carbon atoms, and R ⁴ represents a polymerizable group-containing group. R ⁵ represents a hydrogen atom or —COOR ⁶ (R ⁶ represents an alkyl group having 1 to 3 carbon atoms). R ⁷ and R ⁸ each independently represents an alkyl group having 1 to 3 carbon atoms. R ⁹ represents an adamantyl group or a tricyclodecanyl group. m represents an integer of 1 to 5.
In the comonomer, examples of the alkyl group having 1 to 3 carbon atoms represented by R ³ and R ⁶ include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. Examples of the cyclic hydrocarbon group having 3 to 10 carbon atoms represented by R ³ include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polymerizable group in the polymerizable group-containing group represented by R ⁴ include an acryloyl group, a methacryloyl group, a vinyl group, and a vinylsulfonyl group.

  Specific examples of the above (I) are shown below, but are not particularly limited thereto.

  Specific examples of the above (II) are shown below, but are not particularly limited thereto.

Specific examples of the above (III) are shown below, but are not particularly limited thereto.

  Although the specific example of said (IV) is shown below, it is not specifically limited to these.

  Specific examples of the above (V) are shown below, but are not particularly limited thereto.

  Specific examples of the above (VI) are shown below, but not limited thereto.

  Specific examples of the above (VII) are shown below, but are not particularly limited thereto.

  Specific examples of the above (VIII) are shown below, but are not particularly limited thereto.

  Specific examples of the above (IX) are shown below, but not limited thereto.

  Although the specific example of said (X) is shown below, it is not specifically limited to these.

  Among the above, the comonomer is preferably a comonomer represented by the above formula (I), (II), (IV), (V) or (VII), more preferably And a comonomer represented by the formula (II) and a comonomer represented by the formula (VII).

<< Manufacture of polymer compounds >>
The polymer compound 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 as well as one or more acrylic ester derivatives (1) and, if necessary, one or more of the above comonomer as necessary. And polymerizing in the presence of a chain transfer agent.
There is no restriction | limiting in particular in the implementation method of radical polymerization, For example, the usual method used when manufacturing acrylic resin, such as solution polymerization method, emulsion polymerization method, suspension polymerization method, block polymerization method, etc. 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-cumi Dialkyl peroxide compounds such as ruperoxide; diacyl peroxide compounds such as benzoyl peroxide and diisobutyryl peroxide; 2,2′-azobisisobutyronitrile, dimethyl-2,2′-azobisisobutyrate, azobisiso Examples include azo compounds such as dimethyl butyrate.
The amount of radical polymerization initiator used is appropriately selected according to the polymerization conditions such as the acrylate derivative (1), copolymerization monomer, chain transfer agent, solvent used and the polymerization temperature used in the polymerization reaction. The total amount of all polymerizable compounds [acrylic ester derivative (1) and comonomer, and so on. The amount is usually preferably 0.005 to 0.2 mol, more preferably 0.01 to 0.15 mol per 1 mol.

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 amount of the solvent used is usually preferably 0.5 to 20 parts by mass and more preferably 1 to 10 parts by mass from the viewpoint of economy with respect to 1 part by mass of the total polymerizable compound.

  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 0.005 to 0.2 mol, more preferably 0.01 to 0.15 mol, per 1 mol of all polymerizable compounds.

The polymerization temperature is usually preferably 40 to 150 ° C., and more preferably 60 to 120 ° C. from the viewpoint of the stability of the polymer compound produced.
The polymerization reaction time 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 is usually preferably 30 minutes. It is -48 hours, More preferably, it is 1 hour-24 hours.
The polymerization reaction is preferably carried out in an inert gas atmosphere such as nitrogen or argon.

The polymer compound 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, hexane, and heptane; alicyclic hydrocarbons such as cyclohexane; aromatic hydrocarbons such as benzene and xylene; methylene chloride, chloroform, chlorobenzene, di- Halogenated hydrocarbons such as chlorobenzene; nitrated 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; acetic acid and the like Carboxylic acids; Esters such as ethyl acetate and butyl acetate; Carbonates such as dimethyl carbonate, diethyl carbonate, and ethylene carbonate; Methanol, ethanol, propanol, isopropyl Include water; alcohols, alcohols such as butanol. You may use these individually by 1 type or in mixture of 2 or more types.
The amount of the solvent used in the reprecipitation operation varies depending on the type of polymer compound and the type of solvent, but is usually preferably 0.5 to 100 parts by mass with respect to 1 part by mass of the polymer compound. From a viewpoint of property, it is more preferable that it is 1-50 mass parts.

Although there is no restriction | limiting in particular in the mass mean molecular weight (Mw) of a high molecular compound, Preferably it is 500-50,000, More preferably, it is 1,000-30,000, More preferably, it is 5,000-15,000. The utility as a component of the photoresist composition mentioned later is high. The mass average molecular weight is a value in terms of standard polystyrene determined by gel permeation chromatograph (GPC) measurement.
The molecular weight distribution (Mw / Mn) of the polymer compound is not particularly limited, but is preferably 1.0 to 3.0, more preferably 1.0 to 2.0. It is highly useful as a component. Such Mw and Mn are values in terms of standard polystyrene determined by gel permeation chromatograph (GPC) measurement.

<< Photoresist composition >>
A photoresist composition is prepared by blending the above-described polymer compound, photoacid generator and solvent, and if necessary, a basic compound, a surfactant and other additives. Hereinafter, each component will be described.

<Photo acid generator>
As the photoacid generator, known photoacid generators conventionally used for chemically amplified resists can be used without particular limitation. Examples of the photoacid generator include onium salt photoacid generators such as iodonium salts and sulfonium salts; oxime sulfonate photoacid generators; bisalkyl or bisarylsulfonyldiazomethane photoacid generators; nitrobenzyl sulfonate light Examples include acid generators; iminosulfonate photoacid generators; disulfone photoacid generators. These may be used individually by 1 type and may use 2 or more types together. Among these, an onium salt photoacid generator is preferable, and the following fluorine-containing onium salt containing a fluorine-containing alkyl sulfonate ion as an anion is preferable from the viewpoint that the strength of the generated acid is strong.

Specific examples of the fluorine-containing onium salt include, for example, diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate; bis (4-tert-butylphenyl) iodonium trifluoromethanesulfonate or nonafluorobutanesulfonate; triphenylsulfonium trifluoromethane. Sulfonate, heptafluoropropane sulfonate or nonafluorobutane sulfonate; tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, heptafluoropropane sulfonate or nonafluorobutane sulfonate; dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethane sulfonate, heptafluoro Propanesulfonate or nonafluorobuta Sulfonate; Triphenylmethane sulfonate, heptafluoropropane sulfonate or nonafluorobutane sulfonate of monophenyldimethylsulfonium; Trifluoromethane sulfonate, heptafluoropropane sulfonate or nonafluorobutane sulfonate of diphenylmonomethylsulfonium; Trifluoro of (4-methylphenyl) diphenylsulfonium L-methanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate; trifluoromethanesulfonate of (4-methoxyphenyl) diphenylsulfonium, heptafluoropropanesulfonate or nonafluorobutanesulfonate; trifluoromethanes of tri (4-tert-butyl) phenylsulfonium Honeto and heptafluoropropane sulfonate or nonafluorobutane sulfonates. These may be used individually by 1 type and may use 2 or more types together.
Moreover, what replaced the anion part of these onium salt by the anion represented by d-camphor-10-sulfonate or a following formula (b1) can be used.

  The blending amount of the photoacid generator is usually preferably 0.1 to 30 parts by mass, more preferably 100 parts by mass with respect to 100 parts by mass of the polymer compound from the viewpoint of ensuring the sensitivity and developability of the photoresist composition. 0.5 to 10 parts by mass.

<Solvent>
Examples of the solvent to be blended in the photoresist composition include propylene glycol monoethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), 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 isopropyl ketone, methyl isobutyl ketone Methyl amyl ketone, cyclopentanone, Ketones such as cyclohexanone diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, ethers such as 1,4-dioxane. These may be used individually by 1 type and may use 2 or more types together.
The amount of the solvent is usually preferably 1 to 50 parts by mass, and preferably 2 to 25 parts by mass with respect to 1 part by mass of the polymer compound.

<Basic compound>
In order to improve the resolution by suppressing the acid diffusion rate in the photoresist film, a basic compound is added to the photoresist composition in an amount that does not impair the characteristics of the photoresist composition as necessary. be able to. 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-butoxycarbonylpyrrolidine, piperidine, tetrazole, morpholine, 4-methylmorpholine, piperazine, 1,4-diazabicyclo [2.2.2 ] Amines such as octane, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine and triethanolamine can be mentioned. These may be used individually by 1 type and may use 2 or more types together.
When a basic compound is blended, the blending amount varies depending on the type of the basic compound used, but is usually preferably 0.01 to 10 mol, more preferably 0.05 to 1 mol of the photoacid generator. ~ 1 mole.

<Surfactant>
In order to improve applicability, the photoresist composition may further contain a surfactant in an amount that does not impair the characteristics of the photoresist composition, if desired.
Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, and the like. These may be used individually by 1 type and may use 2 or more types together.
When the surfactant is blended, the blending amount is usually preferably 2 parts by mass or less with respect to 100 parts by mass of the polymer compound.

<Other additives>
Furthermore, the photoresist composition has other additives such as organic acids such as salicylic acid, sensitizers, antihalation agents, shape improvers, storage stabilizers, antifoaming agents, etc. It can be blended in an amount that is not inhibited.

(Photoresist pattern formation method)
A photoresist composition is applied to a substrate, usually pre-baked at 70 to 160 ° C. for 1 to 10 minutes, irradiated with radiation through a predetermined mask (exposure), and preferably at 1 to 5 at 70 to 160 ° C. A predetermined resist pattern can be formed by post-exposure baking for minutes to form a latent image pattern and then developing with a developer.

For exposure, various wavelengths of radiation, such as ultraviolet rays and X-rays, can be used. For semiconductor resists, excimer lasers such as g-line, i-line, XeCl, KrF, KrCl, ArF, and ArCl are usually used. However, among these, it is preferable to use an ArF excimer laser from the viewpoint of fine processing.
Exposure amount is preferably from 0.1~1000mJ / cm ^2, and more preferably 1 to 500 mJ / cm ^2.

Examples of the developer include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate and aqueous ammonia; alkylamines such as ethylamine, diethylamine and triethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; tetramethylammonium hydroxy And an alkaline aqueous solution in which a quaternary ammonium salt such as tetraethylammonium hydroxide is dissolved. Among these, it is preferable to use an alkaline aqueous solution in which a quaternary ammonium salt such as tetramethylammonium hydroxide or tetraethylammonium hydroxide is dissolved.
In general, the concentration of the developer is preferably from 0.1 to 20% by mass, and more preferably from 0.1 to 10% by mass.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not restrict | limited at all by these Examples.
In the analysis by NMR, the internal standard of ¹ H-NMR and the internal standard of ¹³ C-NMR is tetramethylsilane (TMS). The internal standard of ¹⁹ F-NMR is hexafluorobenzene (however, the peak of hexafluorobenzene was set to −160 ppm).

<Example 1>
Synthesis of 5-hydroxy-2,6-norbornane sultone (alcohol derivative):
A four-necked flask with an internal volume of 2 L equipped with a stirrer and a thermometer was charged with 0.80 g of phenothiazine, 2308.1 g of tetrahydrofuran (THF), and 174.0 g (2.64 mol) of cyclopentadiene and stirred at 5 ° C. or less. Cooled to. Next, 391.4 g (2.40 mol) of 2-chloroethanesulfonyl chloride and 293.45 g (2.9 mol) of triethylamine were put in separate dropping funnels, respectively, and dripping was simultaneously performed at an internal temperature of 5 to 10 ° C. over 4 hours. It was.
After completion of the dropwise addition, the reaction mixture was stirred at 5 to 10 ° C. for 5 hours, and then the precipitated salt was filtered under reduced pressure. The filtrate is referred to as “filtrate (A)”). The filtrate (A) was analyzed by gas chromatography and found to contain 356.4 g (1.85 mol) of 5-norbornene-2-sulfonyl chloride (yield: 77.1% based on 2-chloroethanesulfonyl chloride). ).
1800 g of water was placed in a three-necked flask having an internal volume of 5 L equipped with a stirrer and a thermometer, and cooled to 20 ° C. or lower. While stirring, 160.6 g (4.02 mol) of sodium hydroxide was added so that the internal temperature would be 20 ° C. or lower. 2600 g of filtrate (A) (5-norbornene-2-sulfonyl chloride: 283.8 g (1.474 mol)) was added dropwise at an internal temperature of 20 to 25 ° C. over 5 hours.
One hour after the completion of the dropwise addition, the reaction mixture was analyzed by gas chromatography. As a result, 5-norbornene-2-sulfonyl chloride had completely disappeared. The reaction mixture was concentrated under reduced pressure to remove THF, then transferred to a 5 L separatory funnel and washed three times with 600 g of toluene to obtain 2144.6 g of an aqueous solution containing 5-norbornene-2-sulfonic acid sodium salt. (This aqueous solution is referred to as “aqueous solution (A)”).
All of the aqueous solution (A) was put into a three-necked flask having an internal volume of 5 L equipped with a stirrer and a thermometer, and cooled to 10 ° C. After 186.54 g (4.02 mol) of 99% formic acid was added dropwise at an internal temperature of 10 to 15 ° C., the mixture was heated to an internal temperature of 50 to 52 ° C., and 325.0 g (2. 86 mol) was added dropwise over 3 hours. The internal temperature was maintained at around 50 ° C. even after completion of the dropwise addition, and the reaction mixture was analyzed by high performance liquid chromatography (HPLC) 21 hours after the completion of the dropwise addition. As a result, the conversion of 5-norbornene-2-sulfonic acid was 99. 2%.
After cooling the reaction mixture to 15 ° C., 73.1 g (0.58 mol) of sodium sulfite was slowly added at an internal temperature of 10 to 16 ° C., and it was confirmed that no hydrogen peroxide was detected by starch paper. 9 g (3.36 mol) was slowly added at an internal temperature of 12 to 15 ° C. to adjust the pH of the reaction mixture to 7.2. Extraction was performed twice with 1800 g of ethyl acetate, and the obtained organic layers were combined and concentrated under reduced pressure to obtain 141.9 g of a yellowish white solid. This solid was dissolved in 280 g of ethyl acetate at 50 ° C., and then slowly cooled to 10 ° C., and the precipitated crystals were filtered. The crystals separated by filtration were washed with 70 g of ethyl acetate at 5 ° C. and dried under reduced pressure at 40 ° C. for 2 hours, whereby 113.2 g of 5-hydroxy-2,6-norbornane sultone having the following structure (purity: 99.3%) , 0.6 mol) (yield 40.4% based on 5-norbornene-2-sulfonyl chloride).

¹ H-NMR (400 MHz, CDCl ₃ , TMS, ppm) δ: 1.72 (1H, dd, J = 11.6, 1.6 Hz), 2.06-2.1 (3H, m), 2. 22 (1H, dd, J = 11.2, 1.6 Hz), 2.44 (1H, m), 3.44 (1H, m), 3.50-3.53 (1H, m), 3. 93 (1H, brs), 4.61 (1H, d, J = 4.8 Hz)

Production of 5-chloromethoxy-2,6-norbornane sultone (first step):
In a three-necked flask with an internal volume of 300 mL equipped with a stirrer and a thermometer, 25.1 g (0.132 mol) of 5-hydroxy-2,6-norbornane sultone obtained by the synthesis of the above (alcohol derivative), paraformaldehyde 6 .6 g (0.22 mol) and 230 g of dichloromethane were charged and cooled to 5 ° C. or lower with stirring. Next, hydrogen chloride gas was blown in, and disappearance of the alcohol (5-hydroxy-2,6-norbornane sultone) was confirmed by gas chromatography.
After completion of the reaction, a liquid separation operation was performed to remove the aqueous layer, and 234.5 g (5-hydroxy-2) of a dichloromethane solution containing 24.1 g (0.1 mol) of 5-chloromethoxy-2,6-norbornane sultone having the following structure , 6-norbornane sultone, yield 76.5%).

¹ H-NMR (400 MHz, CDCl ₃ , TMS, ppm) δ: 1.67-1.76 (1H, m), 2.01-2.18 (3H, m), 2.62 (1H, m) 3.40-3.46 (1H, m), 3.48-3.53 (1H, m), 3.91 (1H, d, J = 1.7 Hz), 4.74 (1H, d, J = 4.6 Hz), 5.45-5.54 (2H, m)

Methacrylic acid-4-oxa-5-thio-5,5-dioxide - tricyclo [4,2,1,0 ^3,7] Production of nonyl-2-oxymethyl (Second Step):
A dichloromethane solution containing 24.1 g (0.1 mol) of 5-chloromethoxy-2,6-norbornane sultone obtained in the first step in a three-necked flask with an internal volume of 300 mL equipped with a stirrer and a thermometer 234. 5 g, 0.035 g (0.28 mmol) of 4-methoxyphenol and 10.7 g (0.124 mol) of methacrylic acid were charged. Subsequently, 11.9 g (0.118 mol) of triethylamine was added dropwise over 30 minutes at an internal temperature of 2 to 8 ° C. with stirring.
After completion of dropping, the mixture was stirred at 25 ° C. for 2 hours, and 150 g of water was added. Subsequently, the aqueous layer obtained by liquid separation was extracted twice with 100 g of ethyl acetate, and the obtained organic layers were combined and washed with 100 g of water, and then concentrated under reduced pressure to obtain 28.7 g of a brown solid. Obtained. By purifying this solid by silica gel column chromatography (developing solvent: hexane / ethyl acetate = 3/7), methacrylic acid-4-oxa-5-thio-5,5-dioxide-tricyclo [4, having the following structure: 2,1,0 ^3,7] was obtained nonyl-2-oxymethyl 10.49g (0.036mol, 31.6% yield based on 5-chloro-methoxy-2,6-norbornane sultone).

¹ H-NMR (400 MHz, CDCl ₃ , TMS, ppm) δ: 1.68 (1H, dd, J = 11.5, 1.6 Hz), 1.96 (3H, s), 2.04-2. 13 (3H, m), 2.54 (1H, brs), 3.38-3.49 (2H, m), 3.80 (1H, d, J = 1.4 Hz), 4.69 (1H, d, J = 4.8 Hz), 5.37 (2H, dd, J = 9.5, 6.4 Hz), 5.66 (1H, s), 6.17 (1H, s)

<Example 2>
Synthesis of 2-hydroxy-4,8-dioxa-5-thiatricyclo [4.2.1.0 ^3,7 ] nonane = 5,5-dioxide (alcohol derivative):
As a raw material, methyl vinyl sulfonate was obtained from Angew. Chem. , 77 (7), 291-302 (1965). Specifically, first, 326.0 g (2.00 mol) of 2-chloroethanesulfonyl chloride was placed under a nitrogen atmosphere in a 2 L four-necked flask equipped with a stirrer, a thermometer, a dropping funnel, and a three-way cock. After cooling in an ice bath, 25 mass% sodium methoxide (methanol solution) was added dropwise from the dropping funnel so that the internal temperature was in the range of 2 to 5 ° C. After completion of dropping, the ice bath was removed and the mixture was stirred at room temperature for 1 hour. The reaction solution was filtered, the filtrate was concentrated under reduced pressure, and the concentrate was subjected to simple evaporation to obtain 197.2 g (purity 97.3%, 1.571 mol) of methyl vinyl sulfonate (2-chloroethanesulfonyl). (Yield 78.5% based on chloride).

Next, 2-hydroxy-4,8-dioxa-5-thiatricyclo [4.2.1.0 ^3,7 ] nonane = 5,5-dioxide, which is the target product, is described in JP-A-2007-31355. Was synthesized according to Example 2.
A 300 mL four-necked flask equipped with a stirrer, a dropping funnel and a thermometer was charged with 150 g of furan (2.20 mol) and 15.0 g of zinc iodide at 25 to 27 ° C. from the dropping funnel. Methyl 41.5 g (0.34 mol) was added. After stirring for 2 days at the same temperature, the reaction solution was transferred to a 1 L separatory funnel. After washing twice with 300 mL of water, unreacted furan was distilled off under reduced pressure to obtain 22.0 g of methyl 7-oxabicyclo [2.2.1] heptan-2-ene-5-sulfonate.
To a 1000 mL four-necked flask equipped with a stirrer, a dropping funnel and a thermometer, 22.0 g of methyl 7-oxabicyclo [2.2.1] heptan-2-ene-5-sulfonate and 450 g of methylene chloride were added. Were sequentially cooled to 4 ° C., and 22.9 g (0.17 mol) of m-chloroperbenzoic acid was slowly added with stirring to a temperature of 10 ° C. or lower. After stirring at 5-7 ° C. for 4 hours, 100 g of a saturated aqueous sodium sulfite solution was added and stirred for 30 minutes. The mixture was allowed to stand for liquid separation, and then washed with 100 g of a saturated aqueous sodium hydrogen carbonate solution three times. The obtained organic layer was concentrated under reduced pressure to obtain 20.2 g of methyl 2,3-epoxy-7-oxabicyclo [2.2.1] heptan-2-ene-5-sulfonate.
A 300 mL internal volume four-necked flask equipped with a stirrer, a dropping funnel and a thermometer was charged with 5.0 (mol / L) sodium hydroxide aqueous solution, and 2,3-epoxy-7-oxabicyclo was added from the dropping funnel. [2.2.1] Methyl heptane-2-ene-5-sulfonate (29.5 g) was added dropwise in the range of 20 to 23 ° C. After stirring for 4 hours after the completion of dropping, concentrated hydrochloric acid was added dropwise while cooling with ice water to adjust the pH to 7.3, followed by extraction four times with 300 mL of ethyl acetate, and the combined organic layers were concentrated and concentrated. The concentrate was separated and purified by silica gel column chromatography to give 2-hydroxy-4,8-dioxa-5-thiatricyclo [4.2.1.0 ^3,7 ] nonane = 5,5-dioxide 4.75 g. (Purity 98.8%, 0.024 mol) was obtained.

¹ H-NMR (400 MHz, CD ₃ OD, TMS, ppm) δ: 2.17 (1H, dd, J = 2.6, 14.4 Hz), 2.28 (1H, ddd, J = 5.5, 10.7, 14.4 Hz), 3.81 (1 H, ddd, J = 2.6, 4.9, 10.7 Hz), 3.92 (1 H, s), 4.54 (1 H, d, J = 5.5 Hz), 4.65 (1H, dd, J = 1.4, 4.8 Hz), 5.52 (1H, dd, J = 4.8, 4.8 Hz)

Production of 2-chloromethoxy-4,8-dioxa-5-thiatricyclo [4.2.1.0 ^3,7 ] nonane = 5,5-dioxide (first step):
2-hydroxy-4,8-dioxa-5-thiatricyclo [4.2.1.0 ^3,7 ] nonane = 5,5-dioxide was added to a 100 mL four-necked flask equipped with a stirrer and a thermometer. 4.0 g (20.8 mmol), 1.04 g of paraformaldehyde (34.7 mmol in terms of formaldehyde) and 32.4 g of methylene chloride were charged and cooled to 5 ° C. or lower while stirring. Subsequently, hydrogen chloride gas was blown in, and disappearance of 2-hydroxy-4,8-dioxa-5-thiatricyclo [4.2.1.0 ^3,7 ] nonane = 5,5-dioxide was confirmed by gas chromatography.
After the reaction, a liquid separation operation was performed to remove the aqueous layer, and 2-chloromethoxy-4,8-dioxa-5-thiatricyclo [4.2.1.0 ^3,7 ] nonane = 5,5-dioxide 3.78 g. 32.6 g of a methylene chloride solution containing (15.7 mmol) was obtained (yield 75%).

¹ H-NMR (400 MHz, CDCl ₃ , TMS, ppm) δ: 2.28-2.44 (2H, m), 3.68 (1H, m), 4.13 (1H, s), 4.70 (1H, m), 4.86 (1H, m), 5.52 (3H, m)

Production of 2-methacryloxymethoxy-4,8-dioxa-5-thiatricyclo [4.2.1.0 ^3,7 ] nonane = 5,5-dioxide (second step):
In a four-necked flask with an internal volume of 100 ml equipped with a stirrer and a thermometer, 2-chloromethoxy-4,8-dioxa-5-thiatricyclo [4.2.1.0 ^3,7 ] nonane = 5,5- 10.0 g of methylene chloride solution containing 1.16 g (4.82 mmol) of dioxide, 1 mg of 4-methoxyphenol, and 0.52 g (6.0 mmol) of methacrylic acid were charged. Subsequently, 0.57 g (5.64 mmol) of triethylamine was added dropwise over 30 minutes at an internal temperature of 2 to 9 ° C. with stirring.
After completion of dropping, the mixture was stirred at 10 ° C. for 30 minutes, and 10 g of water was added. Subsequently, liquid separation was performed, and the obtained organic layer was concentrated under reduced pressure to obtain 2.54 g of a residue. This residue was recrystallized using ethyl acetate as a solvent, and 2-methacryloxymethoxy-4,8-dioxa-5-thiatricyclo [4.2.1.0 ^3,7 ] nonane = 5,5-dioxide 1.17 g. (4.03 mmol) was obtained (yield 84%).

¹ H-NMR (400 MHz, CDCl ₃ , TMS, ppm) δ: 1.96 (3H, s), 2.26-2.40 (2H, m), 3.66 (1H, m), 4.06 (1H, s), 4.77 (1H, m), 4.83 (1H, m), 5.43 (2H, m), 5.52 (1H, m), 5.71 (1H, m) 6.20 (1H, m)

<Synthesis Example 1 of Polymer Compound>
Synthesis of polymer compound (a):
In a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, 11.95 g (50.55 mmol) of the compound (II-2) represented by the following chemical formula (II-2), 17.75 g of methyl ethyl ketone, and cyclohexanone 17 .75 g was added and dissolved and heated to 80 ° C. In this solution, 19.34 g (84.75 mmol) of compound (VII-10) represented by the following chemical formula (VII-10), 2.99 g (12.64 mmol) of compound (II-2), obtained in Example 1 methacrylic acid-4-oxa-5-thio-5,5-dioxide - as tricyclo [4,2,1,0 ^3,7] nonyl-2-oxymethyl 11.41g (39.56mmol) and a polymerization initiator A solution prepared by dissolving 4.31 g (18.75 mmol) of dimethyl 2,2′-azobisisobutyrate in a mixed solution of 42.44 g of methyl ethyl ketone and 42.44 g of cyclohexanone was added dropwise over 4 hours under a nitrogen atmosphere.
After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization liquid is dropped into a large amount of n-heptane to precipitate a polymer, and the precipitated white powder is filtered off, washed with methanol and dried, and the following polymer compound (a) 28. 78 g was obtained.
With respect to this polymer compound (a), the weight average molecular weight (Mw) in terms of standard polystyrene determined by gel permeation chromatography (GPC) measurement was 9,200, and the molecular weight distribution (Mw / Mn) was 1.68. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by ¹³ C-NMR (600 MHz) is 1 / m / n = 45.2 / 33.7 / 21.1. Met.

<Synthesis Example 2 of polymer compound>
Synthesis of polymer compound (b):
11.95 g (50.55 mmol) of compound (II-2), 17.75 g of methyl ethyl ketone and 17.75 g of cyclohexanone were dissolved in a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, and the mixture was dissolved at 80 ° C. Heated. In this solution, 19.34 g (84.75 mmol) of compound (VII-10), 2.99 g (12.64 mmol) of compound (II-2), compound (IV-2) represented by the following chemical formula (IV-2) ) 8.79 g (39.56 mmol) and 4.31 g (18.75 mmol) of dimethyl 2,2′-azobisisobutyrate as a polymerization initiator dissolved in a mixed solution of 42.44 g of methyl ethyl ketone and 42.44 g of cyclohexanone, The solution was added dropwise over 4 hours under a nitrogen atmosphere.
After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization liquid is dropped into a large amount of n-heptane to precipitate a polymer, and the precipitated white powder is filtered off, washed with methanol and dried to obtain a polymer compound (b ) 26.32 g was obtained.
With respect to this polymer compound (b), the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 7,800, and the molecular weight distribution (Mw / Mn) was 1.91. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by ¹³ C-NMR (600 MHz) is 1 / m / n = 45.1 / 33.8 / 21.1. Met.

<Synthesis Example 3 of Polymer Compound>
Synthesis of polymer compound (c):
11.95 g (50.55 mmol) of compound (II-2), 17.75 g of methyl ethyl ketone and 17.75 g of cyclohexanone were dissolved in a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, and the mixture was dissolved at 80 ° C. Heated. In this solution, 19.34 g (84.75 mmol) of compound (VII-10), 2.99 g (12.64 mmol) of compound (II-2), compound (VI-2) represented by the following chemical formula (VI-2) ) 7.84 g (39.56 mmol) and 4.31 g (18.75 mmol) of dimethyl 2,2′-azobisisobutyrate as a polymerization initiator were dissolved in a mixed solution of 42.44 g of methyl ethyl ketone and 42.44 g of cyclohexanone. The solution was added dropwise over 4 hours under a nitrogen atmosphere.
After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization liquid is dropped into a large amount of n-heptane to precipitate a polymer, and the precipitated white powder is filtered off, washed with methanol and dried to obtain the target polymer compound (c ) 26.58 g was obtained.
With respect to this polymer compound (c), the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 10,300, and the molecular weight distribution (Mw / Mn) was 1.86. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by ¹³ C-NMR (600 MHz) is 1 / m / n = 45.2 / 33.7 / 21.1. Met.

<Synthesis Example 4 of polymer compound>
Synthesis of polymer compound (d):
11.95 g (50.55 mmol) of compound (II-2), 17.75 g of methyl ethyl ketone and 17.75 g of cyclohexanone were dissolved in a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, and the mixture was dissolved at 80 ° C. Heated. To this solution, 19.34 g (84.75 mmol) of compound (VII-10), 2.99 g (12.64 mmol) of compound (II-2), compound (IX-2) represented by the following chemical formula (IX-2) ) A solution prepared by dissolving 10.22 g (39.56 mmol) and 4.31 g (18.75 mmol) of dimethyl 2,2′-azobisisobutyrate as a polymerization initiator in a mixed solution of 42.44 g of methyl ethyl ketone and 42.44 g of cyclohexanone, The solution was added dropwise over 4 hours under a nitrogen atmosphere.
After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization liquid is dropped into a large amount of n-heptane to precipitate a polymer, and the precipitated white powder is filtered off, washed with methanol and dried to obtain the target polymer compound (d ) 27.12 g was obtained.
With respect to this polymer compound (d), the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 8,800, and the molecular weight distribution (Mw / Mn) was 1.75. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by ¹³ C-NMR (600 MHz) is 1 / m / n = 45.2 / 33.7 / 21.1. Met.

<Synthesis Example 5 of Polymer Compound>
Synthesis of polymer compound (e):
11.95 g (50.55 mmol) of compound (II-2), 17.75 g of methyl ethyl ketone and 17.75 g of cyclohexanone were dissolved in a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, and the mixture was dissolved at 80 ° C. Heated. In this solution, 19.34 g (84.75 mmol) of compound (VII-10), 2.99 g (12.64 mmol) of compound (II-2), compound (IX-5) represented by the following chemical formula (IX-5) ) A solution prepared by dissolving 12.51 g (39.56 mmol) and 4.31 g (18.75 mmol) of dimethyl 2,2′-azobisisobutyrate as a polymerization initiator in a mixed solution of 42.44 g of methyl ethyl ketone and 42.44 g of cyclohexanone, The solution was added dropwise over 4 hours under a nitrogen atmosphere.
After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization liquid is dropped into a large amount of n-heptane to precipitate a polymer, and the precipitated white powder is filtered, washed with methanol and dried to obtain a polymer compound (e ) 28.54 g was obtained.
With respect to this polymer compound (e), the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 9,000, and the molecular weight distribution (Mw / Mn) was 1.72. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by ¹³ C-NMR (600 MHz) is 1 / m / n = 45.2 / 33.7 / 21.1. Met.

<Synthesis Example 6 of polymer compound>
Synthesis of polymer compound (f):
11.95 g (50.55 mmol) of compound (II-2), 17.75 g of methyl ethyl ketone and 17.75 g of cyclohexanone were dissolved in a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, and the mixture was dissolved at 80 ° C. Heated. To this solution, 19.34 g (84.75 mmol) of compound (VII-10), 2.99 g (12.64 mmol) of compound (II-2), 2-methacryloxymethoxy-4,8-dioxa-5-thiatricyclo [ 4.2.1.0 ^3,7 ] nonane = 5,5-dioxide 11.48 g (39.56 mmol) and 4.31 g (18.75 mmol) of dimethyl 2,2′-azobisisobutyrate as a polymerization initiator were added to methyl ethyl ketone 42. A solution dissolved in a mixed solution of .44 g and cyclohexanone 42.44 g was added dropwise over 4 hours under a nitrogen atmosphere.
After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization solution was dropped into a large amount of n-heptane to precipitate a polymer, and the precipitated white powder was filtered off, washed with methanol and dried, and the following polymer compound (f) 28. 02 g was obtained.
With respect to this polymer compound (f), the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 9,400, and the molecular weight distribution (Mw / Mn) was 1.70. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by ¹³ C-NMR (600 MHz) is 1 / m / n = 45.0 / 33.8 / 21.2. Met.

<Preparation of photoresist composition (1)>
(Reference Examples 1 and 19; Comparative Examples 1 to 4)
100 parts by mass of the polymer compounds (a), (b), (c), (d), (e), and (f) obtained in Synthesis Examples 1 to 6 of the polymer compound, a photoacid generator "TPS-109" (product name, component; nonafluoro-n-butanesulfonic acid triphenylsulfonium, manufactured by Midori Chemical Co., Ltd.) 4.5 parts by mass, solvent as propylene glycol monomethyl ether acetate / cyclohexanone mixed solvent (mass ratio = 1: 1) 1896 parts by mass of the mixture were mixed to prepare a photoresist composition of each example.

[Formation of resist pattern]
The photoresist composition in each example was filtered using a membrane filter having a pore size of 0.2 μm.
Next, a cresol novolak resin (“PS-6937” manufactured by Gunei Chemical Industry Co., Ltd.) is applied with a 6% by mass propylene glycol monomethyl ether acetate solution by a spin coating method and heated on a hot plate at 200 ° C. for 90 seconds. The photoresist composition of each example was applied by a spin coating method on a silicon wafer having a diameter of 10 cm on which an antireflection film (underlayer film) having a thickness of 100 nm was formed, and was heated at 130 ° C. for 90 seconds on a hot plate. Pre-baking was performed to form a 300 nm thick resist film. 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.

[Evaluation]
The developed wafer was cleaved and observed with a scanning electron microscope (SEM), and the pattern shape observation and line width variation (LWR) of the exposure amount obtained by resolving the line-and-space with a line width of 100 nm at 1: 1. Measurements were made.
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. Moreover, the cross-sectional shape of the pattern was observed using a scanning electron microscope (SEM), and the pattern having high rectangularity was evaluated as “good”, and the pattern having low shortness was evaluated as “defective”. The results are shown in Table 1.

  From Table 1, the photoresist composition containing the polymer compound (a) or (f) containing the structural unit based on the acrylic ester derivative (1) of the present invention is the acrylic ester derivative ( Compared with a photoresist composition containing a polymer compound not containing 1) (polymer compounds (b) to (e)), a well-shaped photoresist pattern could be formed, and the LWR was improved. That is, it was possible to achieve both formation of a high-resolution photoresist pattern and reduction of LWR.

<Synthesis Example 7 of Polymer Compound>
<Synthesis of Polymer Compound 1>
21.6 g of 10.0 g (34.71 mmol) of compound (1) and 6.24 g (26.63 mmol) of compound (2) were added to a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube. In methyl ethyl ketone (MEK). To this solution, 0.77 mmol of dimethyl azobisbutyrate (V-601) was added as a polymerization initiator and dissolved. The resultant was dropwise added to 16.24 g of MEK heated to 80 ° C. in a nitrogen atmosphere over 3 hours. After completion of dropping, the reaction solution was heated and stirred for 4 hours, and then the reaction solution was cooled to room temperature.
The obtained reaction polymerization solution was dropped into a large amount of a normal heptane / 2-propanol mixed solution to precipitate a polymer, and the precipitated white powder was separated by filtration, into a normal heptane / 2-propanol mixed solution, methanol. After washing and drying, 11.3 g of the target polymer compound 1 was obtained.
For this polymer compound 1, the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 7,300, and the molecular weight dispersity (Mw / Mn) was 1.82. The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m = 60/40. .

<Synthesis Examples 8 to 26 of polymer compound>
<Synthesis of polymer compounds 2-20>
Synthesis was performed in the same manner as in <Polymer Compound Synthesis Example 7> using predetermined amounts of the following compounds (1) to (12), to obtain polymer compounds 2 to 20, which were target products.
About the obtained high molecular compounds 1-20, the mass mean molecular weight (Mw) and the molecular weight dispersion degree (Mw / Mn) were written together in Table 2,3.

<Preparation of photoresist composition (2)>
(Reference Examples 2-18, Comparative Examples 5-7)
The photoresist compositions of each example were prepared by mixing and dissolving the components shown in Tables 4 and 5.

In Tables 4 and 5, each symbol has the following meaning. The numerical value in [] is a blending amount (part by mass).
(A) -1 to (A) -20: The polymer compounds 1 to 20, respectively.
(B) -1: a compound represented by the following structural formula (B) -1.
(B) -2: A compound represented by the following structural formula (B) -2.
(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(S) -1: PGMEA.
(S) -2: PGME.

  Using the obtained photoresist composition, a resist pattern was formed according to the following procedure, and the following evaluations were performed. The evaluation results (lithographic properties of the photoresist composition) are shown in Table 6.

[Formation of resist pattern]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a film thickness of 89 nm was formed.
Then, the photoresist composition of each example is applied onto the organic antireflection film using a spinner, prebaked (PAB) at a hot plate temperature of 110 ° C. for 60 seconds, and dried. Thus, a resist film having a thickness of 90 nm was formed.
Next, a protective film forming coating solution “TILC-057” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied onto the resist film using a spinner and heated at 90 ° C. for 60 seconds. A top coat having a thickness of 35 nm was formed.
Next, an ArF excimer laser (193 nm) using an ArF exposure apparatus NSR-609B (manufactured by Nikon; NA (numerical aperture) = 1.07, Cross pole (in / out = 0.78 / 0.97) with Polaro) Was selectively irradiated to the resist film having the top coat formed thereon through a mask.
Then, a post-exposure heating (PEB) treatment for 60 seconds was performed at the temperature shown in Table 6, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, Tokyo, Japan) at 23 ° C. (Oka Kogyo Co., Ltd.) was subjected to alkali development for 10 seconds, rinsed with pure water for 15 seconds, and then shaken and dried.
Subsequently, post-baking was performed on a hot plate at 100 ° C. for 45 seconds.
As a result, a 1: 1 line and space (LS) pattern having a line width of 49 nm and a pitch of 98 nm was formed.

The optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming the LS pattern was determined. The results are also shown in Table 6. Further, the limit resolution (nm) in the above Eop is also shown in Table 6 (in Table 6, the limit resolution is expressed as “resolution (nm)”).

[LWR (line width roughness) evaluation]
In the LS pattern formed by the Eop, the line width was measured at 400 points in the longitudinal direction of the line with a length measuring SEM (scanning electron microscope, acceleration voltage 300V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). Then, a triple value (3 s) of the standard deviation (s) was obtained from the result, and an averaged value for 3 s at 400 locations was calculated as a scale indicating LWR. The results are shown in Table 6.
A smaller value of 3s means that the roughness of the line width is smaller, and an LS pattern having a more uniform width is obtained.

[Evaluation of resist pattern shape]
In the LS pattern formed by Eop, the cross-sectional shape of the formed LS pattern was observed using a scanning electron microscope (trade name: SU-8000, manufactured by Hitachi High-Technology Corporation), and the shape was evaluated as follows. Evaluation was made according to the criteria. The results are shown in Table 6.
(Evaluation criteria)
○: High rectangularity and good shape.
X: Tapered shape (bottom shape).

  From Table 6, the photoresist composition containing the high molecular compounds 1-17 containing the structural unit based on the acrylic ester derivative (1) of this invention contains the acrylic ester derivative (1) of this invention. As compared with the photoresist composition containing the polymer compound (polymer compounds 18 to 20) that does not, a photoresist pattern having a good shape can be formed, and the LWR is improved. That is, it was possible to achieve both formation of a high-resolution photoresist pattern and reduction of LWR.

  The acrylic ester derivative (1) of the present invention is useful as a raw material for a polymer compound for a photoresist composition that has an improved LWR and forms a high-resolution resist pattern, and is useful in the production of semiconductors and printed boards. It is.

Claims (3)

The following general formula (1)

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ² represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom.)
An acrylic ester derivative represented by The acrylic ester derivative according to claim 1, wherein R ¹ in formula (1) is a hydrogen atom.   The acrylic ester derivative according to claim 1 or 2, wherein X in the general formula (1) is a methylene group, an ethylene group or an oxygen atom.