JP2002234918A - Maleimide copolymer and composition for resist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition excellent in dry etching resistance and adhesion to a substrate, and a maleimide copolymer useful therefor. SOLUTION: This resist composition contains a maleimide copolymer containing units represented by formulas (1) to (3) (wherein R1 is an optionally substituted alkyl group; R2 is a leaving group; R3 is H or methyl; Z1 is an alicyclic group having at least one group selected from among hydroxyl group, oxo group, and lactone ring; and x is an integer of 0-3).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist composition suitable for forming a pattern (microfabrication of a semiconductor or the like) using ultraviolet rays or the like, and a maleimide-based copolymer useful for obtaining the composition. About coalescence.

[0002]

2. Description of the Related Art In the field of photoresists, as a resist excellent in resolution, an alternating copolymer obtained by a radical copolymerization of a norbornene derivative and maleic anhydride is known. In such a resist, since a norbornene derivative is used (particularly, since a unit of the norbornene derivative is introduced into the main chain of the resin), the resist exhibits a certain degree of dry etching resistance to a plasma gas, but has a maleic anhydride unit. Reduce the percentage,
It has been difficult to greatly improve dry etching resistance. As described above, since maleic anhydride is essential in the conventional main chain type resist, it contains a large amount of highly reactive acid anhydride residues, and is a secondary component in polymerization, recovery, purification, and storage. In some cases, a reaction occurred, and there was a problem in stability of resist performance.

Therefore, use of a maleimide monomer instead of maleic anhydride has been studied. JP-A-11-171935 discloses a copolymer resin obtained by copolymerizing alkoxycarbonyl norbornene, carboxynorbornene, and a maleimide-based monomer having a hydroxyalkyl group or the like at a nitrogen atom of maleimide,
And a photoresist containing the copolymer resin. JP-A-11-228536 discloses a copolymer resin for a photoresist obtained from a substituted alkylmaleimide or a mono- or dihydroxyalkylmaleimide and a bicycloalkenecarboxylic acid or an ester thereof. JP-A-11-349637 discloses, as a photoresist polymer, a substituted C _0-10 alkylmaleimide or a substituted benzylmaleimide, a t-butyl ester of bicycloalkanecarboxylic acid, and a hydroxyalkyl ester of bicycloalkanecarboxylic acid. A copolymer having each unit is disclosed. However, with such a resin, although the stability of the resist performance can be improved to some extent, the effect of improving the dry etching resistance and the adhesion to the substrate is insufficient, and the resist film swells due to the alkali developing solution, and the resolution, etc. The resist performance of the sample is reduced.

Japanese Patent Application Laid-Open No. Hei 5-297593 discloses a copolymer of bicyclo [2.2.1] hept-5-ene-2-carboxylic acid ester and N-cyclohexylmaleimide, and an acid generator. Are disclosed. In such a resist, although the maleimide monomer has an alicyclic group, the etching resistance can be improved to some extent, but such a maleimide monomer is expensive and economically disadvantageous.

Furthermore, such a norbornene derivative and a maleimide monomer alone have low polymerizability, so that the molecular weight cannot be greatly improved, and are not suitable for resist applications. When a hydroxyalkylmaleimide or the like is used as the maleimide-based monomer, the adhesion to the substrate can be improved to some extent, but when used in a large amount, the dry etching resistance decreases.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a maleimide-based copolymer which can improve dry etching resistance, resist performance, and stability of resist performance, and is economically advantageous, and a maleimide copolymer. An object of the present invention is to provide a resist composition containing a system copolymer.

Another object of the present invention is to provide a maleimide copolymer which can improve the adhesion of a resist to a substrate and is useful for forming a pattern with high precision, and a resist composition containing the maleimide copolymer. To provide things.

[0008]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and as a result, have found that inexpensive conventional alkylmaleimides or hydroxyalkylmaleimides can be used.
When combined with an alicyclic olefin having a leaving group (especially an acid leaving group) and a monomer having adhesion to a substrate, dry etching resistance and resist performance (resolution, etc.) are greatly improved in resist applications. The inventors have found that this is possible and completed the present invention.

That is, the maleimide-based copolymer of the present invention contains units represented by the following formulas (1) to (3).

[0010]

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(Wherein, R ¹ represents an alkyl group which may have a substituent, R ² represents a leaving group, R ³ represents a hydrogen atom or a methyl group. Z ¹ represents a hydroxyl group, An alicyclic group having at least one selected from an oxo group, a hydroxyalkyl group, a carboxyl group, an alkoxycarbonyl group, and a lactone ring, and x represents an integer of 0 to 3.) In the formula (2), R ² The leaving group represented by may be removable by the action of an acid. In the formula (1), R ¹ may be a C _1-6 alkyl group, a hydroxy C _1-6 alkyl group, or the like. In the formula (3), the alicyclic group represented by Z ¹ may be a polycycloalkyl group, and at least one of the alicyclic groups constituting the polycycloalkyl group may be a polycycloalkyl group.
Two rings may form a lactone ring. The maleimide-based copolymer may further have maleic anhydride or an ester thereof as a unit. The maleimide copolymer has a weight average molecular weight of 1,000 to 100,0.
It may be about 00.

The present invention also includes a resist composition containing the maleimide-based copolymer and a photoacid generator.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The maleimide copolymer of the present invention contains units represented by the above formulas (1) to (3). Therefore, the maleimide copolymer of the present invention is inexpensive but has excellent properties such as resolution, and is useful as a functional polymer such as a photosensitive resin. In particular, when used for a photoresist, dry etching resistance, adhesion to a substrate, and stability of resist performance can be greatly improved.

Such a maleimide-based copolymer comprises at least a maleimide-based monomer corresponding to the unit of the formula (1) and an alicyclic olefin having an ester group corresponding to the unit of the formula (2). And a (meth) acrylic monomer having an alicyclic group corresponding to the unit of the formula (3).

In the above formula (1), examples of the alkyl group represented by R ¹ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, and a tert-butyl group.
And a straight-chain or branched-chain C _1-6 alkyl group (particularly a C _1-4 alkyl group) such as a -butyl group. Examples of the substituent of the alkyl group include a hydroxyl group,
Alkoxy group (C _1-4 alkoxy group such as methoxy group and ethoxy group), carboxyl group, alkoxycarbonyl group (C _1-4 alkoxy-carbonyl group such as methoxycarbonyl group and ethoxycarbonyl group), acyl group (acetyl) A C _1-4 acyl group such as a group). Preferred substituents are hydroxyl groups.

The maleimide-based monomer corresponding to the unit of the formula (1) includes N-methylmaleimide, N-ethylmaleimide, Nn-propylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide and the like. C
_1-6 alkyl maleimide; N- (2-hydroxyethyl) maleimide, N- (3-hydroxyethyl) maleimide, N- (2-hydroxy-n-propyl) maleimide, N- (3-hydroxy-n-propyl) Examples thereof include N-hydroxy C _1-6 alkylmaleimide such as maleimide.

In the above formula (2), R^TwoProlapse represented by
The leaving group can be removed by the action of an acid (acid leaving group)
It is preferred that When an acid leaving group is used,
Solubility in alkaline developer
It can greatly improve the resolution. Such desorption
Examples of the group include C, ethyl, t-butyl and the like.
_1-6Alkyl groups (especially C-_1-4Alkyl
Groups); tetrahydrofuranyl, tetrahydropyrani
5- to 8-membered (especially 5- or 6-membered) oxacycloa such as
Alkyl group; 2-oxepanyl group and the like. Ma
In the formula (2), the group —C (＝ O) —O—R^TwoPlace
The replacement position is not particularly limited, and may be at the bridgehead position of the norbornene ring.
Although it may be present, the methylene unit (secondary carbon source)
Child).

X is an integer of 0 to 3, preferably an integer of 0 to 2, and more preferably 0 or 1 (particularly 0).

The unit of the above formula (2) has a substituent
May be. As the substituent, an alkyl group (methyl,
C such as ethyl and butyl groups_1-6Alkyl group), al
Coxy groups (such as methoxy, ethoxy, t-butoxy groups, etc.)
C_1-4Alkoxy group), alkoxycarbonyl group
(C such as methoxycarbonyl and ethoxycarbonyl groups
_1-4Alkoxycarbonyl group), cycloalkyl
Xycarbonyl group (cyclohexyloxycarbonyl group
Such as C_5-8A cycloalkyloxycarbonyl group
), Aryloxycarbonyl group (phenoxycarbo
An aralkyloxycarbonyl group (such as benzyl group)
Loxycarbonyl group), hydroxyl group, hydro
Xymethyl group, carboxyl group, oxo group, nitro group,
Amino group, N-substituted amino group (NC_1-4Alkyl substitution
Amino group), nitrile group, carbamoyl group or N-
Substituted carbamoyl group (NC_1-4Alkyl carbamoyl
Group), halogen atoms (fluorine, chlorine, bromine and
Iodine atom).

Examples of the alicyclic olefin corresponding to the unit of the formula (2) include norbornenes, for example, lower alkoxy-carbonyl norbornenes such as 5-methoxycarbonylnorbornene, 5-ethoxycarbonylnorbornene and 5-t-butoxycarbonylnorbornene. 5-
Oxacycloalkylnorbornenes such as (2-tetrahydropyranyloxycarbonyl) norbornene and 5- (2-tetrahydrofuranyloxycarbonyl) norbornene are exemplified, and norbornenes having a t-butyl group as a leaving group are particularly preferred. The alicyclic olefins can be used alone or in combination of two or more.

When such an alicyclic olefin is copolymerized, dry etching resistance can be improved by the alicyclic moiety, and a carboxylic acid ester moiety can be introduced into the polymer. The leaving group R ² is eliminated to form a free carboxyl group, which is useful for accelerating the solubilization of the resin accompanying alkali development.

The proportion of the alicyclic olefin corresponding to the unit of the formula (2) is 10 to 300 parts by weight, preferably 50 to 300 parts by weight, based on 100 parts by weight of the maleimide monomer corresponding to the unit (1). It is about 250 parts by weight, more preferably about 100 to 200 parts by weight.

In the above formula (3), R ³ is a hydrogen atom or a methyl group.

The alicyclic group represented by Z ¹ is a hydroxyl group, an oxo group, a hydroxyalkyl group (a hydroxy C _1-4 alkyl such as a hydroxymethyl group) for improving the adhesion to a substrate in resist applications. Group), a carboxyl group, an alkoxycarbonyl group (C _1-4 alkoxycarbonyl group such as methoxycarbonyl, ethoxycarbonyl group, etc.), a lactone ring, and the like, and is usually non-eliminable to acids. .

The alicyclic group may be a cycloalkyl group, for example, a monocycloalkyl group (eg, a C _5-8 cycloalkyl group; a cycloalkylalkyl group such as a C _5-8 cycloalkyl-C _1-10 alkyl group). Group), polycycloalkyl groups [for example, bicycloalkyl groups such as norpinyl and norbornyl groups; adamantyl, tricyclo [2.2.1.1 ^3,5 ] octyl, tricyclo [5.
2.1.0 ^2,6 ] decyl, tricyclo [4.3.1.1]
^2,5 ] undecyl group and other tricycloalkyl groups; tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] tetracycloalkyl groups such as dodecyl groups; and polycycloalkylalkyl groups (including polycycloalkyl C _1-10 alkyl groups) corresponding to the above-mentioned polycycloalkyl groups. Further, the alicyclic group includes a group in which one or two (particularly one) of the carbon atoms constituting the ring of the cycloalkyl group is substituted with an oxygen atom. From the viewpoint of etching resistance, as the alicyclic group, a polycyclic alicyclic group,
In particular, a crosslinked cyclic alicyclic group such as a polycycloalkyl group is preferable.

Of the groups or rings for improving the adhesion,
Particularly, a hydroxyl group, an oxo group, and a lactone ring are preferable. In addition, the substitution position of the hydroxyl group may be a secondary carbon atom of the cycloalkane ring constituting the cycloalkyl group, and is usually a tertiary carbon atom in the polycycloalkyl ring. The substitution position of the oxo group is the secondary carbon atom of the cycloalkane ring. When the alicyclic group has a lactone ring, at least one ring constituting a cycloalkyl group (particularly, a polycycloalkyl group) usually forms a lactone ring.

The unit of the formula (3) is a group or ring (hydroxyl group, oxo group,
In addition to the lactone ring), such as C _1-4 alkyl group such as an alkyl group (methyl group), which may have a substituent such as an alkoxy group (such as a C _1-4 alkoxy group).

(Meth) acrylate corresponding to the above formula (3) (substrate contact type (meth) acrylate)
Is, for example, a polycycloalkyl (meth) acrylate having a lactone ring [2-acryloyloxy-
4-oxatricyclo [4.2.1.0 ^3,7 ] nonane-5
Tricyclo [2.2.1.1 ^3,5 ] such as -one, 2-acryloyloxy-7-methoxycarbonyl-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-5-one;
Secondary carbon atoms of the octane ring (e.g., 2 at positions 7 and 8)
(Meth) acrylate in which a quaternary carbon atom) is substituted with a group —C (＝ O) —O—; 4-oxatricyclo [4.
3.1.1 ^3,8 ] undecane-5-one-1-yl (meth) acrylate, etc., based on the secondary carbon atom of the adamantane ring (for example, secondary carbon atom at 4-, 6- and 10-position) Adamantyl (meth) acrylate analogs substituted with -C (= O) -O-; 4-oxatricyclo [4.
3.1.1 ^3,8 ] Secondary carbon atoms of the adamantane ring such as undecane-5-one-1-yl-methyl (meth) acrylate (for example, secondary carbon atoms at 4-, 6- and 10-positions) Adamantyl C _1-10 alkyl (meth) acrylate analogs wherein is substituted with the group —C (＝ O) —O—, etc.], hydroxyl group-containing polycycloalkyl (meth)
Acrylates [hydroxynorbornyl (meth) acrylates such as 4-hydroxynorbornyl (meth) acrylate; 1- to 3-, 5- and 7-positions of the adamantane ring
Adamantyl (meth) acrylate having three (particularly one or two) hydroxyl groups (3-hydroxyadamantyl (meth) acrylate, 3,5-dihydroxyadamantyl (meth) acrylate, 3,5,7-trihydroxyadamantyl ( Oxo group-containing polycycloalkyl (meth) acrylate [1 to 3 at the 2-, 3- and 7-positions of the norbornane ring.
Oxonorbornyl (meth) acrylate having 2 (preferably 1 or 2, especially 1) oxo group (eg, 2-oxonorbornyl (meth) acrylate, 3-oxonorbornyl (meth) acrylate) Monooxonorbornyl (meth) acrylate; dioxonorbornyl (meth) acrylate such as 2,3-dioxonorbornyl (meth) acrylate; and 2 of the adamantane ring
Oxoadamantyl (meth) acrylate (2-oxoadamantyl) (meth) acrylate having 1 to 3 (preferably 1 or 2, especially 1) oxo groups at the-, 4-, 6- and 8 to 10 positions Monooxoadamantyl maleimides such as 2,4-oxoadamantyl (meth) acrylate; 2,4-dioxoadamantyl (meth) acrylate, 2,6-dioxoadamantyl (meth) acrylate, N- (4,6-dioxoadamantyl) ) Dioxoadamantyl maleimide such as (meth) acrylate; trioxoadamantyl (meth) acrylate such as 2,4,6-trioxoadamantyl (meth) acrylate, etc.); and polycycloalkyl (meth) containing a hydroxyl group and an oxo group. ) Acrylate [4-hydroxy-2-oxono Bornyl (meth) acrylate,
Hydroxyoxonorbornyl (meth) such as 4-hydroxy-3-oxonorbornyl (meth) acrylate
Acrylate; the oxo group-containing adamantyl (meth)
1-3 at the 3-, 5- and 7-positions of the acrylate (especially 1
Or an oxo group-containing adamantyl (meth) acrylate having a hydroxyl group having two or more hydroxyl groups).

The introduction of a hydroxyl group into the cycloalkyl group can be obtained by a conventional oxidation method, for example, an oxidation method using nitric acid or chromic acid, an oxygen oxidation method using a cobalt salt as a catalyst, a biochemical oxidation method, or the like. Can be
It can also be obtained by introducing a halogen atom (such as a bromine atom) into a cycloalkyl group, and hydrolyzing with an inorganic salt such as silver nitrate or silver sulfate to introduce a hydroxyl group. In addition, an imide compound [an imide compound (an N-hydroxyimide compound such as N-hydroxyphthalimide) derived from an alicyclic or aromatic polycarboxylic anhydride (particularly, an aromatic polycarboxylic anhydride)] and the like ], The hydroxyl group may be introduced by oxygen oxidation in the presence of the oxidation catalyst constituted as described above. The imide compound may be, if necessary, a compound containing a transition metal [metal oxide, organic acid salt (eg, acetate), inorganic acid salt (eg, nitrate, sulfate), halide (eg, chloride), coordination compound (eg, acetyl). Complex or complex salt such as an acetonate complex), a heteropolyacid or a salt thereof (such as cobalt molybdate, molybdenum tungstate, or vanadium molybdate), or a boron compound. For details of the imide compound and the cocatalyst, reference can be made to JP-A-8-38909 and JP-A-11-106360.

The introduction of an oxo group into a cycloalkyl group
The reaction can be carried out by contacting oxygen with the imide compound and, if necessary, the cocatalyst in the presence of a strong acid such as sulfuric acid.

Compounds in which at least one of the hydrocarbon rings constituting the alicyclic group forms a lactone ring include, for example, ketone compounds (adamantyl (meth) acrylate having an oxo group, such as adamantyl (meth) acrylate). A (meth) acrylate having a tanone moiety) in the presence of the imide compound and, if necessary, the co-catalyst (e.g., a cobalt compound such as cobalt acetate or cobalt acetylacetonate) as a primary or co-oxidizing agent. Bayer biliger which is oxidized by molecular oxygen together with secondary alcohol (C _1-6 alkyl alcohol such as methanol, C _5-8 cycloalkanol such as cyclohexanol, aralkyl alcohol such as 1-phenylethanol, benzhydrol, etc.) Reaction, or the ketone compound and peroxide (peroxide) It may be obtained by conventional Baeyer-Villiger reaction with a peroxide, etc.) such as hydrogen peroxide; acid, peracetic acid, such as m- chloroperbenzoic acid.

The hydroxylation, oxoation and lactone ring formation reactions are carried out in a solvent inert to the reaction, for example,
Organic acids, nitriles (acetonitrile, benzonitrile, etc.), amides (formamide, acetamide, dimethylformamide (DMF), dimethylacetamide, etc.), alcohols, aliphatic hydrocarbons (hexane, etc.), aromatic hydrocarbons ( Benzene, toluene, etc.),
In the presence of organic solvents such as halogenated hydrocarbons (eg, chloroform), nitro compounds, esters (eg, ethyl acetate, butyl acetate, isobutyl acetate), ethers (eg, dioxane, diethyl ether, tetrahydrofuran), and mixtures thereof. May go. The reaction is 0-30
0 ° C (for example, 10 to 200 ° C), preferably 30 to 1
It can be carried out at a temperature of about 50 ° C. under normal pressure or under pressure. When an imide compound is used as a catalyst, the amount of the imide compound used is 0.001 mol (0.1 mol%) to 1 mol (100 mol%), preferably 0.001 mol (0 mol), per 1 mol of the substrate. .1 mol%) to 0.5 mol (50
Mol%). When a co-catalyst is used, the ratio of the co-catalyst is 0.001 to 1 mol of the imide compound.
It is about 10 mol, preferably about 0.01 to 5 mol. The amount of oxygen used is 0.5 to 1 with respect to 1 mol of the substrate.
The amount is about 00 mol, preferably about 1 to 50 mol. In the oxo-formation reaction, the amount of the strong acid used is 0.00001 to 1
Mol (0.001 to 100 mol%). Preferably 0.0
It is about 005 to 0.7 mol (0.05 to 70 mol%). For details of the hydroxylation reaction, see, for example,
Reference can be made to JP-A-106360. Further, for details of the oxo-forming reaction, for example, JP-A-10-309469 can be referred to.

In the present invention, since the monomer corresponding to the unit (3) is copolymerized, the degree of polymerization of the copolymer can be improved,
A copolymer suitable for resist applications can be obtained.
The proportion of the substrate contact type (meth) acrylate corresponding to the unit (3) is determined by the ratio of the maleimide monomer 10
1 to 400 parts by weight, preferably 10 parts by weight, per 0 parts by weight
The amount is about 300 to 300 parts by weight (for example, 10 to 200 parts by weight), and more preferably about 20 to 200 parts by weight.

The maleimide-based copolymer of the present invention may contain other copolymerizable components such as a conventional copolymerizable monomer, a monomer capable of reducing cost, and a monomer for improving dry etching resistance. It may be a copolymer with a body or a monomer for imparting a function. Examples of such a monomer include maleic anhydride or an ester thereof, a crosslinked cyclic olefin, a maleimide having a hydrocarbon ring group, and (meth)
Acrylic acid or its ester is mentioned. These copolymerizable components can be used alone or in combination of two or more.

(Maleic anhydride or ester thereof) In the present invention, maleic anhydride is copolymerized to introduce a maleic anhydride unit into the polymer within a range that does not impair the dry etching resistance and the stability of the copolymer. You may. By introducing maleic anhydride, the cost of the polymer can be reduced without lowering the efficiency of the polymerization reaction (such as the introduction ratio of other units).

The proportion of maleic anhydride is 0 to 50 parts by weight, preferably about 1 to 40 parts by weight, based on 100 parts by weight of the maleimide monomer. In order to suppress a decrease in dry etching resistance, the proportion of maleic anhydride is 20% by weight or less (0 to 10%) of the total amount of monomers constituting the copolymer.
About 20% by weight), preferably 10% by weight or less (0 to 1%).
(About 0% by weight).

(Bridged cyclic cyclic olefin) In the present invention,
In order to further improve the dry etching resistance, it may have a crosslinked cyclic cyclic olefin unit represented by the following formula (4).

[0038]

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(Wherein R ⁴ represents a hydrogen atom, an alkyl group which may have a substituent, a glycidyl group, or a cycloalkyl group. X and R ³ are the same as those described above). Examples of the monomer (cyclic olefin) to be used include norbornenes, for example, C such as norbornene, 2-bornene, and 7,7-dimethyl-2-norbornene.
_Examples include norbornene which may be substituted with a _1-4 alkyl group. Such monomers include C _1-4 alkyl groups (such as methyl and ethyl groups), hydroxyl groups, hydroxy C _1-4 alkyl groups (such as hydroxymethyl groups),
It may have a substituent such as a carboxyl group or an oxo group.

The ratio of the monomer corresponding to the unit of the formula (4) is based on 100 parts by weight of the maleimide monomer.
It is about 0 to 200 parts by weight, preferably about 10 to 100 parts by weight, and more preferably about 30 to 90 parts by weight (for example, about 50 to 90 parts by weight).

(Maleimide having a hydrocarbon ring group) The copolymer of the present invention may further have a maleimide having an alicyclic group as a unit. When a maleimide having an alicyclic group is used, dry etching resistance can be further improved.

As such a maleimide unit having an alicyclic group, the maleimide-based copolymer of the present invention may include a unit represented by the following formula (5).

[0043]

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(Wherein, ring Z ² represents an optionally substituted hydrocarbon ring, X represents an alkylene group, and n represents 0)
Or 1) In the formula (5), examples of the hydrocarbon ring represented by Z ² include a monocyclic hydrocarbon ring [an alicyclic hydrocarbon ring (a C _5-8 cycloalkane ring such as a cyclohexane ring; A C _5-8 cycloalkene ring such as a cyclohexene ring), a polycyclic hydrocarbon ring (a bridged cyclic hydrocarbon ring, a condensed cyclic hydrocarbon ring and the like), and the like. The hydrocarbon ring may be aromatic, but when used in a photoresist, it is usually non-aromatic. When maleimide in which Z ² is a polycyclic hydrocarbon ring is used, dry etching resistance can be greatly improved.

Among the polycyclic hydrocarbon rings, bridged cyclic hydrocarbon rings (bridged cyclic hydrocarbon rings) include, for example, pinane, bornane, norpinane, norbornane (bicyclo [2.2.1] heptane) A) a bicyclic hydrocarbon ring such as a ring;
Homobredan, adamantane (tricyclo [3.3.
1.1 ^3,7 ] decane), tricyclo [5.2.1.
Tricyclic hydrocarbon rings such as 0 ^2,6 ] decane and tricyclo [4.3.1.1 ^2,5 ] undecane rings; tetracyclo [4.
4.0.1 ^2,5 . 1 ^7,10 ] dodecane, perhydro-1,
4-cyclic hydrocarbon rings such as 4-methano-5,8-methanonaphthalene ring; pentacyclo [7.3.1 ^4,12 . 0 ^2,7 .
^0,11 ] pentacyclic hydrocarbon ring such as a tetradecane ring; dimeric hydrogenated diene [eg, cyclo C _4-20 alkadiene such as cyclopentadiene, cyclohexadiene, cycloheptadiene (preferably cycloalkyl); C _6-12 alkadiene) dimer or hydrogenated product thereof (for example, perhydro-4,7-methanoindene and the like), butadiene dimer (vinylcyclohexene) or hydrogenated product thereof,
Butadiene and cyclopentadiene dimer (vinyl norbornene) or hydrogenated product thereof].

Among the above polycyclic hydrocarbon rings, condensed polycyclic hydrocarbon rings (condensed hydrocarbon rings) include, for example, 5 to 8 such as naphthalene, anthracene, phenanthrene, acenaphthene, fluorene, indene and phenalene rings. Examples thereof include a condensed ring in which member rings are condensed or a hydrogenated condensed ring thereof. Further, the condensed hydrocarbon ring may be crosslinked. Examples of such a ring include a tricyclo [5.2.0.0 ^2,6 ] nonane ring and a tricyclo [5.
2.1.0 ^2,6 ] decane ring, tricyclo [8.4.0.
0 ^3,8 ] tetradecane ring. In addition, the condensed ring in which the hydrocarbon ring (particularly, the non-aromatic hydrocarbon ring) is condensed may be any one of an ortho-condensation and an ortho-and peri-condensation.

In the polycyclic hydrocarbon ring (particularly, a bridged cyclic hydrocarbon ring such as an adamantane ring), at least one (preferably one) of the hydrocarbon rings constituting the polycyclic hydrocarbon ring is used. Or two rings) may constitute a lactone ring.

Preferred polycyclic hydrocarbon rings include alicyclic hydrocarbon rings (non-aromatic rings), for example, bridged cyclic hydrocarbon rings (for example, bicyclic or tricyclic such as bornane, norbornane and adamantane). Hydrocarbon ring), condensed hydrocarbon ring (for example, decalin ring, perhydroanthracene ring, etc.)
Or a condensed alicyclic hydrocarbon ring in which a 6-membered cycloalkane ring is condensed. Particularly, a bicyclic or tricyclic hydrocarbon ring (such as an adamantane ring) is preferable.

These ring Z ² (polycyclic hydrocarbon ring) may have a substituent (such as the substituent exemplified in the above formula (2)). Preferred substituents are an alkyl group (C _1-3 alkyl group, especially a methyl group) or a polar group (for example, a hydroxyl group, an alkoxy group, an oxo group, a carboxyl group,
Oxygen-containing groups such as an alkoxycarbonyl group and a hydroxymethyl group). In the case of photoresist applications, the substituent may be a polar group (particularly, an oxygen-containing group such as a hydroxyl group, a carboxyl group, or an oxo group), or at least one hydrocarbon constituting the polycyclic hydrocarbon ring. By making the ring a lactone ring, the adhesion to the substrate can be improved.

The position of the substituent with respect to the polycyclic hydrocarbon ring is not particularly limited. For example, in a bridged cyclic hydrocarbon ring, a divalent group such as an oxo group may be a methylene unit constituting the ring. (A secondary carbon atom), and a monovalent group (hydroxyl group, carboxyl group, etc.) may be substituted on a methylene unit (secondary carbon atom), particularly on a bridgehead position (tertiary carbon atom). Further, the number and types of the substituents in the hydrocarbon ring are not particularly limited.
Or a plurality of the same or different substituents (for example, 2 to 6
(Preferably 2 to 4).

Particularly preferred polycyclic hydrogen ring is adamantane which may have a substituent such as a hydroxyl group, a carboxyl group or an oxo group (for example, about 1 to 3, especially about 1 or 2 substituents). And a ring in which at least one of the rings constituting the adamantane ring forms a lactone ring.

In the above formula (5), examples of the alkylene group represented by X include methylene, methylmethylene, dimethylmethylene, ethylene, trimethylene, methylethylene, tetramethylene, 1,1-dimethylethylene,
Examples thereof include a linear or branched C _1-10 alkylene group such as a 2-dimethylethylene group (preferably a C _1-6 alkylene group, particularly a C _1-4 alkylene group). These alkylene groups may have an exemplary substituents as the substituent for the ring Z ^2.

In the above formula (5), n is 0 or 1, and preferably n is 0.

In the maleimide-based monomer corresponding to the unit of the above formula (5), the maleimide-based monomer wherein n is 0 is a 2- or 3-ring in which the ring Z ² may have a substituent. And a maleimide-based monomer that is a crosslinked cyclic hydrocarbon ring (such as norbornane and adamantane).

Examples of the norbornylmaleimide monomer include unsubstituted N-norbornylmaleimide; substituted norbornylmaleimide, for example, N-norbornyl having a hydroxyl group or a carboxyl group at the 4-position of the norbornane ring. Maleimide (N- (4-hydroxynorbornyl)
Maleimide, N- (4-carboxynorbornyl) maleimide, etc.) and N having 1 to 3 (preferably 1 or 2, especially 1) oxo groups at the 2-, 3- and 7-positions of the norbornane ring -Norbornylmaleimide (N- (2-oxonorbornyl) maleimide, N- (3-oxonorbornyl) maleimide, etc .; monooxonorbornylmaleimide; N- (2,3-dioxonorbornyl) ) Dioxonorbornyl maleimide such as maleimide),
The N- (norbornyl) maleimide having an hydroxyl group or a carboxyl group at the 4-position of the norbornane ring of the N- (norbornyl) maleimide having an oxo group (N- (4
-Hydroxy-3-oxonorbornyl) maleimide and the like.

Examples of the adamantyl maleimide-based monomer include unsubstituted N-adamantyl maleimide and substituted adamantyl maleimide [3-, 5- and 7 of an adamantane ring.
1 selected from hydroxyl group and carboxyl group
Monosubstituted adamantyl maleimide such as N- (adamantyl) maleimide (N- (3-hydroxyadamantyl) maleimide, N- (3-carboxyadamantyl) maleimide having up to 3 (particularly 1 or 2) substituents;
Disubstituted adamantyl maleimides such as N- (3,5-dihydroxyadamantyl) maleimide, N- (3,5-dicarboxyadamantyl) maleimide, N- (3-carboxy-5-hydroxyadamantyl) maleimide; 5,7-trihydroxyadamantyl)
Maleimide, N- (3,5,7-tricarboxyadamantyl) maleimide, N- (3-carboxy-5,7-
Tri-substituted adamantyl maleimide such as dihydroxyadamantyl) maleimide);
N- (adamantyl) maleimide (N- (2-oxoadamantyl) maleimide having 1-3 oxo groups (preferably 1 or 2, especially 1) at the 4-, 6- and 8-10 positions; Monooxoadamantylmaleimide such as-(4-oxoadamantyl) maleimide; N- (2,
4-dioxoadamantyl) maleimide, N- (2,6
-Dioxoadamantyl) maleimide, N- (4,6-
Dioxoadamantylmaleimides such as dioxoadamantyl) maleimide; trioxoadamantylmaleimides such as N- (2,4,6-trioxoadamantyl) maleimide; etc .; 1 to 3 (particularly 1 or 2) selected from hydroxyl group and carboxyl group
) -Substituted N- (adamantyl) maleimide (N- (3-hydroxy-4-oxoadamantyl) maleimide, N- (3-hydroxy-6-oxoadamantyl) maleimide and the like. Or carboxy-oxoadamantyl) maleimide) and the like],
Maleimide in which at least one of the rings constituting the adamantane ring forms a lactone ring [that is, the 2-, 4-, 6- and 8 to 10-positions (preferably 4-, 6- and N- (adamantyl) maleimide analogs (N-) in which the secondary carbon atom at the 10-position is substituted with one or two (especially one) group -C (= O) -O-
(Eg, 4-oxatricyclo [4.3.1.1 ^3,8 ] undecane-5-one-1-yl) maleimide) and the like.

In the above maleimide monomer,
When the norbornene ring or the adamantane ring has a plurality of hydroxyl groups and carboxyl groups, it preferably has the same kind of substituent as a dihydroxyl compound or a dicarboxyl compound.

When n is 1 and X is C_1-4Archire
Examples of the maleimide-based monomer that is a
N-norborny corresponding to a maleimide monomer in which n is 0
Alkylmaleimide [N-norbornylmethylmale
N-norbornyl C such as mido_1-4(Especially C_1-2) Archi
Lumaleimide; N- (4-hydroxynorbornylmethyl)
Le) maleimide, N- (4-carboxynorbornylme)
N- (4-hydroxy or carboxy) such as tyl) maleimide
Boxy-norbornyl-C_1-4(Especially C_1-2) Alkyl)
Maleimide; N- (3-oxonorbornylmethyl) ma
N- (oxonorbornyl C_1-4(In particular
C_1-2) Alkyl) maleimide; N- (4-hydroxy
-3-oxonorbornylmethyl) maleimide
-(4-hydroxy or carboxy-oxonorborny
Le-C_1-4(Especially C_1-2) Alkyl) maleimide, etc.
And adamantyl alkylmaleimide [N-adamantyl
N- (adamantyl C) such as methyl maleimide_1-4(Special
To C_1-2) Alkyl) maleimide; N- (3-hydroxy
Cyanadamantylmethyl) maleimide, N- (3,5-di
Hydroxyadamantylmethyl) maleimide, N- (3
N-carboxyadamantylmethyl) maleimide
-(Hydroxy or carboxy-adamantyl C
_1-4(Especially C_1-2) Alkyl) maleimide; N- (4-O
Xoadamantylmethyl) maleimide, N- (2,4-
N- such as dioxoadamantylmethyl) maleimide
(Oxoadamantyl C_1-4(Especially C_1-2) Alkyl) ma
Reimide; N- (3-hydroxy-6-oxoadaman
N- (hydroxy or potassium) such as tylmethyl) maleimide
Ruboxy-oxoadamantyl C_1-4(Especially C_1-2) Al
Kill) maleimide); N- (4-oxatricyclo
[4.3.1.1.^3,8] Undecane-5-one-1-a
N- (4-oxatrice) such as ru-methyl) maleimide
Black [4.3.1.1.^3,8] Undecane-5-one-1
-Il-C_1-4(Especially C_1-2) Alkyl) maleimide
Etc.].

Such maleimide monomers include, for example, maleic acid or a derivative thereof [maleic anhydride, maleic halide (maleic acid chloride, etc.), maleic acid ester (maleic acid such as methyl maleate, etc.).
_1-3 ) and a compound represented by the following formula (5a), and the maleic acid or a derivative thereof is ring-opened to produce an amic acid, and the obtained amic acid is subjected to a dehydration reaction. And ring-closing.

[0060]

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(Where Z is^Two, X and n are the same as described above.) The amines represented by the formula (5a)
It may be prepared by a conventional method. Especially complex
Amines having a polycyclic structure include, for example, ring Z ^TwoCompatible with
Having a polycyclic hydrocarbon ring (amine precursors)
A nitro group is introduced into the
It can also be prepared by converting to a thio group.

The method for introducing a nitro group includes (i) nitrogen oxides [N ₂ O ₃ , NO _2, etc., in the presence of a catalyst composed of the imide compound exemplified in the section of the above formula (3); _p
A method of introducing a nitro group by reaction with O _q (where p represents an integer of 1 or 2 and q represents an integer of 1 to 6) or a nitrogen oxide containing the same as a main component, (ii) Examples include a method of introducing a nitro group using nitrogen oxide and / or oxygen of at least one of nitrous oxide and nitric oxide, and (iii) a method of introducing a nitro group by a reaction of nitrogen dioxide. The imide compound may be used in combination with the cocatalyst exemplified in the section of the unit of the formula (3).

The amount of the imide compound used is 0.001 mol (0.1 mol%) to 1 mol of the amine precursor.
It is about 1 mol (100 mol%), preferably about 0.001 mol (0.1 mol%) to 0.5 mol (50 mol%). The amount of the cocatalyst used is 0.0001 mol (0.01 mol%) to 0.7 mol (7 mol) with respect to 1 mol of the amine precursor.
0 mol%), preferably about 0.001 mol (0.1 mol%) to 0.5 mol (50 mol%). When a heteropoly acid or a salt thereof is used as a cocatalyst, the amount is 0.1 to 25 parts by weight, preferably about 0.5 to 10 parts by weight, based on 100 parts by weight of the amine precursor. The used amount of the nitrogen oxide is 1 to 50 mol per 1 mol of the amine precursor,
Preferably it is about 1.5 to 30 mol.

The nitration reaction is usually carried out in an organic solvent inert to the reaction. Examples of the organic solvent include the solvents exemplified in the section of the hydroxylation or oxo-formation reaction of the unit (3), preferably an organic acid (for example, a carboxylic acid such as acetic acid or acetic anhydride or an anhydride thereof), or a nitrile. (Eg, benzonitrile) and halogenated hydrocarbons (eg, dichloroethane) in many cases.

The reaction temperature is, for example, from 0 to 150 ° C., preferably from 25 to 125 ° C., more preferably from 30 to 100 ° C., depending on the type of the imide compound or the amino precursor.
You can choose from a range of degrees. The nitration reaction can be performed under normal pressure or under pressure.

As a method for reducing a compound having a nitro group, a conventional method, for example, a catalytic hydrogenation method using hydrogen as a reducing agent [as a catalyst, for example, a simple substance of a metal of Group 9 to 11 of the periodic table such as platinum or the like] , A catalytic hydrogenation method using compounds containing these metal elements (such as platinum oxide and palladium carbon), and a reduction method using a hydride reducing agent (such as aluminum hydride and lithium aluminum hydride). it can.

The introduction of a substituent (hydroxyl group or oxo group) into the ring Z ² may be carried out by the same method as the introduction of a hydroxyl group or an oxo group into the cycloalkyl group in the above item (3). Can be. The lactone ring can be introduced by a Bayer-Villiger-type reaction of a ketone compound (such as an adamantanone compound) or a conventional Bayer-Villiger reaction in the same manner as described above.

The introduction of a carboxyl group into the ring Z ²
Carboxyl groups can be introduced by contacting carbon monoxide and oxygen in the presence of an oxidation catalyst composed of the imide compound and, if necessary, the cocatalyst.

The carboxylation reaction may be carried out in the presence of a solvent inert to the reaction, for example, the organic solvent exemplified in the hydroxylation or oxolation reaction. The carboxylation reaction can be carried out in the same range as the temperature exemplified in the section of the hydroxylation or oxo-formation reaction, and can be carried out under normal pressure or under pressure. When an imide compound is used as a catalyst, the amount of the imide compound used can be selected from the range exemplified in the section of the nitration reaction per 1 mol of the substrate. When a co-catalyst is used, the ratio of the co-catalyst is 0.001 to 1 per 1 mol of the imide compound.
0 mol, preferably about 0.01 to 5 mol. The amount of carbon monoxide to be used is 2 to 50 mol, preferably about 5 to 30 mol, per 1 mol of the substrate. For details of the carboxylation reaction, for example, JP-A-11-106360 can be referred to.

The ratio of the unit of the formula (5) is, for example, 0 to 100 parts by weight, preferably 0.1 to 70 parts by weight, based on 100 parts by weight of the maleimide monomer corresponding to the unit of the formula (1). Parts by weight, more preferably about 1 to 50 parts by weight (for example, 5 to 30 parts by weight).

((Meth) acrylic acid or its ester)
In the present invention, various functions (such as easy developability, dry etching resistance, and film properties) may be imparted to the polymer by further copolymerizing (meth) acrylic acid or an ester thereof. As such a (meth) acrylic monomer, a (meth) acrylic monomer excluding a monomer corresponding to the unit of the formula (3), for example, a unit represented by the following formula (6) Can be exemplified.

[0072]

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(Wherein, R ⁴ represents a hydrogen atom, an alkyl group which may have a substituent, a glycidyl group, or a cycloalkyl group. R ³ is the same as described above.) As the (meth) acrylate, alkyl (meth) acrylate [methyl (meth) acrylate, ethyl (meth) acrylate,
N-butyl (meth) acrylate, t- (meth) acrylate
C _1-20 alkyl (meth) acrylates (meth) acrylic acid such as -butyl, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate (Preferably C _1-6 alkyl ester, especially C _1-4 alkyl (meth) acrylate), hydroxyalkyl (meth) acrylate (such as hydroxy C _2-4 alkyl (meth) acrylate), glycidyl ( Meta)
Acrylate, cycloalkyl (meth) acrylate,
And polycycloalkyl (meth) acrylate. The cycloalkyl (meth) acrylate and polycycloalkyl (meth) acrylate also include cycloalkylalkyl (meth) acrylate and polycycloalkylalkyl (meth) acrylate, and further include a cycloalkyl group and a polycycloalkyl group. (Meth) acrylates in which one or two (particularly one) of the carbon atoms constituting the above are substituted by an oxygen atom.

The (meth) acrylic acid or its ester can be used alone or in combination of two or more. In resist applications, in order to improve solubility in a developing solution, it is desirable that the (meth) acrylic acid ester be eliminated by the action of an acid to generate a carboxyl group (acid-elimination type).

The cycloalkyl (meth) acrylate includes cycloalkyl (meth) acrylates [cyclopentyl (meth) acrylate, cyclohexyl (meth)
_C5-8 cycloalkyl- (meth) acrylate such as acrylate (especially _C5-6 cycloalkyl (meth) acrylate); 2-tetrahydrofuranyl (meth) acrylate, 2-tetrahydropyranyl (meth) acrylate, 4-tetrahydro 2-, 3- or 4-oxacycloalkyl (meth) such as pyranyl (meth) acrylate
Acrylates (e.g. 5-8 members, especially 5 or 6
)], Cycloalkyl-alkyl (meth) acrylates [C _5-8 cycloalkyl-C _1-10 alkyl (meth) acrylates such as cyclohexylmethyl (meth) acrylate and cyclohexyldimethylmethyl (meth) acrylate (preferably C _5-6 cycloalkyl -C _2-8 alkyl (especially branched C _3-7 alkyl) (meth) acrylate); 2-tetrahydropyranyl-methyl (meth) 5-8 membered, such as acrylates (especially 5 or 6-membered) 2-, 3
-Or 4-oxacycloalkyl-C _1-10 alkyl (preferably C _2-8 alkyl, especially C _3-7 alkyl)
(Meth) acrylate, etc.]. The oxacycloalkyl (meth) acrylate and the cycloalkylalkyl (meth) acrylate are preferred.

The polycycloalkyl (meth) acrylate includes polycycloalkyl (meth) acrylates [polycycloalkyl (meth) acrylates, for example, bicycloalkyl (meth) acrylates such as norpinyl (meth) acrylate and norbornyl (meth) acrylate. Acrylate; adamantyl (meth) acrylate, tricyclo [5.2.1.0 ^2,6 ] decyl (meth) acrylate,
Tricyclo [4.3.1.1 ^2,5 ] undecyl (meth)
Tricycloalkyl (meth) acrylates such as acrylate; tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ]
Tetracycloalkyl (meth) acrylates such as dodecyl (meth) acrylate, etc.], polycycloalkyl-alkyl (meth) acrylates [polycycloalkyl-alkyl (meth) acrylates, for example, norbornylmethyl (meth) acrylate, nor bicycloalkyl C _1-10 alkyl such as bornyl dimethyl methyl (meth) acrylate (preferably C _2-8 alkyl, especially branched C _3-7 alkyl) (meth) acrylate; adamantylmethyl (meth) acrylate, adamantyl ethyl ( Meth) acrylate, adamantyl dimethylmethyl (meth) acrylate, adamantyl isopropylmethylmethyl (meth) acrylate, tricyclo [5.2.
1.0 ^2,6 ] decyldimethylmethyl (meth) acrylate and the like, and cycloalkyl C _1-10 alkyl (preferably C _2-8 alkyl, particularly branched C _3-7 alkyl) (meth)
Acrylate; tetracyclo [4.4.0.1 ^2,5 . 1
^7,10 ] dodecyldimethylmethyl (meth) acrylate, etc., and tetracycloalkyl C _1-10 alkyl (preferably C _2-8 alkyl, particularly branched C _3-7 alkyl) (meth) acrylate.

In the above cycloalkyl (meth) acrylate or polycycloalkyl (meth) acrylate, a cycloalkyl group or a polycycloalkyl group (including a group having an oxygen atom as a structural unit of a cycloalkane ring) may be an alkyl group or the like. It may have a substituent.
The substitution position of the alkyl group is polycycloalkyl (meth)
The acrylate may be a tertiary carbon atom of the cycloalkane ring, but is usually a secondary carbon atom.

By appropriately selecting a cycloalkyl group (including a polycycloalkyl group, a cycloalkylalkyl group and a polycycloalkylalkyl group) and the substituents of these cycloalkyl groups, the elimination of the cycloalkyl group To generate free carboxyl groups. For example, when the (meth) acrylate is oxacycloalkyl (meth) acrylate, cycloalkylalkyl (meth) acrylate, polycycloalkylalkyl (meth) acrylate,
For example, when the cycloalkane ring is unsubstituted or has a substituent such as an alkyl group, the dissolution of the resist accompanying alkali development can be promoted in resist applications.

Such (meth) acrylates (eliminating monomers) include unsubstituted bi- or tricycloalkyl-branched alkyl (meth) acrylates [norbornyldimethylmethyl (meth) acrylate, adamantyldimethyl Methyl (meth) acrylate, adamantyl isopropylmethylmethyl (meth) acrylate, etc.], alkyl-substituted bi- or tricycloalkyl-branched alkyl (meth) acrylate [2-, 3- or 7-norbornyl group
1 to 3 (preferably 1 or 2) C _1-6 alkyl groups (preferably C _1-4 alkyl groups, particularly C ₁ ) at the 2-, 4-, 8- or 10-position of the adamantyl group. _-2 alkyl group) having alkyl norbornyl or adamantyl C
_1-10 alkyl (meth) acrylate, etc.], oxacycloalkyl (meth) acrylate [2-, 3- or 4-oxa such as 2-tetrahydropyranyl (meth) acrylate or 4-tetrahydropyranyl (meth) acrylate] Cycloalkyl (meth) acrylate, etc.], unsubstituted bi- or tricycloalkyl (meth) acrylate [norbornyl (meth) acrylate, adamantyl (meth) acrylate, etc.], alkyl-substituted bi- or tricycloalkyl methacrylate [norbornyl group 2
-, 3- or 7-position, or adamantyl group 2-, 4-,
1-3 (preferably 1 or 2) C _1-6 alkyl groups (preferably C _1-4 alkyl groups, especially C
Alkyl norbornyl (meth) acrylate or alkyl adamantyl (meth) acrylate having a ( _1-2 alkyl group)].

The ratio of the (meth) acrylic monomer corresponding to the unit (6) is 0 to 100 parts by weight of the maleimide monomer corresponding to the unit of the formula (1).
It is about 300 parts by weight, preferably about 10 to 200 parts by weight, more preferably about 20 to 150 parts by weight (particularly about 30 to 100 parts by weight).

The copolymer of the present invention further comprises the following formula (7)
May be provided. When such a unit is used, it has an alicyclic ring, so that dry etching resistance can be improved, and since it has a lactone ring, adhesion to a substrate can be further improved.

[0082]

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(Wherein, ring Z ³ represents a lactone ring, and y represents an integer of 0 to 4) In the above formula (7), y is preferably an integer of 0 to 2,
More preferably, it is 0 or 1 (especially 0). The number of members of the lactone ring Z ³ constituting the unit of the formula (7) is
It is not particularly limited and has 5 to 8 members, preferably 5 or 6 members. Further, the methylene carbon atom constituting the lactone ring may have a substituent (particularly, a C _1-4 alkyl group such as a methyl group) exemplified in the above formula (2).

The unit of the formula (7) can be introduced into the copolymer by copolymerizing the monomer constituting the maleimide-based copolymer with the monomer corresponding to the unit of the formula (7). The monomer corresponding to the unit (7) includes 4-
Oxatricyclo [5.2.1.0 ^2,6 ] decane-8-
Ene-5-one, 3-oxatricyclo [5.2.1.
0 ^2,6 ] decane-8-en-4-one, 5-oxatricyclo [6.2.1.0 ^2,7 ] undecane-9-ene-
6-one, 4-oxatricyclo [6.2.1.
^0,7 ] undecane-9-en-5-one and other tricyclo compounds (corresponding to y = 0); 4-oxapentacyclo [6.5.1.1 ^9,12 . 0 ^2,6 . 0 ^8,13 ] pentadecane-10-en-5-one, 3-oxapentacyclo [6.5.1.1 ^9,12 . 0 ^2,6 . 0 ^8,13] pentadecane-10-en-4-one, 5-oxa penta cyclo [6.6.1.1 ^{10, 13.} 0 ^2,7 . 0 ^9,14] hexadecane-11-en-6-one, 4-oxa-penta cyclo [6.6.1.1 ^{10, 13.} 0 ^2,7 . 0 ^9,14 ] hexadecane-11-en-5-one (y = 1
And the like). Particularly, a tricyclo form is preferable. The monomers may be used alone or in combination of two or more.

The monomer corresponding to the unit (7) is, for example, a compound having a double bond in the lactone ring, which corresponds to the lactone ring of the formula (7), and a cyclopentadiene and a Diels-Alder It can be produced by reacting. Also, J.I. Org. Chem. , Volume 41,
No. 7, p. 1221 (1976); Org. Ch
em. , Vol. 50, No. 25, p. 5193 (198
5), Tetrahedron. Lett. , 409
It may be produced by the method described on page 9, (1976) and the like.

The proportion of the monomer corresponding to the unit (7) is 0 to 300 parts by weight, preferably 5 to 200 parts by weight, based on 100 parts by weight of the maleimide monomer corresponding to the unit of the formula (1). Parts, more preferably about 10 to 150 parts by weight.

The maleimide copolymer of the present invention has a weight average molecular weight Mw of 1,000 to 100,000, preferably 3,000 to 50,000, and more preferably 50,000.
It is about 00 to 30,000. When the weight average molecular weight is Mw and the number average molecular weight is Mn, the molecular weight distribution M
w / Mn is about 1 to 3, preferably about 1 to 2.5.

The method for polymerizing the maleimide copolymer is as follows:
There is no particular limitation, and conventional polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be employed. Also,
The polymerization can be initiated by applying heat, light, radiation, etc. to the system, and conventional polymerization initiators (azo compounds, peroxides,
Photopolymerization initiator).

The polymerization may be carried out in the presence of a solvent. The solvent is not particularly limited, and a conventional solvent such as an aromatic hydrocarbon (benzene, toluene, ethylbenzene, xylene, etc.), an alicyclic hydrocarbon (cyclohexane, etc.), an aliphatic hydrocarbon (hexane, octane, etc.) ), Ketones (eg, methyl ethyl ketone), esters (eg, ethyl acetate, n-butyl acetate), ethers (eg, 1,4-dioxane), and the like. The amount of the solvent used is, for example, 30 to 8 with respect to the entire reaction mixture.
0% by weight, preferably in the range of about 30 to 70% by weight.

The polymerization can be carried out under normal pressure or under pressure. Further, the polymerization temperature can be selected from the range of about 50 to 150 ° C., preferably about 60 to 120 ° C., depending on the type of the polymerization method, the type of the polymerization initiator, the polymerization rate, and the like. The polymerization is
Usually, the reaction can be performed in an atmosphere of an inert gas such as nitrogen, helium, or argon.

The polymerization can be carried out by any of a batch system, a semi-batch system and a continuous system.

The maleimide-based copolymer obtained by the above-mentioned method may be used in a conventional manner, for example, by diluting with a solvent if necessary and precipitating in a poor solvent, or by removing volatile components such as monomers and solvents. May be removed or separated and purified by a method such as chromatography.

The maleimide copolymer of the present invention is useful as a resist composition because of its excellent dry etching resistance in resist applications. In particular, the copolymer of the present invention has a unit of the above formula (2) which is eliminated by an acid and solubilized by an acid. Therefore, when a resist composition is constituted in combination with a photoacid generator or the like, a developing solution is exposed to light. This is advantageous because it can be solubilized in an alkaline developer or the like.

The photoacid generator can be efficiently exposed to light.
Conventional compounds that produce acids (protic or Lewis acids),
For example, diazonium salt, iodonium salt, sulfonium
Salt, oxathiazole derivative, s-triazine derivative
Body, imide compound, oxime sulfonate, diazonaph
Toquinone, sulfonic acid ester [1-phenyl-1-
(4-methylphenyl) sulfonyloxy-1-benzo
Ilmethane, 1,2,3-trisulfonyloxymethyl
Benzene, 1,3-dinitro-2- (4-phenylsulfur
(Honyloxymethyl) benzene, 1-phenyl-1-
(4-methylphenyl) sulfonyloxymethyl-1-
Hydroxy-1-benzoylmethane, disulfone derivative
(Such as diphenyldisulfone), benzoin tosylate
And Lewis acid salts (triphenylsulfonium hexa
Fluoroantimony (Ph)_ThreeS⁺SbF ₆ ^-, Trifeni
Rusulfonium hexafluorophosphate (Ph)_Three
S⁺PF₆ ^-, Triphenylsulfonium methanesulfoni
Le (Ph)_ThreeS⁺CH_ThreeSO_Three ^-, Diphenyl iodohexa
And the like can be used. In addition,
Ph represents a phenyl group. These photoacid generators alone
Alternatively, two or more kinds can be used in combination.

The amount of the photoacid generator to be used can be selected according to the strength of the acid generated by irradiation with light, for example, 0.1 to 30 parts by weight, preferably 0.1 to 30 parts by weight, per 100 parts by weight of the maleimide copolymer. Is 1 to 25 parts by weight, more preferably 5
It can be selected from a range of about to 20 parts by weight. Further, an acid desorption type unit (unit of the formula (2),
The acid-eliminating unit of the formula (6)), that is, 0 to 80 parts by weight based on 100 parts by weight of the total amount of the acid-eliminating monomer,
0.1 to 60 parts by weight, preferably about 1 to 50 parts by weight.

If necessary, the resist composition may contain an alkali-soluble component such as an alkali-soluble resin (eg, a novolak resin, a phenol resin, and a carboxyl group-containing resin).
It may contain a colorant (such as a dye) and an organic solvent. Examples of the organic solvent include hydrocarbons, halogenated hydrocarbons, alcohols (such as ethanol and isopropanol), esters (such as ethyl acetate), ketones (such as acetone and methyl ethyl ketone), and ethers (such as dioxane and tetrahydrofuran). ), Cellosolves (methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc.), carbitols, glycol ether esters (mono or polyalkylene glycol monoalkyl ether esters, for example, cellosolve acetate such as ethyl cellosolve acetate, propylene glycol monomethyl ether acetate) Propylene glycol monoethyl ether acetate) and their mixed solvents.

Further, impurities may be removed from the resist composition by conventional separation and purification means such as a filter.

The resist composition of the present invention can be prepared by mixing the maleimide-based copolymer and a photoacid generator. The resist composition is applied to a substrate by a coating means such as spin coating. After drying, the formed coating film (resist film) is exposed to a predetermined pattern, baked, a latent image pattern is formed, and then developed to form a fine pattern. High resolution is high.

The substrate can be selected according to the use of the resist composition, and may be a silicon wafer, metal, plastic, glass, ceramic, or the like. The resist composition can be applied by a conventional method according to the application, for example, a method such as spin coating or roll coating. The thickness of the coating film of the resist composition, for example,
It can be appropriately selected from the range of about 0.1 to 10 μm, preferably about 0.1 to 5 μm, and more preferably about 0.1 to 2 μm.

Light beams having various wavelengths, for example, ultraviolet rays and X-rays can be used for the exposure. For resists for semiconductor production, g-rays, i-rays, excimer lasers (for example,
XeCl, KrF, KrCl, ArF, ArCl, etc.)
Etc. are available.

An acid is generated from the acid generator by light irradiation, and the leaving group of the unit (2) is released by the acid generated by baking, so that a carboxyl group contributing to solubilization is generated. Therefore, it is possible to form a predetermined pattern by developing with a water developing solution or an alkali developing solution. In particular, the resist composition of the present invention comprises a maleimide unit of the formula (1), an acid-eliminable alicyclic olefin unit of the formula (2), and a substrate adhesion type (meth) of the formula (3).
Since it has an acrylic unit, it can greatly improve the dry etching resistance and the adhesion to the base material, suppress the swelling of the developer, and form the circuit pattern with high accuracy. Can be formed with high accuracy.

The present invention can be applied to various uses, for example, circuit forming materials (resist for semiconductor production, printed wiring boards, etc.),
It can be used for image forming materials (printing plate materials, relief images, etc.).

[0103]

Since the maleimide-based copolymer of the present invention contains specific units (1) to (3), especially for resist applications, the dry etching resistance, the resist performance, and the stability of the resist performance are improved. Can be improved,
It is economically advantageous. Further, the adhesiveness of the resist to the substrate can be improved, which is useful for forming a pattern with high accuracy.

[0104]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1 In a three-necked flask equipped with a stirrer and a reflux tube, 2.9 g (23 mmol) of ethylmaleimide (1a) and 4.4 g (2) of t-butyl norbornenecarboxylic acid (2) were added.
3 mmol), 2-acryloyloxy-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-5-one (3
a) 2.7 g (11 mmol) and n-butyl acetate 10
g was added and dissolved. Dimethyl N, N-azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] as an initiator
After adding 1.0 g, the reaction system is polymerized while maintaining the reaction system at 70 ° C. under a nitrogen atmosphere. After 6 hours, the reaction product is reprecipitated from a mixed solvent of hexane: isopropanol = 3: 1 (v / v). And purified. By repeating the reprecipitation operation three times, 6.5 g of a resin having Mw of 6,000 and Mw / Mn of 2.0 was obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-3.0 ppm (broad), 1.7, 2.1,
Clear signals were observed at 2.8, 3.2 and 4.7 ppm.

In this example, each monomer (1a), (2)
And the ratio (molar ratio) of (3a) is (1a) :( 2):
(3a) = 40: 40: 20.

The 2-acryloyloxy-4-
Oxatricyclo [4.2.1.0 ^{3 , 7} ] nonan-5-one (hereinafter sometimes referred to as δ-acryloylnorbornane lactone) (3a) is represented by the following formula, Prepared.

[0109]

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(I) Preparation of δ-hydroxynorbornane lactone In a flask equipped with a dropping funnel and a stirrer, 200 g (1.45 mol) of norbornene carboxylic acid, 27 g of tungstic acid and 633 g of water were added, and the mixture was heated to 50 ° C. while stirring. The temperature was raised, and 173 of 30% by weight hydrogen peroxide was dropped from the dropping funnel.
g (1.52 mol) over 2 hours at a temperature of 50-60 ° C.
It was dripped while controlling with. Thereafter, stirring was continued at 50 to 55 ° C for 5 hours. The reacted liquid was cooled to room temperature and 10%
Weight sodium sulfite (Na ₂ SO ₃₎ was added an aqueous solution 500 g. From the obtained mixture, water 8 was added using an evaporator.
70 ml was distilled off, and the concentrated liquid was neutralized with a 10% by weight aqueous sodium carbonate solution. Ethyl acetate 13
The mixture was extracted twice with 00 g, the ethyl acetate layers were combined, concentrated by an evaporator, and 150 ml of n-hexane was added and mixed to precipitate crystals. The crystals were filtered and dried to obtain 143 g of δ-hydroxynorbornane lactone.
(0.93 mol) was obtained. The yield was 64.1% based on the norbornene carboxylic acid used, and the yield was 78.2% based on the endo form. (Ii) Acrylation of δ-hydroxynorbornane lactone In the esterification reaction, a 10-stage perforated plate batch distillation column equipped with a condenser and a decanter at the top was used. 100 g (0.65 mol) of the δ-hydroxynorbornane lactone obtained in (i) above in a distillation can at the bottom of the distillation column;
Acrylic acid 118 g (1.63 mol), hydroquinone monomethyl ether 0.9 g, sulfuric acid 6 g, toluene 40
0 g, and 40 g of nitrogen gas containing 5% by volume of oxygen.
Dehydration distillation was performed while flowing at a rate of ml / min. The distillation was stopped when about 11 ml of water was distilled off from the decanter at the top of the column. The liquid in the distillation can is cooled to room temperature, and toluene 250
g was added. The mixed solution was washed with 1,000 ml of water and then sequentially washed with 1000 ml of a 10% by weight aqueous sodium carbonate solution, 1000 ml of a 10% by weight saline solution, and 1000 ml of water. After the toluene layer after washing was concentrated by an evaporator, 220 g of isopropyl ether was added to precipitate crystals. After filtration, the crystals were rinsed with 30 ml of isopropyl ether and dried. 92.0 g (0.44 mol) of δ-acryloylnorbornane lactone was obtained (yield 67).
%).

Example 2 In a three-necked flask equipped with a stirrer and a reflux tube, 2.5 g (20 mmol) of ethylmaleimide (1a) and 3.9 g (2) of t-butyl norbornenecarboxylic acid (2) were added.
0 mmol), 2-acryloyloxy-7-methoxycarbonyl-4-oxatricyclo [4.2.1.
0 ^3,7 ] nonan-5-one (3b) 1.1 g (4 mmol
l) and 7.5 g of n-butyl acetate were added and dissolved. After adding 1.0 g of dimethyl N, N-azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] as an initiator, polymerization was carried out at 70 ° C. under a nitrogen atmosphere, and after 6 hours, The reaction product was treated with hexane: isopropanol = 3: 1.
Purification was performed by reprecipitation from a mixed solvent of (v / v). By repeating the reprecipitation operation three times, the Mw becomes 9,000.
0, Mw / Mn 72.3g of resin of 2.33 was obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-3.0 ppm (broad), 1.9, 2.1,
Clear signals were observed at 2.6, 3.2 and 4.5 ppm.

In this example, each monomer (1a), (2)
And the ratio (molar ratio) of (3b) is (1a) :( 2):
(3a) = 45: 45: 10.

The above-mentioned 2-acryloyloxy-7-
Methoxycarbonyl-4-oxatricyclo [4.2.
1.0 ^3,7 ] nonan-5-one (3b) is represented by the following formula and was prepared by the following method.

[0115]

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Preparation method: 6.6 g of cyclopentadiene
(0.1 mol), maleic acid monomethyl ester13.
0 g (0.1 mol), 200 ml of ethyl acetate as solvent
And stirred in an autoclave at 100 ° C. for 2 hours. After cooling to room temperature, the reaction mixture was placed in a flask equipped with a reflux condenser and a dropping funnel, further added with 0.2 g of tungstic acid and mixed, and at a temperature of 50 ° C., 14.3 g (0.13 g) of 30% by weight hydrogen peroxide was added. Mol) was added dropwise in 10 minutes. The reaction was continued at the same temperature for 5 hours, cooled to room temperature, and washed with water. The organic layer was placed in a rotary evaporator, and the solvent, ethyl acetate, was distilled off. The remaining liquid was mixed with 200 ml of tetrahydrofuran, placed in a flask equipped with a reflux condenser and a dropping funnel, further added with 30.3 g (0.3 mol) of triethylamine, and added with 9.1 g (0.1 mol) of acrylic acid chloride. The mixture was added dropwise at room temperature over 30 minutes with stirring. Stirring was continued at room temperature for a further 6 hours. When the reaction mixture was analyzed by gas chromatography,
The target 2-acryloyloxy-7-methoxycarbonyl-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-5-one was detected in an amount of 14.4 g (0.054 mol). After the reaction mixture was filtered, the target monomer was separated and purified by column chromatography. The target is NM
Identification was performed using each spectrum of R and IR, and the results are shown below.

¹ H-NMR (400 MHz, CDC
l ₃ ): δ1.8 (1H, ddd), δ2.0 (1H,
ddd), δ2.8 (1H, m), δ2.9 (1H,
m), δ3.1 (1H, dd), δ3.2 (1H, d
d), δ4.1 (3H, S), δ4.6 (1H, d
d), δ4.7 (1H, dd), δ5.6 (1H,
d), δ 6.1 (1H, d) FT-IR (NaCl) (cm ^-1 ): 1800,173
Example 17 In a three-necked flask equipped with a stirrer and a reflux tube, 2.5 g (20 mmol) of ethylmaleimide (1a) and 3.9 g (2) of t-butyl norbornenecarboxylic acid (2) were added.
0 mmol), 4-oxatricyclo [4.3.1.1.
^[3,8 ] undecane-5-one-1-yl acrylate (3c) (hereinafter sometimes referred to as hyperlactone acrylate) (1.0 g, 4 mmol) and n-butyl acetate 7.5 g were added and dissolved. N, N- as initiator
Dimethyl azobisisobutyrate [Wako Pure Chemical Industries, Ltd., V
After adding 0.75 g, polymerization was performed under a nitrogen atmosphere while maintaining the reaction system at 70 ° C., and after 6 hours, the reaction product was re-used from a mixed solvent of hexane: isopropanol = 3: 1 (v / v). Purified by precipitation. Reprecipitation operation 3
By repeating the above, Mw is 7500 and Mw / Mn is 1.
5.5 g of 98 resin were obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-3.0 ppm (broad), 1.9, 2.1,
Clear signals were observed at 2.6, 3.2 and 4.6 ppm.

In this example, each monomer (1a), (2)
And the ratio (molar ratio) of (3c) is (1a) :( 2):
(3c) = 45: 45: 10.

The hyperlactone acrylate (3c) was prepared as follows.

0.1 mol of 2-adamantanone, 10 mmol of N-hydroxyphthalimide, 0.33 mmol of vanadium acetylacetonato V (AA) ₃ , 0.17 mmol of manganese acetylacetonato Mn (AA) ₂ , and 250 mL of acetic acid Under an oxygen atmosphere, 1 atm,
Stirred at 80 ° C. for 10 hours. After the reaction mixture was concentrated, it was extracted with ethyl acetate. After partially concentrating the organic layer, it was crystallized by cooling to obtain 5-hydroxy-2-adamantanone (yield 48%). The spectrum data is shown below. The conversion of 2-adamantanone was 74%. IR (cm ^-1 ): 3410, 2920, 2810, 17
20, 1440, 1330, 1240, 1060, 88
0 MS m / e: 166 ([M ⁺ ]), 148, 119

5-Hydroxy-2-adamantanone 10
0 mmol, 200 mmol of benzhydrol, 10 mmol of N-hydroxyphthalimide, cobalt acetate (I
I) A mixture of 0.1 mmol and 200 mL of benzonitrile was stirred at 1 atm and 75 ° C. for 6 hours in an oxygen atmosphere. After concentrating the reaction mixture, the mixture was separated and purified by silica gel column chromatography, and 1-hydroxy-4-
Oxatricyclo [4.3.1.1 ^3,8 ] undecane-
5-one was obtained with a yield of 48%. The spectrum data is shown below. The conversion of 5-hydroxy-2-adamantanone was 67%. MS M / e: 182 ([M ⁺ ]), 138, 120

A mixture of 50 mmol of 1-hydroxy-4-oxatricyclo [4.3.1.1 ^3,8 ] undecane-5-one, 150 mmol of acrylic acid chloride, 150 mmol of triethylamine and 250 mL of toluene was heated at 60 ° C. For 4 hours. After the reaction mixture was concentrated, it was separated and purified by silica gel column chromatography to give 4-oxatricyclo [4.3.1.1 ^3,8 ] undecane-5-one-4-ylacrylate (6a) in a yield of 50. %. The spectrum data is shown below. In addition, 1-hydroxy-4-oxatricyclo [4.3.
1.1 ^3,8 ] undecane-5-one was 73% in conversion. MS m / e: 236 ([M ⁺ ]), 190, 120,
55

Example 4 In a three-necked flask equipped with a stirrer and a reflux tube, 2.5 g (20 mmol) of ethylmaleimide (1a) and 3.8 g (2) of t-butyl norbornenecarboxylic acid (2) were added.
0 mmol), 4.4 g (10 mmol) of monohydroxyadamantyl acrylate (3d) and 10.1 g of n-butyl acetate were added and dissolved. N, N- as initiator
Dimethyl azobisisobutyrate [Wako Pure Chemical Industries, Ltd., V
-601], and the reaction system was polymerized under a nitrogen atmosphere while maintaining the reaction system at 70 ° C. After 6 hours, the reaction product was re-used from a mixed solvent of hexane: isopropanol = 3: 1 (v / v). Purified by precipitation. By repeating the reprecipitation operation three times, Mw is 7,100 and Mw / Mn is 1.8.
7.5 g of resin No. 7 was obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-3.0 ppm (broad), 1.9, 2.1,
Clear signals were observed at 2.6 and 4.6 ppm.

In this example, each monomer (1a), (2)
And the ratio (molar ratio) of (3d) is (1a) :( 2):
(3d) = 40: 40: 20.

Example 5 In a three-necked flask equipped with a stirrer and a reflux tube, 3.2 g (23 mmol) of propylmaleimide (1b) and 4.5 g of t-butyl norbornenecarboxylic acid (2) were placed.
(23 mmol), 2.2 g (12 mmol) of 2-acryloyloxy-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-5-one (3a) and 10 g of n-butyl acetate are added and dissolved. Was. Dimethyl N, N-azobisisobutyrate [V-60 manufactured by Wako Pure Chemical Industries, Ltd.] as an initiator
1] After adding 1.0 g, the reaction system was set to 70 under a nitrogen atmosphere.
After 6 hours, the reaction product was treated with hexane:
Purification was performed by reprecipitation from a mixed solvent of isopropanol = 3: 1 (v / v). By repeating the reprecipitation operation three times, 7.5 g of a resin having Mw of 7,300 and Mw / Mn of 2.11 was obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-3.0 ppm (broad), 1.7, 2.1,
Clear signals were observed at 2.8, 3.2 and 4.5 ppm.

In this example, each monomer (1b), (2)
And the ratio (molar ratio) of (3a) is (1b) :( 2):
(3a) = 40: 40: 20.

Example 6 In a three-necked flask equipped with a stirrer and a reflux tube, 2.8 g (20 mmol) of propylmaleimide (1b) and 3.9 g of t-butyl norbornenecarboxylic acid (2) were placed.
(20 mmol), hyperlactone acrylate (3
c) 1.0 g (4 mmol) and n-butyl acetate 7.7
g was added and dissolved. Dimethyl N, N-azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] as an initiator
After adding 0.75 g, the reaction system was heated to 70 ° C. in a nitrogen atmosphere.
After 6 hours, the reaction product was purified by reprecipitation from a mixed solvent of hexane: isopropanol = 3: 1 (v / v). By repeating the reprecipitation operation three times, 5.9 g of a resin having Mw of 7,300 and Mw / Mn of 2.01 was obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-3.0 ppm (broad), 1.9, 2.1,
Clear signals were observed at 2.6, 3.2 and 4.6 ppm.

In this example, each monomer (1b), (2)
And the ratio (molar ratio) of (3c) is (1b) :( 2):
(3c) = 45: 45: 10.

Example 7 In a three-necked flask equipped with a stirrer and a reflux tube, 2.8 g (20 mmol) of propylmaleimide (1b) and 3.8 g of t-butyl norbornenecarboxylic acid (2) were placed.
(20 mmol), 4.4 g (10 mmol) of 2-hydroxyadamantyl acrylate (3d) and 10.3 g of n-butyl acetate were added and dissolved. N, as an initiator
Dimethyl N-azobisisobutyrate [Wako Pure Chemical Industries, Ltd.
, V-601] was added under nitrogen atmosphere.
The reaction system was maintained at 70 ° C. for polymerization, and after 6 hours, the reaction product was purified by reprecipitation from a mixed solvent of hexane: isopropanol = 3: 1 (v / v). By repeating the reprecipitation operation three times, 7.7 g of a resin having Mw of 8,300 and Mw / Mn of 2.24 was obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-3.0 ppm (broad), 1.9, 2.1,
Clear signals were observed at 2.6 and 4.6 ppm.

In this example, each monomer (1b), (2)
And the ratio (molar ratio) of (3d) is (1b) :( 2):
(3d) = 40: 40: 20.

Example 8 3.2 g (23 mmol) of hydroxyethylmaleimide (1c) was placed in a three-necked flask equipped with a stirrer and a reflux tube.
l), 4.5 g (23 mmol) of norbornenecarboxylic acid t-butyl ester (2), 2-acryloyloxy-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-5-one (3a) 2.2 g (12 mmol) and n
-10 g of butyl acetate was added and dissolved. After adding 1.0 g of dimethyl N, N-azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] as an initiator, the reaction system is maintained at 70 ° C. under a nitrogen atmosphere, and polymerized. Hexane: isopropanol = 3: 1 (v /
Purified by reprecipitation from the mixed solvent of v). By repeating the reprecipitation operation three times, Mw becomes 7300 and Mw /
7.1 g of a resin having an Mn of 2.05 was obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-3.0 ppm (broad), 1.7, 2.1,
Clear signals were observed at 2.8, 3.2, 4.5 and 4.6 ppm.

In this example, each monomer (1c), (2)
And the ratio (molar ratio) of (3a) is (1c) :( 2):
(3a) = 40: 40: 20.

Example 9 In a three-necked flask equipped with a stirrer and a reflux tube, 3.4 g (23 mmol) of hydroxypropylmaleimide (1d) was placed.
l), 4.5 g (23 mmol) of norbornenecarboxylic acid t-butyl ester (2), 2-acryloyloxy-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-5-one (3a) 2.2 g (12 mmol) and n
-10 g of butyl acetate was added and dissolved. After adding 1.0 g of dimethyl N, N-azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] as an initiator, the reaction system is maintained at 70 ° C. under a nitrogen atmosphere, and polymerized. Hexane: isopropanol = 3: 1 (v /
Purified by reprecipitation from the mixed solvent of v). By repeating the reprecipitation operation three times, Mw becomes 7300 and Mw /
7.1 g of a resin having an Mn of 2.05 was obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-3.0 ppm (broad), 1.7, 2.1,
Clear signals were observed at 2.8, 3.2, 4.5 and 4.6 ppm.

In this example, each monomer (1d), (2)
And the ratio (molar ratio) of (3a) is (1d) :( 2):
(3a) = 40: 40: 20.

Comparative Example 1 The amounts of ethylmaleimide (1a) and t-butyl norbornenecarboxylate (2) used were each 4.0 g.
(32 mmol) and 6.0 g (32 mmol),
2-acryloyloxy-4-oxatricyclo [4.
2.1.0 ^3,7 ] Non-n-5-one (3a) was used in the same manner as in Example 1 except that Mw was 2,000,
A resin having Mw / Mn of 1.7 was obtained.

In this example, the ratio (molar ratio) of each of the monomers (1a) and (2) is (1a) :( 2) = 50:
It was 50.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2H025 AA02 AA09 AA14 AB16 AC08 AD03 BE00 BE10 BG00 CB08 CB10 CB41 CB55 4J100 AK32S AL08R AL36S AM43P AM45P AM47P AR11Q BA02Q BA03P BA03Q BA03R BA20Q BA11Q BA12R CA05 CA06 DA01 JA37

Claims (9)

[Claims] 1. A maleimide-based copolymer containing units represented by the following formulas (1) to (3). Embedded image (Wherein, R ¹ represents an alkyl group which may have a substituent, R ² represents a leaving group, R ³ represents a hydrogen atom or a methyl group. Z ¹ represents a hydroxyl group, an oxo group, Represents an alicyclic group having at least one selected from a hydroxyalkyl group, a carboxyl group, an alkoxycarbonyl group, and a lactone ring, and x represents an integer of 0 to 3) 2. The maleimide-based copolymer according to claim 1, wherein the leaving group represented by R ² in the formula (2) is removable by the action of an acid. 3. The leaving group represented by R ² in the formula (2) is at least one selected from a C _1-6 alkyl group, a 5- to 8-membered oxacycloalkyl group and an oxepanyl group. The maleimide-based copolymer according to the above. Wherein formula (1) in the maleimide-based copolymer of R ¹ is claimed in claim 1 which is selected from C _1-6 alkyl and hydroxy C _1-6 alkyl group. 5. The maleimide-based copolymer according to claim 1, wherein in the formula (3), Z ¹ is a polycycloalkyl group having at least one selected from a hydroxyl group, an oxo group, and a lactone ring. 6. In the formula (3), the alicyclic group represented by Z ¹ is a polycycloalkyl group, and at least one ring constituting the polycycloalkyl group forms a lactone ring. Item 4. The maleimide-based copolymer according to Item 1. 7. The maleimide-based copolymer according to claim 1, further comprising maleic anhydride or an ester thereof as a unit. 8. A composition having a weight average molecular weight of 1,000 to 100,
The maleimide-based copolymer according to claim 1, which has a molecular weight of 000. 9. A resist composition comprising the maleimide-based copolymer according to claim 1 and a photoacid generator.