WO2016125782A1

WO2016125782A1 - Novel alicyclic ester compound, (meth)acrylic copolymer, and functional resin composition containing same

Info

Publication number: WO2016125782A1
Application number: PCT/JP2016/053035
Authority: WO
Inventors: 宏幸棚木; 博康田中; 哲彦水阪; 古川　喜久夫; 堀越　裕
Original assignee: 三菱瓦斯化学株式会社
Priority date: 2015-02-05
Filing date: 2016-02-02
Publication date: 2016-08-11
Also published as: JPWO2016125782A1; TW201634454A

Abstract

As a chemically amplified resist, the present invention provides a resist and compound having a good balance by which line edge roughness (LER) is improved without impairing basic physical properties inherent in a resist, such as base adhesion properties and resistance to dry etching. Provided are a lactone ester compound represented by general formula (1), a method for producing same, a (meth)acrylic copolymer comprising general formula (1), and a photosensitive resin composition containing same. (In formula (1): R¹ denotes a hydrogen atom or a methyl group; R² denotes a hydrogen atom, an aliphatic alkyl group having 1-10 carbon atoms or an alkyl group having an alicyclic structure having 3-10 carbon atoms; R³ denotes a hydrogen atom, an alkoxycarbonyl group represented by formula (2), an aliphatic alkyl group having 1-10 carbon atoms or an alkyl group having an alicyclic structure having 3-10 carbon atoms; here, R² and R³ may bond to each other to form an alicyclic structure having 3-10 carbon atoms; and n1 is an integer between 0 and 2.) (In formula (2): R⁴ denotes an aliphatic alkyl group having 1-13 carbon atoms or an alkyl group having an alicyclic structure having 3-13 carbon atoms; and the dotted line denotes the bonding location in the compound represented by formula (1).)

Description

Novel alicyclic ester compound, (meth) acrylic copolymer, and functional resin composition containing the same

The present invention includes a novel lactone (meth) acrylate compound suitable for resists for KrF, ArF, and F2 excimer lasers, and chemically amplified resist materials for X-rays, electron beams, and EUV (extreme ultraviolet light), and the novel compounds. The present invention relates to a (meth) acrylic copolymer and a photosensitive resin composition containing the copolymer.

Semiconductor devices have a strong demand for further miniaturization as the capacity of flash memory as a storage device increases and the market for image sensors for high-resolution cameras of mobile phones and smartphones expands. Photolithography is widely used in the manufacture of various electronic devices. In photolithography, miniaturization has been promoted by shortening the wavelength of the light source. When using a short wavelength light source after the KrF excimer laser as a light source, a chemically amplified resist is generally used. In general, a composition of a chemically amplified resist used as a solution is composed of a functional resin as a main agent, and It contains a photoacid generator, as well as several additives. Among them, the functional resin, which is the main component, is important to have well-balanced characteristics such as etching resistance, substrate adhesion, transparency to the light source used, and development speed, which determine resist performance. .

The functional resin used in the photoresist for excimer laser is generally a polymer having a vinyl compound or acrylate as a repeating unit. For example, as a resist for KrF excimer laser lithography, a hydroxystyrene resin is proposed (Patent Document 1), and as a resist for ArF excimer laser lithography, an acrylic resin having adamantyl (meth) acrylate as a basic skeleton is proposed ( Patent Documents 2 to 6).

In recent years, the lithography process has been further miniaturized, and ArF excimer laser lithography continues to advance to immersion exposure and further to double patterning exposure. In addition, various developments have been continued for lithography using extreme ultraviolet light (EUV), which has been attracting attention as a next-generation lithography technology, direct drawing with an electron beam, and negative tone development. Under such circumstances, development of a new functional monomer suitable for miniaturization is desired.

As the circuit width is reduced due to miniaturization, the influence of line edge roughness (LER) due to diffusion of acid generated from the photoacid generator after exposure is becoming more serious. Therefore, in order to prevent the deterioration of LER, a method for controlling acid diffusion has been studied. Examples include a method using a photoacid generator having a large skeleton structure (Non-patent Document 1), a method using a resin containing a monomer having a photoacid generator (Patent Document 7, Non-Patent Document 2), and a resist. There has been proposed a method of inhibiting the acid diffusion path by extending the pendant portion of the polymer from the conventional one (Patent Documents 8 and 9).

However, in order to cope with further miniaturization, further improvement in resist performance is indispensable, and high-sensitivity and high-resolution resists are required. However, simply increasing the sensitivity simply reduces the resolution and LER. As new problems such as deterioration occur, combinations of resins that control acid diffusion and various photoacid generators have been studied and further improvements are being made.

JP 2006-243474 A Japanese Patent Laid-Open No. 4-39665 JP 10-319595 A JP 2000-26446 A JP 2003-167346 A JP 2004-323704 A JP 2012-168502 A JP 2005-331918 A JP 2008-129388 A

In view of such circumstances, the problem of the present invention is that the KrF excimer laser, ArF excimer laser, F2 excimer laser, X-ray, electron beam, and resist material for EUV lithography impair sensitivity, resolution, substrate adhesion, and etching resistance. And developing a resist capable of improving line edge roughness (LER), and providing a functional resin composition that is technically preferable for increasing the integration density of semiconductor substrate circuits, which will continue to advance in the future. . *

As a result of intensive studies aimed at solving the above-mentioned problems, the present inventors have found that a lactone (meth) acrylate compound having a specific structure is a KrF excimer laser, ArF excimer laser, F2 excimer laser, X-ray, electron beam or It has been found that it is a useful compound capable of forming a fine pattern in a lithography operation performed by EUV (extreme ultraviolet light) or the like. That is, the present invention is as follows.

1. A lactone (meth) acrylate compound represented by the general formula (1).

(In formula (1), R ¹ represents a hydrogen atom or a methyl group;
R ² represents hydrogen, an aliphatic alkyl group having 1 to 10 carbon atoms, or an alkyl group having an alicyclic structure having 3 to 10 carbon atoms;
R ³ represents hydrogen, an alkoxycarbonyl group represented by the formula (2), an aliphatic alkyl group having 1 to 10 carbon atoms, or an alkyl group having an alicyclic structure having 3 to 10 carbon atoms;
In this case, R ² and R ³ may be bonded to each other to form an alicyclic structure having 3 to 10 carbon atoms;
n ₁ represents an integer of 0-2. )

(In the formula (2), R ⁴ represents an aliphatic alkyl group having 1 to 13 carbon atoms or an alkyl group having an alicyclic structure having 3 to 13 carbon atoms; the broken line represents a bond in the compound of the formula (1). Represents the location.)

2. 1. a step of reacting a hydroxylactone compound represented by the general formula (4) with a (meth) acrylic acid compound represented by the general formula (5); A process for producing a lactone (meth) acrylate compound as described in 1. above.

(In the formula (4), R ² , R ³ and n ₁ are the same as those in the general formula (1).)

(In formula (5), R ¹ is the same as in general formula (1). R ⁵ is one group selected from the group consisting of a hydroxyl group, a halogen atom, and a (meth) acryloyloxy group. .)

3. A (meth) acrylic copolymer having a repeating unit represented by the general formula (6).

(In the formula (6), R ¹ to R ³ and n1 are the same as in the formula (1), and the point * represents a bonding site with an adjacent repeating unit.)

4). Further, one or both of the repeating units represented by the general formula (7) or (8) and the repeating unit represented by the general formula (9) are included. (Meth) acrylic copolymer described in 1.

(In formula (7), R ²¹ represents hydrogen or a methyl group, R ²² represents an alkyl group having 1 to 4 carbon atoms, and R ²³ represents a cycloalkyl group or alicyclic alkyl group having 5 to 20 carbon atoms. (The point * represents a bonding point with an adjacent repeating unit.)

(In Formula (8), R ⁴¹ represents hydrogen or a methyl group, R ₄₂ to R ₄₃ may be the same or different, each represents an alkyl group having 1 to 4 carbon atoms, and R ₄₄ represents 1 to 4 carbon atoms) Or an cycloalkyl group having 5 to 20 carbon atoms, or one group selected from the group consisting of alicyclic alkyl groups, and a point * represents a bonding point with an adjacent repeating unit.)

(In the formula (9), R ⁴¹ represents hydrogen or a methyl group, and R ⁴² to R ⁴⁴ may be the same or different and each represents one group selected from the group consisting of a hydrogen element, a hydroxyl group, a methyl group, and an ethyl group. (The point * represents a bonding point with an adjacent repeating unit.)

5. 20 to 80 mol% of the repeating unit represented by the general formula (6) is contained, and 20 to 80 mol% of the repeating units represented by the general formulas (7) and (8) are contained in total. 3. containing 10 to 50 mol% of the repeating unit represented (Meth) acrylic copolymer described in 1.
6.3. ~ 5. A photosensitive resin composition comprising the (meth) acrylic copolymer according to any one of the above and a photoacid generator.

The lactone (meth) acrylate compound of the present invention is suitable as a raw material for various resin compositions such as various functional polymers having heat resistance, surface hardness, chemical resistance, and lipophilicity. The lactone (meth) acrylate compound of the present invention is a component of a chemically amplified resist copolymer especially for KrF excimer laser, ArF excimer laser, F2 excimer laser, X-ray, electron beam, and EUV (extreme ultraviolet light). When used as, the line edge roughness (LER) can be improved without impairing the etching resistance and substrate adhesion.

Hereinafter, the present invention will be described in more detail. The lactone (meth) acrylate compound of the present invention is represented by the general formula (1).

(In formula (1), R ¹ represents a hydrogen atom or a methyl group;
R ² represents an aliphatic alkyl group having 1 to 10 carbon atoms or an alkyl group having an alicyclic structure having 3 to 10 carbon atoms, and preferably R ² represents an aliphatic alkyl group having 1 to 5 carbon atoms or 3 carbon atoms. An alkyl group having an alicyclic structure of ˜8, more preferably R ² is an aliphatic alkyl group having 1 to 3 carbon atoms or an alkyl group having an alicyclic structure having 5 to 7 carbon atoms;
R ³ represents an alkoxycarbonyl group represented by the formula (2), an aliphatic alkyl group having 1 to 10 carbon atoms (preferably 1 to 5 carbon atoms), or 3 to 10 carbon atoms (preferably 5 to 8 carbon atoms). Represents an alkyl group having the following alicyclic structure;
In this case, R ² and R ³ may be bonded to each other to form an alicyclic structure having 3 to 10 carbon atoms, preferably an alicyclic structure having 5 to 8 carbon atoms;
n ₁ represents an integer of 0-2. )

(In the formula (2), R ⁴ represents an aliphatic alkyl group having 1 to 13 carbon atoms or an alkyl group having an alicyclic structure having 3 to 13 carbon atoms. Preferably, R ⁴ represents 2 to 8 carbon atoms. Or an alkyl group having an alicyclic structure of 5 to 10 carbon atoms; a broken line represents a bonding site in the compound of the formula (1).)

The lactone (meth) acrylate compound (1) of the present invention is specifically exemplified below. However, it is not limited to these.

(In formula (12), R ¹ is a hydrogen atom or a methyl group. R ³ is exemplified below.)

In addition, the broken line in Formula (13) represents the coupling | bond part in the compound of Formula (12).

As a manufacturing method of the lactone (meth) acrylate compound represented by the general formula (1) of the present invention, for example, the ketolactone compound represented by the general formula (3) is subjected to a reduction reaction and represented by the general formula (4). After the hydroxylactone compound to be obtained is obtained, the (meth) acrylic acid compound represented by the general formula (5) can be reacted, but is not limited thereto.

(In the formula (3), R ² , R ³ and n ₁ are the same as those in the general formula (1).)

(In formula (5), R ¹ is the same as in general formula (1). R ⁵ is one group selected from the group consisting of a hydroxyl group, a halogen atom, and a (meth) acryloyloxy group. Preferably a halogen atom such as chlorine.)

The ketolactone compound represented by the general formula (3) of the present invention is exemplified below.

(In formula (14), R ³ is the same as in general formula (1).)
Among these compounds, 1-oxaspiro [4.5] decane-2,6-dione, 7-methyl-1-oxaspiro [4.5] decane-2,6-dione, 9-methyl-1-oxaspiro [ 4.5] Decane-2,6-dione, 1-oxaspiro [4.4] nonane-2,6-dione, 1-oxaspiro [4.6] undecane-2,6-dione, tertiary butyl 2-acetyl -5-Oxotetrahydrofuran-2-carboxylate is preferable from the viewpoint of availability, and for example, those synthesized according to the methods described in Non-Patent Documents 3 to 5 can be used.

The hydroxylactone compound represented by the general formula (4) of the present invention can be exemplified below.

(In formula (15), R ³ is the same as in general formula (1).)

The (meth) acrylic acid compound represented by the general formula (5) of the present invention is exemplified below.

Of these compounds, (meth) acrylic acid chloride is preferable from the viewpoint of reactivity, and commercially available products such as acryloyl chloride (model number A0147) and methacryloyl chloride (model number M0556) manufactured by Tokyo Chemical Industry Co., Ltd. can be obtained. .

Next, the manufacturing method of the lactone (meth) acrylate compound represented by the general formula (1) will be described in detail.
First, the reduction reaction of the ketolactone compound represented by the general formula (3) will be described. A known reduction reaction is used for this reaction, but the reaction by hydride reduction is preferable because the operation is easy and the yield is good. The reducing agent is added in an amount of 0.5 to 5.0 molar equivalents, preferably 0.6 to 3.0 molar equivalents, more preferably 0.8 to 1.5 molar equivalents relative to the ketolactone compound. If it is in the above-mentioned range, the reaction proceeds sufficiently, and the yield of the hydroxylactone compound represented by the general formula (4), which is the target product, is high and economically preferable.

As the compound that can be used as the reducing agent, commercially available products can be used. For example, sodium borohydride, lithium triethyl borohydride, lithium tri (secondary butyl) borohydride, potassium tri (secondary butyl) borohydride, lithium borohydride, lithium aluminum hydride, bis (2-methoxyethoxy hydride) ) Aluminum sodium, diborane, diisobutylaluminum hydride and the like.

As the solvent, commercially available products that are generally available can be used, and various solvents such as alcohols, ethers, hydrocarbons, and halogen-based solvents can be appropriately used as long as they do not inhibit the reaction.
When using a reducing agent such as sodium borohydride with a relatively low reducing power, an alcohol solvent is suitable. When using a reducing agent such as lithium aluminum hydride with a high reducing power, a dehydrating solvent should be used. preferable. The amount of the solvent is 1 to 100 parts by mass, preferably 5 to 10 parts by mass with respect to 1 part by mass of the ketolactone compound represented by the general formula (3).

Although the reaction temperature and reaction time depend on the substrate concentration and the catalyst used, the reaction temperature is generally −20 ° C. to 100 ° C., the reaction time is 1 hour to 10 hours, and the pressure is normal pressure, reduced pressure or increased pressure. it can. In addition, the reaction can be performed by appropriately selecting a known method such as a batch system, a semi-batch system, or a continuous system.

Next, the reaction between the hydroxylactone compound represented by the general formula (4) and the (meth) acrylic acid compound represented by the general formula (5) will be described.
For this reaction, a known esterification reaction such as an acid anhydride method using (meth) acrylic anhydride, an acid halogen method using (meth) acrylic acid chloride or the like, or esterification with a dehydration condensing agent may be applied. it can.
However, an acid anhydride method using (meth) acrylic anhydride or (meth) acrylic acid chloride, which has the advantage of being able to suppress side reactions such as ester decomposition of the alkoxycarbonyl group bonded to the lactone group, The acid halogen method using the above is preferred. Further, after the reduction reaction of the ketolactone compound represented by the general formula (3), the (meth) acrylic compound represented by the general formula (5) is isolated without isolating the hydroxylactone compound represented by the general formula (4). The lactone (meth) acrylate compound of the general formula (1) can also be obtained by reacting with an acid compound.

The (meth) acrylic acid compound represented by the general formula (5) is 0.5 to 100 molar equivalents, preferably 1 to 20 molar equivalents relative to the hydroxylactone compound represented by the general formula (4). Preferably 1.2 to 5 molar equivalents are used. If it is this range, reaction will fully advance and the yield of the lactone (meth) acrylate compound represented by General formula (1) which is a target object is also high and economically preferable.

The lactone (meth) acrylate compound represented by the general formula (1) from the reaction of the hydroxylactone compound represented by the general formula (4) of the present invention and the (meth) acrylic acid compound represented by the general formula (5) As the solvent used for obtaining the product, commercially available products can be used. For example, various solvents such as alcohols, ethers, hydrocarbons, and halogen solvents can be appropriately used as long as they do not inhibit the reaction. Since water inhibits the reaction, it is preferable to use a dehydrated solvent.

In addition, a polymerization inhibitor may be added to the series of reactions, and commercially available products can be used. For example, 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl, N-nitrosophenylhydroxylamine ammonium salt, N-nitrosophenylhydroxylamine aluminum salt, N-nitroso-N- (1-naphthyl) Nitroso compounds such as hydroxylamine ammonium salt, N-nitrosodiphenylamine, N-nitroso-N-methylaniline, nitrosonaphthol, p-nitrosophenol, N, N'-dimethyl-p-nitrosoaniline, phenothiazine, methylene blue, 2-mercapto Sulfur-containing compounds such as benzimidazole, N, N′-diphenyl-p-phenylenediamine, N-phenyl-N′-isopropyl-p-phenylenediamine, 4-hydroxydiphenylamine, aminophenol, etc. Quinones such as hydroxynes, hydroxyquinoline, hydroquinone, methylhydroquinone, p-benzoquinone, hydroquinone monomethyl ether, p-methoxyphenol, 2,4-dimethyl-6-t-butylphenol, catechol, 3-s-butylcatechol, 2 , 2-methylenebis- (6-t-butyl-4-methylphenol) and other phenols, N-hydroxyphthalimide and other imides, cyclohexane oxime, p-quinone dioxime and other oximes, and dialkylthiodipropinates Can be mentioned. The addition amount is 0.001 to 10 parts by mass, preferably 0.01 to 1 part by mass with respect to 100 parts by mass of the (meth) acrylic acid compound represented by the general formula (5).

The lactone (meth) acrylate compound represented by the general formula (1) obtained by the reaction is separated by known purification methods such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, activated carbon and the like. It can be isolated and purified as a desired high purity monomer by a purification method or a combination thereof.

A (meth) acrylic copolymer can be obtained by copolymerizing the lactone (meth) acrylate compound represented by the general formula (1) of the present invention. The (meth) acrylic copolymer can be used for a functional resin used in a photoresist.

The (meth) acrylic copolymer of the present invention has a repeating unit represented by the general formula (6) derived from the general formula (1). Furthermore, a copolymer containing at least one kind selected from the repeating units represented by the general formulas (7) to (8) and the repeating unit represented by the general formula (9) is preferable in order to improve resist performance. is there. The (meth) acrylic copolymer may contain a structure represented by the general formula (9) or the general formulas (10) to (11) as a repeating unit.

(In the formula (6), R ¹ to R ³ and n ₁ are the same as in the formula (1), and the point * represents a bonding site with an adjacent repeating unit.)

(In formula (7), R ²¹ represents hydrogen or a methyl group, R ²² represents an alkyl group having 1 to 4 carbon atoms, and R ²³ represents a cycloalkyl group or alicyclic alkyl group having 5 to 20 carbon atoms. (The point * represents a bonding point with an adjacent repeating unit.)
Preferably, R ²² represents an alkyl group having 1 to 3 carbon atoms, and R ²³ is a cycloalkyl group having 5 to 10 carbon atoms or an alicyclic alkyl group.

(In the formula (8), R ³¹ represents hydrogen or a methyl group, R ³² to R ³³ may be the same or different, each represents an alkyl group having 1 to 4 carbon atoms, and R ³⁴ represents 1 to 4 carbon atoms. Or a group selected from the group consisting of a cycloalkyl group having 5 to 20 carbon atoms and an alicyclic alkyl group, and any two of R ³² to R ³⁴ are bonded to each other to form a carbon number 2 to 20 alicyclic structures may be formed, and the point * represents a bonding site with an adjacent repeating unit.)
Preferably, R ²² represents an alkyl group having 1 to 3 carbon atoms, and R ²³ is a cycloalkyl group having 5 to 10 carbon atoms or an alicyclic alkyl group. The alicyclic structure may include a plurality of rings such as an adamantyl group.

(In Formula (9), R ⁴¹ represents hydrogen or a methyl group, R ⁴² to R ⁴⁴ may be the same or different, and one group selected from the group consisting of a hydrogen element, a hydroxyl group, a methyl group, and an ethyl group) And the point * represents a bonding point with an adjacent repeating unit.)

(In the formula (10), R ⁵¹ represents hydrogen or a methyl group, R ⁵² represents a methyl group or an ethyl group, n ₅₁ represents 0 to 2, n ₅₂ represents 1 to 3, and a point * is adjacent. Represents the point of attachment with the repeating unit.)

(In the formula (11), R ⁶¹ represents hydrogen or a methyl group, R ⁶² represents methylene (—CH ₂ —) or oxa (—O—), R ⁶³ is the same or different, and represents a hydroxyl group, a halogen group, A nitrile group, a carboxylic acid group, an alkyl group having 1 to 4 carbon atoms, an alkoxide group having 1 to 4 carbon atoms, n ₆₁ represents 0 to 2, and a point * represents a bonding site with an adjacent repeating unit. To express.)

As the monomer raw material of the repeating unit represented by the general formula (7), 2-methyl-2- (meth) acryloyloxyadamantane, 2-ethyl-2- (meth) acryloyloxyadamantane, 2-isopropyl-2 -(Meth) acryloyloxyadamantane, 2-n-propyl-2- (meth) acryloyloxyadamantane, 2-n-butyl-2- (meth) acryloyloxyadamantane, 1-methyl-1- (meth) Acryloyloxycyclopentane, 1-ethyl-1- (meth) acryloyloxycyclopentane, 1-methyl-1- (meth) acryloyloxycyclohexane, 1-ethyl-1- (meth) acryloyloxycyclohexane, 1 -Methyl-1- (meth) acryloyloxycycloheptane, -Ethyl-1- (meth) acryloyloxycycloheptane, 1-methyl-1- (meth) acryloyloxycyclooctane, 1-ethyl-1- (meth) acryloyloxycyclooctane, 2-ethyl-2- (Meth) acryloyloxydecahydro-1,4: 5,8-dimethanonaphthalene, 2-ethyl-2- (meth) acryloyloxynorbornane and the like. Commercial products can be used as these monomers, and products of Osaka Organic Chemical Industry Co., Ltd. can be easily obtained.

As the monomer raw material of the repeating unit represented by the general formula (8), 2-cyclohexyl-2- (meth) acryloyloxypropane, 2- (4-methylcyclohexyl) -2- (meth) acryloyloxypropane, Examples thereof include 2-adamantyl-2- (meth) acryloyloxypropane and 2- (3- (1-hydroxy-1-methylethyl) adamantyl) -2- (meth) acryloyloxypropane. Commercial products can be used as these monomers, and Daicel products can be easily obtained.

As the monomer raw material of the repeating unit represented by the general formula (9), 1- (meth) acryloyloxyadamantane, 3-hydroxy-1- (meth) acryloyloxyadamantane, 3,5-dihydroxy-1- (meth) Acryloyloxyadamantane, 3,5-dimethyl-1- (meth) acryloyloxyadamantane, 5,7-dimethyl-3-hydroxy-1- (meth) acryloyloxyadamantane, 7-methyl-3,5-dihydroxy-1- (Meth) acryloyloxyadamantane, 3-ethyl-1- (meth) acryloyloxyadamantane, 5-ethyl-3-hydroxy-1- (meth) acryloyloxyadamantane, 7-ethyl-3,5-dihydroxy-1- ( And (meth) acryloyloxyadamantane . Commercial products can be used as these monomers, and products such as Mitsubishi Gas Chemical Co., Ltd. and Daicel Corp. can be easily obtained.

As the monomer raw material of the repeating unit represented by the general formula (10), α- (meth) acryloyloxy-γ-butyrolactone, β- (meth) acryloyloxy-γ-butyrolactone, (meth) acryloyloxypant Examples include lactones. Commercial products can be used as these monomers, and products of Osaka Organic Chemical Industry Co., Ltd. can be easily obtained.

As a monomer raw material of the repeating unit represented by the general formula (11), 2- (meth) acryloyloxy-5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonane, 7 Or 8- (meth) acryloyloxy-3-oxo-4-oxatricyclo [5.2.1.0 ^2,6 ] decane, 9- (meth) acryloyloxy-3-oxo-2-oxa- 6-oxa-tricyclo [4.2.1.0 ^4,8 ] nonane, 2- (meth) acryloyloxy-5-oxo-4-oxa-8-oxatricyclo [4.2.1.0 ^{3 , 7} ] nonane, 2- (meth) acryloyloxy-9-methoxycarbonyl-5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonane, 2- (meth) acryloyloxy -5-oxo-4-oki Satricyclo [4.2.1.0 ^3,7 ] nonane-6-carbonitrile and the like. Commercial products can be used as these monomers, and Daicel products can be easily obtained.

The repeating units represented by the general formulas (7) and (8) have a function of dissociating with an acid. That is, when the repeating unit represented by the general formulas (7) and (8) reacts with an acid generated from a photoacid generator at the time of exposure, a carboxylic acid group is generated, so that the copolymer is converted to alkali-soluble. be able to. In the (meth) acrylic copolymer in the present invention, a repeating unit having such a structure and performance is defined as an acid dissociable group.

The repeating unit represented by the general formula (9) can further improve solvent solubility, substrate adhesion, and affinity for an alkaline developer. In particular, a repeating unit having a hydroxyl group is preferable because it has a high effect of improving resolution. In the (meth) acrylic copolymer in the present invention, a repeating unit having such a structure and performance is defined as a polar group.

The repeating unit represented by the general formulas (10) and (11) has a lactone group, and improves solvent solubility, substrate adhesion, and affinity for an alkaline developer. In the (meth) acrylic copolymer in the present invention, a repeating unit having such a structure and performance is defined as a lactone group.
The repeating unit represented by the general formula (6) also has a lactone and therefore belongs to the lactone group.

Regarding the copolymerization ratio of the (meth) acrylic copolymer, the repeating unit represented by the general formula (6) contains 20 to 80 mol%, preferably 30 to 60 mol%.
When the polymer contains the repeating units represented by the general formulas (7) to (11), at least one repeating unit represented by the general formulas (7) to (8) is 20 to 80 in total. Mol%, preferably 40 to 60 mol%. The repeating unit represented by the general formula (9) contains 10 to 50 mol%, preferably 15 to 40 mol%.
When the polymer contains the repeating units represented by the general formulas (10) to (11), it contains 5 to 40 mol% in all components. Since it has a lactone group as in the general formula (6), it can be used by substituting a part of the general formula (6), but the repeating unit represented by the general formula (6) is composed of all components. If the content is less than 20 mol%, LER deteriorates, which is not preferable.

Next, the polymerization reaction of the (meth) acrylic copolymer will be described. The polymerization reaction is performed while dissolving a monomer as a repeating unit in a solvent, adding a catalyst, and heating or cooling. The reaction conditions can be arbitrarily set depending on the type of initiator, the starting method such as heat and light, temperature, pressure, concentration, solvent, additive, etc. In the polymerization of the (meth) acrylic copolymer of the present invention. Can be carried out by a known method such as radical polymerization using a radical generator such as azoisobutyronitrile or peroxide, or ionic polymerization using a catalyst such as alkyllithium or Grignard reagent.

As the solvent used in the polymerization reaction, commercially available products can be used. For example, various solvents such as alcohols, ethers, hydrocarbons, and halogen solvents can be appropriately used as long as they do not inhibit the reaction.

The (meth) acrylic copolymer obtained by the polymerization reaction can be purified by a known method. Specifically, ultrafiltration, crystallization, microfiltration, acid washing, water washing with an electric conductivity of 10 mS / m or less, and extraction can be performed in combination.

The polystyrene-reduced weight average molecular weight (hereinafter referred to as “Mw”) of the (meth) acrylic copolymer of the present invention measured by gel permeation chromatography (GPC) is 1,000 to 500,000, preferably 3, 000 to 100,000. The ratio (Mw / Mn) between the Mw of the (meth) acrylic copolymer and the polystyrene-equivalent number average molecular weight (hereinafter referred to as “Mn”) measured by GPC is 1 to 10, preferably 1 to 5. is there. A large value of this ratio is not preferable because photoresist performance such as sensitivity, resolution, and roughness deteriorates. Moreover, in this invention, a (meth) acryl copolymer can be used individually or in mixture of 2 or more types.

What contains the (meth) acrylic copolymer of this invention and the photo-acid generator is a photosensitive resin composition.
Photoacid generators can be used as acid generators for chemically amplified resist compositions depending on the wavelength of the exposure light, while considering the thickness range of the resist coating film and its own light absorption coefficient. Can be appropriately selected.
For example, examples of photoacid generators that can be used in the far ultraviolet region include onium salt compounds, sulfonimide compounds, sulfone compounds, sulfonic acid ester compounds, quinonediazide compounds, and diazomethane compounds. Can be used. Of these, onium salt compounds such as sulfonium salts, iodonium salts, phosphonium salts, diazonium salts, and pyridinium salts are suitable for KrF excimer laser, EUV, and electron beams. Specifically, triphenylsulfonium triflate, triphenylsulfonium nonafluorobutyrate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, (hydroxyphenyl) benzylmethylsulfonium toluenesulfonate, diphenyliodonium triflate, diphenyl Examples thereof include iodonium pyrenesulfonate, diphenyliodonium dodecylbenzenesulfonate, diphenyliodonium hexafluoroantimonate, and the like, and the photoacid generators can be used alone or in combination of two or more.
The amount of the photoacid generator used is 0.1 to 20 parts by weight, preferably 0.5 to 15 parts by weight, per 100 parts by weight of the photosensitive resin composition.

The photosensitive resin composition may be used after being dissolved in a solvent. A commercially available product can be used as the solvent used. For example, linear ketones such as 2-pentanone and 2-hexanone, cyclic ketones such as cyclopentanone and cyclohexanone, propylene glycol monoalkyl acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate, ethylene Ethylene glycol monoalkyl ether acetates such as glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate, propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether Ethylene glycol monoalkyl ethers such as diethylene glycol Call dimethyl ether, diethylene glycol alkyl ethers such as diethylene glycol diethyl ether, ethyl acetate, esters such as ethyl lactate, cyclohexanol, alcohols such as 1-octanol, ethylene carbonate, and γ- butyrolactone. These solvents can be used alone or in admixture of two or more. When the solvent is used, the amount used is 100 to 5000 parts by mass, preferably 1000 to 2000 parts by mass with respect to 100 parts by mass of the photosensitive resin composition.

The photosensitive resin composition may further contain an acid diffusion controller.
The acid diffusion control agent controls the diffusion phenomenon in the resist film of the acid generated from the acid generator by exposure, and has an action of suppressing an undesirable chemical reaction in the non-exposed region. As the acid diffusion controller, a nitrogen-containing organic compound whose basicity is not changed by exposure or heat treatment in the resist pattern forming step is preferable. As such nitrogen-containing organic compounds, commercially available products can be used. For example, monoalkylamines such as n-hexylamine, n-heptylamine and n-octylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine; triethanolamine, tripropanolamine Substituted trialcoholamines such as tributanolamine, tripentanolamine and trihexanolamine, trialkoxyalkylamines such as trimethoxyethylamine, trimethoxypropylamine, trimethoxybutylamine and triethoxybutylamine; aniline, N, Aromatic amines such as N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline and diphenylamine; amine compounds such as ethylenediamine, formaldehyde Amide compounds such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone, urea compounds such as urea, imidazoles such as imidazole and benzimidazole, pyridines such as pyridine and 4-methylpyridine In addition, 1,4-diazabicyclo [2.2.2] octane and the like can be mentioned.
When the acid diffusion control agent is used, the blending amount is 15 parts by mass or less, preferably 0.001 to 10 parts by mass, more preferably 0.005 to 5 parts by mass per 100 parts by mass of the photosensitive resin composition. .

Furthermore, the photosensitive resin composition of the present invention may contain various additives such as a surfactant, a quencher, a sensitizer, an antihalation agent, a storage stabilizer, and an antifoaming agent as necessary. it can.

A method for forming a resist pattern using the photosensitive resin composition of the present invention will be described. A resist film is formed by applying the photosensitive resin composition onto a substrate such as a silicon wafer, metal, plastic, glass, or ceramic by an application means such as a spin coater, a dip coater, or a roller coater. After the coating is formed, heat treatment is appropriately performed at about 50 ° C. to 200 ° C., and exposure is performed through a predetermined mask pattern.

The thickness of the coating film (resist coating) is 0.01 to 5 μm, preferably 0.02 to 1 μm, more preferably 0.02 to 0.1 μm. Light beams of various wavelengths can be used for the exposure. For example, as a light source, far ultraviolet rays such as F ₂ excimer laser (wavelength 157 nm), ArF excimer laser (wavelength 193 nm), KrF excimer laser (wavelength 248 nm), EUV ( Wavelength 13 nm), X-rays, electron beams and the like. The exposure conditions such as the exposure amount are appropriately selected according to the composition of the photosensitive resin composition, the type of each additive, and the like.

In order to stably form a high-precision fine pattern, it is preferable to perform a heat treatment for 30 seconds or more at a temperature of 50 to 200 ° C. after exposure. If the temperature is less than 50 ° C., the variation in sensitivity depending on the type of substrate is not preferable.
As a final step, a predetermined resist pattern is formed by developing with an alkali developer at 10 to 50 ° C. for 10 to 200 seconds, preferably at 20 to 25 ° C. for 15 to 1200 seconds.

As the above alkaline developer, commercially available products can be used. For example, alkali metal hydroxide, aqueous ammonia, alkylamines, alkanolamines, heterocyclic amines, tetraalkylammonium hydroxides, choline, 1,8-diazabicyclo- [5.4.0] -7- Examples include alkaline compounds such as undecene and 1,5-diazabicyclo- [4.3.0] -5-nonene, and 0.0001 to 10% by mass, preferably 0.01 to 5% by mass, and more preferably 0.8. Used as 1 to 3% by weight alkaline aqueous solution. The developer composed of the alkaline aqueous solution may contain a water-soluble organic solvent or a surfactant.

According to the present invention, a resist having excellent adhesion to a substrate and having alkali solubility can be produced, and a fine pattern can be formed with high accuracy.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, as long as there exists an effect of this invention, an embodiment can be changed suitably. In the examples, the purity and yield of the novel (meth) acrylic compound were determined by gas chromatography (GC), and the structure was determined by ¹ H and ¹³ C-NMR. The measurement conditions for GC are as follows. In addition, unless otherwise indicated, the part and% in an example are a mass part and the mass%, respectively.
<GC conditions>
Column: TC-17 (0.53 mm ID × 30 m), injection temperature: 280 ° C., oven temperature: 70 ° C. (1 minute hold) → temperature rise at 10 ° C./minute→280° C. (10 minute hold), detection Vessel: FID, mobile phase: helium.

[Synthesis Example 1]
<Synthesis of 1- (cyclohex-1-en-1-yl) pyrrolidine>

A 100 mL round bottom flask equipped with a stirrer, thermometer, Dimroth, and Dean-Stark tube was charged with 9.8 g (100 mmol) of cyclohexanone (Tokyo Chemical Industry Co., Ltd .: C0489), 34.4 g of benzene, and 8.5 g (120 mmol) of pyrrolidine, The solution temperature was heated to 74 ° C. and stirred for 4 hours. The solution temperature was allowed to cool to 40 ° C. and concentrated by an evaporator to obtain 15.0 g of 1- (cyclohex-1-en-1-yl) pyrrolidine. It was used in the next step without further purification.

[Synthesis Example 2]
<Synthesis of ethyl 3- (2-oxocyclohexyl) propanoate>

15.0 g (99.2 mmol) of 1- (cyclohexa) -1-en-1-yl) pyrrolidine obtained in Synthesis Example 1 and 15.0 g of ethyl acrylate were added to a 100 mL round bottom flask equipped with a stirrer, thermometer and Dimroth. (150 mmol) and 37.8 g of tetrahydrofuran were charged. The solution temperature was heated to 70 ° C. and stirred for 6 hours. After allowing the solution temperature to cool to 40 ° C., 6.5 g of ion exchange water was added, and the solution temperature was kept at 20 to 30 ° C. and stirred for 15 hours. The reaction solution was transferred to a separatory funnel, 80 g of diisopropyl ether was added, 150 g of a 5% by mass sulfuric acid aqueous solution was added for washing, and washing with 60 g of ion-exchanged water was further performed twice. Concentration with an evaporator gave 18.2 g of ethyl 3- (2-oxocyclohexyl) propanoate. It was used in the next step without further purification.

[Synthesis Example 3]
<Synthesis of 3- (oxocyclohexyl) propanoic acid>

In a 100 mL round bottom flask equipped with a stirrer, a thermometer, and a Dimroth, 18.2 g (91.8 mmol) of ethyl 3- (oxocyclohexyl) propanoate obtained in Synthesis Example 2 and 60 g of a 10 mass% sodium hydroxide aqueous solution (sodium hydroxide) 6.0 g) was charged. The solution temperature was adjusted to 40 ° C. and stirred for 1 hour. The reaction solution was allowed to cool to 30 ° C., 100 g of heptane and 60 g of ion-exchanged water were added, transferred to a separatory funnel and shaken well, and the aqueous layer was recovered. After adding 18.5 g of 85 mass% phosphoric acid and 150 g of toluene to the aqueous layer and shaking well, the organic layer and the aqueous layer were separated. To the aqueous layer, 150 g of toluene was added again, and after shaking well, the organic layer was recovered. The collected organic layers were mixed and washed with 50 g of ion exchange water. 200 g of heptane was added, the solution temperature was cooled to 0 ° C., crystals were precipitated and stirred for 2 hours. Suction filtration was performed using 5C filter paper, and the recovered crystals were washed twice with 30 g of ice-cooled heptane. The crystals were dried at 40 ° C. under reduced pressure to obtain 10.9 g (yield 69.7%) of 3- (oxocyclohexyl) propanoic acid.

[Synthesis Example 4]
<Synthesis of 1-oxaspiro [4,5] decane-2,6-dione>

In a 1 L round bottom flask equipped with a stirrer, thermometer, Dimroth, and liquid feed pump, 30.0 g (176 mmol) of 3- (oxocyclohexyl) propanoic acid obtained in Synthesis Example 3 and 13.1 g of tetrabutylammonium iodide (35 .4 mmol) and 320 g of ethyl acetate were charged. The solution temperature was kept at 50 to 60 ° C., and 22.0 g (194 mmol) of 30% aqueous hydrogen peroxide was added dropwise with a liquid feed pump over 2 hours (0.18 g / min). After completion of the dropwise addition, the mixture was stirred for 30 minutes and allowed to cool to a solution temperature of 20 to 30 ° C. The reaction solution was transferred to a separatory funnel and washed with 250 g of a 20% by mass aqueous sodium sulfite solution. Then, 200 g of ethyl acetate was added to the separated aqueous layer to extract the organic layer. The collected organic layers were combined, washed with 200 g of ion exchange water, and this was performed twice. The organic layer was concentrated with an evaporator to make the solution weight 65 g. The mixture was cooled at 0 ° C. for 24 hours, and the precipitated crystals were collected by filtration. The collected crystals were dried under reduced pressure at 40 ° C. to obtain 19.1 g of 1-oxaspiro [4,5] decane-2,6-dione (yield 64.5%).

[Synthesis Example 5]
<Synthesis of 6-hydroxy-1-oxaspiro [4,5] decan-2-one>

To a 1 L three-necked round bottom flask equipped with a stirrer and a thermometer, 9.70 g (57.2 mmol) of 1-oxaspiro [4,5] decane-2,6-dione obtained in Synthesis Example 4 and 453 g of methanol were added. The solution temperature was kept at 20-30 ° C. 2.60 g (68.7 mmol) of sodium borohydride was charged, and the mixture was stirred for 5 hours while maintaining the solution temperature of 20-30. Thereafter, the solvent was concentrated in vacuo using an evaporator. 100 g of ethyl acetate was added, and the mixture was transferred to a 2 L separatory funnel. The organic layer was washed with 100 g of a 5% by mass sulfuric acid aqueous solution and further washed with 100 g of ion-exchanged water, and the organic layer was recovered. The solvent was concentrated in vacuo and purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/1 (v / v), Rf value: 0.43). As a clear liquid, 7.76 g (yield: 80.0%) of 6-hydroxy-1-oxaspiro [4,5] decan-2-one was obtained.

[Example 1]
<Synthesis of 2-oxo-1-oxaspiro [4,5] decan-6-yl methacrylate>

To a 100 mL three-necked round bottom flask equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel, 4.09 g of 6-hydroxy-1-oxaspiro [4,5] decan-2-one obtained in Synthesis Example 5 (24 0.1 mmol), 4.15 g (41.1 mmol) of triethylamine, 4.83 mg (0.0242 mmol) of phenothiazine, and 20.5 g of 1,2-dichloroethane, and the solution temperature was kept at 5 to 10 ° C. The dropping funnel was charged with 3.76 g (36.0 mmol) of methacrylic acid chloride and added dropwise to the reaction solution. The solution temperature was raised to 70 ° C. and stirred for 8 hours. The solution temperature was brought to room temperature, 50 g of 1,2-dichloroethane was added, and then 30 g of ion-exchanged water was added for quenching. The reaction solution was transferred to a 2 L separatory funnel, and the organic layer was collected. The organic layer was further washed with 30 g of 5% aqueous sodium hydrogen carbonate solution and 30 g of ion-exchanged water. The solvent was concentrated in vacuo, purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/10 (v / v), Rf value: 0.12), and the solvent was distilled off by vacuum concentration. As a yellow liquid, 5.88 g (yield: 95.3%) of 2-oxo-1-oxaspiro [4,5] decan-6-yl methacrylate was obtained. The stereoisomer ratio was 3: 1.
Stereoisomer 1: ¹ H-NMR spectrum (CDCl ₃ ): δ1.43 to 2.69 ppm (12H, m, cyclohexane ring, methylene group of butyrolactone ring), 2.05 ppm (3H, s, methyl group of methacryloyl group) ), 4.80 ppm (1H, m, methine group of cyclohexane ring), 5.56 ppm (1H, s, methacryloyl group double bond), 6.00 ppm (1H, s, methacryloyl group double bond). ¹³ C-NMR spectrum (CDCl ₃ ): 15.2 ppm, 18.5 ppm, 19.3 ppm, 24.4 ppm, 25.6 ppm, 28.0 ppm, 72.3 ppm, 82.8 ppm, 122.9 ppm, 132.9 ppm, 163.1ppm, 173.3ppm
Stereoisomer 2: ¹ H-NMR spectrum (CDCl ₃ ): δ1.43 to 2.69 ppm (methylene group of 12H, m, cyclohexane ring, butyrolactone ring), 2.05 ppm (3H, s, methyl group of methacryloyl group) ), 4.93 ppm (1H, m, methine group of cyclohexane ring), 5.60 ppm (1H, d, methacryloyl group double bond), 6.08 ppm (1H, d, methacryloyl group double bond). ¹³ C-NMR spectrum (CDCl ₃ ): 15.2 ppm, 18.9 ppm, 20.4 ppm, 25.1 ppm, 26.0 ppm, 28.0 ppm, 72.3 ppm, 83.2 ppm, 123.6 ppm, 133.1 ppm, 163.2ppm, 173.8ppm

[Synthesis Example 6]
<Synthesis of 4- (tertiary butoxycarbonyl) -5-oxohexanoic acid>

To a 3 L round bottom flask equipped with a stirrer, a thermometer, and a dropping funnel, 80.0 g (506 mmol) of tert-butyl acetoacetate (manufactured by Tokyo Chemical Industry Co., Ltd .: A0816) and 722 mL of tetrahydrofuran were added, and the atmosphere in the flask was replaced with nitrogen. 3.41 g (30.4 mmol) of potassium tertiary butoxide was added, and the system was ice-cooled and maintained at 0 to 10 ° C. 37.0 g (430 mmol) of methyl acrylate was added and added dropwise over 20 minutes. After completion of the dropwise addition, the liquid temperature was adjusted to 20 to 30 ° C. and the mixture was stirred for 2 hours. The system was cooled again with ice and maintained at 0 to 10 ° C., and 1.0 L of a 10 mass% sodium hydroxide aqueous solution (100 g of sodium hydroxide) was added and stirred for 20 hours. The reaction solution was transferred to a separatory funnel, and 500 g of diisopropyl ether was added to wash the aqueous layer. After this was performed three times, the aqueous layer was transferred to a round bottom flask, cooled on ice, and kept at 0-10 ° C. 1N Hydrochloric acid (520 g) was added, and the mixture was transferred to a separatory funnel and extracted with 800 mL of ethyl acetate. This was done twice. The collected organic layer was washed with 350 g of saturated brine and concentrated with an evaporator. It was dried under reduced pressure at 40 ° C. to obtain 92.5 g (yield: 79.4%) of 4- (tertiary butoxycarbonyl) -5-oxohexanoic acid.

[Synthesis Example 7]
<Synthesis of tertiary butyl 2-acetyl-5-oxotetrahydrofuran-2-carboxylate>

92.5 g (402 mmol) of 4- (tertiary butoxycarbonyl) -5-oxohexanoic acid obtained in Synthesis Example 6 in a 2 L round bottom flask equipped with a stirrer, thermometer, Dimroth, and liquid feed pump, tetrabutylammonium iodide 26.2 g (70.8 mmol) and 640 g of ethyl acetate were charged. The solution temperature was kept at 50 to 60 ° C., and 37.1 g (389 mmol) of 35% aqueous hydrogen peroxide was added dropwise with a liquid feed pump over 3 hours (0.21 g / min). After completion of the dropwise addition, the mixture was stirred for 30 minutes and allowed to cool to a solution temperature of 20 to 30 ° C. The reaction solution was transferred to a separatory funnel and washed by adding 325 g of a 20% by mass aqueous sodium sulfite solution. Then, 300 mL of ethyl acetate was added to the separated aqueous layer to extract the organic layer. The collected organic layers were combined, washed with 500 g of a 5% by mass aqueous sodium hydrogen carbonate solution, and then washed with 500 g of saturated brine. The organic layer was concentrated with an evaporator to obtain 50.8 g. It was used in the next step without further purification.

[Synthesis Example 8]
<Synthesis of tertiary butyl 2- (1-hydroxyethyl) -5-oxotetrahydrofuran-2-carboxylate>

A 3 L four-necked round bottom flask equipped with a stirrer and a thermometer was charged with 40.4 g (177 mmol) of tertiary butyl 2-acetyl-5-oxotetrahydrofuran-2-carboxylate obtained in Synthesis Example 8 and 1333 g of tetrahydrofuran. The solution temperature was kept at 5-10 ° C. 8.02 g (212 mmol) of sodium borohydride was charged and stirred for 4 hours. To prevent the solution temperature from exceeding 20 ° C., 300 g of a 20% by mass aqueous ammonium chloride solution was added. The solution was transferred to a 5 L separatory funnel, and 486 g of ethyl acetate was added to extract the organic layer. The aqueous layer was again transferred to a separatory funnel, and 486 g of ethyl acetate was added to further extract the organic layer. The organic layers were combined and transferred to a separatory funnel, and the organic layer was washed with 400 g of 5% aqueous sodium hydrogen carbonate solution and 400 g of ion-exchanged water. The solvent was concentrated in vacuo and purified by silica gel column chromatography (developing solvent: chloroform / ethyl acetate = 4/1 (v / v), Rf value: 0.28), and the solvent was distilled off as a pale yellow liquid. Tertiary butyl 2- (1-hydroxyethyl) -5-oxotetrahydrofuran-2-carboxylate (25.7 g, yield 63.1%) was obtained.

[Example 2]
<Synthesis of tertiary butyl 2- (1-methacryloyloxy) ethyl-5-oxotetrahydrofuran-2-carboxylate>

Into a 200 mL three-necked round bottom flask equipped with a stirrer, thermometer, reflux condenser, and dropping funnel was added 9.73 g (42.3 mmol) of tertiary butyl 2- (1-hydroxyethyl) -5-oxotetrahydrofuran-2-carboxylate. ), 12.0 g (118 mmol) of triethylamine, 84.0 mg (0.420 mmol) of phenothiazine, 5.00 mg (0.0114 mmol) of N-nitrosophenylhydroxylamine aluminum salt, 48.7 g of 1,2-dichloroethane, and the solution temperature Was maintained at 5 to 10 ° C. A dropping funnel was charged with 11.0 g (106 mmol) of methacrylic acid chloride and dropped into the reaction solution. The solution temperature was raised to 53 ° C. and stirred for 8 hours. The solution temperature was brought to room temperature and quenched by adding 50 g of ion exchange water. The solution was transferred to a 500 mL separatory funnel and the organic layer was recovered, and further washed with 50 g of ion exchange water to recover the organic layer. The solvent was concentrated in vacuo and purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1/3 (v / v), Rf value: 0.32). 10.6 g (84.4% yield) of butyl 2- (1-methacryloyloxy) ethyl-5-oxotetrahydrofuran-2-carboxylate was obtained. The stereoisomer ratio was 6: 1.
Stereoisomer 1: ¹ H-NMR spectrum (CDCl ₃ ): δ 1.27 (3H, d, C H ₃ —CH (—O—) C—), 1.42 ppm (9H, s, t-butyl group) 1.90 (3H, s, methyl group of methacryloyl group), 2.24 to 2.60 ppm (4H, m, methylene group of butyrolactone ring), 5.38 ppm (1H, m, CH ₃ —C H (— O-) C-), 5.58 ppm (1H, d, methacryloyl group double bond), 6.10 ppm (1H, d, methacryloyl group double bond). ¹³ C-NMR spectrum (CDCl ₃ ): 10.6 ppm, 15.2 ppm, 24.5 ppm, 24.7 ppm, 24.8 ppm, 68.5 ppm, 80.5 ppm, 84.5 ppm, 123.6 ppm, 132.7 ppm, 162.9ppm, 163.2ppm, 172.6ppm
Stereoisomer 2: ¹ H-NMR spectrum (CDCl ₃ ): δ 1.29 (3H, d, C H ₃ —CH (—O—) C—), 1.42 ppm (9H, s, t-butyl group) 1.90 (3H, s, methyl group of methacryloyl group), 2.24 to 2.60 ppm (4H, m, methylene group of butyrolactone ring), 5.38 ppm (1H, m, CH ₃ —C H (— O-) C-), 5.64 ppm (1H, d, methacryloyl group double bond), 6.19 ppm (1H, d, methacryloyl group double bond). ¹³ C-NMR spectrum (CDCl ₃ ): 11.1 ppm, 16.1 ppm, 24.5 ppm, 24.7 ppm, 24.8 ppm, 68.8 ppm, 80.9 ppm, 84.9 ppm, 124.0 ppm, 133.3 ppm, 164.4ppm, 165.4ppm, 172.7ppm

[Synthesis Example 9]
<Synthesis of 1-ethyl-1-methacryloyloxycyclohexane>

In a 500 mL three-necked round bottom flask equipped with a stirrer, thermometer, reflux condenser, and dropping funnel, 12.8 g (100 mmol) of 1-ethylcyclohexanol (Tokyo Chemical Industry Co., Ltd .: E1136), 20.3 g (200 mmol) of triethylamine , 199 mg (1.00 mmol) of phenothiazine and 100 g of 1,2-dichloroethane were added, and the solution temperature was kept at 5 to 10 ° C. A dropping funnel was charged with 20.7 g (200 mmol) of methacrylic acid chloride and dropped into the reaction solution. The solution temperature was raised to 50 ° C. and stirred for 8 hours. The solution temperature was brought to room temperature, and quenched by adding 100 g of ion exchange water. The solution was transferred to a 500 mL separatory funnel and the organic layer was recovered, and then washed with 100 g of ion-exchanged water to recover the organic layer. The solvent was concentrated in vacuo, purified by silica gel column chromatography, and the solvent was distilled off to obtain 16.2 g (yield 82.4%) of 1-ethyl-1-methacryloyloxycyclohexane.

[Example 3]
<Resin synthesis example 1>
4.15 g of 2-oxo-1-oxaspiro [4,5] decan-6-yl methacrylate (hereinafter referred to as monomer A1) obtained in Example 1, 2-ethyl-2-methacryloyloxyadamantane (manufactured by Tokyo Chemical Industry Co., Ltd.) E0909) (hereinafter referred to as monomer B1) 4.02 g, 3-hydroxy-1-adamantyl methacrylate (manufactured by Mitsubishi Gas Chemical Company, Inc .: HADM) (hereinafter referred to as monomer C1) 1.91 g, azobisisobutyronitrile 0.74 g The polymer was dissolved in 100 mL of tetrahydrofuran and polymerized for 24 hours while maintaining the reaction temperature at 55 ° C. in a nitrogen atmosphere (monomer charge ratio: A1 / B1 / C1 = 40/40/20 mol%). After the polymerization, the reaction solution was dropped into 500 mL of n-hexane to coagulate and purify the generated resin, and the generated white powder was filtered through a membrane filter and washed with 1000 mL of n-hexane. The white powder was collected and dried overnight at 40 ° C. under reduced pressure to obtain 6.32 g of methacrylic copolymer P1.

[Example 4]
<Resin synthesis example 2>
3.11 g of monomer A1, 3.18 g of 1-ethyl-1-methacryloyloxycyclohexane (hereinafter referred to as monomer B2) obtained in Synthesis Example 9, 2-methacryloyloxy-2- (3- (2-hydroxy-2-) Propyl) -1-adamantyl) propane (Mitsubishi Gas Chemical Co., Ltd .: ADPM) (hereinafter, monomer B3) 1.95 g, 3,5-dihydroxy-1-adamantyl methacrylate (Mitsubishi Gas Chemical Co., Ltd .: DHADM) (hereinafter, monomer) C2) 1.53 g and azobisisobutyronitrile 0.74 g were dissolved in 82 mL of tetrahydrofuran and polymerized for 24 hours while maintaining the reaction temperature at 55 ° C. in a nitrogen atmosphere (the monomer charge ratio was A1 / B2 / B3 / C2 = 30/40/15/15 mol%). After the polymerization, the reaction solution was dropped into 500 mL of n-hexane to coagulate and purify the resin, and the resulting white powder was filtered through a membrane filter and washed with 1000 mL of n-hexane. The white powder was collected and dried overnight at 40 ° C. under reduced pressure to obtain 6.77 g of methacrylic copolymer P2.

[Example 5]
<Resin synthesis example 3>
Tertiary butyl 2- (1-methacryloyloxy) ethyl-5-oxotetrahydrofuran-2-carboxylate obtained in Example 2 (hereinafter referred to as monomer A2) 3.13 g, monomer B1 3.35 g, monomer C1 1 .42 g and 0.49 g of azobisisobutyronitrile were dissolved in 79 mL of tetrahydrofuran and polymerized for 24 hours while maintaining the reaction temperature at 55 ° C. in a nitrogen atmosphere (monomer charge ratio was A2 / B1 / C1 = 35/45/20 mol%). After the polymerization, the reaction solution was dropped into 500 mL of n-hexane to coagulate and purify the resin, and the resulting white powder was filtered through a membrane filter and washed with 1000 mL of n-hexane. The white powder was collected and dried overnight at 40 ° C. under reduced pressure to obtain 4.94 g of methacrylic copolymer P3.

[Example 6]
<Resin synthesis example 4>
2.68 g of monomer A2, 2.06 g of monomer B2, 1.92 g of monomer C2, 1.13 g of monomer C3, and 0.49 g of azobisisobutyronitrile were dissolved in 78 mL of tetrahydrofuran and reacted under a nitrogen atmosphere. Polymerization was carried out for 24 hours while maintaining the temperature at 55 ° C. (monomer charge ratio was A2 / B2 / C2 / C3 = 30/35/20/15 mol%). After the polymerization, the reaction solution was dropped into 500 mL of n-hexane to coagulate and purify the resin, and the resulting white powder was filtered through a membrane filter and washed with 1000 mL of n-hexane. The white powder was collected and dried overnight at 40 ° C. under reduced pressure to obtain 5.45 g of methacrylic copolymer P4.

[Example 7]
<Resist performance evaluation 1>
100 parts by mass of each of the methacrylic copolymers P1, P2, P3 and P4 obtained in Examples 3 to 6 and 10 parts by mass of triphenylsulfonium nonafluorobutanesulfonate (TPS-109 manufactured by Midori Chemical Co., Ltd.) Photopolymer compositions R1, R2, R3, and R4 were prepared by dissolving in a propylene glycol monomethyl ether acetate solvent so that the polymer concentration was 6.3% by mass. After applying an antireflection film (ARC-29 made by Nissan Chemical Co., Ltd.) on a silicon wafer (silicon wafer made by Wanxing Silicon-Peak Electronics), this photoresist resin composition was applied on the antireflection film by spin coating. A photosensitive layer having a thickness of 100 nm was formed. After pre-baking for 60 seconds at a temperature of 90 ° C. on a hot plate, the photosensitive layer is irradiated with a 100 nm half pitch line and space pattern (8 lines) using an electron beam drawing apparatus (ELS-7700, manufactured by Elionix). did. Further, post-baking (PEB) was performed at a predetermined temperature for 90 seconds. Next, the film was developed with a 0.3 M aqueous solution of tetramethylammonium hydroxide for 60 seconds and rinsed with pure water to obtain a line and space pattern.

[Comparative Example 1]
Instead of monomer A1, 3.63 g of 2-oxohexahydro-2H-3,5-methanocyclopenta [b] furan-6-yl methacrylate (manufactured by Daicel: MNBL) (hereinafter referred to as monomer A4) was used. Performed the same operation as in Example 3 (monomer charge ratio: A4 / B1 / C1 = 40/40/20 mol%) to obtain 6.81 g of methacrylic copolymer P5.

[Comparative Example 2]
The same procedure as in Example 3 was performed except that 2.76 g of α-methacryloyloxy-γ-butyrolactone (manufactured by Osaka Organic Chemical Industry Co., Ltd .: GBLMA) (hereinafter referred to as monomer A3) was used instead of monomer A1. The ratio was A3 / B1 / C1 = 40/40/20 mol%), and 5.69 g of methacrylic copolymer P6 was obtained.

<Resist performance evaluation 2>
The same operation as in Resist Performance Evaluation 1 was performed to prepare a photosensitive resin composition R5 using P5 obtained in Comparative Example 1 instead of methacrylic copolymers P1, P2, P3, and P4, and further comparison A photosensitive resin composition R6 was prepared using P6 obtained in Example 2. And about these photosensitive resin compositions R5 and R6, the resist performance was evaluated similarly to the resist performance evaluation 1.

The obtained line and space pattern was observed with FE-SEM, and the resolution and line edge roughness (LER) were measured. The results are shown in Table 4. When the LER values of the respective photosensitive resin compositions at the same level of resolution were compared, the photosensitive resin compositions R1 and R3 had the same structure and composition other than the lactone as R1 and R3, respectively. It turned out that the value of LER is smaller than the thing R5 and R6. The repeating units A1 and A2 contained in the photosensitive resin compositions R1 and R3 have a structure that is sterically bulkier than the repeating units A3 and A4 contained in R5 and R6. Therefore, it is considered that the diffusion of the acid dissociated during electron beam drawing was suppressed, and as a result, the roughness could be reduced.

Table 5 shows the results of the photosensitive resin compositions R2 and R4. The copolymer composition of the photosensitive resin compositions R2 and R4 is different from the above-described R1 and R3, but these photosensitive resin compositions R2 and R4 also have the same degree as the photosensitive resin compositions R1 and R3. Good results were shown. That is, it was confirmed that the photosensitive resin compositions R2 and R4 can realize excellent resolution and a small value of LER. These results are also due to the same reason that the LER values of the photosensitive resin compositions R1 and R3 are smaller than the LER values of R5 and R6, that is, mainly due to the difference in the three-dimensional bulkiness of the repeating units. I can think of it.

Claims

A lactone (meth) acrylate compound represented by the general formula (1).

(In formula (1), R 1 represents a hydrogen atom or a methyl group;
R 2 represents hydrogen, an aliphatic alkyl group having 1 to 10 carbon atoms, or an alkyl group having an alicyclic structure having 3 to 10 carbon atoms;
R 3 represents hydrogen, an alkoxycarbonyl group represented by the formula (2), an aliphatic alkyl group having 1 to 10 carbon atoms, or an alkyl group having an alicyclic structure having 3 to 10 carbon atoms;
In this case, R 2 and R 3 may be bonded to each other to form an alicyclic structure having 3 to 10 carbon atoms;
n 1 represents an integer of 0-2. )

(In the formula (2), R 4 represents an aliphatic alkyl group having 1 to 13 carbon atoms or an alkyl group having an alicyclic structure having 3 to 13 carbon atoms; the broken line represents a bond in the compound of the formula (1). Represents the location.)
The lactone (meth) acrylate compound according to claim 1, comprising a step of reacting the hydroxylactone compound represented by the general formula (4) and the (meth) acrylic acid compound represented by the general formula (5). Production method.

(In the formula (4), R 2 , R 3 and n 1 are the same as those in the general formula (1).)

(In formula (5), R 1 is the same as in general formula (1). R 5 is one group selected from the group consisting of a hydroxyl group, a halogen atom, and a (meth) acryloyloxy group. .)
A (meth) acrylic copolymer having a repeating unit represented by the general formula (6).

(In the formula (6), R 1 to R 3 and n 1 are the same as in the formula (1), and the point * represents a bonding site with an adjacent repeating unit.)
The (meth) acrylic copolymer according to claim 3, further comprising one or both of the repeating units represented by the general formula (7) or (8) and the repeating unit represented by the general formula (9). .

(In formula (7), R 21 represents hydrogen or a methyl group, R 22 represents an alkyl group having 1 to 4 carbon atoms, and R 23 represents a cycloalkyl group or alicyclic alkyl group having 5 to 20 carbon atoms. (The point * represents a bonding point with an adjacent repeating unit.)

(In Formula (8), R 41 represents hydrogen or a methyl group, R 42 to R 43 may be the same or different, each represents an alkyl group having 1 to 4 carbon atoms, and R 44 represents 1 to 4 carbon atoms) Or an cycloalkyl group having 5 to 20 carbon atoms, or one group selected from the group consisting of alicyclic alkyl groups, and a point * represents a bonding point with an adjacent repeating unit.)

(In Formula (9), R 41 represents hydrogen or a methyl group, R 42 to R 44 may be the same or different, and one group selected from the group consisting of a hydrogen element, a hydroxyl group, a methyl group, and an ethyl group) And the point * represents a bonding point with an adjacent repeating unit.)
20 to 80 mol% of the repeating unit represented by the general formula (6) is included, and 20 to 80 mol% in total of the repeating units represented by the general formulas (7) and (8) is included. The (meth) acrylic copolymer according to claim 4, comprising 10 to 50 mol% of the repeating unit represented by 9).
A photosensitive resin composition comprising the (meth) acrylic copolymer according to any one of claims 3 to 5 and a photoacid generator.