Preparation of tertiary ester-containing aromatic vinyl monomer

Abstract

To provide a novel method for preparing a tertiary ester-containing aromatic vinyl monomer, characterized by higher efficiency and higher quality than in the conventional formulation, the monomer being applicable in resist compositions for EB lithography and EUV (wavelength 13.5 nm) lithography.SOLUTION: The present invention provides a method for preparing a tertiary ester-containing aromatic vinyl monomer by using a metal alkoxide as a reaction promoter.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing a tertiary ester-containing aromatic vinyl monomer. [Background technology]

[0002] In recent years, the increasing integration of integrated circuits has led to a demand for finer pattern formation, and chemically amplified resists using acid as a catalyst are used exclusively for processing patterns of 0.2 μm or less. In addition, high-energy rays such as ultraviolet rays, far ultraviolet rays, and electron beams (EB) are used as exposure sources for this purpose, and electron beam lithography, which is used as an ultrafine processing technology, is also indispensable as a processing method for photomask blanks when producing photomasks for semiconductor manufacturing.

[0003] Polymers having a large amount of aromatic skeletons with acidic side chains, such as polyhydroxystyrene, have been usefully used as materials for resist compositions for KrF lithography using KrF excimer lasers, but have not been used as materials for resist compositions for ArF lithography using ArF excimer lasers because they exhibit high absorption for light with wavelengths of around 200 nm. However, they are important materials for resist compositions for EB lithography and extreme ultraviolet (EUV) lithography, which are effective techniques for forming patterns smaller than the processing limit of ArF excimer lasers, because they provide high etching resistance.

[0004] As the base polymer of a positive EB lithography resist composition or an EUV lithography resist composition, a material is mainly used that uses an acid generated from a photoacid generator by irradiation with high energy rays as a catalyst to deprotect an acid-labile protecting group (acid labile group) masking an acidic functional group of a phenol side chain of the base polymer, and dissolves it in an alkaline developer. As the acid-labile protecting group, a tertiary alkyl group, a tert-butoxycarbonyl group, an acetal group, etc. have been mainly used. Here, the use of a protecting group such as an acetal group, which requires a relatively small activation energy for deprotection, has the advantage of being able to obtain a highly sensitive resist film, but if the diffusion of the generated acid is not sufficiently suppressed, a deprotection reaction will occur even in the unexposed parts of the resist film, leading to problems such as deterioration of line edge roughness (LER) and deterioration of pattern dimensional uniformity (CDU).

[0005] It has been pointed out that a resist composition for ArF lithography containing a polymer in which a carboxyl group such as methacrylic acid is substituted with an acid labile group swells in an alkaline developer. On the other hand, a resist composition for KrF lithography containing a polymer in which a phenol group such as hydroxystyrene is substituted with an acid labile group swells less. However, hydroxystyrene has a large acid diffusion property, which may lead to a decrease in resolution. In addition, a structural unit in which a carboxyl group of styrene carboxylic acid is substituted with an acid labile group has also been proposed (Patent Documents 1 to 3).

[0006] A method for producing a tertiary ester-containing vinyl aromatic monomer by converting a carboxy group of styrene carboxylic acid, vinyl naphthalene carboxylic acid, etc. into a tertiary ester has been reported (Patent Documents 1-3). Specifically, a method for producing a tertiary ester-containing styrene monomer by using a corresponding tertiary alcohol, deriving a styrene carboxylic acid, etc. into a corresponding acid chloride, and carrying out an esterification reaction in the presence of an organic base such as triethylamine, and a method for producing a tertiary ester-containing styrene monomer by reacting an acid chloride of styrene carboxylic acid with a tertiary alkoxide generated by reacting an organometallic reagent with a ketone compound have been proposed. However, there are many problems, such as the conversion rate of the reaction, anionic polymerization during the reaction, and competition.

[0007] In order to meet the future demands for finer resist patterns, it is important to improve the production method for tertiary ester-containing vinyl aromatic monomers, and there is a demand for the development of an efficient and high-quality production method for tertiary ester-containing vinyl aromatic monomers. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2006-335715 A [Patent Document 2] Patent No. 7055070 [Patent Document 3] Patent No. 6694451 Summary of the Invention [Problem to be solved by the invention]

[0009] In acid-catalyzed chemically amplified resist compositions, tertiary ester-containing vinyl aromatic monomers have been attracting attention for fine pattern formation. It is desirable to develop a method for producing tertiary ester-containing vinyl aromatic monomers that are more efficient and of higher quality than conventional methods.

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a novel method for producing a tertiary ester-containing vinyl aromatic monomer that is more efficient and of higher quality than conventional formulations, particularly for use in resist compositions for EB lithography and resist compositions for 13.5 nm EUV lithography. [Means for solving the problem]

[0011] As a result of intensive research conducted by the present inventors in order to achieve the above-mentioned object, it was found that the use of a metal alkoxide as a reaction accelerator in the production of a tertiary ester-containing aromatic vinyl monomer is extremely effective in obtaining a high-quality tertiary ester-containing aromatic vinyl monomer in a higher yield than conventional production methods, and thus the present invention was completed.

[0012] That is, the present invention provides the following method for producing a tertiary ester-containing aromatic vinyl monomer. 1. A method for producing a tertiary ester-containing aromatic vinyl monomer using a metal alkoxide as a reaction accelerator. 2. A method for producing a tertiary ester-containing aromatic vinyl monomer according to 1, comprising reacting an N-acylimidazole compound with a tertiary alcohol compound using a metal alkoxide as a reaction promoter. 3. A method for producing a tertiary ester-containing aromatic vinyl monomer according to 2, wherein the N-acylimidazole compound is represented by the following formula (A1), the tertiary alcohol compound is represented by the following formula (A2), and the tertiary ester-containing aromatic vinyl monomer is represented by the following formula (A3). [ka] (In the formula, n1 is 0 or 1. n2 is 1 or 2. n3 is an integer from 0 to 6. However, when n1 is 0, 1≦n2+n3≦5, and when n1 is 1, 1≦n2+n3≦7. R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R 1represents a halogen atom, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom. R L1 , R L2 and R L3 are each independently a hydrocarbyl group having 1 to 30 carbon atoms; R L1 , R L2 and R L3 Any two of the above may be bonded to each other to form a ring together with the carbon atom to which they are bonded. In addition, -CH2- contained in the hydrocarbyl group and the ring group may be substituted with -O- or -S-. 4. The method for producing a tertiary ester-containing aromatic vinyl monomer according to any one of 1 to 3, wherein the metal alkoxide is an alkali metal alkoxide or an alkaline earth metal alkoxide. 5. The method for producing a tertiary ester-containing aromatic vinyl monomer according to 4, wherein the metal alkoxide is an alkali metal alkoxide. 6. The method for producing a tertiary ester-containing aromatic vinyl monomer according to 5, wherein the cation of the alkali metal alkoxide is a sodium cation or a potassium cation. 7. The method for producing a tertiary ester-containing aromatic vinyl monomer according to 5 or 6, wherein the anion of the alkali metal alkoxide is an alkoxide anion bonded to a tertiary carbon atom. Effect of the Invention

[0013] By using the production method of the present invention, it is possible to obtain a high-quality tertiary ester-containing aromatic vinyl monomer in high yield. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The method for producing a tertiary ester-containing aromatic vinyl monomer of the present invention is characterized by using a metal alkoxide as a reaction promoter. Specifically, the method uses a metal alkoxide as a reaction promoter to react a tertiary alcohol compound with an N-acylimidazole compound to produce a tertiary ester-containing aromatic vinyl monomer.

[0015] The N-acylimidazole compound is preferably one represented by the following formula (A1) (hereinafter also referred to as compound (A1)), the tertiary alcohol compound is preferably one represented by the following formula (A2) (hereinafter also referred to as compound (A2)), and the resulting tertiary ester-containing aromatic vinyl monomer is preferably one represented by the following formula (A3) (hereinafter also referred to as compound (A3)). [ka]

[0016] In formulae (A1) and (A3), n1 is 0 or 1. When n1 is 0, it represents a benzene ring, and when n1 is 1, it represents a naphthalene ring, but from the viewpoint of solvent solubility, it is more preferable that n1 is 0 and is a benzene ring. n2 is 1 or 2. n3 is an integer of 0 to 6, with the proviso that 1≦n2+n3≦5 when n1 is 0, and 1≦n2+n3≦7 when n1 is 1.

[0017] In formulas (A1) and (A3), R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Of these, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred.

[0018] In formulas (A1) and (A3), R 1 represents a halogen atom, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom.

[0019] R 1 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom or an iodine atom being preferred.

[0020] R 1The hydrocarbyl group represented by the formula (I) and the hydrocarbyl portion of the hydrocarbyloxy group may be saturated or unsaturated and may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl groups; cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl groups; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl groups; cyclic unsaturated hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl groups; aryl groups having 2 to 20 carbon atoms, such as phenyl and naphthyl groups; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl groups; and groups obtained by combining these groups. Of these, aryl groups are preferred. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH2- constituting the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, etc. When n3≧2, a plurality of R 1 may be bonded to each other to form a ring structure together with the carbon atoms on the aromatic ring to which they are attached.

[0021] The compound having an N-acylimidazole structure represented by formula (A1) is preferably obtained by mixing the corresponding aromatic carboxylic acid with N,N-carbonyldiimidazole, and more preferably used in the next reaction without purification after being generated in the reaction system.

[0022] The aromatic carboxylic acid which is a precursor of the compound having an N-acylimidazole structure represented by formula (A1) is preferably an aromatic carboxylic acid having a styrene carboxylic acid or a vinyl naphthalene carboxylic acid structure which may have a substituent, and may be commercially available or may be procured by using a known organic synthesis reaction.

[0023] In formulas (A2) and (A3), R L1 , R L2 and R L3 are each independently a hydrocarbyl group having 1 to 30 carbon atoms; R L1 , R L2 and R L3 Any two of these may be bonded to each other to form a ring together with the carbon atom to which they are bonded. In addition, -CH2- contained in the hydrocarbyl group and the ring group may be substituted with -O- or -S-.

[0024] In formulae (A2) and (A3), -C(R L1 )(R L2 )(R L3 Specific examples of the structure (acid labile group) represented by the formula (I) include, but are not limited to, those shown below. In the following formula, * represents a bond to the adjacent hydroxy group. [ka]

[0025] [ka]

[0026] [ka]

[0027] [ka]

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] [ka]

[0032] [ka]

[0033] [ka]

[0034] [ka]

[0035] In the reaction of compound (A1) with compound (A2), the amount of compound (A2) used is not particularly limited, but from the viewpoint of obtaining compound (A3) in good yield, the amount is preferably 1.0 to 2.0 mol, more preferably 1.0 to 1.5 mol, per 1 mol of compound (A1).

[0036] In the reaction of compound (A1) with compound (A2), a metal alkoxide is used as a reaction promoter to obtain compound (A3) in good yield. The metal alkoxide is preferably an alkali metal alkoxide or an alkaline earth metal alkoxide.

[0037] Examples of the alkali metal alkoxide include lithium alkoxide, sodium alkoxide, potassium alkoxide, etc., and from the viewpoint of procurement and preparation, sodium alkoxide or potassium alkoxide is preferable. Examples of the alkaline earth metal alkoxide include magnesium alkoxide, calcium alkoxide, strontium alkoxide, etc., and from the viewpoint of procurement and preparation, magnesium alkoxide is preferable.

[0038] The metal alkoxide is preferably an alkali metal alkoxide.

[0039] Examples of the anion of the metal alkoxide include an alkoxide anion bonded to a primary carbon atom, an alkoxide anion bonded to a secondary carbon atom, and an alkoxide anion bonded to a tertiary carbon atom, with an alkoxide anion bonded to a tertiary carbon atom being preferred.

[0040] Examples of the alkoxide anion bonded to the tertiary carbon atom include t-butoxy anion, t-amyloxy anion, 1-adamantyloxy anion, etc., and t-butoxy anion is preferred from the viewpoint of availability. Alternatively, an alkoxide anion obtained by deprotonating the hydroxyl group in the compound (A2) may be separately prepared and used in the reaction.

[0041] The alkoxide anion obtained by deprotonation of the hydroxy group in compound (A2) can be prepared by reacting compound (A2) with an alkali metal hydride such as sodium hydride or potassium hydride, or an organometallic reagent such as n-butyllithium or a Grignard reagent, but is not limited to these.

[0042] The amount of the metal alkoxide used is preferably 0.01 to 0.4 mol, and more preferably 0.01 to 0.2 mol, per 1 mol of compound (A1).

[0043] In the reaction between compound (A1) and compound (A2), a solvent may be used. The solvent is not particularly limited as long as it is a solvent that does not react with compound (A1) and compound (A2). For example, aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as hexane, heptane, octane, and cyclohexane; ether solvents such as diethyl ether, diisopropyl ether, t-butyl methyl ether, tetrahydrofuran, and dioxane; and polar aprotic solvents such as acetonitrile, N,N-dimethylformamide, and N,N-dimethylacetamide. The solvent may be used alone or in combination of two or more. The amount of the solvent used may be appropriately set, but is usually about 100 to 500 parts by mass relative to 100 parts by mass of compound (A1).

[0044] In the reaction between compound (A1) and compound (A2), a polymerization inhibitor may be added to suppress polymerization in the reaction system. Examples of the polymerization inhibitor include, but are not limited to, hydroquinone monomethyl ether, hydroquinone, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-t-butylpyrocatechol, t-butylhydroquinone, dibutylhydroxytoluene, phenothiazine, copper salts, etc. The polymerization inhibitor may be used alone or in combination of two or more.

[0045] In the reaction between compound (A1) and compound (A2), the reaction temperature may be any temperature used in a typical esterification reaction. From the viewpoint of shortening the reaction time, the reaction temperature is preferably from 40° C. to the boiling point of the solvent used, and more preferably 100° C. or less, and even more preferably 80° C. or less, in order to suppress side reactions, polymerization reactions, etc. The reaction time varies depending on the reaction temperature, etc., so it may be appropriately determined, but is usually preferably about 0.5 to 30 hours.

[0046] It is preferable to purify the compound (A3) obtained by the reaction of the compound (A1) with the compound (A2). The purification of the compound (A3) can be carried out by appropriately combining known purification methods such as washing with alkaline water, washing with water, distillation, recrystallization, and filtration, taking into consideration the physical properties of the product and the type of solvent. EXAMPLES

[0047] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The apparatus used is as follows. IR: Thermo Fisher Scientific, NICOLET 6700 · 1 H-NMR: ECA-500 manufactured by JEOL Ltd.

[0048] [1] Synthesis of monomer [Example 1] Synthesis of Monomer A3-1-1 [ka]

[0049] In a nitrogen atmosphere, N,N-carbonyldiimidazole (102.2 g) was suspended in toluene (270 g) in a reaction vessel, and 4-styrenecarboxylic acid (88.9 g) was added thereto. After confirming that the reaction system was transparent with foaming, the temperature in the reaction vessel was raised to 50°C and aged for 2 hours. After aging, t-butoxypotassium (3.37 g) was added. After the addition, 2-methyl-3-buten-2-ol (62.0 g) was added dropwise. After the dropwise addition, the temperature in the reaction vessel was raised to 80°C and aged for 24 hours. Thereafter, the reaction liquid was cooled, and a 1% by mass aqueous sodium hydroxide solution (150 g) was added to stop the reaction. Thereafter, a normal aqueous work-up was performed, the solvent was distilled off, and then the product was purified by distillation to obtain 122.0 g of Monomer A3-1 as a colorless oil (yield 94%).

[0050] IR spectrum data of monomer A3-1 and 1 The H-NMR results are shown below. IR(D-ATR): ν= 3089, 2981, 2936, 1714, 1644, 1630, 1608, 1567, 1507, 1470, 1403, 1379, 1365, 1312, 1285, 1236, 1201, 1178, 1166, 1136, 1105, 1016, 989, 917, 861, 783, 713, 683, 433 cm -1 . 1 H-NMR(600MHz in DMSO-d6): δ= 7.87(2H, d), 7.58(2H, d), 6.80 (1H, dd), 6.17 (1H, dd), 5.96(1H,d), 5.40(1H, d), 5.25(1H, d), 5.10(1H, d), 1.59(6H, s) ppm.

[0051] [Examples 2 to 10] Using the corresponding raw materials, monomers having the structures shown in Tables 1 and 2 were synthesized according to the recipe of Example 1. Each N-acylimidazole intermediate shown as A1 in the following table was synthesized from the corresponding aromatic carboxylic acid and N,N-carbonyldiimidazole, and was used in the next step as it was after being synthesized in the reaction system. The structures of the raw materials (A1 and A2) used and the obtained monomer (A3) are shown in Tables 1 and 2 below.

[0052] [Table 1]

[0053] [Table 2]

[0054] [Comparative Example 1] Synthesis of Monomer A3-1-2 [ka]

[0055] Under a nitrogen atmosphere, a solution of 2-methyl-3-buten-2-ol (51.7 g) dissolved in THF (100 mL) was added dropwise to methyl magnesium chloride (3.0 mol / L THF solution, 200 mL) in an ice bath and stirred for 1 hour. Then, a solution of an acid chloride prepared from p-styrene carboxylic acid (106.7 g) dissolved in THF (100 mL) was added dropwise in an ice bath and stirred at room temperature for 3 hours. Then, the reaction solution was cooled and saturated sodium bicarbonate water (250 g) was added to stop the reaction. Insoluble matter precipitated in the reaction solution, so these were filtered off, toluene (400 mL) was added to the filtrate to extract the target product, and a normal aqueous work-up was performed. After distilling off the solvent, the product was purified by silica gel column chromatography to obtain 38.9 g of monomer A1 as a colorless oil (yield 30%).

[0056] [Comparative Example 2] Synthesis of Monomer A3-1-3 [ka]

[0057] Under a nitrogen atmosphere, p-styrene carboxylic acid (106.7 g) was suspended in toluene (500 mL) and oxalyl chloride (109.7 g) was added dropwise. After the addition, the temperature in the reaction vessel was raised to 50°C and aged for 6 hours. Then, the reaction solution was cooled to room temperature and the solvent was concentrated to obtain an acid chloride. 2-methyl-3-buten-2-ol (51.7 g), 4-dimethylaminopyridine (7.3 g), and acetonitrile (450 mL) were added thereto and cooled in an ice bath. A solution consisting of triethylamine (85.0 g) and acetonitrile (50 mL) was added dropwise while maintaining the temperature in the reaction vessel at 20°C or less. After the addition, the temperature in the reaction vessel was raised to 60°C and aged for 18 hours. Then, the reaction solution was cooled and saturated sodium bicarbonate water (250 g) was added to stop the reaction. Extraction with toluene (400 mL), normal aqueous work-up, removal of the solvent, and purification by silica gel column chromatography gave 22.1 g of Monomer A1 as a colorless oil (yield 17%).

[0058] [Comparative Example 3] Synthesis of Monomer A3-1-4 [ka]

[0059] Under a nitrogen atmosphere, p-styrene carboxylic acid (88.9 g), pyridine (189.8 g), and 2-methyl-3-buten-2-ol (62.0 g) were dissolved in N,N-dimethylacetamide (216 g). The temperature in the reaction vessel was raised to 50°C, and a solution consisting of p-toluenesulfonyl chloride (137.3 g) and N,N-dimethylacetamide (120 g) was dropped, and the temperature in the reaction vessel was raised to 70°C and aged for 18 hours. Thereafter, the reaction liquid was cooled, and a 5% by mass aqueous sodium hydroxide solution (360 g) was added to stop the reaction. The mixture was extracted with toluene (600 mL), and a normal aqueous work-up was performed. After the solvent was distilled off, the mixture was purified by distillation to obtain 62.3 g of Monomer A1 as a colorless oil (yield 48%).

[0060] As described above, by using the method for producing a tertiary ester-containing aromatic vinyl monomer of the present invention, it is possible to obtain a high-quality monomer in a higher yield than by existing production methods.

Claims

1. A method for producing a tertiary ester-containing aromatic vinyl monomer using a metal alkoxide as a reaction accelerator.

2. 2. The method for producing a tertiary ester-containing aromatic vinyl monomer according to claim 1, wherein the N-acylimidazole compound is reacted with a tertiary alcohol compound using a metal alkoxide as a reaction accelerator.

3. The method for producing a tertiary ester-containing aromatic vinyl monomer according to claim 2, wherein the N-acylimidazole compound is represented by the following formula (A1), the tertiary alcohol compound is represented by the following formula (A2), and the tertiary ester-containing aromatic vinyl monomer is represented by the following formula (A3). 【Chemistry 1】 (In the formula, n1 is 0 or 1. n2 is 1 or 2. n3 is an integer from 0 to 6. However, when n1 is 0, 1≦n2+n3≦5, and when n1 is 1, 1≦n2+n3≦7. R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R 1 represents a halogen atom, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom. R L1 , R L2 and R L3 are each independently a hydrocarbyl group having 1 to 30 carbon atoms; R L1 , R L2 and R L3 Any two of the above may be bonded to each other to form a ring together with the carbon atoms to which they are bonded. 2 - may be replaced by -O- or -S-.

4. The method for producing a tertiary ester-containing aromatic vinyl monomer according to any one of claims 1 to 3, wherein the metal alkoxide is an alkali metal alkoxide or an alkaline earth metal alkoxide.

5. 5. The method for producing a tertiary ester-containing aromatic vinyl monomer according to claim 4, wherein the metal alkoxide is an alkali metal alkoxide.

6. 6. The method for producing a tertiary ester-containing aromatic vinyl monomer according to claim 5, wherein the cation of the alkali metal alkoxide is a sodium cation or a potassium cation.

7. 6. The method for producing a tertiary ester-containing aromatic vinyl monomer according to claim 5, wherein the anion of the alkali metal alkoxide is an alkoxide anion bonded to a tertiary carbon atom.

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