JP2000119588A - (meth)acrylic acid ester derivative, acid-responding polymer and resin composition for photoresist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition, quickly dissolving into a developing liquid by an irradiation of a light, capable of forming a fine pattern stably and in a high precision, and excellent in resolution by containing a polymer having a specific structural unit and a photo acid generating agent. SOLUTION: This acid-responding polymer contains a polymer having a structural unit of the formula (R is H or methyl; X, Y are each a single bond or O, and at least one of X, Y is the single bond) and a photoacid generating agent (e.g.; a diazonium salt, an iodonium salt, etc., and diphenyliodohexafluorophosphate, etc.). The polymer is used in forming a resist pattern for a fine processing, etc., of a semiconductor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoresist resin composition for use in forming a resist pattern such as microfabrication of a semiconductor, and an acid-sensitive polymer useful for producing the photoresist resin composition. The present invention relates to (meth) acrylate derivatives and ε-caprolactone derivatives.

[0002]

2. Description of the Related Art To form a fine pattern of a semiconductor integrated circuit, a substrate on which a thin film is formed is covered with a resist, a latent image of a desired pattern is formed by selective exposure, and a resist pattern is formed by development. A lithography technique for performing a dry etching using this pattern as a mask and thereafter removing a resist to obtain a desired pattern is used. In this lithography technology,
Ultraviolet rays such as g-rays and i-rays are used as the exposure source, but with the miniaturization of patterns, radiations such as far ultraviolet rays with shorter wavelengths, vacuum ultraviolet rays, excimer laser beams, electron beams, and X-rays are used. It has become so.

In order to form a fine pattern using an exposure source having a short wavelength (such as an ArF excimer laser) as described above, the resist used is excellent in transparency at the wavelength of the exposure source, and has good adhesion to a substrate. , Dry etching resistance, and excellent developer solubility during development.

Japanese Patent Application Laid-Open No. Hei 9-73173 discloses a photoresist suitable for a short-wavelength exposure source, a structural unit which is protected with an alicyclic hydrocarbon group such as adamantane and which is eliminated by an acid to become alkali-soluble. There has been proposed a resist material containing a polymer containing and a acid generator. Since this resist material does not contain an aromatic ring, it is transparent to the above-mentioned ArF excimer laser light and the like, and has excellent dry etching resistance. However, during development, the resist material does not have sufficient releasability of the protective part due to the acid generated by light irradiation, and may not be rapidly dissolved in the developer. Therefore, it cannot be said that the resolution (photosensitivity, sensitivity) is sufficient.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photoresist resin composition which can be rapidly dissolved in a developer by the action of an acid generated by light irradiation and can form a fine pattern stably and with high precision. And an acid-sensitive polymer useful for obtaining the resin composition for a photoresist and a raw material compound thereof.

Another object of the present invention is to provide a photoresist resin composition capable of forming a resist film having excellent adhesion to a substrate, and an acid-sensitive polymer useful for obtaining the photoresist resin composition. It is to provide the starting compound.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, when a polymer containing a structural unit having a specific cyclic group is used as a resin for a photoresist, light irradiation The acid generated from the photoacid generator allows the cyclic group site to be rapidly eliminated from the polymer, and the polymer and the eliminated component can be easily dissolved and removed in a developing solution. The inventors have found that the efficiency can be greatly improved, and completed the present invention.

That is, the present invention provides the following formula (1)

Embedded image (Wherein, R represents a hydrogen atom or a methyl group; X and Y
Represents the same or different and represents a single bond or an oxygen atom. However, at least one of X and Y is a single bond) and a resin composition for a photoresist containing a polymer having a structural unit represented by formula (I) and a photoacid generator.

The present invention also provides the following formula (1a)

Embedded image (Wherein, R represents a hydrogen atom or a methyl group; X ¹ and Y ¹
Represents the same or different and represents a single bond or an oxygen atom. However, when X ¹ is a single bond, Y ¹ is an oxygen atom and X ¹
When Y is an oxygen atom, Y ¹ is a single bond).

The present invention further provides the following formula (2a):

Embedded image (Wherein, R represents a hydrogen atom or a methyl group; X ¹ and Y ¹
Represents the same or different and represents a single bond or an oxygen atom. However, when X ¹ is a single bond, Y ¹ is an oxygen atom and X ¹
(Wherein is an oxygen atom, Y ¹ is a single bond).

The present invention further provides the following formula (3a):

Embedded image (Wherein X ¹ and Y ¹ are the same or different and represent a single bond or an oxygen atom. However, when X ¹ is a single bond, Y ¹ is an oxygen atom, and when X ¹ is an oxygen atom, to provide ε- caprolactone derivative represented by Y ¹ is a single bond).

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the above formula (1), R represents a hydrogen atom or a methyl group, and X and Y each represent a single bond or an oxygen atom. However, at least one of X and Y is a single bond.
That is, in the formula (1), the structure of the cyclic portion is any one of the following three formulas (4), (5) and (6).

[0013]

Embedded image The structural unit represented by the formula (1a) corresponds to the structural unit represented by the formula (1) whose cyclic portion has the structure of the above (5) or (6).

The polymer having the structural unit represented by the formula (1) may have only one type of the structural unit,
You may have two or more types. The polymer having the structural unit represented by the formula (1) is represented by the following formula (2)

Embedded image (Wherein, R, X, and Y are the same as described above) (meta)
It can be obtained by homopolymerization of an acrylate derivative or copolymerization with a copolymerizable monomer.

Among the (meth) acrylate derivatives represented by the formula (2), a derivative in which X and Y are both a single bond can be obtained, for example, by the following formula.
In the formula, R has the same meaning as described above.

[0016]

Embedded image That is, isophorone (7) is reacted with hydrogen peroxide to give isophorone oxide (8) (epoxidation), and then this isophorone oxide (8) is hydrogenated to give 3-hydroxy-3,5,5-trimethylcyclohexanone (3b). )
Then, the compound (3b) is reacted with (meth) acrylic acid (9) or a derivative thereof (esterification) to produce a corresponding (meth) acrylate derivative (2b).

The above epoxidation reaction is usually carried out in a solvent such as methanol or water, in the presence of an alkali such as sodium hydroxide, using an excess of hydrogen peroxide. The reaction temperature is, for example, about 0 to 50 ° C. Note that, instead of hydrogen peroxide, a peracid such as m-chloroperbenzoic acid (MCPBA), perbenzoic acid, peracetic acid, and trifluoroperacetic acid can also be used. After completion of the reaction, the reaction product can be purified by conventional separation and purification means such as extraction, concentration, and distillation.

The above-mentioned hydrogenation reaction is carried out, for example, at a temperature of 0 to 5 in the presence of a conventional hydrogenation catalyst such as a palladium catalyst.
The reaction can be carried out at about 0 ° C. under normal pressure or under pressure.
The hydrogenation reaction product can be purified by conventional separation and purification means such as filtration, crystallization, and recrystallization.

In the esterification method, (i) compound (3b) and (meth) acrylic acid (9) are reacted with an acid catalyst such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, and a strongly acidic cation exchange resin. (Ii) a method of reacting compound (3b) with a (meth) acrylic halide in the presence of a base such as triethylamine, and (iii)
A method in which the compound (3b) is transesterified with the (meth) acrylic ester in the presence of a transesterification catalyst may be mentioned. In the methods (i) and (ii), the reaction can be carried out under ordinary esterification conditions. Also,
In the above method (iii), the transesterification reaction may be carried out using a conventional transesterification catalyst such as sodium alkoxide, aluminum alkoxide, titanate, or the like. By using vinyl, C _2-4 alkenyl (meth) acrylate such as isopropenyl (meth) acrylate, and using a Group 3 element compound of the periodic table as a transesterification catalyst, compound (2b) can be obtained in high yield. Obtainable.

In the transesterification reaction using the compound of the Group 3 element in the Periodic Table, preferred Group 3 elements of the Periodic Table include rare earth elements such as samarium. Examples of the group 3 element compounds of the periodic table include simple metals, halides (eg, chloride, bromide, iodide, etc.), oxides, hydroxides, and inorganic acid salts (eg, nitrate, sulfate, phosphate, Coordination of carbonates, etc., organic acid salts (eg, acetate, trifluoroacetate, trifluoromethanesulfonate, etc.), alkoxides, complexes (eg, acetylacetone, cyclopentadienyl, pentamethylcyclopentadienyl, etc.) And the like as a child). The amount of the transesterification catalyst to be used is, for example, about 0.1 to 100 mol%, preferably about 0.5 to 30 mol%, relative to compound (3b). The amount of the (meth) acrylic acid ester to be used is, for example, from 0.5 to 1 mol of the compound (3b).
It is about 5 mol. The transesterification is carried out in the presence or absence of a solvent (e.g., hydrocarbons, ketones, ethers, aprotic polar solvent and the like) at 0 to 150C,
Preferably, it can be performed at a temperature of about 25 to 120 ° C. This reaction may be performed in the presence of an oxime such as cyclohexanone oxime and acetophenone oxime. The amount of oxime used is based on the amount of compound (3b)
For example, it is about 0.1 to 100 mol%. The reaction product can be purified by conventional separation and purification means.

Among the (meth) acrylate derivatives represented by the formula (2), the compound represented by the formula (2a) can be obtained, for example, by the following formula. In addition,
In the formula, R has the same meaning as described above.

[0022]

Embedded image That is, the compound (3b) obtained by the above method is reacted with a peroxide such as a peracid, hydrogen peroxide, or alkyl hydroperoxide to give a corresponding ε-caprolactone derivative (3a), and then the ε-caprolactone derivative By reacting (3a) with (meth) acrylic acid (9) or a derivative thereof (esterification), the corresponding (meth)
The acrylate derivative (2a) can be obtained.
The ε-caprolactone derivative (3a) and the (meth) acrylate derivative (2a) thus obtained are novel compounds.

Examples of the peracid include m-chloroperbenzoic acid (MCPBA), perbenzoic acid, peracetic acid, and trifluoroperacetic acid. The reaction of the compound (3b) with a peroxide such as a peracid is usually carried out in a solvent such as methylene chloride, if necessary, in the presence of a base such as sodium hydrogen carbonate at a temperature of about -40 to 50 ° C. Will be The amount of the peroxide such as a peracid is used per 1 mole of the compound (3b).
For example, it is about 1 to 3 mol. By this reaction, two regioisomers, that is, a compound (β-hydroxy-) of formula (3a) wherein X ¹ is a single bond and Y ¹ is an oxygen atom
β, δ, δ-trimethyl-ε-caprolactone) and X
^A compound in which ¹ is an oxygen atom and Y ¹ is a single bond (δ-hydroxy-β, β, δ-trimethyl-ε-caprolactone) is produced. Although it depends on the reaction conditions, the former compound is often produced preferentially. The reaction product can be purified by conventional separation and purification means such as filtration, liquid property adjustment, extraction, distillation, and column chromatography.

Compound (3a) and (meth) acrylic acid (9)
Alternatively, the reaction with the derivative thereof can be carried out according to the reaction between the compound (3b) and the (meth) acrylic acid (9) or a derivative thereof. In the reaction, only one of the two regioisomers may be used as the compound (3a), or a mixture of the two regioisomers may be used. The reaction product can be purified by conventional separation and purification means.

The copolymerizable monomer used for producing the copolymer of the (meth) acrylate derivative represented by the formula (2) includes, for example, an unsaturated carboxylic acid [(meth) acrylic acid]. , Fumaric acid, maleic acid, itaconic acid, etc.], esters of the unsaturated carboxylic acids [unsaturated carboxylic acids and aliphatic, alicyclic or aromatic alcohols which may have a substituent, phenols, hydroxy Esters with lactones (such as β-hydroxy-β-methyl-δ-valerolactone)], (meth) acrylonitrile, and styrene monomers.

Preferred copolymerizable monomers include the following formula (1)
0)

Embedded image [Wherein, R ^a represents a hydrogen atom or a methyl group, and R ^b represents the following formula (11) or (12)

Embedded image (Wherein, R ¹ , R ² , and R ³ each represent a hydrogen atom or an aliphatic or alicyclic hydrocarbon group, and ring A is an alicyclic hydrocarbon ring which may have a substituent. And n represents 0 or 1), Z represents a single bond or a linking group], and a (meth) acrylate derivative represented by the formula: Esters of acids or itaconic acids are included. When a polymer containing such a (meth) acrylic acid ester derivative or the like as a comonomer is used as a photoresist resin, the etching resistance is greatly improved due to the hydrophobicity of the ring A, and the silicon wafer protection during plasma exposure is improved. Can be significantly increased.

Examples of the aliphatic hydrocarbon group for R ¹ , R ² and R ³ include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, isopentyl and 1-methylbutyl. , 1
-Ethylpropyl, hexyl, isohexyl, 1-methylpentyl, 1-ethylbutyl, 1-methylhexyl,
1-ethylpentyl, 1-propylbutyl, octyl,
Examples thereof include an alkyl group having about 1 to 10 carbon atoms, preferably about 1 to 6 (particularly about 1 to 4), such as isooctyl, 1-ethylhexyl, nonyl, and decyl groups. Examples of the alicyclic hydrocarbon group, for example, cyclopropyl,
And cycloalkyl groups such as cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, and cyclodecyl groups (preferably, a cycloalkyl group having about 3 to 10 members).

R ¹ is preferably a hydrogen atom or an alkyl group having about 1 to 4 carbon atoms, and in particular, is often a hydrogen atom or a methyl group. Note that when R ^2, R ³ is a hydrocarbon group having a methine carbon atom at the bonding site with the adjacent carbon atoms (e.g., 1-C _1-2 alkyl -C _2-4 alkyl groups) In addition, the polymer has the advantage that the decomposition and elimination properties by acid are greatly improved, and the polymer in the exposed area is rapidly and reliably dissolved in the developing solution during development.

The ring A includes various alicyclic hydrocarbon rings, for example, a monocyclic hydrocarbon ring, a polycyclic hydrocarbon ring (for example, a spiro hydrocarbon ring, a ring assembly hydrocarbon ring, a bridged cyclic ring). Hydrocarbon rings). Examples of the monocyclic hydrocarbon ring include 4- to 10-membered cycloalkane rings such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane rings. Examples of the spiro hydrocarbon ring include spiro hydrocarbon rings having about 8 to 16 carbon atoms, such as spiro [4.4] nonane, spiro [4.5] decane, and spiro [5.6] undecane ring. The ring-assembled hydrocarbon ring includes, for example, a ring-assembled hydrocarbon ring in which a plurality of 5- to 12-membered cycloalkane rings such as a bicyclohexane and a biperhydronaphthalene ring are bonded.

Examples of the bridged cyclic hydrocarbon ring (including a non-aromatic condensed cyclic hydrocarbon ring) include perhydroindene, perhydronaphthalene (decalin), perhydroanthracene, perhydrophenanthrene, perhydro A non-aromatic condensed cyclic hydrocarbon ring obtained by condensing a plurality of (for example, about 2 to 5) 5- to 8-membered cycloalkane rings such as phenalene, perhydroacenaphthene, and perhydrofluorene rings; norpinane, pinane, Bicyclic bridged cyclic hydrocarbon rings such as norbornane and bornane rings; adamantane, tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [4.3.1.1 ^2,5 ] undecane, etc. Tricyclic bridged cyclic hydrocarbon ring; tetracyclo [4.4.0.1
^2,5 . [ ^7,10 ] Dodecane and other four-ring bridged cyclic hydrocarbon rings; dienes (eg, butadiene, cyclopentadiene, cyclohexadiene, cycloheptadiene, etc.)
And the like. Preferred ring A
Include bridged cyclic hydrocarbon rings such as norbornane, bornane, and adamantane rings. In equation (11),
The indicated carbon atom in ring A is often a bridgehead carbon atom. In the formula (11), the indicated carbon atom of the ring A is often a bridgehead carbon atom.

Ring A may have a substituent. As such a substituent, for example, a halogen atom, an oxo group,
Hydroxyl group, hydroxymethyl group, mercapto group,
A substituted oxy group (eg, an alkoxy group, an aryloxy group, an acyloxy group, etc.), a substituted thio group, a carboxyl group, a substituted oxycarbonyl group, a substituted or unsubstituted carbamoyl group, a cyano group, a nitro group, a substituted or unsubstituted amino group, Examples include an alkyl group (eg, a C _1-4 alkyl group), an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group (eg, a phenyl, naphthyl group, etc.), an aralkyl group, and a heterocyclic group. . In addition, a hydroxyl group, a hydroxymethyl group, a mercapto group, a carboxyl group, an amino group, a carboxyl group, and the like may be protected by a conventional protecting group.

Examples of the linking group in Z include a linear or branched alkylene group (eg, a C _1-4 alkylene group), an ether bond, an ester bond, an amide bond, and combinations thereof.

As typical examples of the (meth) acrylate derivative represented by the formula (10), for example, compounds having an adamantane ring include 1- (meth) acryloyloxyadamantane, 1- (meth) acryloyloxy Methyl adamantane, 1- [2- (meth) acryloylethyloxycarbonyl] adamantane, 1- [1- (meth) acryloyloxyethyl] adamantane, 1-
[1- (meth) acryloyloxy-1-methylethyl] adamantane, 2- (meth) acryloyloxy-
2-methyladamantane and the like are included.

In the polymer having the structural unit represented by the formula (1), the ratio of the structural unit represented by the formula (1) is, for example, 10 to 100% by weight (for example, 10 to 90% by weight).
%), Preferably about 20 to 80% by weight, and more preferably about 30 to 70% by weight.

The homopolymerization or copolymerization of the (meth) acrylate derivative represented by the formula (2) can be carried out by a conventional polymerization method. The (meth) acrylate derivative represented by the formula (2) and the copolymerizable monomer can be used alone or in combination of two or more.

In the thus obtained polymer having the structural unit represented by the formula (1), the cyclic portion of the structural unit is very easily eliminated by the action of an acid generated from the photoacid generator, and the polymer is converted to an alkali. Not only can it be solubilized in the developing solution, but it also has the property that the detached annular site is easily dissolved in the developing solution. In particular, in the case of an acid-sensitive polymer having a structural unit represented by the formula (1a), the solubility of the eliminated portion in a developer is very high. Therefore, the resin in the exposed portion can be easily and quickly removed. Further, since the cyclic portion has a carbonyl group or an ester group, the adhesion to the substrate is high. Therefore, the polymer having the structural unit represented by the above formula (1) is useful as a photoresist resin having excellent resolution (photosensitivity, sensitivity) and substrate adhesion.

The photoresist resin composition of the present invention comprises:
It is characterized by including a polymer having a structural unit represented by the formula (1) and a photoacid generator.

As the photoacid generator, a conventional compound which efficiently generates an acid upon exposure, for example, a diazonium salt,
Iodonium salts (eg, diphenyliodohexafluorophosphate), sulfonium salts (eg, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium methanesulfonate, etc.), sulfonic acid esters [eg, 1-phenyl -1
-(4-methylphenyl) sulfonyloxy-1-benzoylmethane, 1,2,3-trisulfonyloxymethylbenzene, 1,3-dinitro-2- (4-phenylsulfonyloxymethyl) benzene, 1-phenyl-1 −
(4-methylphenylsulfonyloxymethyl) -1-
Hydroxy-1-benzoylmethane], oxathiazole derivatives, s-triazine derivatives, disulfone derivatives (such as diphenyldisulfone), imide compounds, oxime sulfonates, diazonaphthoquinone, benzoin tosylate and the like. These photoacid generators can be used alone or in combination of two or more.

The amount of the photoacid generator used can be appropriately selected according to the strength of the acid generated by light irradiation, the content of the structural unit represented by the formula (1) in the polymer, and the like.
0.1 to 30 parts by weight based on 100 parts by weight of the polymer,
Preferably 1 to 25 parts by weight, more preferably 2 to 20 parts by weight
It can be selected from a range of about parts by weight.

The resin composition for a photoresist includes an alkali-soluble component such as an alkali-soluble resin (eg, a novolak resin, a phenol resin, an imide resin, and a carboxyl group-containing resin), a coloring agent (eg, a dye), and an organic solvent. (For example, hydrocarbons, halogenated hydrocarbons, alcohols, esters, ketones, ethers, cellosolves, carbitols, glycol ether esters, mixed solvents thereof, and the like). .

The photoresist resin composition of the present invention comprises:
The polymer can be prepared by mixing the polymer, the photoacid generator, and the organic solvent as necessary, and removing impurities by a conventional solid separation means such as a filter as necessary.

After coating the photoresist resin composition on a substrate or substrate and drying, the coating film (resist film) is exposed to a light beam through a predetermined mask (or further baked after exposure). The fine pattern can be formed with high precision by forming a latent image pattern and then developing.

As the substrate or substrate, a silicon wafer,
Examples include metal, plastic, glass, and ceramic. The application of the resin composition for a photoresist can be performed using a conventional application means such as a spin coater, a dip coater, and a roller coater. The thickness of the coating film is, for example, about 0.1 to 20 μm, and preferably about 0.3 to 2 μm.

Light of various wavelengths, such as ultraviolet rays and X-rays, can be used for exposure. For semiconductor resists, g-rays, i-rays, excimer lasers (eg, XeC
1, KrF, KrCl, ArF, ArCl, etc.) are used. Exposure energy is, for example, 1 to 1000 m
J / cm ² , preferably about 10 to 500 mJ / cm ² .

An acid is generated from the photoacid generator by light irradiation,
Due to this acid, the cyclic portion of the structural unit of the formula (1) of the polymer is rapidly eliminated, and a carboxyl group contributing to solubilization is generated. Therefore, a predetermined pattern can be accurately formed by development with water or an alkali developing solution.

The resin composition of the present invention can be used in various applications, for example, circuit forming materials (resist for semiconductor production, printed wiring boards, etc.), image forming materials (printing plate materials, relief images, etc.).

[0047]

According to the photoresist resin composition of the present invention, since it contains a polymer having a specific structural unit, it can be rapidly and reliably developed by an acid generated from a photoacid generator by light irradiation. Solubilized in liquid. Therefore, the developing efficiency can be improved, the resolution is excellent, and a fine pattern can be formed stably and with high accuracy. Also,
The adhesion of the resist film to the substrate can be improved.

The acid-sensitive polymer, (meth) acrylate derivative and ε-caprolactone derivative of the present invention are:
It is useful for obtaining the photoresist resin composition.

[0049]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

Example 1 A mixture of 552 g (4.0 mol) of isophorone and 4 l of methanol was mixed with 1.15 l of a 30% by weight aqueous hydrogen peroxide solution.
(12.0 mol), 330 ml (2.0 mol) of a 6N sodium hydroxide aqueous solution was added to the mixture at an internal temperature of 15 to 20 ° C.
The solution was added dropwise over 1 hour and 15 minutes while adjusting the temperature. 20-2
After stirring at a temperature of 5 ° C. for 3 hours, the reaction mixture was poured into 5 l of water and extracted twice with 4 l of diethyl ether. The obtained organic layer was washed twice with water, dried over magnesium sulfate, concentrated (25 ° C./100 mmHg), and distilled (66-69 ° C./6 mmHg) to obtain 452 g of isophorone oxide (yield 73). %).

Hydrogen was bubbled through a mixture of 450 g (2.9 mol) of isophorone oxide, 292 g of 5 wt% Pd / C and 5.8 l of tetrahydrofuran at a flow rate of 0.7 to 1 l / min for about 11 hours. After removing the catalyst by filtration and concentrating, 1.2 l of hexane was added, and the mixture was heated and stirred for 30 minutes. The mixture was cooled to 5 ° C., and after 1 hour, the precipitated solid was filtered to obtain 189 g of 3-hydroxy-3,5,5-trimethylcyclohexanone (yield: 42%).

A mixture of 15.6 g (100 mmol) of 3-hydroxy-3,5,5-trimethylcyclohexanone and 300 ml of methylene chloride was added at 0 ° C. with 16.8 g (200 mmol) of sodium hydrogen carbonate and m-chloroform. 49.2 g of perbenzoic acid (MCPBA) (purity 70%)
(200 mmol) and stirred at room temperature for 24 hours.
23.2 g (400 mmol) of KF was added to the reaction mixture, and 300 ml of methylene chloride was further added. After stirring for 2 hours, the solid was filtered off, washed successively with 5% by weight aqueous sodium bicarbonate and water, dried over magnesium sulfate and concentrated. The concentrated residue was subjected to silica gel column chromatography (elution solvent: hexane / ethyl acetate = 1/2), and β-hydroxy-β, δ, δ-trimethyl-ε-caprolactone and δ
A mixture with -hydroxy-β, β, δ-trimethyl-ε-caprolactone (former: latter = approximately 98: 2) was prepared at 9.7.
g (gas chromatography purity 90%, total yield 56%).

IR (cm ^-1 ): 3420, 2980, ¹
700, 1320, 1220, 1050 MS m / e: 156 ¹ NMR (CDCl ₃ ) δ: 090, 1.18, 1.3
5, 1.70, 2.35, 2.80, 3.91.

Example 2 A mixed solution of 10 mmol of 3-hydroxy-3,5,5-trimethylcyclohexanone, 1 mmol of samarium iodide (SmI ₂ ), 11 mmol of isopropenyl acrylate, and 20 ml of dioxane was heated at 50 ° C. for 6 hours. Stirred. The reaction mixture was concentrated, and the concentrated residue was subjected to silica gel column chromatography to give 3-acryloyloxy-
3,5,5-Trimethylcyclohexanone was obtained (85% yield).

MS m / e: 208 ¹ NMR (CDCl ₃ ) δ: 1.65, 1.70, 2.2
2, 2.37, 2.70, 2.85, 5.78, 6.0
0,6.30 100 parts by weight of a monomer mixture of 50% by weight of 3-acryloyloxy-3,5,5-trimethylcyclohexanone and 50% by weight of 1- (1-acryloyloxy-1-methylethyl) adamantane are polymerized. Polymerization was carried out in toluene using 5 parts by weight of an initiator (benzoyl peroxide).
Methanol was added to the reaction mixture to precipitate the polymer. Purification was repeated by repeating the operation of dissolving the precipitate in toluene and precipitating with methanol to obtain a copolymer having a weight average molecular weight of about 10,000 (polystyrene-equivalent molecular weight by GPC).

Example 3 The same operation as in Example 2 was carried out except that 2-acryloyloxy-2-methyladamantane was used instead of 1- (1-acryloyloxy-1-methylethyl) adamantane, and the weight average was calculated. A copolymer having a molecular weight of about 10,000 (molecular weight in terms of polystyrene by GPC) was obtained.

Example 4 Instead of 3-hydroxy-3,5,5-trimethylcyclohexanone, β-hydroxy-β, δ, δ-trimethyl-ε-caprolactone and δ-hydroxy-β, β, δ
Mixture with trimethyl-ε-caprolactone (the former:
The same operation as in Example 2 was carried out except that the latter was used (approximately 98: 2), and β-acryloyloxy-β, δ, δ-trimethyl-ε-caprolactone and δ-acryloyloxy-β, β, δ- A mixture with trimethyl-ε-caprolactone (former: latter = about 98: 2) was obtained (total yield 82%).

MS m / e: 214 ¹ NMR (CDCl ₃ ) δ: 0.97, 1.10, 1.5
5, 1.64, 2.62, 2.97, 3.21, 3.8
3,4.17,5.81,6.02,6.37 The above β-acryloyloxy-β, δ, δ-trimethyl-ε-caprolactone and δ-acryloyloxy-β,
50% by weight of a mixture with β, δ-trimethyl-ε-caprolactone (the former: about 98: 2) and 1- (1-acryloyloxy-1-methylethyl) adamantane 5
The polymerization was carried out in toluene using 100 parts by weight of a 0% by weight monomer mixture and 5 parts by weight of a polymerization initiator (benzoyl peroxide). Methanol was added to the reaction mixture to precipitate the polymer. Purification by repeating the operation of dissolving the precipitate in toluene and precipitating with methanol,
A copolymer having a weight average molecular weight of about 10,000 (molecular weight in terms of polystyrene by GPC) was obtained.

Example 5 The same operation as in Example 2 was performed except that 2-acryloyloxy-2-methyladamantane was used instead of 1- (1-acryloyloxy-1-methylethyl) adamantane, and the weight average was calculated. A copolymer having a molecular weight of about 10,000 (molecular weight in terms of polystyrene by GPC) was obtained.

Example 6 A resin composition for a photoresist was prepared from the copolymers obtained in Examples 2 to 5 as follows. That is, 100 parts by weight of the copolymer, 15 parts by weight of triphenylsulfonium hexafluoroantimonate, and toluene as a solvent were mixed to prepare a resin composition for a photoresist.

The photoresist resin composition was applied to a silicon wafer by spin coating to form a photosensitive layer having a thickness of 1.0 μm. 6 on hot plate
After pre-baking at a temperature of 0 ° C. for 10 seconds, exposure was performed at a dose of 100 mJ / cm ² using a KrF excimer stepper, followed by baking at a temperature of 100 ° C. for 60 seconds. Then
When developed with an alkaline aqueous solution (NMD-3, manufactured by Tokyo Ohka Co., Ltd.) for 60 seconds and rinsed with pure water, a desired pattern can be formed accurately with any photoresist resin composition. Obtained.

Claims (4)

[Claims] [Claim 1] The following formula (1) (Wherein, R represents a hydrogen atom or a methyl group; X and Y
Represents the same or different and represents a single bond or an oxygen atom. However, at least one of X and Y is a single bond), and a resin composition for a photoresist containing a polymer having a structural unit represented by the formula (I) and a photoacid generator. 2. The following formula (1a): (Wherein, R represents a hydrogen atom or a methyl group; X ¹ and Y ¹
Represents the same or different and represents a single bond or an oxygen atom. However, when X ¹ is a single bond, Y ¹ is an oxygen atom and X ¹
When Y is an oxygen atom, Y ¹ is a single bond). 3. The following formula (2a): (Wherein, R represents a hydrogen atom or a methyl group; X ¹ and Y ¹
Represents the same or different and represents a single bond or an oxygen atom. However, when X ¹ is a single bond, Y ¹ is an oxygen atom and X ¹
(Wherein is an oxygen atom, Y ¹ is a single bond). 4. The following formula (3a): (Wherein X ¹ and Y ¹ are the same or different and represent a single bond or an oxygen atom. However, when X ¹ is a single bond, Y ¹ is an oxygen atom, and when X ¹ is an oxygen atom, ε- caprolactone derivative represented by Y ¹ is a single bond) in the.