JP6913031B2 - Methods for Producing Polymers, Radiation Sensitive Compositions, Compounds and Devices - Google Patents

Description

Some aspects of the invention relate to polymers and compounds useful as chemically amplified photoresist materials. Further, some embodiments of the present invention is facilitated by irradiation of deep-UV, KrF excimer laser light, ArF excimer laser, F ₂ excimer laser light, electron beam, X-ray or EUV (extreme ultraviolet) active energy rays such as The present invention relates to a radiation-sensitive composition containing a radiation-sensitive acid generator that decomposes into and generates an acid, and the above-mentioned polymer, and a method for producing a device using the same.

In semiconductor devices, for example, highly integrated circuit elements typified by DRAM and the like, there is a high demand for higher density, higher integration, or higher speed. Along with this, in various electronic device manufacturing fields, there is an increasing demand for establishment of microfabrication technology on the order of half micron, for example, development of photolithography technology for fine pattern formation. In order to form fine patterns in photolithography technology, it is necessary to improve the resolution. Here, the resolution (R) of the reduced projection exposure apparatus is represented by Rayleigh's equation R = k · λ / NA (where λ is the wavelength of the exposure light, NA is the numerical aperture of the lens, and k is the process factor). Therefore, the resolution can be improved by shortening the wavelength λ of the active energy ray (exposure light) used when forming the pattern of the resist.

As a photoresist material suitable for short wavelengths, a chemically amplified type has been proposed (Patent Document 1). The characteristic of the chemically amplified photoresist material is that protonic acid is generated from the radiation-sensitive acid generator, which is a contained component, by irradiation with exposure light, and this protonic acid undergoes an acid-catalyzed reaction with a resist compound or the like by heat treatment after exposure. To wake up. Most of the photoresist materials currently being developed are chemically amplified.
For example, as a positive type chemically amplified resist polymer when an alkaline developer is used as the developer, a polymer that is unstable to acid and protected by a substituent that can control the solubility in the alkaline developer has been proposed. , Study of miniaturization is being carried out (Patent Document 2).

Regardless of whether it is a positive type or a negative type, the chemically amplified resist not only has excellent resolution and rectangularity of the cross-sectional shape of the resist pattern as miniaturization progresses, but also has LWR (Line Width Roughness) and CDU (Critical Dimension). Uniformity) and EL (exposure latitude) performance are required. Conventionally, various compounds constituting a polymer contained in a radiation-sensitive composition have been studied, but it is difficult to satisfy these performances at the same time.

Japanese Unexamined Patent Publication No. 9-90637 JP-A-2007-65504

In view of such circumstances, it is an object of some aspects of the present invention to provide a radiation-sensitive composition having excellent LWR performance, CDU performance and EL performance, and a compound and a polymer used therein.
Another object of the present invention is to provide a method for manufacturing a device using the above-mentioned radiation-sensitive composition.

As a result of diligent studies to solve the above problems, the present inventors are excellent in LWR performance, CDU performance and EL performance when a polymer having a structural unit containing a specific group is used in a radiation-sensitive composition. , And have completed some aspects of the present invention.
One aspect of the present invention that solves the above problems is a polymer having a structural unit (I) containing a group represented by the following formula (1).

In the above formula (1), R ¹ and R ² are linear or branched monovalent aliphatic hydrocarbon groups having 1 to 10 carbon atoms, which may independently have substituents; substituents. A monovalent alicyclic hydrocarbon group having 3 to 15 carbon atoms; at least one methylene group of the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is a divalent heteroatom-containing group. A group consisting of a substituted group; an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent; and an aromatic heterocyclic group having 6 to 30 carbon atoms which may have a substituent. R ¹ and R ² are either directly bonded to each other in a single bond, or have a ring structure selected from the group consisting of an oxygen atom, a sulfur atom and a methylene group. ^{R 3} may be formed, and R 3 is a monovalent bridging fat having 3 to 15 carbon atoms and containing any selected from the group consisting of a lactone skeleton, a sulton skeleton and a lactam skeleton, which may have a substituent. It is a cyclic hydrocarbon group, X is a single bond or a divalent linking group, and * indicates a bond site with a polymer main chain portion.

One aspect of the present invention is a compound represented by the following formula (3).

In the above formula (3), R ^{1 to} R ^{3 and X are independently selected from the options of R 1 to} R ³ and X in the above formula (1), respectively, and Y contains a polymerizable group. It is a monovalent group.

One aspect of the present invention is a step of forming a resist film on a substrate using the radiation-sensitive composition, a step of exposing the resist film using radiation, and developing the exposed resist film. A process and a method of manufacturing a device including.

By using the polymer of one aspect of the present invention as a component of a radiation-sensitive composition, a resist pattern having excellent LWR performance, CDU performance and EL performance can be formed.

Hereinafter, some aspects of the present invention will be described in detail.
<1> Polymer (structural unit (I))
The polymer of one embodiment of the present invention has a structural unit (I) containing a group represented by the above general formula (1). The structural unit (I) has ^{carbon bonded to X and R 1 to} R ³ (hereinafter, also referred to as “quaternary carbon”), and R ³ is composed of a group consisting of a lactone skeleton, a sultone skeleton, and a lactam skeleton. It has a monovalent bridging alicyclic hydrocarbon group with 3 to 15 carbon atoms containing at least one of the selected carbon atoms. The structural unit (I) in the polymer has an acid dissociation ability by having a quaternary carbon. Further, since the polymer has ^{a group that is structurally moderately bulky and polar as R 3} , it has an excellent balance between polarity and hydrophobicity, and when the polymer is used as a component of a radiation-sensitive composition, the resolution is improved. improves.
When the polymer of one embodiment of the present invention has a structural unit other than the structural unit (I) containing the group represented by the general formula (1), the structural unit containing the group represented by the general formula (1) ( The hydrophobic interaction between I) and other structural units can be increased, and incompatibility can be reduced. Further, since the glass transition temperature (Tg) is moderately high and the rigidity of the polymer is increased, the acid diffusivity of the radiation-sensitive acid generator can be suppressed. Thereby, LWR performance, CDU performance, EL performance and the like can be further improved.

In some aspects of the invention, "acid dissociation ability" refers to decomposition and deprotection by the action of an acid.
In the above formula (1), R ¹ and R ² are linear or branched monovalent aliphatic hydrocarbon groups having 1 to 10 carbon atoms, which may independently have substituents; substituents. A monovalent alicyclic hydrocarbon group having 3 to 15 carbon atoms; at least one methylene group of the aliphatic hydrocarbon group and the alicyclic hydrocarbon group becomes a divalent heteroatom-containing group. A group consisting of a substituted group; an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent; and an aromatic heterocyclic group having 6 to 30 carbon atoms which may have a substituent. R ¹ and R ² are either directly bonded to each other in a single bond, or have a ring structure selected from the group consisting of an oxygen atom, a sulfur atom and a methylene group. It may be formed. When R ¹ and R ² have a substituent, ^{the total carbon number of R 1} and R ² described above preferably includes the substituent.

Examples of the aliphatic hydrocarbon groups of R ¹ and R ² include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, t-butyl group, n-pentyl group and i-pentyl group. Alkyl groups such as n-hexyl group, i-hexyl group, n-octyl group, i-octyl group, 2-ethylhexyl group and n-decyl group; at least one of the carbon-carbon single bonds of the alkyl group is carbon- An alkenyl group or an alkynyl group substituted with a carbon double bond or a carbon-carbon triple bond; and the like can be mentioned.
At ^{least one methylene group in the aliphatic hydrocarbon groups of R 1} and R ² may be substituted with a divalent heteroatom-containing group. The divalent heteroatom-containing group is a group consisting of -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -S-, -SO-, -SO _2-, and the like. Examples are selected from the above. When R ¹ and R ² have a heteroatom-containing group and the heteroatom-containing substituent has a substituent such as an alkyl group or an aryl group, the total number of carbon atoms including those substituents is the above-mentioned carbon number. Is preferable.

The alicyclic hydrocarbon groups of R ¹ and R ² include monocyclic aliphatic hydrocarbon groups, spirocyclic aliphatic hydrocarbon groups, condensed polycyclic aliphatic hydrocarbon groups, and at least 2 of these. Examples thereof include linked polycyclic aliphatic hydrocarbon groups in which one or more groups are directly bonded by a single bond or a linking group containing a double bond.
Examples of the monocyclic aliphatic hydrocarbon group include a cyclopropyl group, a cyclopentyl group and a cyclohexyl group.

Examples of the spirocyclic aliphatic hydrocarbon group include spiro [3,4] octane and spirobicyclopentane.
Examples of the condensed polycyclic aliphatic hydrocarbon group include those having a skeleton in which two or more monocyclic hydrocarbons such as norbornane, tricyclodecane, tetracyclododecane and adamantane are bridged.
Further, at least one methylene group in the alicyclic hydrocarbon groups of ^{R 1} and R ^{2 may be substituted with the divalent heteroatom-containing group.}

Examples of the aromatic hydrocarbon groups of R ¹ and R ² include monocyclic aromatic hydrocarbon groups and condensed polycyclic aromatic hydrocarbon groups obtained by condensing at least two rings of the monocyclic aromatic hydrocarbons. These aromatic hydrocarbon groups may have the above-mentioned substituents.

Examples of the monocyclic aromatic hydrocarbon group include groups having a skeleton such as cyclopentene and benzene.

Examples of the condensed polycyclic aromatic hydrocarbon group include groups having a skeleton such as indene, naphthalene, azulene, anthracene, phenanthrene, naphthalene and fluorene.
R ¹ and R ² may be aromatic heterocyclic groups. Aromatic heterocyclic groups include furan, thiophene, pyrrole, imidazole, pyran, pyridine, pyrimidine, pyrazine, indole, purine, quinoline, isoquinoline, chromen, thianthrene, dibenzothiophene, phenothiazine, phenoxazine, xanthene, aclysine, phenazine and Examples thereof include monovalent groups having a skeleton such as carbazole.

The above R ¹ and R ² may be directly bonded to each other by a single bond to form a ring structure with each other. For example, R ¹ and R ² may form a cyclopentane skeleton, a cyclohexane skeleton, an adamantane skeleton, or the like. Further, R ¹ and R ² may form a ring structure with each other via any one selected from the group consisting of an oxygen atom, a sulfur atom and a methylene group.

The ^{substituents that R 1} and R ² may have include a linear or cyclic alkyl group; an alkyl fluoride group in which at least one hydrogen atom in the alkyl group is substituted with a fluorine atom; an alkoxy group; an acyl. Group; alkoxycarbonyl group; aryloxy group; phosphino group; silyl group; alkyl group containing the hetero atom-containing group in the skeleton instead of at least one methylene group of the alkyl group; aryl group; heteroaryl group; hydroxy group; Halogen atom; carboxy group; etc. may be mentioned.

The structural unit (I) preferably has an acid dissociation ability. Since the structural unit (I) has an acid dissociation ability, it is preferable that the carbon atom next to the quaternary carbon has a hydrogen atom. That is, at least one of the ^{carbon atoms next to the quaternary carbon in R 1} and R ² and the carbon atom next to the quaternary carbon in R ^{3 has at least one hydrogen atom.} It is preferable to have.

R ³ is a monovalent alicyclic hydrocarbon group having 3 to 15 carbon atoms and containing at least one selected from the group consisting of a lactone skeleton, a sultone skeleton and a lactam skeleton, which may have a substituent. Is. The lactone backbone is a cyclic ester containing a -OC (= O) -group in the ring. The sultone skeleton is a cyclic sulfonic acid ester containing a −OS (= O) _{2-group in the ring.} The lactam skeleton is a ring formed by dehydration condensation of a carboxyl group and an amino group.
R ³ is not particularly limited as long as it contains at least one of these skeletons and has a bridging ring structure. In ^{addition to the above-mentioned bridged ring structure, R 3} may have a spiro-cyclic group having another ring structure and a condensed polycyclic group.

In some aspects of the invention, the "bridged ring structure" is defined as a ring in which two non-adjacent vertices of at least one of the skeletons selected from the group consisting of a lactone skeleton, a sultone skeleton and a lactam skeleton are rings. Refers to a shared structure. A fused ring in which two adjacent vertices in the skeleton share a ring is not included in the "bridged ring structure". However, if the ring structure condensed with the lactone skeleton or the like has a bridging structure, it corresponds to the "crosslinked ring structure" in some aspects of the present invention.
The ring constituting the bridge in the bridged ring structure may be composed of a carbon atom, or may be a ring composed of a skeleton containing a hetero atom such as an oxygen atom and a sulfur atom.

The structural unit (I) has a bridging alicyclic hydrocarbon group containing at least one of a lactone skeleton, a sultone skeleton, and a lactam skeleton as R ³ , and thus has an excellent balance between polarity and hydrophobicity. When the polymer having (I) is used as a component of the radiation-sensitive composition, the acid diffusivity of the radiation-sensitive acid generator can be suppressed, the resolution can be improved, and the LWR performance and the EL performance can be further improved.
Further, since the structural unit (I) is bulky, the acid diffusivity of the radiation-sensitive acid generator can be suppressed, thereby increasing the resolution.

R ³ may be a saturated alicyclic hydrocarbon group as well as a group in which at least one carbon-carbon single bond is substituted with a double bond or a triple bond. Since the structural unit (I) preferably has an acid dissociation ability, it is preferable that the carbon atom next to the quaternary carbon has a hydrogen atom. That is, it is preferable that the carbon atom next to the quaternary carbon ^{in R 3 has at least one hydrogen atom.} This does not apply when the carbon atom adjacent to the quaternary carbon in ^{R 1} and R ^{2 has at least one hydrogen atom.}

Examples of the cross-linked alicyclic hydrocarbon group containing the lactone skeleton of ^{R 3 include those shown below.} In the following formula, the portion represented by ** is the portion bonded to the quaternary carbon in the above formula (1).

Instead of the lactone skeleton shown above, it may have a sultone skeleton and a lactam skeleton. ^{Further, R 3} in the polymer of one aspect of the present invention may have a plurality of these skeletons in combination.
R ³ is preferably a cross-linked alicyclic hydrocarbon group containing a lactone skeleton.

The ^{substituent that R 3} may have is a linear or cyclic alkyl group; a fluorinated alkyl group in which at least one hydrogen atom in the alkyl group is substituted with a fluorine atom; at least one of the alkyl groups. Examples thereof include an alkyl group containing the heteroatom-containing group in the skeleton instead of the methylene group; an aryl group; a heteroaryl group; a hydroxy group; a halogen atom; and the like. When R ³ has a substituent, the above-mentioned total carbon number of ^{R 3 preferably includes the substituent.}

X is not particularly limited as long as it is a single bond or a divalent linking group that bonds the main chain constituting the polymer and the ^{quaternary carbon bonded to R 1 to} R ^{3 in the above formula (1), but for example.} The divalent linking group includes a carbonyloxy group; an oxy group; a divalent organic group in which at least one of an alkandiyl group and an arenediyl group and at least one of a carbonyloxy group and an oxy group are appropriately combined; and the like. It is preferably one of the more selected.
As X, a carbonyloxy group or the like is preferable because it can be easily synthesized.

The structural unit (I) is preferably composed of a compound in which a group containing a polymerizable group shown below is bonded to a quaternary carbon in the above formula (1). The group containing the polymerizable group may contain X of the above formula (1).
Examples of the polymerizable group include a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a fluorovinyl group, a difluorovinyl group, a trifluorovinyl group, a difluorotrifluoromethylvinyl group, a trifluoroallyl group, a perfluoroallyl group, and a tri. Fluoromethylacryloyl group, nonylfluorobutylacryloyl group, vinyl ether group, fluorine-containing vinyl ether group, allyl ether group, fluorine-containing allyl ether group, styryl group, vinylnaphthyl group, fluorine-containing styryl group, fluorine-containing vinylnaphthyl group, norbornyl group, Examples thereof include a fluorine-containing norbornyl group and a silyl group. The polymerizable group may have a substituent, and the substituent may be, for example, a monovalent group such as an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a hydroxy group, a thiol group, an amino group or a phenyl group. Examples thereof include a divalent group such as a group or an ether bond or a phenylene group.

The structural unit (I) is preferably represented by the following formula (2).

In the above formula (2), R ¹ , R ² , R ³ and X are the same as those in the above formula (1), and R ⁴ is a hydrogen atom; a fluorine atom; a linear, branched or cyclic carbon number 1 to 6. and straight-chain alkenyl group having 1 to 6 carbon atoms, branched or cyclic; alkyl group is any one selected from the group consisting of, at least one in the alkyl group and alkenyl group in the R ⁴ The hydrogen atom may be replaced with a fluorine atom.

Examples of the linear alkyl group having 1 to 6 carbon atoms of R ⁴ include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group and an n-hexyl group.
Examples of the branched alkyl group having 1 to 6 carbon atoms of R ⁴ include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a tert-pentyl group and a 2-ethylexyl group.
Examples of the cyclic alkyl group having 1 to 6 carbon atoms of R ⁴ include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group.

As ^{the linear, branched or cyclic alkenyl group having 1 to 6 carbon atoms of R 4} , at least one of the carbon-carbon single bonds of the linear alkyl group, the branched alkyl group and the cyclic alkyl group shown above is carbon-carbon. Examples thereof include those substituted with double bonds.
Further, it may be an alkyl fluoride group or an alkenyl fluoride group in which at least one hydrogen atom in the alkyl group and the alkenyl group of ^{R 4 is replaced with a fluorine atom.} All hydrogen atoms may be replaced with fluorine atoms. As R ⁴ in which at least one hydrogen atom in R ⁴ is replaced with a fluorine atom, a trifluoromethyl group or the like is preferable as the alkyl fluoride group. It may have a substituent other than fluorine.

Preferred structural units (I) are illustrated below. In the following formula, the part represented by * is the part connected to Y in the above formula (3). However, the present invention is not limited to this.

(Other structural units)
In addition to the structural unit (I), the polymer according to some aspects of the present invention has a structural unit usually used as a radiation-sensitive composition as long as the effects of some aspects of the present invention are not impaired. You may be doing it.
Examples of other structural units include structural units (II) having an acid dissociative group. The acid dissociative group is a group that has an acid dissociation ability that allows at least a part of the bonds in the structure of the acid dissociative group to be cleaved by the action of an acid and produces a polar group by dissociation of a protecting group. Examples of the polar group include a hydroxy group, a carboxy group, an amino group and a sulfo group, and a hydroxy group and a carboxy group are preferable.

Examples of the structural unit (II) include those having an acid dissociative group in the *** portion of the following formula (5). More specifically, the structural unit (II) having an acid dissociative group includes a structural unit (IIa) represented by the following formula (6a), a structural unit (IIb) represented by the following formula (6b), and the like. Be done.

In the formula (6a) and (6b), R ⁴ and X are the same as in the above formula (2). However, R ⁴ and X may be the same or different in the above formulas (6a) and (6b) and the above formula (2).
In the case of the structural unit (IIa) represented by the above formula (6a), X is preferably a carbonyloxy group, an oxy group or a divalent organic group containing at least one of these groups.
R ^{5 to} R ⁷ are monovalent hydrocarbon groups, and R ⁵ and R ⁶ may be bonded to each other to form a ring. Examples of the hydrocarbon groups of R ^{5 to} R ⁷ include those similar to those ^{of R 1} and R ² of the above formula (1).

R ⁸ and R ⁹ are independently hydrogen atoms or monovalent hydrocarbon groups, and R ¹⁰ is a monovalent hydrocarbon group, which ^{is bonded to either R 8} or R ⁹ to form a ring. May be good. Examples of the hydrocarbon groups of R ^{8 to} R ¹⁰ include those similar to those ^{of R 1} and R ² of the above formula (1). When R ¹⁰ is ^{bonded to either R 8} or R ⁹ to form a ring, the cyclic group is preferably a 4- to 7-membered ring, specifically a tetrahydropyranyl group, a tetrohydrofuranyl group or the like. Can be mentioned.

Examples of the structural unit (IIa) and the structural unit (IIb) include the following.

Examples of the monomers constituting the structural unit (IIa) and the structural unit (IIb) include the following. In the following formula, R ^α is the same as R ^{4 in the} above formula (5).

In addition to the structural unit (I) and the structural unit (II), the polymer according to some aspects of the present invention contains a group containing at least one selected from the group consisting of a lactone skeleton, a sultone skeleton and a lactam skeleton. It may have a structural unit (III) to have. The structural unit (III) is different from the structural unit (I), and examples thereof include those represented by the following formula (7).

In the above formula (7), R ⁴ and X are the same as those in the above formula (2). R ¹¹ is a group containing at least one selected from the group consisting of a lactone skeleton, a sultone skeleton and a lactam skeleton. By having the structural unit (III), the adhesion can be improved, and as a result, the EL property, the LWR property, and the CDU property of the radiation-sensitive composition can be improved.
The ^{lactone skeleton, sultone skeleton, and lactam skeleton of the R 11} group may have a bridging structure within the skeleton, and a spirocyclic group and a condensed polycycle having an additional ring structure in addition to the above skeleton. It may be a formula group or the like. The lactone skeleton, sultone skeleton, and lactam skeleton shown below all have a bridging structure, but those without a bridging structure can also be used.
Examples of the R ¹¹ group include those shown below. In the following formula, the part represented by ** is the part connected to X in the above formula (7).

In addition to the structural units (I) to (III), the polymer can have a structural unit having a hydroxyl group or a cyano group (hereinafter, also referred to as “structural unit (IV)”). This makes it possible to improve substrate adhesion and developer affinity. The structural unit having a hydroxyl group or a cyano group is preferably a structural unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, and preferably does not have an acid-degradable group. In the alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, the alicyclic hydrocarbon structure is preferably an adamantyl group, a diamantyl group, or a norbornane group, and more preferably an adamantyl group. Further, it is preferably substituted with a hydroxyl group, and more preferably contains a structural unit having an adamantyl group substituted with at least one hydroxyl group.
In particular, from the viewpoint of suppressing the diffusion of the generated acid, it is most preferable to contain a structural unit having a hydroxyadamantyl group or a dihydroxyadamantyl group.
Specific examples of the structural unit (IV) having a hydroxyl group or a cyano group are given below, but the present invention is not limited thereto.

The polymer may or may not contain a structural unit having a hydroxyl group or a cyano group, but when the polymer contains a structural unit (IV), a structural unit having a hydroxyl group or a cyano group ( The content of IV) is preferably 1 to 50 mol%, more preferably 3 to 50 mol%, still more preferably 3 to 45 mol%, and most preferably 5 to 45 mol% with respect to all the structural units in the polymer. %.
The polymer may have structural units other than the structural units (I) to (IV).

In the polymer according to one aspect of the present invention, the ratio of each structural unit is not particularly limited, but the structural unit (I) is preferably 10 to 70 mol% of the whole. The structural unit (II) is preferably 10 to 70 mol%, the structural unit (III) is preferably 10 to 70 mol%, and the structural unit (IV) is 1 to 50 mol%. Is preferable.

The polymer according to one aspect of the present invention is required to be polymerized by a usual method in an appropriate solvent using the monomer components constituting each of the above structural units and a radical polymerization initiator or the like so as to have the above-mentioned compounding ratio. It can be obtained by purifying with. For example, a batch polymerization method in which each monomer component corresponding to the structural units (I) to (IV) and a radical polymerization initiator are dissolved in a solvent and heated to carry out polymerization, and radical polymerization with each monomer component in a heating solvent. Examples thereof include a drop polymerization method in which a solution containing an initiator or the like is added dropwise over several hours.
The solvent used in the reaction is not particularly limited as long as it is a solvent usually used in the polymerization reaction, but it is preferable to polymerize using the same solvent used in the radiation-sensitive composition of one aspect of the present invention. As the radical polymerization initiator, an azo-based initiator is preferable.
The monomer component concentration of the reaction is not particularly limited, but is preferably 5 to 50% by mass. The reaction temperature is not particularly limited, but is preferably 1 to 150 ° C.
After completion of the reaction, if necessary, purification is performed by a usual purification method such as a liquid extraction method, an ultrafiltration method, or a precipitation method to obtain a polymer.

<2> Compound The compound in one embodiment of the present invention is a monomer for forming the structural unit (I) of the polymer, and is represented by the following formula (3).

In the above formula (3), R ^{1 to} R ³ and X are independently selected from the options ^{of R 1 to} R ³ and X in the above formula (1), respectively. In the above formula (3), Y is a monovalent group containing a polymerizable group.
The polymerizable group of Y is a group that enables the compound having the polymerizable group to be polymerized by radical polymerization or the like, and refers to a group containing multiple bonds between carbon atoms such as an ethylenic double bond. .. More specifically, the polymerizable group includes, for example, a vinyl group, an allyl group, an acryloyl group, a methacryloyl group, a fluorovinyl group, a difluorovinyl group, a trifluorovinyl group, a difluorotrifluoromethylvinyl group, a trifluoroallyl group, and a per. Fluoroallyl group, trifluoromethylacryloyl group, nonylfluorobutylacryloyl group, vinyl ether group, fluorine-containing vinyl ether group, allyl ether group, fluorine-containing allyl ether group, styryl group, vinylnaphthyl group, fluorine-containing styryl group, fluorine-containing vinylnaphthyl Examples thereof include a group, a norbornyl group, a fluorine-containing norbornyl group, and a silyl group. The polymerizable group of Y is preferably an alkylene group which may have a substituent, and examples thereof include a linear, branched or cyclic alkylene group having 1 to 20 carbon atoms or a alkylene group combining these. , 2 to 10 carbon atoms are more preferable. Examples of the substituent include a monovalent group such as an alkyl group having 1 to 5 carbon atoms, an alkoxy group, a hydroxy group, a thiol group, an amino group and a phenyl group, or a divalent group such as an ether bond and a phenylene group. Be done.

The above formula (3) is preferably represented by the following formula (4).

In the above formula (4), R ^{1 to} R ³ are each independently selected from the options ^{of R 1 to} R ³ in the above formula (3). R ⁴ is selected from the group consisting of a hydrogen atom; a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched or cyclic alkenyl group having 1 to 6 carbon atoms; At least one hydrogen atom in the above-mentioned alkyl group and alkenyl group in the ^{R 4 may be substituted with a fluorine atom.}

The compounds of one aspect of the invention can be synthesized by conventional methods. For example, a bridging alicyclic hydrocarbon group corresponding to ^{R 3} of the compound represented by the above formula (3), ^{an alcohol derivative having a group of R 1} and R ² , and a (meth) acrylic acid halide or (meth). It can be synthesized by reacting with acrylic acid by a known method. However, the synthesis of the above compounds is not limited to this.
An alcohol derivative having a cross-linked alicyclic hydrocarbon group, R ¹ and R ^{2 , containing a lactone skeleton corresponding to R 3} of the compound represented by the above formula (3) is synthesized, for example, by the method shown in the following reaction formula. It is possible. In the following reaction formula, X ¹ is a halogen atom such as chlorine. n is an integer of 1 to 15.
^{Specifically, for example, when R 1} and R ² of the compound represented by the above formula (3) are linked to form a ring structure, the acid chloride or alkyl ester having the cross-linked alicyclic hydrocarbon group is formed. Can be obtained by carrying out a Grignard reaction using a dihalogenalkane such as dibromoalkane.

<3> Radiation-sensitive composition The radiation-sensitive composition according to one aspect of the present invention is characterized by containing the above-mentioned polymer and a radiation-sensitive acid generator.
The radiation-sensitive acid generator is not particularly limited as long as it is used in a normal radiation-sensitive composition, and examples thereof include an onium salt compound, an N-sulfonyloxyimide compound, a halogen-containing compound, and a diazoketone compound. Be done.
Examples of the onium salt compound include sulfonium salt, tetrahydrothiophenium salt, iodonium salt, phosphonium salt, diazonium salt, pyridinium salt and the like.
Examples of the anion of the onium salt compound include those described in WO2011 / 093139. Specifically, as the radiation-sensitive acid generator, a sulfonic acid derivative having an anionic structure represented by the following formula (8) is preferable, but the agent is not limited thereto.

^{_{R 12 COOCH 2 CH 2 CFHCF 2}} SO 3 - (8)
In the above formula (8), R ¹² represents a monovalent organic group having 1 to 20 carbon atoms which may have a substituent. The organic group preferably includes a group represented by the following formula having 1 to 20 carbon atoms.
R ^13- (A-R ¹⁴ ) _m- (9)

In the above formula (9), R ¹³ is a linear, branched or cyclic monovalent aliphatic hydrocarbon group; a monovalent aromatic hydrocarbon group; and -O-, -CO-, -COO. -, -OCO-, -O-CO-O-, -NHCO-, -CONH-, -NH-CO-O-, -O-CO-NH-, -NH-, -N =, -S-, Any monovalent group selected from a monovalent aliphatic heterocyclic group or a monovalent aromatic heterocyclic group containing at least one group in the skeleton selected from the group consisting of −SO − and −SO _{2 −.} It is a group.

In addition, A is directly bound to each other independently; or -O-, -CO-, -COO-, -OCO-, -O-CO-O-, -NHCO-, -CONH-, -NH-CO-. It is any group selected from the group consisting of O-, -O-CO-NH-, -NH-, -S- and -CO-O-CH _2-CO-O-.

R ¹⁴ is an independently linear, branched or cyclic divalent aliphatic hydrocarbon group; a divalent aromatic hydrocarbon group; and -O-, -CO-, -COO-,-. OCO-, -O-CO-O-, -NHCO-, -CONH-, -NH-CO-O-, -O-CO-NH-, -NH-, -N =, -S-, -SO- A divalent aliphatic heterocyclic group or a divalent aromatic heterocyclic group containing at least one group selected from the group consisting of and −SO _{2 − in the skeleton; any of the divalent groups selected from.} ..

Further, m is 0 or an integer of 1 to 10. However, when m is 0, R ¹² has the hydroxyl group, and when m is 1 or more, ^{at least one of R 12} and R ¹³ has the hydroxyl group. m is preferably 0 to 5, more preferably 0 to 3.

When R ¹² has a substituent, the number of carbon atoms including the carbon number of the substituent is preferably 1 to 200, more preferably 1 to 100, and the number of carbon atoms is 1. It is more preferably ~ 30, and particularly preferably 3 to 30 carbon atoms. Further, ^{it is preferable that R 12} has a substituent, that is, ^{at least one hydrogen of R 13} and R ¹⁴ is substituted with the substituent.

Examples of the substituent that R ¹² may have include a hydroxy group, a carboxyl group, an alkoxy group, an acyl group, an alkoxycarbonyl group, an aryl group, an aryloxy group, a phosphino group, an alkylthio group and an arylthio group. Yes, but not limited to these.

Examples of the anion of the radiation-sensitive acid generator include other sulfonic acid anions, carboxylic acid anions, imide anions, methide anions, carbo anions, borate anions, halogen anions, and phosphoric acids, in addition to the sulfonic acid anions represented by the above formula (8). Examples thereof include anions such as anions, antimonate anions, and arsenic anions.
More specifically, as an ^{_{anion, ZD a-, (Rf) b}} PF (6-b) -, R 15 c BD (4-c) -, R 15 c GaD (4-c) -, R 16 SO 3 - , (R ¹⁶ SO ₂ ) ₃ C ⁻ or (R ¹⁶ SO ₂ ) ₂ N ⁻ anions are preferred. Two Rf, respectively two in two and R ¹⁶ of R ^15, may be bonded to each other to form a ring.
Z represents a phosphorus atom, a boron atom or an antimony atom. D represents a halogen atom (preferably a fluorine atom).
P represents a phosphorus atom, F represents a fluorine atom, B represents a boron atom, and Ga represents a gallium atom.
S represents a sulfur atom, O represents an oxygen atom, C represents a carbon atom, and N represents a nitrogen atom.

Rf is preferably an alkyl group in which 80 mol% or more of hydrogen atoms are substituted with a fluorine atom, and the alkyl group is preferably an alkyl group having 1 to 8 carbon atoms. Alkyl groups to be converted to Rf by fluorine substitution include linear alkyl groups (methyl, ethyl, propyl, butyl, pentyl, octyl, etc.), branched alkyl groups (isopropyl, isobutyl, sec-butyl, tert-butyl, etc.) and Cycloalkyl groups (cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.) and the like can be mentioned. The ratio of hydrogen atoms of these alkyl groups substituted with fluorine atoms in Rf is preferably 80 mol% or more, more preferably 90, based on the number of moles of hydrogen atoms possessed by the original alkyl group. It is mol% or more, particularly preferably 100 mol%.
When the substitution ratio by the fluorine atom is in these preferable ranges, the photosensitivity of the sulfonium salt is further improved. Particularly preferred Rf are CF ₃ ⁻ , CF ₃ CF ₂ ⁻ , (CF ₃ ) ₂ CF ⁻ , CF ₃ CF ₂ CF ₂ ⁻ , CF ₃ CF ₂ CF ₂ CF ₂ ⁻ , (CF ₃ ) ₂ CFCF ₂ ^−. , CF ₃ CF ₂ (CF ₃ ) CF ⁻ and (CF ₃ ) ₃ C ⁻ . The b Rfs are independent of each other and therefore may be the same or different from each other.

R ¹⁵ represents a phenyl group in which a part of a hydrogen atom is substituted with at least one halogen atom or an electron-withdrawing group. Examples of the halogen atom include a fluorine atom, a chlorine atom and a bromine atom. Examples of the electron attracting group include a trifluoromethyl group, a nitro group and a cyano group. Of these, a phenyl group in which one hydrogen atom is replaced with a fluorine atom or a trifluoromethyl group is preferable. The c R ^15s are independent of each other and may therefore be the same or different from each other.

R ¹⁶ represents an alkyl group having 1 to 20 carbon atoms, a perfluoroalkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and the alkyl group and the perfluoroalkyl group are linear, branched or chain-like. It may be cyclic, and the aryl group may be unsubstituted or having a substituent.

a represents an integer of 4 to 6. b represents an integer of 1 to 5, preferably 2 to 4, particularly preferably 2 or 3. c represents an integer of 1 to 4, preferably 4.

Examples of the _{anion represented by ZD a} ⁻ include anions represented by SbF ₆ ⁻ , PF ₆ ⁻ and BF ₄ ⁻ .

_{(Rf) b PF (6-} b) - as the anion represented by ^{_{the, (CF 3 CF 2) 2}} PF 4 -, (CF 3 CF 2) 3 PF 3 -, ((CF 3) 2 CF) 2 ^{_{PF 4 -, ((CF 3}} ) 2 CF) 3 PF 3 -, (CF 3 CF 2 CF 2) 2 PF 4 -, (CF 3 CF 2 CF 2) 3 PF 3 -, ((CF 3) 2 CFCF ^{_{2) 2 PF 4 -, (}} (CF 3) 2 CFCF 2) 3 PF 3 -, (CF 3 CF 2 CF 2 CF 2) 2 PF 4 - , and _{(CF 3 CF 2 CF 2 CF} 2) 3 PF 3 - Examples thereof include anions represented by. Of ^{_{these, (CF 3 CF 2) 3}} PF 3 -, (CF 3 CF 2 CF 2) 3 PF 3 -, ((CF 3) 2 CF) 3 PF 3 -, ((CF 3) 2 CF) 2 ^{_{PF 4 -, ((CF 3}} ) 2 CFCF 2) 3 PF 3 - , and _{((CF 3) 2 CFCF 2} ) 2 PF 4 - anion represented by are preferred.

The anions represented by ^{R 15} _c BD _(4-c) ⁻ _{include (C 6} F ₅ ) ₄ B ⁻ , ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ B ⁻ , (CF ₃ C ₆ H _{4). ^{) 4 B -, (C 6}} F 5) 2 BF 2 -, C 6 F 5 BF 3 - and _{(C 6 H 3 F 2)} 4 B - anion, and the like represented. Of these, anions represented by _{(C 6} F ₅ ) ₄ B ⁻ and ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ B ^{− are preferred.}

The anions represented by ^{R 15} _c GaD _(4-c) ⁻ _{include (C 6} F ₅ ) ₄ Ga ⁻ , ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ Ga ⁻ , (CF ₃ C ₆ H _4). ) ₄ Ga ⁻ , (C ₆ F ₅ ) _{2 Ga F 2} ⁻ , C ₆ F ₅ Ga F ₃ ⁻ and (C ₆ H _{3 F 2} ) ₄ ^{Ga −} , and the like. Of these, anions represented by _{(C 6} F ₅ ) ₄ Ga ⁻ and ((CF ₃ ) ₂ C ₆ H ₃ ) ₄ Ga ^{− are preferred.}

R ¹⁶ SO ₃ ^- as the anion represented by, trifluoromethanesulfonic acid anion, pentafluoroethanesulfonate anion, heptafluoropropanesulfonate acid anion, nonafluorobutanesulfonic acid anion, pentafluorophenyl sulfonate anion, p- toluene Examples thereof include sulfonic acid anion, benzene sulfonic acid anion, camphor sulfonic acid anion, methane sulfonic acid anion, ethane sulfonic acid anion, propane sulfonic acid anion and butane sulfonic acid anion. Of these, trifluoromethanesulfonic acid anion, nonafluorobutanesulfonic acid anion, methanesulfonic acid anion, butanesulfonic acid anion, benzenesulfonic acid anion and p-toluenesulfonic acid anion are preferable.

The anions represented by (R ¹⁶ SO ₂ ) ₃ C ⁻ _{are (CF 3} SO ₂ ) ₃ C ⁻ , (C ₂ F ₅ SO ₂ ) ₃ C ⁻ , and (C ₃ F ₇ SO ₂ ) ₃ C ^−. and _{(C 4 F 9 SO 2)} 3 C - anion such as represented and the like.

The anions represented by (R ¹⁶ SO ₂ ) ₂ N ⁻ _{are (CF 3} SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , and (C ₃ F ₇ SO ₂ ) ₂ N ^−. And (C ₄ F ₉ SO ₂ ) ₂ N ⁻ anions and the like can be mentioned. In addition, _{a cyclic imide in which the portions corresponding to the two} ^{(R 16} SO 2) are bonded to each other to form a ring structure is also mentioned as an anion represented by ^{(R 16} SO ₂ ) ₂ N ^−.

The monovalent anion, in addition to the above anions, perhalogenated acid ion _{^(ClO 4} ^-, BrO 4 -, etc.), halogenated sulfonic acid ion _{^(FSO 3} ^-, ClSO 3 -, etc.), sulfate ion _(CH 3 SO _{4 ^{-, CF 3 SO 4 -,}} HSO 4 - , etc.), carbonate ions _{^{(HCO 3 -, CH 3 CO}} 3 - , etc.), aluminate ions (AlCl ₄ ^-, AlF ₄ ^-, etc.), hexafluoro bismuthate ions (BiF ₆ ^-), carboxylate ion _{^{(CH 3 COO -, CF 3}} COO -, C 6 H 5 COO -, CH 3 C 6 H 4 COO -, C 6 F 5 COO -, CF 3 C 6 H 4 COO - , etc. ), Arylborate ion (B (C ₆ H ₅ ) ₄ ⁻ , CH ₃ CH ₂ CH ₂ CH ₂ B (C ₆ H ₅ ) ₃ ⁻ etc.), Thiosyanate ion (SCN ⁻ ) and Nitrate ion (NO ₃ ⁻⁾ ) Etc. can be used.

The content of the radiation-sensitive acid generator is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer, which is one aspect of the present invention.

The radiation-sensitive composition of one aspect of the present invention may contain a fluorine-containing water-repellent polymer in addition to the polymer and the radiation-sensitive acid generator.
The fluorine-containing water-repellent polymer is not particularly limited, and examples thereof are those usually used in an immersion exposure process, and a polymer having a higher fluorine atom content than the polymer is preferable. Thereby, when the resist film is formed using the radiation-sensitive composition, the fluorine-containing water-repellent polymer is unevenly distributed on the surface of the resist film due to the water repellency of the fluorine-containing water-repellent polymer. Can be done.
As for the fluorine content of the fluorine-repellent polymer, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon groups in the fluorine-repellent polymer are fluorinated, and 50% or more is fluorinated. More preferred.
The content of the fluorine-repellent polymer in the radiation-sensitive composition is 0.5 to 10 parts by mass with respect to 100 parts by mass of the polymer (non-fluorine-water-repellent polymer) according to one embodiment of the present invention. Is preferable from the viewpoint of improving the hydrophobicity of the resist film. The fluorine-repellent polymer may be used alone or in combination of two or more.

The radiation-sensitive composition according to one aspect of the present invention includes known additives such as sensitizing compounds, quenchers such as trioctylamine, acid diffusion control agents such as photodisintegrating bases, surfactants, fillers, and the like. At least one selected from pigments, antistatic agents, flame retardants, photostabilizers, antioxidants, ion-supplementing agents, solvents and the like may be added.

The acid diffusion control agent has the effect of controlling the diffusion phenomenon of the acid generated from the acid generator by light in the resist film and controlling an unfavorable chemical reaction in the unexposed region. Therefore, the storage stability of the obtained photosensitizing radiation composition is further improved, the resolution as a resist is further improved, and the line width change of the resist pattern due to the fluctuation of the leaving time from the exposure to the development process is suppressed. A photosensitizing radiation composition having excellent process stability can be obtained.
Examples of the acid diffusion control agent include a compound having one nitrogen atom in the same molecule such as trioctylamine, a compound having two nitrogen atoms, a compound having three nitrogen atoms, an amide group-containing compound, and a urea compound. Quenchers such as nitrogen-containing heterocyclic compounds can be mentioned. Further, as the acid diffusion control agent, a photodisintegrating base that is exposed to light and generates a weak acid by exposure can also be used.
The content of the acid diffusion control agent is preferably 0 to 20 parts by mass with respect to 100 parts by mass of the polymer, which is one aspect of the present invention.

The photodisintegrating base is one that is exposed to light by exposure to generate a weak acid, and examples thereof include onium salt compounds and iodonium salt compounds that are decomposed by exposure and lose their acid diffusion controllability. Examples of the photodisintegrating base include the same as the above-mentioned radiation-sensitive acid generator.
When the photo-disintegrating base is contained in the resist composition together with the radiation-sensitive acid generator, the anion of the photo-disintegrating base has an acid strength equal to or less than that of the anion possessed by the radiation-sensitive acid generator. Is preferable from the viewpoint of sensitivity and acid diffusion control because it acts as a photodegradable base. Further, it is preferable that the anion structure is bulky because the resolution is improved.
Examples of the photodisintegrating base include, but are not limited to, compounds represented by the following formulas.
The content of the photodisintegrating base is preferably 0 to 20 parts by mass with respect to 100 parts by mass of the polymer, which is one aspect of the present invention.

The radiation-sensitive acid generator, the sensitizing compound, the acid diffusion control agent, and the like may be included as structural units of the polymer. That is, for example, when the radiation-sensitive acid generator is an onium salt compound, the onium salt compound may be contained in the polymer as a structural unit bonded at the *** portion of the above formula (5).

<4> Method for preparing a radiation-sensitive composition The method for preparing a radiation-sensitive composition according to one aspect of the present invention is not particularly limited, and is known such as mixing, dissolving or kneading the above polymer and other optional components. It can be prepared by the method.
The polymer can be synthesized by appropriately polymerizing the monomer constituting the structural unit (I) and, if necessary, the monomer constituting the other structural unit by a usual method.
However, the method for producing a polymer according to some aspects of the present invention is not limited to this.

<5> Device Manufacturing Method One embodiment of the present invention includes a step of forming a resist film on a substrate using the radiation-sensitive composition and a resist exposed by exposing the resist film with radiation. It is a method for manufacturing a device including a step of obtaining a film and a step of developing the exposed resist film.
One embodiment of the present invention includes a step of forming a resist film using the radiation-sensitive composition, a step of exposing the resist film to obtain an exposed resist film, and developing the exposed resist film. It may be a method of manufacturing a substrate having a pattern before obtaining an individualized chip, which includes a step of performing the process.

The radiation used for the exposure in the exposure step may be an active energy ray or light capable of activating the radiation-sensitive acid generator to generate an acid, and may be KrF excimer laser light, ArF excimer laser light, or F ₂ It means excimer laser light, electron beam, UV, visible light, X-ray, electron beam, ionizing ray, i-ray, EUV and the like.
The amount of light irradiation varies depending on the type and blending ratio of each component in the photocurable composition, the film thickness of the coating film, and the like, but ^{is preferably 1 J / cm 2} or less or 1000 μC / cm ² or less.
When the radiation-sensitive composition contains a sensitizing compound, it is also preferable to perform a second exposure with ultraviolet rays or the like after irradiation with radiation.

Hereinafter, some aspects of the present invention will be described based on examples, but the present invention is not limited to these examples.

[Manufacturing method of monomer]
[Synthesis Example 1] Synthesis of Alcohol A solution of magnesium (2.93 g) in tetrahydrofuran (37.9 mL) is heated at 50 ° C., and then a solution of 1,4-dibromobutane (10.0 g) in tetrahydrofuran (11.2 mL). Was dropped. A solution of tetralide (10.0 g) in tetrahydrofuran (13.0 mL) was added dropwise thereto at 20 ° C. or lower. After stirring for 1 hour, a saturated aqueous solution of ammonium chloride was added dropwise to stop the reaction. After normal aqueous post-treatment (aqueous work-up) and solvent distillation, purification is performed by silica gel column chromatography (n-hexane / ethyl acetate), and alcohol (6.62 g, yield 60%) is added as a highly viscous oil. Obtained as a substance.

1H-NMR (400MHz in DMSO-d6): δ (ppm) = 4.41 (1H, s), 2.23 (1H, ddd) 1.78-1.35 (11H, m), 0.95 ( 3H, s), 0.87 (6H, s).

[Synthesis Example 2] Synthesis of Monomer (M-1) After cooling a solution of alcohol (10.0 g) obtained in Synthesis Example 1 in tetrahydrofuran (50.0 ml) to 10 ° C. or lower, n-butyllithium (1. 6M, 24.9 ml) was added dropwise. After stirring for 1 hour, a solution of methacrylic acid chloride (5.3 g) in tetrahydrofuran (13.2 g) was added dropwise at 20 ° C. or lower.
After stirring for 1 hour, water was added dropwise to stop the reaction. After normal aqueous work-up and solvent distillation, silica gel column chromatography (purification with n-hexane / ethyl acetate, monomer (M-1) (3.9 g, yield 30%)) Was obtained as an oil.

1H-NMR (400MHz in DMSO-d6): δ (ppm) = 5.93 (1H, m), 5.62 (1H, m), 2.44-2.30 (3H, m), 2.04 -1.93 (1H, m), 1.93-1.83 (1H, m), 1.81 (3H, s), 1.80-1.66 (4H, m), 1.64-1 .53 (2H, m), 1.50-1.40 (1H, m), 0.91 (3H, s), 0.90 (3H, s), 0.89 (3H, s).

[Synthesis Example 3] Synthesis of Alcohol A solution of magnesium (2.65 g) in tetrahydrofuran (34.3 mL) was heated at 50 ° C., and then a solution of 1-bromobutane (12.6 g) in tetrahydrofuran (11.2 mL) was added dropwise. .. A solution of tetralide (10.0 g) in tetrahydrofuran (13.0 mL) was added dropwise thereto at 20 ° C. or lower. After stirring for 1 hour, a saturated aqueous solution of ammonium chloride was added dropwise to stop the reaction. After normal aqueous post-treatment (aqueous work-up) and solvent distillation, silica gel column chromatography (purification with n-hexane / ethyl acetate is performed to obtain an alcohol (7.52 g, yield 55%) as an oil. rice field.

1H-NMR (400MHz in DMSO-d6): δ (ppm) = 4.31 (1H, s), 2.28-2.19 (1H, m), 1.78-1.18 (15H, m) , 1.00 (3H, s), 0.96 (3H, s), 0.91-0.84 (9H, m).

[Synthesis Example 4] Synthesis of Monomer (M-2) Monomer (M-2) was synthesized in the same manner as in Synthesis Example 2 except that the alcohol obtained in Synthesis Example 3 was replaced.

1H-NMR (400MHz in DMSO-d6): δ (ppm) = 5.97 (1H, s), 5.65 (1H, m.), 2.21-1.70 (9H, m), 1. 50-1.17 (10H, m), 0.98 (3H, s), 0.94 (3H, s), 0.92 (3H, s), 0.88 (3H, t), 0.87 (3H, t).

[Synthesis of polymers (A-1 to A-5)]
[Synthesis Example 5] Synthesis of Polymer (A-1) 10.0 g (50 mol%) of the monomer (G-1) shown below and 13.9 g (M-1) of the monomer (M-1) obtained in the above Synthesis Example 2 ( 50 mol%) was dissolved in 35.8 g of 2-butanone, and 0.97 g of AIBN (6.5 mol% with respect to the total number of moles of all monomers) was further dissolved as a polymerization initiator to prepare a monomer solution. A 100 ml three-necked flask containing 21.5 g of 2-butanone was purged with nitrogen for 30 minutes, heated to 75 ° C. with stirring, and the prepared monomer solution was added dropwise using a dropping funnel over 4 hours. The start of dropping was set as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization reaction solution was water-cooled and cooled to 30 ° C. or lower. This cooled polymerization reaction solution was put into 328 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 239 g of methanol, filtered, and dried at 50 ° C. for 15 hours to obtain a white powdery polymer (A-1) (yield 19.8 g, yield). Rate 83%). The Mw of the polymer A-1 was 7,200, and the Mw / Mn was 1.68. As a result of 13C-NMR analysis, the content ratios of the structural unit derived from the monomer (G-1) and the structural unit derived from the monomer (M-1) were 50.9 mol% and 49.1 mol%, respectively.

[Synthesis Examples 2 to 5] Synthesis of Polymers (A-2) to (A-5) The polymer (A) is the same as in Synthesis Example 1 except that the types and amounts of the monomers shown in Table 1 below are used. -2)-(A-5) were synthesized. The content ratio, yield (%), Mw and Mw / Mn ratio of each structural unit of these monomers are shown in Table 1.

<Tg simulation>
The glass transition temperature (Tg) of the homopolymer composed of the above monomers was calculated by the Bicerano method using Scigress (manufactured by Fujitsu). The results are shown in Table 2.

<Preparation of photosensitizing radiation composition solution>
[Example 1]
100 parts by mass of polymer (A-1) as a base polymer, triphenylsulfonium 4- (adamantan-1-carbonyloxy) -1,1,2-trifluoro-butane-1-, which is a radiation-sensitive acid generator 5 parts by mass of sulfonate (Triphenyl-sulfonium; 4- (adamantane-1-carbonyloxy) -1,1,2-trifluoro-butane-1-sulfonate), 0.2 parts by mass of triethanolamine as an acid diffusion control agent, solvent After mixing 1250 parts by mass of propylene glycol monomethyl ether acetate, which is a propylene glycol monomethyl ether acetate, the mixture was filtered through a PTFE filter to prepare a radiation-sensitive composition (H-1) solution.

[Example 2 and Comparative Examples 1 to 3]
Radiation-sensitive compositions (H-2) to (H-5) were prepared in the same manner as in Example 1 except that each component of the type and content shown in Table 3 below was used.

<Formation of resist pattern (1)>
After the above radiation-sensitive composition solution is rotationally coated on a silicon wafer, it is prebaked on a hot plate at 110 ° C. for 60 seconds to obtain a resist film having a film thickness of 300 nm. The film is exposed to an ArF excimer laser stepper (wavelength 193 nm) and then post-baked at 110 ° C. for 60 seconds. Then, it was subjected to alkaline development using a 2.38 mass% TMAH aqueous solution as an alkaline developer, washed with water, and dried to form a positive resist pattern.

<Formation of resist pattern (2)>
Negative type resist pattern is operated in the same manner as in the above resist pattern formation (1) except that it is developed with an organic solvent using n-butyl acetate instead of the above TMAH aqueous solution and is not washed with water. Was formed.

<Evaluation>
The resolution, LWR (Line width roughness), and EL (Exposure latitude) are evaluated as follows.
The resolution, LWR, and EL are measured using the radiation-sensitive composition (Comparative Example 1) adjusted according to the above method. Based on these values, if the resolution, LWR, and EL performances of Examples 1 and 2 and Comparative Examples 2 and 3 are improved by 10% or more when compared with the standard, the value is set to "○". An improvement of less than 10%, 5% or more was evaluated as "Δ", and an improvement of less than 5% was evaluated as "x". A scanning electron microscope was used to measure the length of the resist pattern.

The radiation-sensitive compositions of Examples 1 and 2 are superior in resolution in lithography and can reduce LWR in a fine pattern as compared with the radiation-sensitive compositions of Comparative Examples 1 to 3. The reason is considered to be that the polymer containing a structural unit having a bridging alicyclic hydrocarbon group having a lactone skeleton or the like can increase the hydrophobic interaction with other structural units and reduce the incompatibility.
From the above results, it can be seen that the polymer in some aspects of the present invention has an effect of being excellent in resolution in lithography and being able to reduce LWR in a fine pattern.

When used in a radiation-sensitive composition, the polymer according to one aspect of the present invention can be a radiation-sensitive composition having excellent LWR performance and EL performance.

Claims (8)

A polymer having a structural unit (I) containing a group represented by the following formula (1).

A polymer whose structural unit (I) is represented by the following formula (2).

(In the above formula (1), R ¹ and R ² are linear or branched monovalent aliphatic hydrocarbon groups having 1 to 10 carbon atoms, which may independently have substituents; substitutions. A monovalent alicyclic hydrocarbon group having 3 to 15 carbon atoms which may have a group; at least one methylene group of the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is a divalent heteroatom. group substituted with-containing group; an aromatic hydrocarbon group having 6 to 30 carbon atoms; and an aromatic heterocyclic group having 6 to 30 carbon atoms; and any one selected from the group consisting of, and,
R ¹ and R ² form a ring structure by directly bonding to each other in a single bond or via one selected from the group consisting of an oxygen atom, a sulfur atom and a methylene group.
R ³ is a monovalent alicyclic hydrocarbon group having 3 to 15 carbon atoms and containing at least one selected from the group consisting of a lactone skeleton, a sultone skeleton and a lactam skeleton, which may have a substituent. And
X is a carbonyloxy group
* Indicates the binding site with the polymer main chain.
In the formula (2), R ¹ , R ² , R ³ and X are independently selected from the options ^{of R 1} , R ² , R ^{3 and X in the formula (1).}
R ⁴ is selected from the group consisting of a hydrogen atom; a fluorine atom; a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched or cyclic alkenyl group having 1 to 6 carbon atoms; At least one hydrogen atom in the alkyl group and the alkenyl group in the ^{R 4 may be substituted with a fluorine atom.} ) The polymer according to claim 1 , wherein R ³ is a cross-linked alicyclic hydrocarbon group containing a lactone skeleton. A radiation-sensitive composition containing the polymer according to claim 1 or 2 and a radiation-sensitive acid generator. The radiation-sensitive composition according to claim 3 , further containing a photodisintegrating base. The radiation-sensitive composition according to claim 3 or 4 , further containing a fluorine-containing water-repellent polymer. It is a compound represented by the following formula (3).

A compound whose formula (3) is represented by the following formula (4).

(In the above formula (3), R ¹ and R ² are linear or branched monovalent aliphatic hydrocarbon groups having 1 to 10 carbon atoms, which may independently have substituents; substitutions. A monovalent alicyclic hydrocarbon group having 3 to 15 carbon atoms which may have a group; at least one methylene group of the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is a divalent heteroatom. A group substituted with a containing group; an aromatic hydrocarbon group having 6 to 30 carbon atoms which may have a substituent; and an aromatic heterocyclic group having 6 to 30 carbon atoms which may have a substituent; It is any one selected from the group consisting of, and,
R ¹ and R ² form a ring structure with each other by directly bonding with a single bond or via either selected from the group consisting of an oxygen atom, a sulfur atom and a methylene group.
R ³ is a monovalent alicyclic hydrocarbon group having 3 to 15 carbon atoms and containing at least one selected from the group consisting of a lactone skeleton, a sultone skeleton and a lactam skeleton, which may have a substituent. And
X is a carbonyloxy group
Y is a polymerizable group
Polymerizable groups are groups having an ethylenic double bond, group having an ethylenic double bond rather it may also have a substituent,
In the formula (4), R ^{1 to} R ³ are the same as any one independently selected from the options ^{of R 1 to} R ^{3 in} the formula (3).
R ⁴ is selected from the group consisting of a hydrogen atom; a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms; and a linear, branched or cyclic alkenyl group having 1 to 6 carbon atoms; At least one hydrogen atom in the alkyl group and the alkenyl group in the ^{R 4 may be substituted with a fluorine atom.} ) The compound according to claim 6 , wherein R ³ is a cross-linked alicyclic hydrocarbon group containing a lactone skeleton. A step of forming a resist film on a substrate using the radiation-sensitive composition according to any one of claims 3 to 5.
The step of exposing the resist film using radiation and
A method of manufacturing a device, including a step of developing an exposed resist film.