JP2002179744A - Maleimide-based polymer and composition for resist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a maleimide-based polymer useful as a resin for a photoresist having excellent dry-etching resistance. SOLUTION: This maleimide-based polymer comprises at least a unit expressed by the formula (1) (where ring Z denotes a polycyclic hydrocarbon which may have substituent(s); X denotes an alkylene group; and n is 0 or 1), in which Z may be a cross-linked type hydrocarbon ring which may have substituent(s) and at least a ring among hydrocarbon rings constituting the cross-linked hydrocarbon rings may be a ring forming a lactone ring. The maleimide-based polymer is useful to be used as a resist composition in combination with a photo-acid generator.

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 polymer useful for obtaining the composition. About.

[0002]

2. Description of the Related Art In photoresist applications, it is known that resins containing alicyclic hydrocarbon units have high dry etching resistance to plasma gas in fine processing of semiconductors.

However, in order to introduce a cyclic olefin unit such as norbornene into the main chain of a resin by radical polymerization, it is necessary to use maleic anhydride having a high copolymerizability. As such a resin, for example, in a lithography technique requiring high resolution, an alternating copolymer of a cyclic olefin such as a norbornene derivative and maleic anhydride is known. Although maleic anhydride is inexpensive and economically advantageous, it is difficult to reduce the proportion of maleic anhydride units and improve dry etching resistance in the alternating copolymer as described above. Further, when maleic anhydride is used, a side reaction may occur in a polymerization process, a process such as recovery, purification, and storage, and there is 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 an aliphatic cyclic olefin monomer and a maleimide monomer having a hydroxyalkyl group or the like at the nitrogen atom of the maleimide. It has been disclosed. Also, Japanese Patent Application Laid-Open
No. 2,975,591 discloses a positive radiation resist comprising a copolymer of bicyclo [2.2.1] hept-5-ene-2-carboxylic acid ester and N-cyclohexylmaleimide and an acid generator. Is disclosed. However, maleimide monomers having a hydroxyalkyl group or a cyclohexyl group as described above cannot sufficiently satisfy the high dry etching resistance required for miniaturization and high performance in the semiconductor field.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a maleimide polymer having excellent dry etching resistance even if it has a maleimide unit, and a resist composition containing the maleimide polymer. Is to do.

Another object of the present invention is to provide a maleimide polymer capable of improving the resist performance and a resist composition containing the maleimide polymer.

Still another object of the present invention is to provide a maleimide polymer which can improve the adhesion of a resist to a substrate and is useful for forming a pattern with high accuracy, and a resist composition containing the maleimide polymer. To provide.

[0008]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, a polymer containing a specific maleimide derivative unit can improve dry etching resistance in resist applications. The present invention has been completed.

That is, the maleimide polymer of the present invention contains at least a unit represented by the following formula (1).

[0010]

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(Wherein, ring Z represents a polycyclic hydrocarbon ring which may have a substituent, and X represents an alkylene group.
Is 0 or 1.) In the formula (1), Z represents a bridged cyclic hydrocarbon ring which may have a substituent, or a hydrocarbon ring constituting the bridged cyclic hydrocarbon ring. It may be a ring in which at least one ring forms a lactone ring. The maleimide-based polymer may further include at least one selected from units represented by the following formulas (2) to (4).

[0012]

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(Wherein R ¹ represents a leaving group, x and y
Represents an integer of 0 to 4, respectively. (The ring Z ¹ represents a lactone ring.) The maleimide-based polymer may further include, as a unit, at least one selected from (meth) acrylic acid or an ester thereof and maleic anhydride or an ester thereof. The maleimide polymer may have a weight average molecular weight of about 1,000 to 100,000 and a molecular weight distribution of about 1 to 2.5.

The present invention also includes a resist composition containing the maleimide polymer and a photoacid generator.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The maleimide polymer of the present invention comprises:
At least a unit represented by the above formula (1) is included. Therefore, the maleimide-based polymer is useful as a functional polymer such as a photosensitive resin, and particularly when used for a photoresist, can greatly improve etching resistance (particularly dry etching resistance).

In the above formula (1), examples of the polycyclic hydrocarbon ring represented by Z include a bridged cyclic hydrocarbon ring and a condensed cyclic hydrocarbon ring. The polycyclic hydrocarbon ring may be aromatic, but when used in a photoresist, it is usually non-aromatic.

Examples of the bridged cyclic hydrocarbon ring (bridged cyclic hydrocarbon ring) include bicyclic hydrocarbon rings such as pinane, bornane, norpinane and norbornane (bicyclo [2.2.1] heptane) ring. Homobledan, adamantane (tricyclo [3.3.1.1 ^3,7 ] decane), tricyclo [5.2.1.0 ^2,6 ] decane, tricyclo [4.3.
1.1 ^2,5 ] undecane ring and other tricyclic hydrocarbon rings; tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane,
Tetracyclic hydrocarbon ring such as perhydro-1,4-methano-5,8-methanonaphthalene ring; pentacyclo [7.3.
1, ^{4, 12} . 0 ^2,7 . 0 ^6,11 ] pentacyclic hydrocarbon ring such as a tetradecane ring; diene hydrogenated diene [for example,
Dimer of cyclo C _4-20 alkadiene (preferably cyclo C _6-12 alkadiene) such as cyclopentadiene, cyclohexadiene, cycloheptadiene or a hydrogenated product thereof (eg, perhydro-4,7-methanoindene), butadiene (Vinylcyclohexene) or a hydrogenated product thereof, a dimer of butadiene and cyclopentadiene (vinylnorbornene) or a hydrogenated product thereof] and the like.

Condensed polycyclic hydrocarbon ring (condensed hydrocarbon ring)
Examples thereof include a condensed ring obtained by condensing a 5- to 8-membered ring such as naphthalene, anthracene, phenanthrene, acenaphthene, fluorene, indene, and phenalene rings, or a hydrogenated condensed ring thereof. Further, the condensed hydrocarbon ring may be crosslinked. As such a ring,
For example, tricyclo [5.2.0.0 ^2,6 ] nonane ring, tricyclo
[5.2.1.0 ^2,6 ] decane ring, tricyclo [8.4.0.0 ^3,8 ] tetradecane ring and the like. In addition, hydrocarbon ring (especially,
The condensed ring to which the (non-aromatic hydrocarbon ring) is condensed may be any of ortho-condensation and ortho-and peri-condensation.

Although a compound represented by the following formula has been reported, there is no example of using it as a monomer for a photoresist.

[0020]

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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, bi- 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 rings Z (polycyclic hydrocarbon rings) are substituted
It may have a group. As the substituent, an alkyl group
(C such as methyl, ethyl, butyl, etc._1-6Alkyl group,
Preferably C_1-4Alkyl group), alkoxy group (meth
C such as toxic, ethoxy and t-butoxy groups_1-4Arco
Xy group), alkoxycarbonyl group (methoxycal
C such as bonyl and ethoxycarbonyl groups_1-4Alkoxy
Carbonyl group), cycloalkyloxycarbonyl
Group (C such as cyclohexyloxycarbonyl group) _5-8Shi
Chloroalkyloxycarbonyl group), aryloxy
Cicarbonyl group (phenoxycarbonyl group, etc.), ara
Alkyloxycarbonyl group (benzyloxycarbonyl
Group, etc.), hydroxyl group, hydroxymethyl group,
Boxyl group, oxo group, nitro group, amino group, N-substitution
Amino group (NC_1-4Alkyl-substituted amino group, etc.)
Tolyl group, carbamoyl group or N-substituted carbamoyl group
(NC_1-4Alkylcarbamoyl group, etc.), halogen
Atoms (fluorine, chlorine, bromine and iodine atoms)
I will.

Preferred substituents are an alkyl group (C _1-3 alkyl group, especially methyl group) or a polar group (eg, hydroxyl group, alkoxy group, oxo group, 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).

A 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 (1), the alkylene group represented by X includes 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 the substituents exemplified above.

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

Such a maleimide-based polymer may be a homo- or copolymer of the maleimide-based monomer corresponding to the unit of the above formula (1), or may be a copolymer of the maleimide-based monomer and another copolymer. It may be a copolymer with a polymerization component. Other copolymerizable components include conventional components, monomers for improving adhesion, monomers for improving developability, monomers for imparting functions, monomers capable of reducing costs, and the like. No.

In the above formula (1), examples of the maleimide-based monomer in which n is 0 include two or three bridged cyclic hydrocarbon rings (norbornane,
And a maleimide-based monomer such as 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.

Further, 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 its derivatives [maleic anhydride, maleic halide (maleic acid chloride, etc.), maleic ester (maleic acid such as methyl maleate, etc.).
_1-3 ) and a compound represented by the following formula (1a), and the maleic acid or a derivative thereof is opened to form an amic acid, and the obtained amic acid is subjected to a dehydration reaction. And ring-closing.

[0036]

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(Wherein Z, X and n are the same as above) The amines represented by the formula (1a) may be commercially available products or may be prepared by a conventional method. In particular, amines having a complex polycyclic structure include, for example, compounds having a polycyclic hydrocarbon ring corresponding to ring Z (amine precursors)
The nitro group can be prepared by introducing a nitro group into the compound and reducing the nitro group to convert it to an amino group.

The method for introducing a nitro group includes (i) an imide compound derived from an alicyclic or aromatic polycarboxylic anhydride (particularly, an aromatic polycarboxylic anhydride) such as N-hydroxyphthalimide; Nitrogen oxide [N ₂ O ₃ ,
(Wherein, p is an integer of 1 or 2, q is an integer of 1~6) N _p O _q such NO ₂ introduced nitro group by reaction with nitrogen oxides, etc.] containing as a main component thereof, or how to,
(ii) 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. No.

The imide compound is a co-catalyst, for example, a transition metal compound [a transition metal element (a Group 3 element such as Sc or La; a Group 4 element such as Ti; a Group 5 element such as V); Group 6 elements of the periodic table such as Mo and W; Group 7 elements of the periodic table such as Mn; Group 8 elements of the periodic table such as Fe and Ru; C
Periodic Table 9 elements such as o and Rh; Periodic Table 10 such as Ni
Group element such as Cu). Metal compounds include metal oxides, organic acid salts (such as acetates), inorganic acid salts (such as nitrates and sulfates), halides (such as chlorides), and coordination compounds (complexes or complex salts such as acetylacetonato complexes). ),
It may be a heteropoly acid or a salt thereof (such as cobalt molybdate, molybdenum tungstate, or vanadium molybdate), or a boron compound.

For details of the imide compound, cocatalyst, and nitration, reference can be made to JP-A-8-38909 and JP-A-11-106360.

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 performed in an organic solvent inert to the reaction. Examples of the organic solvent include the solvents exemplified above [eg, organic acids, nitriles (acetonitrile, benzonitrile, etc.), amides (formamide, acetamido, dimethylformamide (DMF),
Dimethylacetamide, etc.), alcohols, aliphatic hydrocarbons (hexane, etc.), aromatic hydrocarbons (benzene, toluene, etc.), halogenated hydrocarbons (chloroform, etc.), nitro compounds, esters (ethyl acetate,
Butyl acetate, isobutyl acetate), ethers (dioxane, diethyl ether, tetrahydrofuran, etc.), and mixed solvents thereof. As the solvent, organic acids (for example, carboxylic acids such as acetic acid), nitriles (for example, benzonitrile), and halogenated hydrocarbons (for example, dichloroethane) are often used.

The reaction temperature is, for example, from 0 to 150 ° C., preferably from 25 to 125 ° C., and more preferably from 30 to 100 ° C., depending on the type of the imide compound or 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 Groups 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 hydroxyl group into the ring Z 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. Alternatively, it can be obtained by introducing a halogen atom (such as a bromine atom) into the ring Z, and hydrolyzing with an inorganic salt such as silver nitrate or silver sulfate to introduce a hydroxyl group. Further, a hydroxyl group may be introduced by oxygen oxidation in the presence of an oxidation catalyst composed of the imide compound and, if necessary, the cocatalyst. The carboxyl group can be introduced into the ring Z by bringing carbon monoxide and oxygen into contact with each other in the presence of an oxidation catalyst composed of the imide compound and, if necessary, the cocatalyst.

The introduction of an oxo group into the ring Z 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. The compound in which at least one of the hydrocarbon rings constituting the bridged ring (such as an adamantane ring) forms a lactone ring includes, for example, a ketone compound (such as an adamantane compound), the imide compound and the By the presence of the co-catalyst (cobalt acetate, cobalt compounds such as cobalt acetylacetonate, etc.)
With a primary or secondary alcohol (C _1-6 alkyl alcohol such as methanol, C _5-8 cycloalkanol such as cyclohexanol, aralkyl alcohol such as 1-phenylethanol and benzhydrol) as a co-oxidizing agent Or a Bayer-Villiger-type reaction in which the compound is oxidized by molecular oxygen, or the ketone compound (adamantanone compound or the like) and a peroxide (peracetic acid such as peracetic acid or m-chloroperbenzoic acid); or a peroxide such as hydrogen peroxide. ) Can be obtained by a conventional Bayer-Villiger reaction.

The hydroxylation, carboxylation, oxolation and lactone ring formation reaction may be carried out in the presence of a solvent inert to the reaction, for example, the organic solvent exemplified in the section of the nitration reaction. The reaction can be carried out at a temperature of 0 to 300 ° C (for example, 10 to 200 ° C), preferably about 30 to 150 ° C, 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 0.1 to 1 mol of the imide compound.
It is about 001 to 10 mol, preferably about 0.01 to 5 mol. The amount of oxygen used is
It is about 0.5 to 100 mol, preferably about 1 to 50 mol. In the carboxylation reaction, the amount of carbon monoxide used is 2 to 50 mol, preferably 5 to 1 mol of the substrate.
About 30 mol. In the oxo-forming reaction, the amount of the strong acid used is 0.00001 to 1 mol (0.001 to 10 mol).
0 mol%). It is preferably about 0.0005 to 0.7 mol (0.05 to 70 mol%). Details of the hydroxylation and carboxylation reactions are described in, 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.

The proportion of the unit of the formula (1) in the polymer is, for example, 5 to 100% by weight, preferably 5 to 80% by weight (for example, 5 to 60% by weight), and more Preferably 10 to 50% by weight (for example, 1
5 to 45% by weight).

In order to further improve the resistance to dry etching, the maleimide-based monomer may be copolymerized by using it in combination with a conventional cyclic olefin capable of performing an addition reaction by a double bond in the ring.

As such a cyclic olefin unit, the maleimide-based polymer of the present invention has the formula (2)
At least one selected from the unit represented by (4)
May contain seeds. The unit has the formula (2)
Monomers (cyclic olefins) corresponding to each of (4)
Is obtained by polymerizing The cyclic olefin may have a substituent described above.

In the above formulas (2) and (3), x is 0
An integer of 0 to 4, preferably an integer of 0 to 2, and more preferably 0 or 1 (particularly 0).

Examples of the monomer corresponding to the unit of the formula (2) include norbornenes such as 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.

The ratio of the monomer corresponding to the unit of the formula (2) is 10 parts by weight based on 100 parts by weight of the maleimide monomer.
To 200 parts by weight, preferably 20 to 100 parts by weight, more preferably about 50 to 90 parts by weight.

In the above formula (3), examples of the leaving group represented by R ¹ include C, such as methyl, ethyl and t-butyl.
_1-6 alkyl group (particularly t-butyl group); 5- to 8-membered (particularly 5- or 6-membered) oxacycloalkyl group such as tetrahydrofuranyl and tetrahydropyranyl group; 2-oxepanyl group and the like. In the formula (3), the group-
The substitution position of C (＝ O) —O—R ¹ is not particularly limited,
It may be at the bridgehead of the norbornene ring, but is usually a methylene unit (secondary carbon atom).

Examples of the monomer corresponding to the unit of the formula (3) include norbornenes, for example, lower alkoxy-carbonylnorbornene such as 5-methoxycarbonylnorbornene, 5-ethoxycarbonylnorbornene and 5-tert-butoxycarbonylnorbornene; 5- (2-tetrahydropyranyloxycarbonyl) norbornene,
Oxacycloalkylnorbornenes such as 5- (2-tetrahydrofuranyloxycarbonyl) norbornene and the like can be mentioned, and norbornenes having a t-butyl group as a leaving group are particularly preferable. The monomer alone or 2
More than one species can be used in combination.

When such a monomer is copolymerized, a carboxylic acid ester site can be introduced into the polymer. Therefore, particularly in resist applications, the leaving group R ¹ is eliminated by an acid to form a free carboxyl group. It is useful for accelerating the solubilization of the resin accompanying alkali development.

The ratio of the monomer corresponding to the unit of the formula (3) is 10 parts by weight based on 100 parts by weight of the maleimide monomer.
To 200 parts by weight, preferably 20 to 100 parts by weight, more preferably about 50 to 90 parts by weight.

In the above formula (3), y is an integer of 0-4, preferably an integer of 0-2, more preferably 0 or 1 (particularly 0). Also, number of members in the lactone ring Z ¹ constituting the unit of formula (3) is not particularly limited, 5-8
Members, preferably 5 or 6 members. Further, the methylene carbon atom constituting the lactone ring may have the above-described substituent (particularly, a C _1-4 alkyl group such as a methyl group).

Examples of the monomer corresponding to the unit of the formula (3) include 4-oxatricyclo [5.2.1.0 ^2,6 ] decane-8-en-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-en-6-one, 4-oxatricyclo [6.
2.1.0 ^2,7 ] tricyclo-compounds such as undecane-9-en-5-one (corresponding to y = 0); 4-oxapentacyclo [6.5.1.1 ^9,12 . 0 ^2,6 . 0 ^8,13] pentadecane-10-ene-5-one, 3-oxa penta cyclo [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. When copolymerization is performed using such a monomer, a lactone ring can be introduced into the polymer, and the adhesion to a substrate can be improved. The monomers may be used alone or in combination of two or more.

The monomer corresponding to the formula (3) is
For example, it can be produced by subjecting a compound corresponding to the lactone ring of the formula (3) and having a double bond in the lactone ring to a cyclopentadiene by a Diels-Alder reaction. Also, J.I. Org. Chem. , Vol. 41, No. 7
No. 1221 (1976); Org. Che
m. , 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 ratio of the monomer corresponding to the unit (3) is 1 to 3 with respect to 100 parts by weight of the maleimide monomer.
00 parts by weight, preferably about 5 to 200 parts by weight, and more preferably about 10 to 150 parts by weight.

The maleimide polymer of the present invention may further contain at least one selected from (meth) acrylic acid or its ester and maleic anhydride or its ester as a unit.

By copolymerizing (meth) acrylic acid or its ester, various functions (adhesion,
Easy developability, dry etching resistance, film properties, etc.).

Examples of the (meth) acrylate include alkyl (meth) acrylates [methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylate.
N-butyl acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate,
(Meth) acrylic acid C _1-20 alkyl ester such as lauryl (meth) acrylate (meth) acrylic acid (preferably C _1-6 alkyl ester, especially (meth) acrylic acid C
_1-4 alkyl esters), hydroxyalkyl (meth) acrylates (hydroxy _C2-4 alkyl (meth) acrylates, etc.), glycidyl (meth) acrylate, cycloalkyl (meth) acrylate, bi- or polycycloalkyl ( (Meth) acrylate and the like. The cycloalkyl (meth) acrylate and bi- or polycycloalkyl (meth) acrylate also include cycloalkylalkyl (meth) acrylate and bi- or polycycloalkylalkyl (meth) acrylate, and further include a cycloalkyl group, (Meth) acrylates in which one or two (particularly one) of the carbon atoms constituting the ring of the polycycloalkyl group are substituted with an oxygen atom are also included. In the bi- or polycycloalkyl (meth) acrylate, at least one cycloalkane ring among the rings constituting the bridged ring may form a lactone ring.

The above (meth) acrylic acid or its ester can be used alone or in combination of two or more. Copolymerization of the cycloalkyl (meth) acrylate or bi- or polycycloalkyl (meth) acrylate is advantageous for further improving the dry etching resistance of the maleimide-based polymer.

Cycloalkyl (meth) acrylates include cycloalkyl (meth) acrylates [cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate]
_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 bi- or polycycloalkyl (meth) acrylate includes bi- or polycycloalkyl (meth) acrylates [polycycloalkyl (meth) acrylate,
For example, bicycloalkyl (meth) acrylates such as norpinyl (meth) acrylate and norbornyl (meth) acrylate; adamantyl (meth) acrylate, tricyclo [5.2.1.0 ^2,6 ] decyl (meth)
Acrylates, tricycloalkyl (meth) acrylates such as tricyclo [4.3.1.1 ^2,5 ] undecyl (meth) acrylate; tetracyclo [4.4.0.1
^2,5 . 1 ^7,10 ] tetracycloalkyl (meth) acrylates such as dodecyl (meth) acrylate, etc., and bi- or polycycloalkyl (meth) acrylates having a lactone ring [in the aforementioned bi- or polycycloalkyl (meth) acrylates, (Meth) acrylate in which one cycloalkane ring forms a lactone ring,
That is, the secondary carbon atom of the cycloalkane ring is 1 or 2
Bi- or polycycloalkyl (meth) acrylate substituted with one (particularly one) group —C (＝ O) —O— (for example, 4-oxatricyclo [4.3.1.1 ^3,8 ] Secondary carbon atoms of the adamantane ring of adamantyl (meth) acrylates such as undecane-5-one-1-yl (meth) acrylate (for example, 2-, 2- and 10-position 2
Adamantyl (meth) acrylate analogs, etc., in which a quaternary carbon atom is substituted with a group —C (＝ O) —O—); bi- or polycycloalkyl-alkyl (meth) acrylates [polycycloalkyl-alkyl (Meta)
Acrylates, for example bicycloalkyl C _1-10 alkyl (preferably C _2-8 alkyl, especially branched C _3-7 alkyl) such as norbornylmethyl (meth) acrylate, norbornyldimethylmethyl (meth) acrylate Meth) acrylate; adamantylmethyl (meth) acrylate, adamantylethyl (meth) acrylate, adamantyldimethylmethyl (meth) acrylate, adamantylisopropylmethylmethyl (meth) acrylate, tricyclo [5.2.1.0 ^2,6 ] decyldimethyl Tricycloalkyl C _1-10 alkyl (preferably C _2-8 alkyl, especially branched C _3-7 alkyl) such as methyl (meth) acrylate (meth) acrylate; tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10] dodecyl dimethyl methyl (meth) tetra cycloalkyl C _1-10 alkyl (preferably C _2-8 alkyl, in particular branched C _{3 -7} alkyl), such as acrylates such as (meth) acrylate], a lactone ring A bi- or polycycloalkylalkyl (meth) acrylate having (in the bi- or polycycloalkylalkyl (meth) acrylate, a (meth) acrylate in which at least one cycloalkane ring constituting a polycyclo ring forms a lactone ring, A cycloalkane ring having one or two secondary carbon atoms (especially one)
Or polycycloalkylalkyl (meth) acrylate (4-oxatricyclo [4.3.1.1 ^3,8 ] undecane-5-) substituted with a group -C (= O) -O-
One-1-yl - methyl (meth) acrylate, 4-oxatricyclo [4.3.1.1 ^{3, 8]} undecane -5
Such as -on-1-yl-dimethylmethyl (meth) acrylate, 4-oxatricyclo [4.3.1.1 ^3,8 ] undecane-5-one-1-yl-isopropylmethylmethyl (meth) acrylate Adamantyl C wherein a secondary carbon atom (for example, a secondary carbon atom at the 4-, 6- and 10-position) of the adamantane ring of the adamantyl alkyl (meth) acrylate is substituted by a group -C (= O) -O-
_1-10 alkyl (preferably C _2-8 alkyl, particularly branched C _3-7 alkyl) (meth) acrylate analog, etc.) and the like.

Bi- or tricycloalkyl (meth) acrylates (such as norbornyl (meth) acrylate and adamantyl (meth) acrylate), and bi- or polycycloalkyl (meth) acrylates having the lactone ring (particularly adamantyl (meth) acrylate analogs) ), Bi- or tricycloalkylalkyl (meth) acrylates (especially norbornylalkyl (meth) acrylates,
Adamantylalkyl (meth) acrylate and the like) are preferred.

In the above cycloalkyl (meth) acrylate or bi- or polycycloalkyl (meth) acrylate, a cycloalkyl group, a bi- or polycycloalkyl group (including a group having a lactone ring or an oxygen atom as a structural unit of a cycloalkane ring is also included) ) May have a substituent such as a hydroxyl group, an oxo group, or an alkyl group. The substitution position of the hydroxyl group may be secondary in the cycloalkane ring, and is usually a tertiary carbon atom in bi- or polycycloalkyl (meth) acrylate. The substitution position of the oxo group is the secondary carbon atom of the cycloalkane ring. The substitution position of the alkyl group may be a tertiary carbon atom of the cycloalkane ring in bi- or polycycloalkyl (meth) acrylate, but is usually a secondary carbon atom.

By appropriately selecting a cycloalkyl group (including a bi- or polycycloalkyl group, a cycloalkylalkyl group, a bi- or polycycloalkylalkyl group) and a substituent of these cycloalkyl groups, for example, Various functions can be imparted, such as improving the adhesiveness to the compound, and promoting the elimination of the cycloalkyl group to generate a free carboxyl group. For example,
When the cycloalkane ring contains a lactone ring or has a substituent such as a hydroxyl group or an oxo group, adhesion to a substrate can be improved, particularly for resist applications.

Examples of such a monomer (substrate adhesion type monomer) include bi- or polycycloalkyl (meth) acrylate having a lactone ring (where the secondary carbon atom of the adamantane ring is a group -C (= O) -O-replaced adamantyl (meth) acrylate analogs), hydroxyl-containing bi- or polycycloalkyl (meth) acrylates [hydroxynorbornyl (meth) acrylates such as 4-hydroxynorbornyl (meth) acrylate ) Acrylates; adamantyl (meth) acrylates having 1 to 3 (particularly 1 or 2) hydroxyl groups at the 3-, 5- and 7-positions of the adamantane ring (3-hydroxyadamantyl (meth) acrylate, 3,5- Dihydroxyadamantyl (meth) acrylate, 3,5,7-trihydroxyadamantyl ( Data) acrylate, etc.), etc.],
Oxo group-containing bi- or 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 Monooxoadamantylmaleimides 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 bi- or polycycloalkyl containing a hydroxyl group and an oxo group. (Meth) acrylate [4-
Hydroxyoxonorbornyl (meth) acrylates such as hydroxy-2-oxonorbornyl (meth) acrylate and 4-hydroxy-3-oxonorbornyl (meth) acrylate; 3 of the oxo group-containing adamantyl (meth) acrylate Adamantyl (meth) acrylate containing a hydroxyl group and an oxo group having 1 to 3 (particularly 1 or 2) hydroxyl groups at the-, 5- and 7-positions, etc.].

The (meth) acrylate may be oxacycloalkyl (meth) acrylate, cycloalkylalkyl (meth) acrylate, bi- or polycycloalkylalkyl (meth) acrylate, or the cycloalkane ring may be unsubstituted or alkyl. In the case of having a substituent such as a 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, adamantyldimethylmethyl (meth) ) Acrylate, adamantyl isopropylmethylmethyl (meth) acrylate, etc.], alkyl-substituted bi- or tricycloalkyl-branched alkyl (meth) acrylate [2-, 3- or 7-position of norbornyl group, or 2 of adamantyl group
- a, 4, 1-3, 8 or 10 of the (preferably 1 or 2) C _1-6 alkyl group (preferably a C _{1 -4} alkyl group, particularly C _1-2 alkyl group) Alkyl norbornyl or adamantyl C _1-10 alkyl (meth) acrylate, etc.], oxacycloalkyl (meth) acrylate [2- such as 2-tetrahydropyranyl (meth) acrylate, 4-tetrahydropyranyl (meth) acrylate, etc. , 3- or 4-oxacycloalkyl (meth) acrylate, etc.], unsubstituted bi- or tricycloalkyl (meth) acrylate [norbornyl (meth) acrylate, adamantyl (meth) acrylate, etc.], alkyl-substituted bi- or tricycloalkyl Methacrylate [2-, 3- or 7-position of norbornyl group or 2-, 4-, 8-position of adamantyl group Or 1-3 at position 10 (preferably 1 or 2) C _1-6 alkyl group (preferably C _1-4 alkyl groups, especially C _1-2 alkyl group) alkyl norbornyl having (meth) Acrylate or alkyl adamantyl (meth) acrylate).

The introduction of a substituent (hydroxyl group, oxo group) to a cycloalkyl group, a bi- or polycycloalkyl group (adamantyl group, etc.) can be carried out in the same manner as the introduction of a hydroxyl group or an oxo group into ring Z. Can be performed. In the same manner as in Ring Z, the introduction of a lactone ring can be carried out in the Bayer-Villiger-type reaction of a ketone compound (such as (meth) acrylate having an adamantanone moiety such as adamantyl (meth) acrylate having an oxo group) or in a conventional Bayer-Villiger. It can be performed by a reaction or the like.

The ratio of the (meth) acrylic acid or its ester is based on 100 parts by weight of the maleimide monomer.
It is about 1 to 300 parts by weight, preferably about 10 to 200 parts by weight, and more preferably about 30 to 180 parts by weight.

In the present invention, maleic anhydride may be copolymerized to introduce a maleic anhydride unit into the polymer as long as the resistance to dry etching and the stability of the copolymer are not impaired. 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 (about 0 to 20% by weight), preferably 10% by weight or less (0 to 10% by weight) based on the total amount of the monomers. %).

The weight average molecular weight Mw of the maleimide polymer of the present invention is from 1,000 to 100,000, preferably from 3,000 to 50,000, more preferably from 5,000.
It is about 0 to 30,000. When the weight average molecular weight is Mw and the number average molecular weight is Mn, the molecular weight distribution Mw
/ Mn is about 1 to 3, preferably 1 to 2.5, and more preferably about 1 to 2.

The method of polymerizing the maleimide polymer is not particularly limited, and a conventional polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be employed. Further, the polymerization can be started by applying heat, light, radiation or the like to the system, and a conventional polymerization initiator (azo compound, peroxide, photopolymerization initiator, etc.) may be used.

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 polymer obtained by the above-mentioned method may be diluted by a conventional method, for example, dilution with a solvent, if necessary, to precipitate in a poor solvent, or to remove volatile components such as monomers and solvents. It may be removed or separated and purified by a method such as chromatography.

The maleimide-based polymer of the present invention has excellent dry etching resistance in resist applications.
It is useful as a resist composition. In particular, in addition to units that are desorbed and solubilized by an acid (for example, the unit (3) or the (meth) acrylic acid or an ester thereof, of a desorbable type), a desorbable unit ((meth) acrylic) A polymer having an acid ester or the like can be solubilized by irradiation with light when a composition for a resist is formed by combining it with a photoacid generator 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 light irradiation, and is, 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 polymer. 1 to 25 parts by weight, more preferably 5 to 5 parts by weight
It can be selected from a range of about 20 parts by weight. Further, the acid-eliminating unit contained in the polymer, that is, 0 to 80 parts by weight, 0.1 to 100 parts by weight of the total amount of the acid-eliminating monomer.
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 above polymer and a photoacid generator. The resist composition is applied to a substrate by a coating means such as spin coating and dried. After that, the formed coating film (resist film) is exposed to a predetermined pattern, baked, a latent image pattern is formed, and then developed, a fine pattern can be formed, sensitivity to light rays and high resolution of the pattern Is high.

The substrate can be selected according to the application of the resist composition, and may be a silicon wafer, metal, plastic, glass, ceramics, 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 of 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 irradiation with light, and a protecting group is added to the functional group by the acid generated by baking (for example, a leaving group R ^{1 in the} unit (3), an alkyl group in the (meth) acrylate). Group, bi or polycycloalkyl group) is eliminated, and 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, since the resist composition of the present invention has a maleimide unit having a polycyclic hydrocarbon ring, the dry etching resistance can be significantly improved, and the swelling property with respect to the developing solution is small, so that the circuit pattern can be accurately formed. It is possible to form a fine circuit pattern with high accuracy.

The present invention can be applied to various uses such as 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.).

[0093]

As described above, the maleimide polymer of the present invention contains a maleimide unit having a polycyclic hydrocarbon ring. The etching resistance can be improved. Further, the maleimide-based polymer of the present invention can improve the resist performance and also can improve the adhesion of the resist to the substrate, and is useful for forming a pattern with high accuracy.

[0094]

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 3.6 g (1) of norbornenecarboxylic acid t-butyl ester (3) was placed in a three-necked flask equipped with a stirrer and a reflux tube.
8 mmol), 4.3 g of adamantyl maleimide (1)
(18 mmol), 4-oxatricyclo [4.3.
1.1 ^3,8 ] undecane-5-one-1-yl acrylate (6a) (hereinafter sometimes referred to as hyperacrylate) 2.2 g (9 mmol), n-butyl acetate 1
0 g was added and dissolved. 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 ethyl acetate = 3: 1 (V / V). The resin having Mw of 6000 and Mw / Mn of 2.0 is obtained by repeating the reprecipitation operation three times.
5 g 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), 1.7, 2.1,
Clear signals were observed at 2.8, 3.2 and 4.7 ppm.

In this example, the ratio (molar ratio) of each of the monomers (1), (3) and (6a) is (1) :( 3) :( 6
a) = 40: 20: 20.

The adamantyl maleimide (1)
And 4-oxatricyclo [4.3.1.1 ^3,8 ] undecane-5-one-1-yl acrylate (6a)
It was prepared as follows.

Adamantyl maleimide (1): Dissolve 4.5 g of monoaminoadamantane in 30 mL of acetic acid,
g of maleic anhydride was dissolved. The precipitate that precipitated during the reaction was filtered, washed with acetic acid, and then recrystallized from ethanol to obtain adamantylmaleamic acid. 4.5 g of the obtained adamantyl maleamic acid and 2 g of sodium acetate were dissolved in 10 mL of acetic anhydride, and the mixture was stirred at 100 ° C. for 3 hours in an oil bath. After stopping the reaction, the reaction mixture was poured into cold water, and the precipitate was collected by filtration. The collected precipitate was purified by recrystallization from ethanol to give adamantyl maleimide in a yield of 45%. The spectrum data is as follows. ¹ H-NMR (400 MHz, DMSO-d6): δ
1.73 (6H, d), 2.08 (6H, m), 2.3
8 (6H, d), 6.57 (2H, s)

4-oxatricyclo [4.3.1.1]
^3,8 ] undecane-5-one-1-yl acrylate (6a): 0.1 mol of 2-adamantanone, 10 mmol of N-hydroxyphthalimide, 0.33 mmol of vanadium acetylacetonato V (AA) ₃ , manganese acetyl A mixture of 0.17 mmol of acetonato Mn (AA) ₂ and 250 mL of acetic acid was added under an oxygen atmosphere at 1 atm.
Stirred at 0 ° 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 2 In a three-necked flask equipped with a stirrer and a reflux tube, 4-oxatricyclo [5.2.1.0 ^2,6 decane-8-en-
2.6 g (19 mmol) of 5-one (4), 2.5 g (11 mmol) of adamantylmaleimide (1), 0.7 g (7 mmol) of maleic anhydride (5), 1- (acryloyloxy-1-methylethyl) adamantane (6
b) 4.1 g (17 mmol), 10 g of n-butyl acetate
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, polymerization was carried out while maintaining the reaction system at 70 ° C. under a nitrogen atmosphere, and after 6 hours, the reaction product was reprecipitated from a mixed solvent of hexane: isopropanol = 3: 1 (V / V). Purified. By repeating the reprecipitation operation three times, 7.2 g of a resin having Mw of 9000 and Mw / Mn 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 and 3.2 ppm.

In this example, the ratio (molar ratio) of each monomer
Is (1) :( 4) :( 5) :( 6b) = 20: 35:
15:30.

Example 3 In a three-necked flask equipped with a stirrer and a reflux tube, 4-oxatricyclo [5.2.1.0 ^2,6 ] decane-8-en-5-one (4) 2.6 g (10 mmol), 2.9 g (18 mmol) of adamantyl maleimide (1), 4.2 g (9 mmol) of hyperacrylate (6a), t-butyl norbornenecarboxylic acid (3) 2.4
g (30 mmol) and 10 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. in a nitrogen atmosphere, and the reaction was carried out after 6 hours. Hexane: ethyl acetate = 3:
Purification was performed by reprecipitation from a mixed solvent of 1 (V / V). By repeating this reprecipitation operation three times, Mw becomes 84
Then, 8.2 g of a resin having a Mw / Mn of 2.17 was obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-2.8 ppm (broad), 1.9, 2.2,
Clear signals were observed at 2.6, 3.2 and 4.6 ppm.

In this example, the ratio (molar ratio) of each monomer
Is (1) :( 3) :( 4) :( 6a) = 40: 30:
It was 10:20.

Example 4 In a three-necked flask equipped with a stirrer and a reflux tube, 4-oxatricyclo [5.2.1.0 ^2,6 ] decane-8-en-5-one (4) 1.1 g (8 mmol), 5.6 g (24 mmol) of adamantyl maleimide (1), 1.0 g (5 mm) of norbornene lactone acrylate (6c)
ol) 2.2 g (11 mmol) of norbornenecarboxylic acid t-butyl ester (3), n-butyl acetate 21
g was added and dissolved. Dimethyl N, N-azobisisobutyrate [V-60 manufactured by Wako Pure Chemical Industries, Ltd.] as an initiator
1] After adding 2.1 g, the reaction system was set to 70 under a nitrogen atmosphere.
After 6 hours, the reaction product was purified by reprecipitation from a mixed solvent of hexane: ethyl acetate = 3: 1 (V / V). This reprecipitation operation was repeated three times to obtain 7.4 g of a resin having Mw of 8,500 and Mw / Mn of 2.31.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-2.9 ppm (broad), 1.9, 2.1,
Clear signals were observed at 2.6, 3.2 and 4.4 ppm.

In this example, the ratio (molar ratio) of each monomer
Is (1) :( 3) :( 4) :( 6c) = 45: 30:
15:10.

Example 5 A three-necked flask equipped with a stirrer and a reflux tube was charged with 3.0 g (10 mm) of norbornene lactone acrylate (6c).
ol), 4.2 g of adamantyl maleimide (1) (18
mmol), 3.5 g (18 mmol) of norbornenecarboxylic acid t-butyl ester (3), n-butyl acetate 1
0.5 g was added and dissolved. Dimethyl N, N-azobisisobutyrate [Vako Pure Chemical Industries, Ltd., V-
601], and 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). Was purified. This reprecipitation operation is performed in 3
By repeating the process twice, Mw becomes 6400 and Mw / Mn becomes 2.
6.9 g of resin No. 04 was obtained.

¹ H-NMR (400 MH) of the obtained resin
z, DMSO-d6) When the spectrum was measured,
1.0-2.9 ppm (broad), 1.7, 2.1,
Clear signals were observed at 2.6, 3.2 and 4.6 ppm.

In this example, the ratio (molar ratio) of each monomer
Was (1) :( 3) :( 6c) = 35: 35: 30.

Example 6 In a three-necked flask equipped with a stirrer and a reflux tube, 4-oxatricyclo [5.2.1.0 ^2,6 ] decane-8-en-5-one (4) 2.4 g (17 mmol), adamantyl maleimide (1) 4.0 g (17 mmol), 1-
3.7 g (15 mmol) of (1-acryloyloxy-1-methylethyl) adamantane (6b) and 10 g of n-butyl acetate were added and dissolved. N, N- as initiator
Dimethyl azobisisobutyrate [Wako Pure Chemical Industries, Ltd., V
−601], polymerization was carried out 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: ethyl acetate = 3: 1 (V / V). Purified by precipitation. This reprecipitation operation was repeated three times to obtain 7.6 g of a resin having Mw of 7,500 and Mw / Mn of 2.18. ¹ H-NMR (4
00-MHz, DMSO-d6) spectrum was measured to be 1.0-2.9 ppm (broad), 1.8,
Clear signals were observed at 2.1, 2.6, 3.2 and 4.4 ppm.

In this example, the ratio (molar ratio) of each monomer
Was (1) :( 4) :( 6b) = 35: 35: 30.

Example 7 In a three-necked flask equipped with a stirrer and a reflux tube, 4-oxatricyclo [5.2.1.0 ^2,6 ] decane-8-en-5-one (4) 2.4 g (17 mmol), 40 g (17 mmol) of adamantyl maleimide (1), 2-methyl-2-acryloyloxyadamantane (6d) 7
g (15 mmol) and 21 g of n-butyl acetate were added and dissolved. After adding 2.1 g of dimethyl N, N-azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] as an initiator, polymerization was carried out under a nitrogen atmosphere while maintaining the reaction system at 70 ° C., and the reaction was carried out after 6 hours. Hexane: ethyl acetate = 3:
Purification was performed by reprecipitation from a mixed solvent of 1 (V / V). By repeating this reprecipitation operation three times, Mw is 90
As a result, 7.2 g of a resin having a Mw / Mn of 2.23 was obtained.
¹ H-NMR (400 MHz, DMSO
-D6) When the spectrum was measured, it was found to be 1.0-2.9.
ppm (broad), 1.7, 2.2, 2.6, 3.2
And a clear signal was observed at 4.4 ppm.

In this example, the ratio (molar ratio) of each monomer
Was (1) :( 4) :( 6d) = 35: 35: 30.

Example 8 In a three-necked flask equipped with a stirrer and a reflux tube, 2.3 g (9 mmol) of 4-methoxycarbonyl-norbornene lactone acrylate (6e) and 4.1 g (18 mmol) of adamantyl maleimide (1). 3.6 g (18 mm) of norbornene carboxylic acid t-butyl ester (3)
ol) and 21 g of n-butyl acetate were added and dissolved. After adding 2.1 g of dimethyl N, N-azobisisobutyrate [V-601, manufactured by Wako Pure Chemical Industries, Ltd.] as an initiator, polymerization was carried out under a nitrogen atmosphere while maintaining the reaction system at 70 ° C., and the reaction was carried out after 6 hours. Hexane: ethyl acetate = 3: 1 (V / V)
And purified by reprecipitation from a mixed solvent. By repeating this reprecipitation operation three times, Mw becomes 8400, Mw /
7.4 g of a resin having an Mn of 2.18 was obtained. When the ¹ H-NMR (400 MHz, DMSO-d6) spectrum of the obtained resin was measured, 1.0-2.9 ppm (broad), 1.7, 2.2, 2.6, 3.2, and 4 were obtained. .4p
A clear signal was observed at pm.

In this example, the ratio (molar ratio) of each monomer
Was (1) :( 3) :( 6e) = 40: 40: 20.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08F 222/06 C08F 222/06 222/10 222/10 C08K 5/00 C08K 5/00 C08L 33/02 C08L 33/02 33/04 33/04 35/00 35/00 45/00 45/00 G03F 7/033 G03F 7/033 7/039 601 7/039 601 F term (reference) 2H025 AA09 AB16 AC01 AC04 AC08 AD03 BE00 BE10 BG00 CB08 CB10 CB14 CB41 CB43 CB45 CB55 CB56 4J002 BG011 BG041 BG051 BG071 BH021 BK001 EB116 EQ016 EU026 EU186 EV216 EV246 EV296 EV326 GP03 4J100 AJ02R AK32R AL03R AL04R AL05R AL08R AL09R AL10R AM47P AR09Q AR11Q AR32Q BA03P BA03R BA11P BA11R BA15Q BA16P BA20Q BC03R BC04R BC07P BC07R BC08P BC08R BC09P BC09R BC12P BC12R BC26P BC53P BC53Q BC53R CA01 CA04 CA05 DA01 JA38

Claims (7)

[Claims] 1. A maleimide polymer containing at least a unit represented by the following formula (1). Embedded image (Wherein, ring Z represents a polycyclic hydrocarbon ring which may have a substituent, X represents an alkylene group, and n is 0 or 1) 2. In the formula (1), Z is at least one of a bridged cyclic hydrocarbon ring which may have a substituent or a hydrocarbon ring constituting the bridged cyclic hydrocarbon ring. The maleimide polymer according to claim 1, wherein the ring is a ring forming a lactone ring. 3. In the formula (1), n is 0 and Z
Is an adamantane ring which may have at least one substituent selected from a hydroxyl group, a carboxyl group and an oxo group, or at least one of the hydrocarbon rings constituting the adamantane ring forms a lactone ring The maleimide-based polymer according to claim 1, which is a ring. 4. The maleimide polymer according to claim 1, further comprising at least one selected from units represented by the following formulas (2) to (4). Embedded image (Wherein, R ¹ represents a leaving group, x and y are each 0
Shows an integer of ~ 4. Ring Z ¹ represents a lactone ring) 5. The maleimide polymer according to claim 1, further comprising, as a unit, at least one selected from (meth) acrylic acid or an ester thereof and maleic anhydride or an ester thereof. 6. A weight average molecular weight of 1,000 to 100,
000 and a molecular weight distribution of 1 to 2.5.
The maleimide polymer according to the above. 7. A resist composition comprising the maleimide polymer according to claim 1 and a photoacid generator.