JP6561731B2 - Radiation sensitive resin composition, resist pattern forming method, acid diffusion controller and compound - Google Patents

Description

  The present invention relates to a radiation-sensitive resin composition, a resist pattern forming method, an acid diffusion controller and a compound.

  Radiation sensitive resin compositions used for fine processing by lithography are far ultraviolet rays such as KrF excimer laser light (wavelength 248 nm), ArF excimer laser light (wavelength 193 nm) and extreme ultraviolet light (EUV: Extreme Ultraviolet, wavelength 13.5 nm). The acid is generated in the exposed part by irradiation with charged particle beams such as electron beams, and the chemical reaction using this acid as a catalyst causes a difference in the dissolution rate in the developer between the exposed part and the unexposed part. A resist pattern is formed thereon.

  At present, miniaturization of the resist pattern processing technique is being attempted by using a laser beam having a shorter wavelength, an electron beam, an immersion exposure apparatus, or the like. Such a radiation-sensitive resin composition has not only excellent resolution of the resist pattern to be formed and rectangularity of the cross-sectional shape, but also LWR (Line Width Roughness) performance, depth of focus, and defect suppression. In addition, it is required to obtain a highly accurate pattern with a high yield. The radiation-sensitive resin composition is also required to have excellent storage stability. In response to these requirements, the types, molecular structures, and the like of the acid generators, acid diffusion controllers and other components used in the radiation-sensitive resin composition have been studied in detail. As such an acid diffusion controller, an onium salt compound containing an onium cation and a carboxylic acid anion or a sulfonic acid anion is known (Japanese Patent Laid-Open Nos. 11-125907, 2002-122994, and 2010). No. 061043).

  However, at present, when the miniaturization of the resist pattern has progressed to a level of 45 nm or less, the required level of the performance is further increased, and the conventional radiation-sensitive resin composition satisfies these requirements. I can't make it happen.

Japanese Patent Laid-Open No. 11-125907 JP 2002-122994 A JP 2010-061043 A

  The present invention has been made based on the circumstances as described above, and its purpose is radiation sensitivity excellent in LWR performance, resolution, rectangularity of a cross-sectional shape, depth of focus, defect suppression and storage stability. The object is to provide a resin composition.

The invention made in order to solve the above-mentioned problem is a polymer having a first structural unit (hereinafter also referred to as “structural unit (I)”) containing an acid dissociable group (hereinafter referred to as “[A] polymer”). say), the radiation-sensitive acid generator (hereinafter also referred to as "[B] acid generator"), and nitrogen atom, and -COO ^- acid diffusion controller having an anion and a radiation-sensitive cation containing (hereinafter, " [C] Acid Diffusion Control Agent ”, and the —COO ^{— in the} anion is bonded to a carbon atom, and the carbon atom is further bonded to another atom by a double bond. It is an adhesive resin composition.

  Another invention made in order to solve the above-mentioned problems comprises a step of forming a resist film, a step of exposing the resist film, and a step of developing the exposed resist film, It is the resist pattern formation method formed with a conductive resin composition.

Yet another invention was made to solve the above problems, a nitrogen atom and -COO ^- and a anion and a radiation-sensitive cation containing said -COO in the anion ^- it is bonded to the carbon atom, This is an acid diffusion control agent in which this carbon atom is further bonded to another atom by a double bond. .

Yet another invention was made to solve the above problems, a nitrogen atom and -COO ^- and a anion and a radiation-sensitive cation containing said -COO in the anion ^- it is bonded to the carbon atom, This is a compound in which this carbon atom is further bonded to another atom by a double bond.

  Here, the “double bond” means not only a bond having a bond order of 2, but also a conjugated double bond conjugated with another double bond such as a double bond in butadiene and a double bond in an aromatic ring. The double bond which comprises is also included. “Aromatic ring” includes both aromatic carbocycles and aromatic heterocycles. The “acid-dissociable group” refers to a group that replaces a hydrogen atom such as a carboxy group or a hydroxy group and dissociates by the action of an acid. The “number of ring members” refers to the number of atoms constituting the ring in the alicyclic structure, aromatic ring structure, aliphatic heterocyclic structure or aromatic heterocyclic structure.

  According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, while exhibiting excellent storage stability and depth of focus, LWR is small, resolution is high, cross-sectional rectangularity is excellent, and there are few defects. A resist pattern can be formed. The acid diffusion controlling agent of the present invention can be suitably used as an acid diffusion controlling agent component of the radiation sensitive resin composition. The compound of the present invention can be suitably used as the acid diffusion controller. Therefore, they can be suitably used for pattern formation in semiconductor device manufacturing or the like where further miniaturization is expected.

<Radiation sensitive resin composition>
The radiation sensitive resin composition contains a [A] polymer, a [B] acid generator, and a [C] acid diffusion controller. The radiation-sensitive resin composition has, as a suitable component, a polymer having a larger mass content of fluorine atoms than the [A] polymer (hereinafter also referred to as “[D] polymer”) and / or an [E] solvent. May be contained. Furthermore, the said radiation sensitive resin composition may contain the other arbitrary component in the range which does not impair the effect of this invention. Since the radiation-sensitive resin composition has the above-described configuration, LWR performance, resolution, rectangularity of a cross-sectional shape, depth of focus, and defect suppression (hereinafter, these performances are collectively referred to as “LWR performance, etc.”). And excellent storage stability. Hereinafter, each component will be described.

<[A] polymer>
[A] The polymer is a polymer having the structural unit (I). According to the radiation-sensitive resin composition, the acid-dissociable group of the [A] polymer in the exposed portion is dissociated by the acid generated from the [B] acid generator and the like by irradiation with radiation, and the exposed portion and the unexposed portion. And a difference in solubility in the developer occurs, and as a result, a resist pattern can be formed. [A] The polymer is usually a base polymer in the radiation-sensitive resin composition. The “base polymer” refers to a polymer having the largest content of the polymers constituting the resist pattern, and preferably occupies 50% by mass or more, more preferably 60% by mass or more.

  [A] In addition to the structural unit (I), the polymer is a structural unit containing a lactone structure, a cyclic carbonate structure, a sultone structure or a combination thereof (hereinafter also referred to as “structural unit (II)”), a phenolic hydroxyl group And / or a structural unit containing an alcoholic hydroxyl group (hereinafter also referred to as “structural unit (IV)”). Other structural units other than I) to (IV) may be included. [A] The polymer may have one or more of these structural units. Hereinafter, each structural unit will be described.

[Structural unit (I)]
The structural unit (I) is a structural unit containing an acid dissociable group. Examples of the structural unit (I) include a structural unit represented by the following formula (a-1) (hereinafter also referred to as “structural unit (I-1)”), and a structure represented by the following formula (a-2). A unit (hereinafter also referred to as “structural unit (I-2)”).

In the formula (a-1), R ⁵ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y ¹ is a monovalent acid dissociable group represented by the following formula (Y-1).
In said formula (a-2), R < ⁶ > is a hydrogen atom or a methyl group. Y ² is a monovalent acid dissociable group represented by the following formula (Y-2).

In the above formula (Y-1), R ^e1 is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^e2 and R ^e3 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a ring number of 3 to 3 composed of carbon atoms to which these groups are combined and bonded to each other. 20 alicyclic structures are represented.

In the above formula (Y-2), R ^e4 , R ^e5 and R ^e6 are each independently a hydrogen atom, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, or a monovalent group having 3 to 20 carbon atoms. These are alicyclic hydrocarbon groups, oxy-chain hydrocarbon groups having 1 to 20 carbon atoms, or oxyalicyclic hydrocarbon groups having 3 to 20 carbon atoms. However, R ^e4 , R ^e5 and R ^e6 are not simultaneously hydrogen atoms.

  The “hydrocarbon group” includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. The “hydrocarbon group” may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The “chain hydrocarbon group” refers to a hydrocarbon group that does not include a cyclic structure but includes only a chain structure, and includes both a linear hydrocarbon group and a branched hydrocarbon group. The term “alicyclic hydrocarbon group” refers to a hydrocarbon group that includes only an alicyclic structure as a ring structure and does not include an aromatic ring structure, and includes a monocyclic alicyclic hydrocarbon group and a polycyclic alicyclic group. Includes both hydrocarbon groups. However, it is not necessary to be composed only of the alicyclic structure, and a part thereof may include a chain structure. “Aromatic hydrocarbon group” refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may include a chain structure or an alicyclic structure.

R ⁵ is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoint of copolymerization of the monomer that gives the structural unit (I-1).

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^e1 , R ^e2 and R ^e3 include, for example, a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, and 1 to 3 carbon atoms. Valent alicyclic hydrocarbon group, monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the like.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms represented by R ^e1 , R ^e2 and R ^e3 include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, and an i-propyl group;
An alkenyl group such as an ethenyl group, a propenyl group, a butenyl group;
Examples thereof include alkynyl groups such as ethynyl group, propynyl group, and butynyl group. Among these, an alkyl group is preferable, an alkyl group having 1 to 4 carbon atoms is more preferable, a methyl group, an ethyl group, and an i-propyl group are further preferable, and an ethyl group is particularly preferable.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^e1 , R ^e2 and R ^e3 include monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group;
A monocyclic cycloalkenyl group such as a cyclopentenyl group and a cyclohexenyl group;
A polycyclic cycloalkyl group such as a norbornyl group, an adamantyl group and a tricyclodecyl group;
And polycyclic cycloalkenyl groups such as a norbornenyl group and a tricyclodecenyl group. Among these, a monocyclic cycloalkyl group and a polycyclic cycloalkyl group are preferable, and a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group are more preferable.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R ^e1 , R ^e2 and R ^e3 include a phenyl group, a tolyl group, a xylyl group, a mesityl group, a naphthyl group, a methylnaphthyl group, an anthryl group. Group, aryl group such as methylanthryl group;
Examples include aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, and anthrylmethyl group.

Examples of the alicyclic structure having 3 to 20 carbon atoms configured together with the carbon atom to which the groups of R ^e1 , R ^e2 and R ^e3 are combined with each other include a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, and a cyclohexane structure. A monocyclic cycloalkane structure such as a cycloheptane structure or a cyclooctane structure;
Examples thereof include polycyclic cycloalkane structures such as a norbornane structure, an adamantane structure, a tricyclodecane structure, and a tetracyclododecane structure. Among these, a monocyclic cycloalkane structure having 5 to 8 carbon atoms and a polycyclic cycloalkane structure having 7 to 12 carbon atoms are preferable, and a cyclopentane structure, cyclohexane structure, cyclooctane structure, norbornane structure and adamantane structure are preferable. More preferred are a cyclopentane structure and an adamantane structure.

R ^e2 and R ^e3 are preferably a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms.

R ⁶ is preferably a hydrogen atom from the viewpoint of the copolymerizability of the monomer giving the structural unit (I-2).

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include groups similar to those exemplified as the above R ^e1 , R ^e2 and R ^e3. It is done. Among these, an alkyl group is preferable, an alkyl group having 1 to 4 carbon atoms is more preferable, a methyl group, an ethyl group, and an n-propyl group are further preferable, and a methyl group is particularly preferable.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include groups similar to those exemplified as the above R ^e1 , R ^e2 and R ^e3. Can be mentioned. Among these, a monocyclic cycloalkyl group and a polycyclic cycloalkyl group are preferable, and a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group are more preferable.

Examples of the monovalent oxy-chain hydrocarbon group having 1 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, and n-butoxy. Group, i-butoxy group, sec-butoxy group, t-butoxy group, alkoxy group such as n-pentyloxy group;
Alkenyloxy groups such as ethenyloxy group, propenyloxy group, butenyloxy group, pentenyloxy group;
Examples include alkynyloxy groups such as ethynyloxy group, propynyloxy group, butynyloxy group, and pentynyloxy group. Among these, an alkoxy group is preferable, an alkoxy group having 1 to 4 carbon atoms is more preferable, and a methoxy group, an ethoxy group, and an n-propoxy group are further preferable.

Examples of the monovalent oxyalicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^e4 , R ^e5 and R ^e6 include a cyclopropyloxy group, a cyclobutyloxy group, a cyclopentyloxy group, a cyclohexyloxy group, A monocyclic cycloalkyloxy group such as a cyclooctyloxy group;
A polycyclic cycloalkyloxy group such as a norbornyloxy group, an adamantyloxy group, a tricyclodecyloxy group, a tetracyclododecyloxy group;
A monocyclic cycloalkenyloxy group such as a cyclopropenyloxy group, a cyclobutenyloxy group, a cyclopentenyloxy group, a cyclohexenyloxy group;
Examples thereof include polycyclic cycloalkenyloxy groups such as norbornenyloxy group and tricyclodecenyloxy group. Among these, a monocyclic cycloalkyloxy group and a polycyclic cycloalkyloxy group are preferable, and a cyclopentyloxy group, a cyclohexyloxy group, a norbornyloxy group, and an adamantyloxy group are more preferable.

Examples of the group represented by the formula (Y-2) include a group in which R ^e4 , R ^e5 and R ^e6 are monovalent chain hydrocarbon groups, and R ^e4 and R ^e5 are monovalent chain hydrocarbon groups. And R ^e6 is a monovalent oxy chain hydrocarbon group, and R ^e4 is a monovalent chain hydrocarbon group, and R ^e5 and R ^e6 are monovalent oxy chain hydrocarbon groups. , R ^e4 , R ^e5 and R ^e6 are alkyl groups, R ^e4 and R ^e5 are alkyl groups and R ^e6 is an alkoxy group, and R ^e4 is an alkyl group and R ^e5 and R ^e6 are alkoxy groups. A certain group is more preferable, a group in which R ^e4 , R ^e5 and R ^e6 are alkyl groups is further preferable, and a t-butyl group, a t-pentyl group, a t-hexyl group, and a t-heptyl group are particularly preferable.

As the structural unit (I), for example, as the structural unit (I-1), structural units represented by the following formulas (a-1-1) to (a-1-6) (hereinafter referred to as “structural unit (I) -1-1) to (I-1-6) ");
As the structural unit (I-2), structural units represented by the following formulas (a-2-1) to (a-2-3) (hereinafter, “structural units (I-2-1) to (I-2) -3) ")) and the like.

In the above formulas (a-1-1) to (a-1-6), R ⁵ has the same meaning as the above formula (a-1). R ^{e1 to} R ^e3 have the same ^{meaning as} in the above formula (Y-1). R ^e1 ′ to R ^e3 ′ are monovalent chain hydrocarbon groups having 1 to 10 carbon atoms. i and j are each independently an integer of 1 to 4.
In the formulas (a-2-1) to (a-2-3), R ⁶ has the same meaning as the formula (a-2).

  As the structural unit (I), structural units (I-1-1) to (I-1-5) and a structural unit (I-2-3) are preferable.

  Examples of the structural unit (I-1) include a structural unit represented by the following formula.

In said formula, R < ⁵ > is synonymous with the said Formula (a-1).

  As the structural unit (I), a structural unit derived from 1-alkyl-monocyclic cycloalkane-1-yl (meth) acrylate, a structure derived from 2-alkyl-polycyclic cycloalkane-2-yl (meth) acrylate Preferred are structural units derived from units and structural units derived from 2- (cycloalkane-yl) propan-2-yl (meth) acrylate, and structural units derived from 1-ethyl-cyclopentyl-1-yl (meth) acrylate , Structural unit derived from 2-methyl-adamantyl-2-yl (meth) acrylate, structural unit derived from 2-ethyl-adamantyl-2-yl (meth) acrylate, 2- (adamantanyl-yl) -propane-2 -Structural unit derived from yl (meth) acrylate, 2-cyclohexyl-propan-2-yl (meth) acryl Structural units derived from over preparative and 2-ethyl-2-tetracyclododecane-2-yl (meth) acrylate are more preferred.

  As a minimum of the content rate of structural unit (I), 10 mol% is preferable with respect to all the structural units which comprise a [A] polymer, 20 mol% is more preferable, 30 mol% is further more preferable, 35 mol% % Is particularly preferred. As an upper limit of the said content rate, 80 mol% is preferable, 75 mol% is more preferable, 70 mol% is further more preferable, 60 mol% is especially preferable. By making the content rate of structural unit (I) into the said range, the LWR performance of the said radiation sensitive resin composition etc. can be improved further.

[Structural unit (II)]
The structural unit (II) is a structural unit including a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof. [A] In addition to the structural unit (I), the polymer can further adjust the solubility in the developer by further including the structural unit (II). As a result, the radiation sensitive resin composition LWR performance and the like can be further improved. Moreover, the adhesiveness of the resist pattern formed from the said radiation sensitive resin composition and a board | substrate can be improved.

  Examples of the structural unit (II) include a structural unit represented by the following formula.

In the above formula, R ^L1 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

  As the structural unit (II), a structural unit having a lactone structure is preferable, a structural unit derived from lactone-yl (meth) acrylate is more preferable, and a structural unit derived from norbornanelactone-yl (meth) acrylate, 5-cyano -A structural unit derived from norbornanelactone-yl (meth) acrylate, a structural unit derived from oxynorbornanelactone-yl (meth) acrylate, and a structural unit derived from γ-butyrolactone-yl (meth) acrylate are more preferable.

  [A] When the polymer has the structural unit (II), the lower limit of the content ratio of the structural unit (II) is preferably 10 mol%, preferably 20 mol% with respect to the total structural units in the polymer [A]. Is more preferable, and 30 mol% is still more preferable. As an upper limit of the said content rate, 80 mol% is preferable, 70 mol% is more preferable, and 60 mol% is further more preferable. By making the content rate of structural unit (II) into the said range, the LWR performance of the said radiation sensitive resin composition etc. can be improved further. In addition, the adhesion between the obtained resist pattern and the substrate can be further improved.

[Structural unit (III)]
The structural unit (III) is a structural unit containing a phenolic hydroxyl group. In the case of using KrF excimer laser light, EUV, electron beam, etc. as the radiation to be irradiated in the exposure process in the resist pattern forming method, the sensitivity is further enhanced by having the structural unit (III) in the polymer [A]. Can do.

  Examples of the structural unit (III) include a structural unit represented by the following formula (a-3).

In said formula (a-3), R < ⁷ > is a hydrogen atom or a methyl group. R ⁸ is a monovalent organic group having 1 to 20 carbon atoms. p is an integer of 0-3. When p is 2 or 3, the plurality of R ⁸ may be the same or different. q is an integer of 1 to 3. However, p + q is 5 or less.

  “Organic group” refers to a group containing at least one carbon atom.

R ⁷ is preferably a hydrogen atom from the viewpoint of the copolymerizability of the monomer giving the structural unit (III).

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ⁸ include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and a monovalent alicyclic carbon group having 3 to 20 carbon atoms. A hydrogen group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a group in which part or all of the hydrogen atoms of these groups are substituted with a substituent, and carbon-carbon between these groups -, -CS-, -O-, -S- or -NR "-or a group containing a combination of two or more of these. R" is a hydrogen atom or a monovalent organic group. It is. Among these, a monovalent chain hydrocarbon group is preferable, an alkyl group is more preferable, and a methyl group is more preferable.

  As said p, the integer of 0-2 is preferable, 0 and 1 are more preferable, and 0 is further more preferable.

  As said q, 1 and 2 are preferable and 1 is more preferable.

  Examples of the structural unit (III) include structural units represented by the following formulas (a-3-1) to (a-3-4) (hereinafter referred to as “structural units (III-1) to (III-4)”). Also).

In the above formulas (a-3-1) to (a-3-4), R ⁷ has the same meaning as the above formula (a-3).

  As the structural unit (III), the structural unit (III-1) and the structural unit (III-2) are preferable, and the structural unit (III-1) is more preferable.

  [A] When the polymer has the structural unit (III), the lower limit of the content ratio of the structural unit (III) is preferably 10 mol% with respect to all the structural units constituting the [A] polymer. Mole% is more preferable, and 50 mol% is more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 80 mol% is more preferable, and 75 mol% is further more preferable. By making the content rate of structural unit (III) into the said range, the said radiation sensitive resin composition can further improve a sensitivity.

  In addition, the structural unit (III) is obtained by polymerizing a monomer in which the hydrogen atom of the —OH group of hydroxystyrene is substituted with an acetyl group or the like, and then subjecting the obtained polymer to hydrolysis reaction in the presence of a base such as an amine It can form by performing.

[Structural unit (IV)]
The structural unit (IV) is a structural unit containing an alcoholic hydroxyl group. [A] By having the structural unit (IV), the polymer can adjust the solubility in the developer more appropriately. As a result, the LWR performance of the radiation-sensitive resin composition is further improved. Can be made. In addition, the adhesion of the resist pattern to the substrate can be further improved.

  Examples of the structural unit (IV) include a structural unit represented by the following formula.

In the above formula, R ^L2 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

  As the structural unit (IV), a structural unit containing a hydroxyadamantyl group is preferable, and a structural unit derived from 3-hydroxyadamantyl (meth) acrylate is more preferable.

  [A] When a polymer has a structural unit (IV), as a minimum of the content rate of a structural unit (IV), 3 mol% is preferable with respect to all the structural units which comprise a [A] polymer, 5 Mole% is more preferable, and 10 mol% is more preferable. As an upper limit of the said content rate, 35 mol% is preferable, 30 mol% is more preferable, and 25 mol% is further more preferable. By making the content rate of structural unit (IV) into the said range, the LWR performance etc. of the said radiation sensitive resin composition can further be improved. In addition, the adhesion of the resist pattern to the substrate can be further enhanced.

[Other structural units]
[A] The polymer may have other structural units in addition to the structural units (I) to (IV). Examples of the other structural unit include a structural unit containing a ketonic carbonyl group, a cyano group, a carboxy group, a nitro group, an amino group or a combination thereof, and a non-dissociable monovalent alicyclic hydrocarbon group ( And structural units derived from (meth) acrylic acid esters. As an upper limit of the content rate of another structural unit, 20 mol% is preferable with respect to all the structural units which comprise a [A] polymer, and 10 mol% is more preferable.

  [A] The lower limit of the content of the polymer is preferably 70% by mass, more preferably 80% by mass, and still more preferably 85% by mass with respect to the total solid content of the radiation-sensitive resin composition. “Total solid content” refers to the sum of components other than the solvent [E] in the radiation-sensitive resin composition. The radiation sensitive resin composition may contain one or more [A] polymers.

<[A] Polymer Synthesis Method>
[A] The polymer can be synthesized, for example, by polymerizing monomers that give each structural unit in a suitable solvent using a radical polymerization initiator or the like.

Examples of the radical polymerization initiator include azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropyl). Azo radical initiators such as propionitrile), 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2′-azobisisobutyrate;
And peroxide radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, and the like. Of these, AIBN and dimethyl 2,2′-azobisisobutyrate are preferred, and AIBN is more preferred. These radical polymerization initiators can be used alone or in combination of two or more.

Examples of the solvent used for the polymerization include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane;
Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, norbornane;
Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene;
Halogenated hydrocarbons such as chlorobutane, bromohexane, dichloroethane, hexamethylene dibromide, chlorobenzene;
Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate;
Ketones such as acetone, methyl ethyl ketone, 4-methyl-2-pentanone, 2-heptanone;
Ethers such as tetrahydrofuran, dimethoxyethanes, diethoxyethanes;
Examples include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol. The solvent used for these polymerizations may be used alone or in combination of two or more.

  As a minimum of reaction temperature in superposition | polymerization, 40 degreeC is preferable and 50 degreeC is more preferable. As an upper limit of the said reaction temperature, 150 degreeC is preferable and 120 degreeC is more preferable. As a minimum of reaction time in superposition | polymerization, 1 hour is preferable and 2 hours is more preferable. The upper limit of the reaction time is preferably 48 hours, more preferably 24 hours.

  [A] The lower limit of the weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer is preferably 1,000, more preferably 2,000, still more preferably 2,500, 000 is particularly preferred. The upper limit of Mw is preferably 50,000, more preferably 30,000, still more preferably 20,000, and particularly preferably 15,000. [A] By making Mw of a polymer into the said range, the applicability | paintability and development defect inhibitory property of the said radiation sensitive resin composition improve.

  [A] The lower limit of the ratio (Mw / Mn) of Mw to the number average molecular weight (Mn) in terms of polystyrene by GPC of the polymer is usually 1 and preferably 1.1. As an upper limit of the ratio, 5 is preferable, 3 is more preferable, and 2 is more preferable.

Mw and Mn of the polymer in this specification are values measured using GPC under the following conditions.
GPC column: For example, two “G2000HXL”, one “G3000HXL” and one “G4000HXL” manufactured by Tosoh Corporation Column temperature: 40 ° C.
Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

<[B] Acid generator>
[B] The acid generator is a substance that generates an acid upon exposure. This generated acid dissociates the acid-dissociable group of the [A] polymer and the like to generate a carboxy group, a hydroxy group, and the like, and the solubility of the [A] polymer in the developer changes. A resist pattern can be formed from the conductive resin composition. In the radiation sensitive resin composition, the [B] acid generator is incorporated as a part of the polymer even in the form of a low molecular compound (hereinafter also referred to as “[B] acid generator” as appropriate). Either of these forms may be used.

  [B] Examples of the acid generator include onium salt compounds, N-sulfonyloxyimide compounds, sulfonimide compounds, halogen-containing compounds, and diazoketone compounds.

  Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like.

  [B] Specific examples of the acid generator include compounds described in paragraphs [0080] to [0113] of JP-A-2009-134088.

  [B] Examples of the acid generated from the acid generator include sulfonic acid, imidic acid, amide acid, methide acid, phosphinic acid, and carboxylic acid. Of these, sulfonic acid, imidic acid, amic acid and methide acid are preferred.

  Examples of the [B] acid generator include a compound represented by the following formula (2) (hereinafter also referred to as “[B1] acid generator”).

In the above formula (2), A ⁻ represents a monovalent sulfonate anion, a monovalent imido acid anion, a monovalent amidate anion, or a monovalent methide acid anion. Z ⁺ is a monovalent radiation-sensitive onium cation.

[B1] acid generator, A in the above formula (2) ^- If the sulfonate anion (hereinafter, "[B1a]" acid generator) also called), a sulfonic acid is generated. A ^- is the case of the imide anion (hereinafter, also referred to as "[B1b] acid generator"), imide acid produced. A ^- is the case of the amide anion (hereinafter, also referred to as "[B1c] acid generator"), an amide acid occurs. A ^- is the case of the methide anion (hereinafter, also referred to as "[B1d] acid generator"), methide acid is generated.

  [B1a] Examples of the acid generator include a compound represented by the following formula (2-1) (hereinafter also referred to as “compound (2-1)”). [B1] When the acid generator has the following structure, the diffusion length of the acid generated by exposure in the resist film is appropriately shortened due to the interaction with the structural unit (I) of the polymer [A]. As a result, the LWR performance and the like of the radiation sensitive resin composition can be further improved.

In the above formula (2-1), R ^p1 is a monovalent group containing a ring structure having 6 or more ring members. R ^p2 is a divalent linking group. R ^p3 and R ^p4 are each independently a hydrogen atom, a fluorine atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. R ^p5 and R ^p6 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. n ^p1 is an integer of 0 to 10. n ^p2 is an integer of 0 to 10. n ^p3 is an integer of 0 to 10. When n ^p1 is 2 or more, the plurality of R ^p2 may be the same or different. When n ^p2 is 2 or more, the plurality of R ^p3 may be the same or different, and the plurality of R ^p4 may be the same or different. When n ^p3 is 2 or more, the plurality of R ^p5 may be the same or different, and the plurality of R ^p6 may be the same or different. Z ⁺ has the same ^{meaning as} in the above formula (2).

Examples of the monovalent group including a ring structure having 6 or more ring members represented by R ^p1 include a monovalent group including an alicyclic structure having 6 or more ring members and an aliphatic heterocyclic structure having 6 or more ring members. A monovalent group, a monovalent group containing an aromatic ring structure having 6 or more ring members, a monovalent group containing an aromatic heterocyclic structure having 6 or more ring members, and the like.

Examples of the alicyclic structure having 6 or more ring members include monocyclic cycloalkane structures such as cyclohexane structure, cycloheptane structure, cyclooctane structure, cyclononane structure, cyclodecane structure, and cyclododecane structure;
Monocyclic cycloalkene structures such as cyclohexene structure, cycloheptene structure, cyclooctene structure, cyclodecene structure;
Polycyclic cycloalkane structures such as norbornane structure, adamantane structure, tricyclodecane structure and tetracyclododecane structure;
Examples thereof include polycyclic cycloalkene structures such as a norbornene structure and a tricyclodecene structure.

Examples of the aliphatic heterocyclic structure having 6 or more ring members include lactone structures such as a hexanolactone structure and a norbornane lactone structure;
Sultone structures such as hexanosultone structure and norbornane sultone structure;
An oxygen atom-containing heterocyclic structure such as an oxacycloheptane structure or an oxanorbornane structure;
Nitrogen atom-containing heterocyclic structures such as azacyclohexane structure and diazabicyclooctane structure;
Examples thereof include a sulfur atom-containing heterocyclic structure having a thiacyclohexane structure and a thianorbornane structure.

Examples of the aromatic ring structure having 6 or more ring members include a benzene structure, a naphthalene structure, a phenanthrene structure, and an anthracene structure.

Examples of aromatic heterocyclic structures having 6 or more ring members include oxygen atom-containing heterocyclic structures such as furan structures, pyran structures, and benzopyran structures;
Examples thereof include a nitrogen atom-containing heterocyclic structure such as a pyridine structure, a pyrimidine structure and an indole structure.

The lower limit of the number of ring members of the ring structure of R ^p1 is preferably 7, more preferably 8, more preferably 9, and particularly preferably 10. The upper limit of the number of ring members is preferably 15, more preferably 14, more preferably 13, and particularly preferably 12. By setting the number of ring members in the above range, the acid diffusion length can be further appropriately shortened, and as a result, the LWR performance and the like of the radiation-sensitive resin composition can be further improved.

A part or all of the hydrogen atoms ^{contained in} the ring structure of R ^p1 may be substituted with a substituent. Examples of the substituent include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, hydroxy group, carboxy group, cyano group, nitro group, alkoxy group, alkoxycarbonyl group, alkoxycarbonyloxy group, acyl group, Examples include an acyloxy group. Of these, a hydroxy group is preferred.

R ^p1 is preferably a monovalent group containing an alicyclic structure having 6 or more ring members and a monovalent group containing an aliphatic heterocyclic structure having 6 or more ring members, and 1 containing an alicyclic structure having 9 or more ring members. And a monovalent group containing an aliphatic heterocyclic structure having 9 or more ring members, an adamantyl group, a hydroxyadamantyl group, a norbornane lactone-yl group, a norbornane sultone-yl group, and 5-oxo-4-oxa A tricyclo [4.3.1.1 ^3,8 ] undecan-yl group is more preferred, and an adamantyl group is particularly preferred.

Examples of the divalent linking group represented by R ^p2 include a carbonyl group, an ether group, a carbonyloxy group, a sulfide group, a thiocarbonyl group, a sulfonyl group, and a divalent hydrocarbon group. Among these, a carbonyloxy group, a sulfonyl group, an alkanediyl group and a cycloalkanediyl group are preferred, a carbonyloxy group and a cycloalkanediyl group are more preferred, a carbonyloxy group and a norbornanediyl group are more preferred, and a carbonyloxy group is preferred. Particularly preferred.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^p3 and R ^p4 include an alkyl group having 1 to 20 carbon atoms. Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R ^p3 and R ^p4 include a fluorinated alkyl group having 1 to 20 carbon atoms. R ^p3 and R ^p4 are preferably a hydrogen atom, a fluorine atom and a fluorinated alkyl group, more preferably a fluorine atom and a perfluoroalkyl group, and still more preferably a fluorine atom and a trifluoromethyl group.

Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R ^p5 and R ^p6 include a fluorinated alkyl group having 1 to 20 carbon atoms. R ^p5 and R ^p6 are preferably a fluorine atom and a fluorinated alkyl group, more preferably a fluorine atom and a perfluoroalkyl group, still more preferably a fluorine atom and a trifluoromethyl group, and particularly preferably a fluorine atom.

The n ^p1, preferably an integer of 0 to 5, more preferably an integer of 0 to 3, more preferably an integer of 0 to 2, 0 and 1 are particularly preferred.

The n ^p2, preferably an integer of 0 to 5, more preferably an integer of 0 to 2, more preferably 0 and 1, 0 being particularly preferred.

As a minimum of ^np3 , 1 is preferable and 2 is more preferable. By setting n ^p3 to 1 or more, the strength of the acid generated from the compound (4) can be increased, and as a result, the LWR performance and the like of the radiation-sensitive resin composition can be further improved. The upper limit of n ^p3 is preferably 4, more preferably 3, and even more preferably 2.

The lower limit of n ^p1 + n ^p2 + n ^p3 is preferably 2, more preferably 3, and even more preferably 4. The upper limit of n ^p1 + n ^p2 + n ^p3 is preferably 30, more preferably 20, and even more preferably 10.

Examples of the monovalent radiation-sensitive onium cation represented by Z ⁺ include cations represented by the following formulas (Z-1) to (Z-3) (hereinafter referred to as “cations (Z-1) to (Z−)”. 3) ")) and the like.

In the formula (Z-1), R ^a1 , R ^a2 and R ^a3 each independently represent a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic group having 6 to 12 carbon atoms. family hydrocarbon group, two or more are combined with each other configured ring structure of either a -OSO ₂ -R ^P or _-SO 2 -R ^Q, or their groups. R ^P and R ^Q are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted carbon. It is an aromatic hydrocarbon group of formula 6-12. k1, k2 and k3 are each independently an integer of 0 to 5. R ^a1 to R ^a3 and when ^{R P} and ^{R Q} are a plurality each of the plurality of ^R a1 ^{to R a3} and ^{R P} and ^{R Q} may be the same as or different from each other.

In the above formula (Z-2), R ^a4 is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms. k4 is an integer of 0 to 7. If R ^a4 is plural, the plurality of R ^a4 may be the same or different, and plural R ^a4 may represent a constructed ring aligned with each other. R ^a5 is a substituted or unsubstituted alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms. k5 is an integer of 0-6. If R ^a5 is plural, the plurality of R ^a5 may be the same or different, and plural R ^a5 may represent a keyed configured ring structure. r is an integer of 0-3. R ^a6 is a single bond or a divalent organic group having 1 to 20 carbon atoms. t is an integer of 0-2.

In the above formula (Z-3), R ^a7 and R ^a8 are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon having 6 to 12 carbon atoms. group, or an -OSO ₂ -R ^R or _-SO 2 -R ^S, or two or more are combined with each other configured ring of these groups. R ^R and R ^S are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted carbon. It is an aromatic hydrocarbon group of formula 6-12. k6 and k7 are each independently an integer of 0 to 5. R ^{a7, R} a8, ^R when ^R and ^{R S} is plural respective plurality of ^{R a7,} R a8, ^{R R} and ^{R S} may be the same as or different from each other.

Examples of the alkyl group represented by R ^{a1 to} R ^a3 , R ^a4 , R ^a5 , R ^a7 and R ^a8 include linear alkyl groups such as a methyl group, an ethyl group, an n-propyl group, and an n-butyl group;
Examples thereof include branched alkyl groups such as i-propyl group, i-butyl group, sec-butyl group and t-butyl group.

Examples of the aromatic hydrocarbon group represented by R ^{a1 to} R ^a3 , R ^a4 and R ^a5 include aryl groups such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, and a naphthyl group;
Examples include aralkyl groups such as benzyl group and phenethyl group.

Examples of the aromatic hydrocarbon group represented by R ^a4 and R ^a5 include a phenyl group, a tolyl group, and a benzyl group.

Examples of the divalent organic group represented by R ^a6 include a group obtained by removing one hydrogen atom from the monovalent organic group represented by R ^{4 in} the above formula (a-3).

  Examples of the substituent for substituting the hydrogen atom of the alkyl group and aromatic hydrocarbon group include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, hydroxy group, carboxy group, cyano group, nitro group, alkoxy Group, alkoxycarbonyl group, alkoxycarbonyloxy group, acyl group, acyloxy group and the like. Among these, a halogen atom is preferable and a fluorine atom is more preferable.

R ^{a1 to} R ^a3 , R ^a4 , R ^a5 , R ^a7 and R ^a8 include an unsubstituted alkyl group, a fluorinated alkyl group, an unsubstituted monovalent aromatic hydrocarbon group, —OSO ₂ —R ″ and —SO ₂ —R ″ is preferable, a fluorinated alkyl group and an unsubstituted monovalent aromatic hydrocarbon group are more preferable, and a fluorinated alkyl group is further preferable. R ″ is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

  As k1, k2, and k3 in Formula (Z-1), integers of 0 to 2 are preferable, 0 and 1 are more preferable, and 0 is more preferable. As k4 in Formula (Z-2), an integer of 0 to 2 is preferable, 0 and 1 are more preferable, and 1 is more preferable. k5 is preferably an integer of 0 to 2, more preferably 0 and 1, and still more preferably 0. As r, 2 and 3 are preferable, and 2 is more preferable. As t, 0 and 1 are preferable, and 0 is more preferable. As k6 and k7 in Formula (Z-3), an integer of 0 to 2 is preferable, 0 and 1 are more preferable, and 0 is more preferable.

Among these, as Z ⁺ , a cation (Z-1) and a cation (Z-2) are preferable, and a triphenylsulfonium cation is more preferable.

  [B1a] Examples of the acid generator include compounds represented by the following formulas (2-1-1) to (2-1-15) (hereinafter referred to as “compounds (2-1-1) to (2-1-1-). 15) ")) and the like. [B1b] Examples of the acid generator include compounds represented by the following formulas (2-2-1) to (2-2-3) (hereinafter referred to as “compounds (2-2-1) to (2-2-2)”. 3) ")) and the like. [B1c] Examples of the acid generator include compounds represented by the following formulas (2-3-1) and (2-3-2) (hereinafter referred to as “compounds (2-3-1), (2-3)”. -2) "). [B1d] Examples of the acid generator include compounds represented by the following formulas (2-4-1) and (2-4-2) (hereinafter referred to as “compounds (2-4-1), (2-4)”). -2) ").

Formulas (2-1-1) to (2-1-15), (2-2-1) to (2-2-3), (2-3-1), (2-3-2), In (2-4-1) and (2-4-2), Z ⁺ is a monovalent radiation-sensitive onium cation.

  [B1] As the acid generator, [B1a] acid generator, [B1b] acid generator and [B1d] acid generator are preferable, and compounds (2-1-1) to (2-1-4) and ( 2-1-14), compound (2-2-1) and compound (2-4-2) are more preferred.

  [B1] The acid generator is preferably an onium salt compound, more preferably a sulfonium salt compound, and still more preferably a triphenylsulfonium salt compound.

  [B] The acid generator is also preferably a polymer in which the structure of an acid generator such as a polymer having a structural unit represented by the following formula (2-1 ') is incorporated as a part of the polymer. .

In the above formula (2-1 ′), R ^p7 is a hydrogen atom or a methyl group. L ⁴ is a single bond or —COO— or a divalent carbonyloxy hydrocarbon group. R ^p8 is a fluorinated alkanediyl group having 1 to 10 carbon atoms. Z ⁺ has the same ^{meaning as} in the above formula (2).

R ^p7 is preferably a hydrogen atom and a methyl group, and more preferably a methyl group, from the viewpoint of copolymerization of the monomer that gives the structural unit represented by the above formula (2-1 ′).

L ⁴ is preferably a divalent carbonyloxy hydrocarbon group, more preferably a carbonyloxyalkanediyl group or a carbonylalkanediylarenediyl group.

R ^p8 is preferably a fluorinated alkanediyl group having 1 to 4 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 4 carbon atoms, and still more preferably a hexafluoropropanediyl group.

  [B] When the acid generator is a [B] acid generator, the lower limit of the content of the [B] acid generator is preferably 0.1 parts by mass with respect to 100 parts by mass of the [A] polymer. 0.5 parts by mass is more preferable, 1 part by mass is further preferable, 5 parts by mass is particularly preferable, 10 parts by mass is further particularly preferable, and 15 parts by mass is most preferable. As an upper limit of the said content, 50 mass parts is preferable, 40 mass parts is more preferable, 30 mass parts is further more preferable, 25 mass parts is especially preferable.

  Moreover, as a minimum of content of [B] acid generator, 0.1 mass% is preferable with respect to solid content conversion, ie, the total solid of the said radiation sensitive resin composition, 0.5 mass% is preferable. More preferably, 1% by mass is further preferable, 5% by mass is particularly preferable, 10% by mass is further particularly preferable, and 15% by mass is most preferable. As an upper limit of the said content, 50 mass% is preferable, 40 mass% is more preferable, 30 mass% is further more preferable, 25 mass% is especially preferable.

  [B] By making content of an acid generator into the said range, the sensitivity and developability of the said radiation sensitive resin composition improve, As a result, LWR performance etc. can be improved. In particular, when the exposure light is an electron beam or EUV, from the viewpoint of further increasing the sensitivity of the radiation sensitive resin composition, the lower limit of the content of [B] acid generator is 100 parts by mass of [A] polymer. On the other hand, 10 mass parts is preferable, 15 mass parts is more preferable, and 18 mass parts is further more preferable. Moreover, as a minimum of content of [B] acid generator, 10 mass% is preferable with respect to the total solid of the said radiation sensitive resin composition, 15 mass parts is more preferable, and 18 mass parts is further more preferable. The radiation-sensitive resin composition may contain one or more [B] acid generators.

<[C] acid diffusion controller>
[C] the acid diffusion controller is a nitrogen atom and -COO ^- and a anion and a radiation-sensitive cation containing said in the anion -COO ^- is attached to a carbon atom, the carbon atom two more It is bonded to another atom with a double bond.

The radiation-sensitive resin composition contains a [C] acid diffusion control agent in addition to the [A] polymer and the [B] acid generator, so that LWR performance, resolution, and cross-sectional rectangularity are obtained. , Excellent in depth of focus, defect suppression and storage stability. The reason why the radiation-sensitive resin composition has the above-described configuration and thus exhibits the above-mentioned effects is not necessarily clear, but can be inferred as follows, for example. That, [C] an acid diffusion controller is a nitrogen atom in the anion, and -COO ^- by which the carbon atom bonded are further bound with another atom and double bond, -COO ^- of Charge is dispersed and basicity is moderately reduced. Also, [C] an acid diffusion control agent, such -COO ^- to have a specific structure having a nitrogen atom in the same molecule, compared with the radiation-sensitive resin composition containing a conventional acid diffusion control agent Thus, the amount used can be reduced. As a result, it is considered that the LWR performance, resolution, rectangularity of the cross-sectional shape and depth of focus of the radiation-sensitive resin composition are improved, and storage stability is also improved.

-COO ^- Other atoms in which the carbon atom bonded to double bonded to, for example a carbon atom, an oxygen atom, a sulfur atom, a nitrogen atom and a phosphorus atom. Among these, -COO ^- charge more dispersed, [C] From the viewpoint of basic acid diffusion control agent is reduced more moderately, carbon atoms, preferably an oxygen atom and a sulfur atom, a carbon atom and an oxygen atom Is more preferable.

-COO ^- The double bond between carbon atoms and other atoms bonded to the ethylenic C = C double bond in the aromatic ring C = C double bonds, C = O double bond, C = S double bond, C = N double bond, C = P double bond and the like can be mentioned. That, -COO ^- The structure in which the carbon atom bonded to constitute with other atoms, for example ethenediyl group, an aromatic ring, a carbonyl group, a thiocarbonyl group, an imino group, phosphaalkene diyl group and the like. Among these, the -COO- charge is further dispersed and the basicity of the [C] acid diffusion controller is further moderately reduced, so that the LWR performance and the storage stability of the radiation-sensitive resin composition are improved. From the viewpoint of further improvement, an aromatic ring and a carbonyl group are preferred.

Examples of the aromatic ring include aromatic carbocyclic rings such as a benzene ring, a naphthalene ring, and an anthracene ring;
Examples thereof include aromatic heterocycles such as pyridine ring, pyrrole ring, quinoline ring, indole ring, furan ring, pyran ring and thiophene ring. Among these, a benzene ring, a naphthalene ring, a pyridine ring and a quinoline ring are preferable, and a benzene ring and a pyridine ring are more preferable.

Examples of the [C] acid diffusion controller include compounds represented by the following formula (1) (hereinafter also referred to as “acid diffusion controller (C1)”). L ¹ has a carbon atom bonded to —COO ^— , and this carbon atom is bonded to another atom by a double bond. The radiation sensitive resin composition contains the acid diffusion control agent (C1) as the [C] acid diffusion control agent, so that the LWR performance and the storage stability are further improved.

In the above formula (1), ^{R 1} and ^{R 2} are each independently a monovalent organic group hydrogen atom or a C 1-20. L ¹ is a divalent organic group having 1 to 40 carbon atoms. Two or more of R ¹ , R ² and L ¹ may be combined with each other to form a ring structure having 3 to 20 ring members together with the nitrogen atom to which they are bonded. X ⁺ is a monovalent radiation-sensitive onium cation.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹ and R ² include a monovalent organic group having 1 to 20 carbon atoms represented by R ⁸ in the above formula (a-3). Examples include the same groups as the exemplified groups.

R ¹ and R ² include a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkyloxycarbonylalkyl group, a cycloalkyloxycarbonylalkyl group, a hydroxyalkyl group, a hydroxycycloalkyl group, an acyl group, and an alkoxy group. A carbonyl group, an alkylaminocarbonyl group, a cycloalkylaminocarbonyl group, an alkylaminothiocarbonyl group, a cycloalkylaminothiocarbonyl group, an alkylsulfonyl group and a cycloalkylsulfonyl group are preferred, a hydrogen atom, a methyl group, an ethyl group, and n-propyl. Group, i-propyl group, t-butyl group, adamantyl group, 1-methylcyclopentan-1-yloxycarbonylmethyl group, hydroxyethyl group, phenyl group, xylyl group, benzyl group, acetyl group, - butoxycarbonyl group, cyclohexylcarbonyl group, dimethylaminocarbonyl group, cyclohexylamino thiocarbonyl group, methylsulfonyl group and cyclopentylsulfonyl group.

Examples of the divalent organic group having 1 to 40 carbon atoms represented by L ¹ include a group obtained by removing one hydrogen atom from the monovalent organic group represented by R ^{4 in} the above formula (a-3). It is done. Of these, substituted and unsubstituted divalent hydrocarbon groups and substituted and unsubstituted divalent carbonyloxy hydrocarbon groups are preferred.

Examples of the ring structure formed by combining two or more of R ¹ , R ² and L ¹ include nitrogen atom-containing aliphatic heterocyclic structures such as an azacycloalkane structure and an azacycloalkene structure;
Examples thereof include a nitrogen atom-containing aromatic heterocyclic structure such as a pyridine structure, a quinoline structure, a thiazole structure, and an imidazole structure.

Examples of the monovalent radiation-sensitive onium cation represented by X ⁺ include cations similar to those exemplified as the monovalent radiation-sensitive onium cation represented by Z ⁺ of the [B] acid generator. Can be mentioned. Among these, cations (Z-1) to (Z-3) are preferable, and triphenylsulfonium cation, tolyldiphenylsulfonium cation, phenylsulfanylphenyldiphenylsulfonium cation, cyclohexylsulfonylphenyldiphenylsulfonium cation, t-butylphenyltetrahydrothio. Phenium cation, 4-n-butoxynaphthalen-1-yltetrahydrothiophenium cation, 4- (2-cyclopropylpropan-2-yloxycarbonylmethoxy) naphthalen-1-yltetrahydrothiophenium cation, 2-cyclohexyl Phenylcarbonylpropan-2-yltetrahydrothiophenium cation, diphenyliodonium cation and di (t-butylphenyl) iodonium kathi Down it is preferable.

  Examples of the acid diffusion controller (C1) include compounds represented by the following formula (1-1), (1-2), or (1-3) (hereinafter referred to as “acid diffusion controller (C1-1), ( C1-2) and (C1-3) ”), combinations of these compounds, and the like.

In the formula ^(1-1), R 1, ^{R 2} and ^{X +} is as defined in the above formula (1). L ² is a single bond or a divalent organic group having 1 to 10 carbon atoms. R ³ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, a hydroxy group, a sulfanyl group, or an amino group. n is an integer of 0-4. When n is 2 or more, the plurality of R ³ may be the same or different. ^Two or more of R ¹ , R ² , L ² and one or a plurality of R ³ may be combined with each other to form a ring structure having 3 to 20 ring members together with an atom or an atomic chain to which these are bonded.

In the above formula ^(1-2), R 1, ^{R 2} and ^{X +} is as defined in the above formula (1). L ³ is a single bond or a divalent organic group having 1 to 20 carbon atoms. Two or more of R ¹ , R ² and L ³ may be combined with each other to form a ring structure having 3 to 20 ring members together with the nitrogen atom to which they are bonded.

In the above formula (1-3), X ⁺ has the same meaning as in the above formula (1). R ⁴ is a C 1-8 monovalent hydrocarbon group, hydroxy group, sulfanyl group or amino group. m is an integer of 0-4. When m is 2 or more, the plurality of R ⁴ may be the same or different, and a ring structure having 4 to 20 ring members is formed together with a carbon chain in which two or more of the plurality of R ⁴ are combined with each other and bonded to each other. It may be formed.

Examples of the divalent organic group having 1 to 10 carbon atoms represented by L ² in the formula (1-1) include those having 1 to 10 carbon atoms among those exemplified as the divalent organic group of L ^1. Is mentioned. L ² is preferably a single bond, alkanediyl group or carbonyl fluorinated alkanediyl group, more preferably a single bond, methanediyl group or carbonyldifluoromethyl group, and even more preferably a single bond.

Examples of the monovalent hydrocarbon group having 1 to 6 carbon atoms represented by R ³ include 1 carbon atom among the hydrocarbon groups represented by R ^e1 , R ^e2 and R ^{e3 in} the above formula (Y-1). Group of -6, etc. are mentioned. R ³ is preferably a hydroxy group or an alkyl group, and more preferably a hydroxy group.

Examples of the ring structure having 3 to 20 ring members formed by two or more of R ¹ , R ² , L ² and one or a plurality of R ³ include alicyclic structures such as a cyclopentane structure and a cyclohexane structure;
Aromatic carbocyclic structures such as benzene and naphthalene structures;
Azacyclopentane structure, azacycloalkane structure such as azacyclohexane structure, diazacycloalkane structure such as diazacyclohexane structure, oxacycloalkane structure such as oxacyclopentane structure, oxacyclohexane structure, thiacyclopentane structure, thiacyclohexane structure Aliphatic heterocyclic structures such as thiacycloalkane structures;
Examples thereof include aromatic heterocyclic structures such as a pyridine structure, a pyrrole structure, a quinoline structure, a thiazole structure, and an imidazole structure. Among these, an aromatic carbocyclic structure, an aliphatic heterocyclic structure and an aromatic heterocyclic structure are preferable, and a benzene structure, an azacycloalkane structure, a diazacycloalkane structure, a thiazole structure and an imidazole structure are more preferable.

  As n, an integer of 0 to 2 is preferable, and 0 and 1 are more preferable.

Examples of the divalent organic group having 1 to 20 carbon atoms represented by L ³ in the formula (1-2) include the same groups as those exemplified as the divalent organic group of L ^2. . Examples of the ring structure having 3 to 20 ring members formed by two or more of R ¹ , R ² and L ³ include, for example, R ¹ , R ² , L ² and ^two of one or a plurality of R ³ Examples thereof include the ring structures similar to those exemplified as the ring structure formed above. Among these, an aromatic heterocyclic structure and an aliphatic heterocyclic structure are preferable, and a pyridine structure, a quinoline structure, and an azacycloalkane structure are more preferable.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ⁴ in the above formula (1-3) include hydrocarbon groups represented by R ^e1 , R ^e2 and R ^{e3 in} the above formula (Y-1). And the same groups as those exemplified above. R ⁴ is preferably a hydroxy group or an alkyl group, more preferably a hydroxy group.

Examples of the ring structure having 4 to 20 ring members formed by two or more of a plurality of R ⁴ include, for example, ^two or more of the above R ¹ , R ² , L ² and one or a plurality of R ^3. Among those exemplified as the ring structure, a ring structure having 4 to 20 ring members is exemplified. Among these, an aromatic carbocyclic structure is preferable, and a benzene structure is more preferable.

  As m, the integer of 0-2 is preferable and 0 and 1 are more preferable.

  Examples of the anion constituting the acid diffusion controller (C1-1) include anions represented by the following formulas.

  Examples of the anion constituting the acid diffusion controller (C1-2) include anions represented by the following formulas.

  Examples of the anion constituting the acid diffusion controller (C1-3) include anions represented by the following formulas.

  [C] The lower limit of the content of the acid diffusion controller is preferably 0.1 parts by weight, more preferably 0.5 parts by weight, and even more preferably 1 part by weight with respect to 100 parts by weight of the [A] polymer. 2 parts by mass is particularly preferred. As an upper limit of the said content, 30 mass parts is preferable, 20 mass parts is more preferable, 10 mass parts is further more preferable, and 5 mass parts is especially preferable. [C] By making content of an acid diffusion control agent into the said range, the LWR performance of the said radiation sensitive resin composition etc. and storage stability can further be improved. The radiation sensitive resin composition may contain one or more [C] acid diffusion control agents.

<[D] Polymer>
[D] The polymer is a polymer having a larger mass content of fluorine atoms than the [A] polymer. [D] Since the polymer has a higher mass content of fluorine atoms than the [A] polymer, its distribution tends to be unevenly distributed in the resist film surface layer when the resist film is formed due to its oil-repellent characteristics. is there. As a result, according to the radiation sensitive resin composition, it is possible to prevent the acid generator, the acid diffusion controller, and the like from being eluted into the immersion medium during the immersion exposure. Further, according to the radiation-sensitive resin composition, the forward contact angle between the resist film and the immersion medium can be controlled within a desired range due to the water-repellent characteristics of the [D] polymer, and bubble defects can be prevented from occurring. Can be suppressed. Furthermore, according to the radiation-sensitive resin composition, the receding contact angle between the resist film and the immersion medium is increased, and high-speed scanning exposure is possible without leaving water droplets. The radiation-sensitive resin composition can form a resist film suitable for the immersion exposure method by containing the [D] polymer as described above.

[D] The lower limit of the mass content of fluorine atoms in the polymer is preferably 1% by mass, more preferably 2% by mass, still more preferably 4% by mass, and particularly preferably 7% by mass. As an upper limit of the said mass content rate, 60 mass% is preferable, 50 mass% is more preferable, 40 mass% is further more preferable, 30 mass% is especially preferable. By making the mass content rate of a fluorine atom into the said range, [D] uneven distribution in the resist film of a polymer can be adjusted more appropriately. The mass content of fluorine atoms in the polymer can be calculated from the structure of the polymer obtained by ¹³ C-NMR spectrum measurement.

  [D] The fluorine atom content in the polymer is not particularly limited, and may be bonded to any of the main chain, side chain, and terminal, but is a structural unit containing a fluorine atom (hereinafter, “structural unit (F)”). It is preferable to have (also called). [D] In addition to the structural unit (F), the polymer preferably has a structural unit containing an acid-dissociable group from the viewpoint of improving development defect inhibition of the radiation-sensitive resin composition. Examples of the structural unit containing an acid dissociable group include the structural unit (I) in the [A] polymer.

  [D] The polymer preferably has an alkali dissociable group. [D] When the polymer has an alkali-dissociable group, the resist film surface can be effectively changed from hydrophobic to hydrophilic during alkali development, and the development defect suppression of the radiation-sensitive resin composition is further improved. To do. The “alkali dissociable group” is a group that replaces a hydrogen atom such as a carboxy group or a hydroxy group, and dissociates in an alkaline aqueous solution (for example, an aqueous 2.38 mass% tetramethylammonium hydroxide solution at 23 ° C.). Refers to the group.

  As the structural unit (F), a structural unit represented by the following formula (f-1) (hereinafter also referred to as “structural unit (F-1)”) and a structural unit represented by the following formula (f-2) (Hereinafter also referred to as “structural unit (F-2)”) is preferable. The structural unit (F) may have one or more structural units (F-1) and structural units (F-2).

[Structural unit (F-1)]
The structural unit (F-1) is a structural unit represented by the following formula (f-1). [D] A polymer can adjust the mass content of a fluorine atom by having a structural unit (F-1).

In the above formula (f-1), R ^A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. G is a single bond, an oxygen atom, a sulfur atom, —COO—, —SO ₂ ONH—, —CONH— or —OCONH—. R ^B is a monovalent fluorine-cycloaliphatic hydrocarbon group having a monovalent fluorinated chain hydrocarbon group or a 4 to 20 carbon atoms having 1 to 6 carbon atoms.

^RA is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoint of the copolymerizability of the monomer that provides the structural unit (F-1).

As G, —COO—, —SO ₂ ONH—, —CONH— and —OCONH— are preferable, and —COO— is more preferable.

The monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms represented by R ^B, such as trifluoromethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 2,2 , 3,3,3-pentafluoropropyl group, 1,1,1,3,3,3-hexafluoropropyl group, perfluoro n-propyl group, perfluoro i-propyl group, perfluoro n-butyl group, Examples include perfluoro i-butyl group, perfluoro t-butyl group, 2,2,3,3,4,4,5,5-octafluoropentyl group, perfluorohexyl group and the like.

The monovalent fluorine-cycloaliphatic hydrocarbon group having 4 to 20 carbon atoms represented by R ^B, for example, monofluoromethyl cyclopentyl group, difluorocyclopentyl groups, perfluorocyclopentyl group, monofluoromethyl cyclohexyl group, difluorocyclopentyl groups Perfluorocyclohexylmethyl group, fluoronorbornyl group, fluoroadamantyl group, fluorobornyl group, fluoroisobornyl group, fluorotricyclodecyl group, fluorotetracyclodecyl group and the like.

The R ^B, preferably a fluorinated chain hydrocarbon group, a 2,2,2-trifluoroethyl group and 1,1,1,3,3,3-hexafluoro-2-propyl group is more preferable, 1 1,1,3,3,3-hexafluoro-2-propyl group is more preferable.

  [D] When a polymer has a structural unit (F-1), as a minimum of the content rate of a structural unit (F-1), it is 3 mol% with respect to all the structural units which comprise a [D] polymer. Is preferable, and 5 mol% is more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 70 mol% is more preferable, and 50 mol% is further more preferable. By making the content rate of a structural unit (F-1) into the said range, the mass content rate of the fluorine atom of a [D] polymer can be adjusted further appropriately.

[Structural unit (F-2)]
The structural unit (F-2) is a structural unit represented by the following formula (f-2). [D] By having the structural unit (F-2), the polymer can adjust the mass content of fluorine atoms and change the resist film surface from water-repellent to hydrophilic before and after alkali development.

In the above formula (f-2), R ^C represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^D is an (s + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, or an oxygen atom, a sulfur atom, —NR′—, a carbonyl group, —COO—, or — at the terminal on the R ^E side of this hydrocarbon group. It is a structure in which CONH- is bonded. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^E is a single bond or a divalent organic group having 1 to 20 carbon atoms. W ¹ is a single bond or a divalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms. A ¹ is an oxygen atom, —NR ″ —, —COO— *, or —SO ₂ O— *. R ″ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. * Indicates a site binding to ^{R F.} R ^F is a hydrogen atom or a monovalent organic group having 1 to 30 carbon atoms. s is an integer of 1 to 3. However, when s is 1, ^RD may be a single bond. When s is 2 or 3, a plurality of R ^E , W ¹ , A ¹ and R ^F may be the same or different. When W ¹ is a single bond, R ^F is a group containing a fluorine atom.

As R ^C , a hydrogen atom and a methyl group are preferable, and a methyl group is more preferable from the viewpoint of copolymerizability of the monomer that gives the structural unit (F-2).

Examples of the (s + 1) -valent hydrocarbon group having 1 to 20 carbon atoms represented by ^RD include s hydrogen atoms from the monovalent hydrocarbon group exemplified as R ^{e1 in the} above formula (Y-1). Excluded groups and the like.

  As s, 1 and 2 are preferable and 1 is more preferable.

As ^RD , when s is 1, a single bond and a divalent hydrocarbon group are preferable, a single bond and an alkanediyl group are more preferable, a single bond and an alkanediyl group having 1 to 4 carbon atoms are more preferable, Bonds, methanediyl groups and propanediyl groups are particularly preferred.

The divalent organic group having 1 to 20 carbon atoms represented by R ^E is, for example, one hydrogen from the monovalent organic group having 1 to 20 carbon atoms exemplified as R ^{4 in the} above formula (a-3). Examples include groups other than atoms.

R ^E is preferably a group having a single bond and a lactone structure, more preferably a group having a single bond and a polycyclic lactone structure, and more preferably a group having a single bond and a norbornane lactone structure.

Examples of the divalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms represented by W ¹ include a fluoromethanediyl group, a difluoromethanediyl group, a fluoroethanediyl group, a difluoroethanediyl group, and a tetrafluoroethanediyl group. Fluorinated alkanediyl groups such as hexafluoropropanediyl group, octafluorobutanediyl group;
Examples thereof include fluorinated alkenediyl groups such as a fluoroethenediyl group and a difluoroethenediyl group. Among these, a fluorinated alkanediyl group is preferable, and a difluoromethanediyl group is more preferable.

The A ^1, an oxygen _{atom, -COO - *, - SO 2} O- * are preferable, -COO- * is more preferable.

The monovalent organic group having 1 to 30 carbon atoms represented by R ^F, for example, an alkali dissociative group, the acid-dissociable group, and the like hydrocarbon group having 1 to 30 carbon atoms. Of these, as R ^F , an alkali dissociable group is preferable. By the R ^F and alkali-labile group, upon alkali development, the resist film surface it is possible to effectively alter the hydrophilicity of hydrophobic, development defect suppression of the radiation-sensitive resin composition is further improved .

When R ^F is an alkali-dissociable group, R ^F is preferably a group represented by the following formulas (iii) to (v) (hereinafter also referred to as “groups (iii) to (v)”).

In the above formula (iii), R ^5a and R ^5b are each independently a monovalent organic group having 1 to 20 carbon atoms, or these groups are combined with each other to form a carbon atom to which they are bonded. Represents an alicyclic structure having 3 to 20 ring members.

In the above formula (iv), R ^5c and R ^5d are each independently a monovalent organic group having 1 to 20 carbon atoms, or these groups are combined with each other to form a nitrogen atom to which they are bonded. Represents a heterocyclic structure having 3 to 20 ring members.

In the above formula (v), R ^5e is a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms.

Examples of the monovalent organic group having 1 to 20 carbon atoms and the monovalent hydrocarbon group having 1 to 20 carbon atoms include the same groups as those exemplified as R ^{e1 in the} formula (Y-1). .

  As the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms, for example, part or all of the hydrogen atoms of the group exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms are substituted with fluorine atoms. And the like.

  As the group (iii), groups represented by the following formulas (iii-1) to (iii-4) (hereinafter also referred to as “groups (iii-1) to (iii-4)”) are represented by the group (iv) Is a group represented by the following formula (iv-1) (hereinafter also referred to as “group (iv-1)”), and the group (v) is represented by the following formulas (v-1) to (v-5): The groups represented (hereinafter also referred to as “groups (v-1) to (v-5)”) are preferable.

  Among these, group (v-3) and group (v-5) are preferable.

Moreover, it is preferable that ^RF is a hydrogen atom because the affinity of the [D] polymer for an alkaline developer is improved. In this case, when A ¹ is an oxygen atom and W ¹ is a 1,1,1,3,3,3-hexafluoro-2,2-methanediyl group, the affinity is further improved.

  [D] When a polymer has a structural unit (F-2), as a minimum of the content rate of a structural unit (F-2), it is 10 mol% with respect to all the structural units which comprise a [D] polymer. Is preferable, 20 mol% is more preferable, and 40 mol% is further more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 85 mol% is more preferable, and 80 mol% is further more preferable. By setting the content ratio of the structural unit (F-2) in the above range, the surface of the resist film formed from the radiation-sensitive resin composition can be more appropriately changed from water repellency to hydrophilicity before and after alkali development. .

  As a minimum of the content rate of a structural unit (F), 20 mol% is preferable with respect to all the structural units which comprise a [D] polymer, 30 mol% is more preferable, and 40 mol% is more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 85 mol% is more preferable, and 80 mol% is further more preferable.

  [D] The lower limit of the structural unit containing an acid dissociable group in the polymer is preferably 10 mol%, more preferably 15 mol%, and more preferably 20 mol% with respect to all the structural units constituting the [D] polymer. Is more preferable. As an upper limit of the said content rate, 60 mol% is preferable, 50 mol% is more preferable, and 40 mol% is further more preferable. By making the content rate of the structural unit containing an acid dissociable group into the said range, the development defect inhibitory property of the said radiation sensitive resin composition can further be improved.

  When the said radiation sensitive resin composition contains a [D] polymer, as a minimum of content of a [D] polymer, 0.1 mass part is preferable with respect to 100 mass parts of [A] polymers. 0.2 parts by mass is more preferable, 0.5 parts by mass is further preferable, and 1 part by mass is particularly preferable. As an upper limit of the said content, 30 mass parts is preferable, 20 mass parts is more preferable, 15 mass parts is further more preferable, and 10 mass parts is especially preferable. The radiation sensitive resin composition may contain one or more [D] polymers.

  The [D] polymer can be synthesized by the same method as the above-described [A] polymer.

  [D] The lower limit of Mw by GPC of the polymer is preferably 1,000, more preferably 2,000, further preferably 2,500, and particularly preferably 3,000. The upper limit of Mw is preferably 50,000, more preferably 30,000, still more preferably 20,000, and particularly preferably 15,000. [D] By making Mw of a polymer into the said range, the applicability | paintability and development defect inhibitory property of the said radiation sensitive resin composition improve.

  [D] The lower limit of the ratio of Mw to Mn (Mw / Mn) by GPC of the polymer is usually 1 and preferably 1.2. As an upper limit of the ratio, 5 is preferable, 3 is more preferable, and 2 is more preferable.

<[E] solvent>
The radiation-sensitive resin composition usually contains an [E] solvent. [E] The solvent may be a solvent that can dissolve or disperse at least the [A] polymer, the [B] acid generator, the [C] acid diffusion controller, and the [D] polymer contained as necessary. If it does not specifically limit.

  [E] Examples of the solvent include alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, hydrocarbon solvents, and the like.

Examples of the alcohol solvent include aliphatic monoalcohol solvents having 1 to 18 carbon atoms such as 4-methyl-2-pentanol and n-hexanol;
An alicyclic monoalcohol solvent having 3 to 18 carbon atoms such as cyclohexanol;
A C2-C18 polyhydric alcohol solvent such as 1,2-propylene glycol;
Examples thereof include C3-C19 polyhydric alcohol partial ether solvents such as propylene glycol monomethyl ether.

Examples of ether solvents include dialkyl ether solvents such as diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, diisoamyl ether, dihexyl ether, and diheptyl ether;
Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;
And aromatic ring-containing ether solvents such as diphenyl ether and anisole.

Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, 2-heptanone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, Chain ketone solvents such as di-iso-butyl ketone and trimethylnonanone:
Cyclic ketone solvents such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone and methylcyclohexanone:
2,4-pentanedione, acetonylacetone, acetophenone and the like can be mentioned.

Examples of the amide solvent include cyclic amide solvents such as N, N′-dimethylimidazolidinone and N-methylpyrrolidone;
Examples thereof include chain amide solvents such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, and N-methylpropionamide.

Examples of ester solvents include monocarboxylic acid ester solvents such as n-butyl acetate and ethyl lactate;
Polyhydric alcohol carboxylate solvents such as propylene glycol acetate;
Polyhydric alcohol partial ether carboxylate solvents such as propylene glycol monomethyl ether acetate;
Polycarboxylic acid diester solvents such as diethyl oxalate;
lactone solvents such as γ-butyrolactone and δ-valerolactone;
Examples thereof include carbonate solvents such as dimethyl carbonate, diethyl carbonate, ethylene carbonate, and propylene carbonate.

Examples of the hydrocarbon solvent include aliphatic hydrocarbon solvents having 5 to 12 carbon atoms such as n-pentane and n-hexane;
Examples thereof include aromatic hydrocarbon solvents having 6 to 16 carbon atoms such as toluene and xylene.

  [E] As the solvent, ester solvents and ketone solvents are preferable, polyhydric alcohol partial ether carboxylate solvents and cyclic ketone solvents are more preferable, polyhydric alcohol partial alkyl ether acetates and cycloalkanones are more preferable, Propylene glycol monomethyl ether acetate and cyclohexanone are particularly preferred. The radiation-sensitive resin composition may contain one or more [E] solvents.

<[G] Other acid diffusion controller>
[G] The other acid diffusion controller is an acid diffusion controller other than the [C] acid diffusion controller. [G] The other acid diffusion controller controls the diffusion phenomenon of the acid generated from the acid generator [B] upon exposure in the resist film. As a result, there is an effect of suppressing an undesirable chemical reaction in the unexposed area. Moreover, the storage stability of the radiation sensitive resin composition is further improved. In addition, the resolution of the radiation-sensitive resin composition is further improved, and changes in the line width of the resist pattern due to fluctuations in the holding time from exposure to development processing can be suppressed, and radiation sensitivity with excellent process stability. A resin composition is obtained. [G] The content of the other acid diffusion controller in the radiation-sensitive resin composition may be a low molecular weight compound (hereinafter referred to as “[G] other acid diffusion controller” as appropriate). May be incorporated as a part of or both of these forms. [G] Other acid diffusion controllers may be used singly or in combination of two or more.

  [G] Other acid diffusion control agents include, for example, a compound represented by the following formula (3) (hereinafter also referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule ( Hereinafter, also referred to as “nitrogen-containing compound (II)”, compounds having three nitrogen atoms (hereinafter also referred to as “nitrogen-containing compound (III)”), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, etc. Is mentioned.

In the above formula (3), R ⁹ , R ¹⁰ and R ¹¹ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group or A substituted or unsubstituted aralkyl group;

  Examples of the nitrogen-containing compound (I) include monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine and tri-n-pentylamine; and fragrances such as aniline Group amines and the like.

  Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, and the like.

  Examples of the nitrogen-containing compound (III) include polyamine compounds such as polyethyleneimine and polyallylamine; polymers such as dimethylaminoethylacrylamide.

  Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like. It is done.

  Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tributylthiourea and the like.

  Examples of the nitrogen-containing heterocyclic compound include pyridines such as pyridine and 2-methylpyridine; morpholines such as N-propylmorpholine and N- (undecan-1-ylcarbonyloxyethyl) morpholine; pyrazine, pyrazole and the like. .

  Moreover, the compound which has an acid dissociable group can also be used as a nitrogen-containing compound. Examples of the nitrogen-containing compound having such an acid dissociable group include Nt-butoxycarbonylpiperidine, Nt-butoxycarbonylimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2- Phenylbenzimidazole, N- (t-butoxycarbonyl) di-n-octylamine, N- (t-butoxycarbonyl) diethanolamine, N- (t-butoxycarbonyl) dicyclohexylamine, N- (t-butoxycarbonyl) diphenylamine, Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-amyloxycarbonyl-4-hydroxypiperidine and the like can be mentioned.

  Among these, nitrogen-containing heterocyclic compounds are preferable, morpholines are more preferable, and N- (undecan-1-ylcarbonyloxyethyl) morpholine is more preferable.

  [G] As another acid diffusion controller, a photodegradable base that is exposed to light upon exposure to generate a weak acid can also be used. Examples of the photodegradable base include onium salt compounds that lose acid diffusion controllability by being decomposed by exposure (except for those corresponding to [C] acid diffusion control agents).

  Examples of onium salt compounds include triphenylsulfonium salicylate, 4-cyclohexylphenyldiphenylsulfonium salicylate, triphenylsulfonium acetylacetate, triphenylsulfonium 2,4,6-tri-propylbenzenesulfonate, triphenylsulfonium 10 -Camphorsulfonate, triphenylsulfonium 1-cyclohexylbutane-1,3-dione-2-ate and the like. Among these, 4-cyclohexylphenyldiphenylsulfonium salicylate, triphenylsulfonium acetylacetate, triphenylsulfonium 2,4,6-trii-propylbenzenesulfonate, triphenylsulfonium 10-camphorsulfonate, and triphenylsulfonium 1- Cyclohexylbutane-1,3-dione-2-ate is preferred, and 4-cyclohexylphenyldiphenylsulfonium salicylate and triphenylsulfonium 1-cyclohexylbutane-1,3-dione-2-ate are more preferred.

  When the said radiation sensitive resin composition contains [G] other acid diffusion control agents, as a minimum of content of [G] other acid diffusion control agents, with respect to 100 mass parts of [A] polymers. 0.1 parts by mass is preferable, 0.3 parts by mass is more preferable, 0.5 parts by mass is further preferable, and 1 part by mass is particularly preferable. As an upper limit of the said content, 20 mass parts is preferable, 15 mass parts is more preferable, 10 mass parts is further more preferable, and 5 mass parts is especially preferable.

  Moreover, as a minimum of content of [G] other acid diffusion control agents, 10 mass parts is preferable with respect to 100 mass parts of [C] acid diffusion control agents, 20 mass parts is more preferable, and 25 mass parts is. Further preferred. As an upper limit of the said content, 95 mass parts is preferable, 90 mass parts is more preferable, and 85 mass parts is further more preferable.

<Other optional components>
The said radiation sensitive resin composition may contain other arbitrary components other than the said [A]-[G] component. Examples of other optional components include surfactants, alicyclic skeleton-containing compounds, and sensitizers. Each of these other optional components may be used alone or in combination of two or more.

[Surfactant]
Surfactants have the effect of improving coatability, striation, developability, and the like. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol diacrylate. Nonionic surfactants such as stearate; commercially available products include “KP341” from Shin-Etsu Chemical Co., Ltd., “Polyflow No.75” and “No.95” from Kyoeisha Chemical Co., Ltd., “F-Top” from Tochem Products EF301, EF303, EF352, DIC's "MegaFuck F171", "F173", Sumitomo 3M's "Florard FC430", "FC431", Asahi Glass Industry's "Asahi Guard AG71""SurflonS-382","SC-101","SC-102","SC-103","SC-104","SC-105","SC-106" Etc. The upper limit of the content of the surfactant is preferably 2 parts by mass and more preferably 1 part by mass with respect to 100 parts by mass of the [A] polymer.

[Alicyclic skeleton-containing compound]
The alicyclic skeleton-containing compound has an effect of improving dry etching resistance, pattern shape, adhesion to the substrate, and the like.

[Sensitizer]
A sensitizer exhibits the effect | action which increases the production amount of the acid from a [B] acid generator etc., and there exists an effect which improves the "apparent sensitivity" of the said radiation sensitive resin composition.

  Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines and the like. These sensitizers may be used alone or in combination of two or more. As an upper limit of content of a sensitizer, 2 mass parts is preferable with respect to 100 mass parts of [A] polymer, and 1 mass part is more preferable.

<Method for preparing radiation-sensitive resin composition>
The radiation sensitive resin composition includes, for example, [A] polymer, [B] acid generator, [C] acid diffusion controller, [D] polymer contained as necessary, [E] solvent, and others. Can be prepared by, for example, filtering the obtained mixed solution with a filter having a pore size of about 0.2 μm, for example. As a minimum of solid content concentration of the radiation sensitive resin composition, 0.1 mass% is preferred, 0.5 mass part is more preferred, and 1 mass% is still more preferred. As an upper limit of the said solid content concentration, 50 mass% is preferable, 30 mass% is more preferable, and 20 mass% is further more preferable.

  The radiation-sensitive resin composition can be used for forming a positive pattern using an alkaline developer and for forming a negative pattern using a developer containing an organic solvent. Among these, when used for forming a negative pattern using a developer containing an organic solvent, the radiation-sensitive resin composition can exhibit higher resolution.

<Resist pattern formation method>
The resist pattern forming method includes a step of forming a resist film (hereinafter also referred to as “resist film forming step”), a step of exposing the resist film (hereinafter also referred to as “exposure step”), and the exposed resist. A step of developing the film (hereinafter also referred to as “developing step”). In the resist pattern forming method, the resist film is formed from the radiation-sensitive resin composition.

  According to the resist pattern forming method, since the radiation-sensitive resin composition described above is used, LWR performance, CDU performance, resolution, and cross-sectional rectangular shape while exhibiting excellent depth of focus and MEEF performance. A resist pattern having excellent properties can be formed. Hereinafter, each step will be described.

[Resist film forming step]
In this step, a resist film is formed from the radiation sensitive resin composition. Examples of the substrate on which the resist film is formed include a silicon wafer and a wafer coated with aluminum. A resist film is formed by applying the radiation sensitive resin composition on the substrate. The method for applying the radiation-sensitive resin composition is not particularly limited, and examples thereof include known methods such as a spin coating method. When applying the radiation sensitive resin composition, the amount of the radiation sensitive resin composition to be applied is adjusted so that the formed resist film has a desired thickness. In addition, after apply | coating the said radiation sensitive resin composition on a board | substrate, in order to volatilize a solvent, you may perform soft baking (henceforth "SB"). As a minimum of the temperature of SB, 30 degreeC is preferable and 50 degreeC is more preferable. As an upper limit of the said temperature, 200 degreeC is preferable and 150 degreeC is more preferable. The lower limit of the SB time is preferably 10 seconds, and more preferably 30 seconds. The upper limit of the time is preferably 600 seconds, and more preferably 300 seconds. The lower limit of the average thickness of the resist film is preferably 10 nm, and more preferably 20 nm. The upper limit of the average thickness is preferably 1,000 nm, and more preferably 200 nm.

[Exposure process]
In this step, the resist film formed in the resist film forming step is exposed. In some cases, this exposure is performed by irradiating with radiation through a mask having a predetermined pattern through an immersion exposure liquid such as water.

  As the immersion exposure liquid, a liquid having a refractive index larger than that of air is usually used. Specific examples include pure water, long-chain or cyclic aliphatic compounds, and the like. In this state through the immersion exposure liquid, that is, in a state where the immersion exposure liquid is filled between the lens and the resist film, the exposure apparatus irradiates radiation, and the resist film is formed through a mask having a predetermined pattern. Exposure.

  The radiation is appropriately selected from visible rays, ultraviolet rays, far ultraviolet rays, X-rays, charged particle beams and the like according to the type of the radiation-sensitive acid generator to be used. Among these, ArF excimer is used. Far ultraviolet rays such as laser light (wavelength 193 nm) and KrF excimer laser light (wavelength 248 nm) are preferred, and ArF excimer laser light (wavelength 193 nm) is more preferred. In addition, exposure conditions, such as exposure amount, can be suitably selected according to the compounding composition of the resist composition for immersion exposure, the kind of additive, etc.

  It is preferable to perform a heat treatment (hereinafter also referred to as “post-exposure baking (PEB)”) on the resist film after exposure. By this PEB, the dissociation reaction of an acid dissociable group such as the [A] polymer can be smoothly advanced. The heating conditions for PEB are appropriately adjusted depending on the composition of the radiation sensitive resin composition, but the lower limit of the PEB temperature is preferably 30 ° C, more preferably 50 ° C, and even more preferably 60 ° C. As an upper limit of the said temperature, 200 degreeC is preferable, 150 degreeC is more preferable, and 120 degreeC is further more preferable. The lower limit of the PEB time is preferably 10 seconds, more preferably 30 seconds. The upper limit of the time is preferably 600 seconds, and more preferably 300 seconds.

  In order to maximize the potential of the radiation-sensitive resin composition, for example, as disclosed in Japanese Patent Publication No. 6-12452, Japanese Patent Application Laid-Open No. 59-93448, etc., on the substrate to be used. An organic or inorganic antireflection film can also be formed. In order to prevent the influence of basic impurities contained in the ambient atmosphere, a protective film can be provided on the resist film as disclosed in, for example, Japanese Patent Laid-Open No. 5-188598.

[Development process]
In this step, the resist film exposed in the exposure step is developed. Examples of the developer used for the development include an aqueous alkali solution (alkaline developer) and a solution containing an organic solvent (organic solvent developer). Thereby, a predetermined resist pattern is formed.

  Examples of the alkali developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine. , Ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4 .3.0] -5 aqueous solution in which at least one alkaline compound such as 5-nonene is dissolved. In these, a TMAH aqueous solution is preferable and a 2.38 mass% TMAH aqueous solution is more preferable.

  Examples of the organic solvent developer include organic solvents such as hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, alcohol solvents, and liquids containing organic solvents. Examples of the organic solvent include one or more of the solvents exemplified as the [E] solvent of the above-described radiation-sensitive resin composition. Among these, ester solvents and ketone solvents are preferable. As the ester solvent, an acetate solvent is preferable, and n-butyl acetate is more preferable. As the ketone solvent, a chain ketone is preferable, and 2-heptanone is more preferable. The lower limit of the content of the organic solvent in the organic solvent developer is preferably 80% by mass, more preferably 90% by mass, further preferably 95% by mass, and particularly preferably 99% by mass. Examples of components other than the organic solvent in the organic solvent developer include water and silicone oil.

  These developers may be used alone or in combination of two or more. In general, after development, the substrate is washed with water or the like and dried.

<Acid diffusion control agent>
The acid diffusion control agent is a nitrogen atom and -COO ^- and a anion and a radiation-sensitive cation containing said in the anion -COO ^- is attached to a carbon atom, the carbon atoms are more double bonds It is an acid diffusion controller bonded to other atoms. Since the acid diffusion control agent has the above-mentioned properties, it can be suitably used as an acid diffusion control agent component of the radiation-sensitive resin composition. The LWR performance, resolution, The rectangularity of the cross-sectional shape, defect suppression, depth of focus and storage stability can be improved.

<Compound>
The compounds, nitrogen atom and -COO ^- and a anion and a radiation-sensitive cation containing said in the anion -COO ^- is attached to a carbon atom, other at the carbon atoms are more double bonds A compound that is bonded to an atom. The compound can be suitably used as the acid diffusion controller.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The measuring method of various physical property values is shown below.

[Mw, Mn and Mw / Mn]
Mw and Mn of the polymer were measured by GPC using Tosoh's GPC columns ("G2000HXL", "G3000HXL" and "G4000HXL") under the following conditions. Mw / Mn was calculated from the measurement results of Mw and Mn.

Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Column temperature: 40 ° C
Detector: Differential refractometer Standard material: Monodisperse polystyrene

[ ¹³ C-NMR analysis]
The ¹³ C-NMR analysis for determining the content ratio of each structural unit of the polymer was measured using a nuclear magnetic resonance apparatus (“JNM-ECX400” manufactured by JEOL Ltd.) and using deuterated chloroform as a measurement solvent.

<Synthesis of polymer>
The monomers used for the synthesis of [A] polymer and [D] polymer are shown below.

[[A] Synthesis of polymer]
[Synthesis Example 1]
9.38 g (50 mol%) of compound (M-1) and 10.62 g (50 mol%) of compound (M-8) are dissolved in 40 g of 2-butanone, and azobisisobutyroyl as a radical polymerization initiator is further dissolved. Nitrile (AIBN) 0.785 g (5 mol% based on the total amount of monomers) was dissolved to prepare a monomer solution. Next, a 200 mL three-necked flask containing 20 g of 2-butanone was heated to 80 ° C. with stirring in a nitrogen atmosphere, and the prepared monomer solution was added dropwise over 3 hours. After completion of the dropwise addition, the polymerization reaction was carried out by heating at 80 ° C. for 3 hours. After completion of the polymerization reaction, the polymerization reaction solution was cooled to room temperature, poured into 300 g of methanol, and the precipitated solid was separated by filtration. The solid separated by filtration was washed twice with 60 mL of methanol, filtered, and then dried under reduced pressure at 50 ° C. for 15 hours to synthesize polymer (A-1) (yield 15.8 g, yield 78.9). %). Mw of the polymer (A-1) was 6,100, and Mw / Mn was 1.41. As a result of ¹³ C-NMR analysis, the content ratios of structural units derived from (M-1) and (M-8) were 49.8 mol% and 50.2 mol%, respectively.

[Synthesis Examples 2 to 7]
Polymers (A-2) to (A-7) were synthesized by performing the same operations as in Synthesis Example 1 except that the types and amounts of monomers shown in Table 1 were used. The yield (%), Mw, Mw / Mn, and the content ratio (mol%) of each structural unit are shown in Table 1 below.

[Synthesis Example 8] Synthesis of Polymer (A-8) Compound (M-15) 45.24 g (50 mol%), Compound (M-1) 54.76 g (50 mol%), as a radical polymerization initiator After dissolving 4.58 g of AIBN (5 mol% based on the total amount of monomers) and 1,14 g of t-dodecyl mercaptan in 100 g of propylene glycol monomethyl ether, the reaction temperature was maintained at 70 ° C. in a nitrogen atmosphere. The polymerization reaction was performed for 16 hours. After completion of the polymerization reaction, the polymerization reaction solution was dropped into 1,000 g of n-hexane for coagulation purification, and then 150 g of propylene glycol monomethyl ether was added again to the obtained solid, and further 150 g of methanol, 34 g of triethylamine and 6 g of water. And a hydrolysis reaction was performed for 8 hours while refluxing at the boiling point. After completion of the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the resulting solid was dissolved in 150 g of acetone, then dropped into 2,000 g of water to solidify, and the resulting solid was filtered and filtered at 50 ° C. for 17 hours. By drying, a white powdery polymer (A-8) was obtained (yield 63.8 g, yield 72.3%). Mw of the polymer (A-8) was 6,400, and Mw / Mn was 1.72. As a result of ¹³ C-NMR analysis, the content ratios of the p-hydroxystyrene unit and the structural unit derived from (M-1) were 51.2 mol% and 48.8 mol%, respectively.

[[D] Synthesis of polymer]
[Synthesis Example 9]
21.5 g (70 mol%) of the compound (M-16) and 8.5 g (30 mol%) of the compound (M-17) were dissolved in 20 g of 2-butanone, and further 1.38 g (single unit) of AIBN as a radical polymerization initiator. A monomer solution was prepared by dissolving 5 mol%) with respect to the total amount of the monomer. Next, a 100 mL three-necked flask containing 10 g of 2-butanone was heated to 80 ° C. with stirring in a nitrogen atmosphere, and the prepared monomer solution was added dropwise over 3 hours. After completion of the dropwise addition, the polymerization reaction was carried out by heating at 80 ° C. for 3 hours. After completion of the polymerization reaction, the polymerization reaction solution was cooled to room temperature. After transferring the polymerization reaction liquid to a separatory funnel, the polymerization reaction liquid was uniformly diluted with 45 g of n-hexane, and 180 g of methanol was added and mixed. Next, 9 g of distilled water was added, and the mixture was further stirred and allowed to stand for 30 minutes. Next, the lower layer was recovered, and the solvent was replaced with propylene glycol monomethyl ether acetate to obtain a propylene glycol monomethyl ether acetate solution containing the polymer (D-1) (yield 60.0%). Mw of the polymer (D-1) was 7,200, and Mw / Mn was 2.00. As a result of ¹³ C-NMR analysis, the content ratios of structural units derived from (M-16) and (M-17) were 71.1 mol% and 28.9 mol%, respectively.

<Preparation of radiation-sensitive resin composition>
[B] acid generator, [C] acid diffusion control agent, and [E] solvent used for preparation of the radiation sensitive resin composition are shown below.

[[B] acid generator]
Compounds represented by the following formulas (B-1) to (B-7).

[[C] acid diffusion controller]
Examples: Compounds represented by the following formulas (C-1) to (C-16).
Comparative Example: Compounds represented by the following formulas (CC-1) to (CC-6).

[[E] solvent]
E-1: Propylene glycol monomethyl ether acetate E-2: Cyclohexanone E-3: γ-butyrolactone

[Preparation of radiation-sensitive resin composition for ArF exposure]
[Example 1]
[A] 100 parts by weight of (A-1) as a polymer, 7.9 parts by weight of (B-1) as an acid generator [B], [C] (C-1) 1 as an acid diffusion controller .6 parts by weight, (D-1) 3.0 parts by weight as a polymer, and (E-1) 2,240 parts by weight as (E) solvent, (E-2) 960 parts by weight and (E-3) 30 parts by mass was mixed, and the resulting mixed solution was filtered with a filter having a pore size of 0.20 μm to prepare a radiation sensitive resin composition (J-1).

[Examples 2 to 30 and Comparative Examples 1 to 8]
Except having used each component of the kind and content shown in the following Table 2 and Table 3, it operated similarly to Example 1 and the radiation sensitive resin composition (J-2)-(J-30) and ( CJ-1) to (CJ-8) were prepared.

<Formation of resist pattern (1)>
A 12-inch silicon wafer surface was coated with a composition for forming a lower antireflection film (“ARC66” from Brewer Science) using a spin coater (“CLEAN TRACK ACT12” from Tokyo Electron), and then 205 ° C. Was heated for 60 seconds to form a lower antireflection film having an average thickness of 105 nm. On the lower antireflection film, each of the prepared radiation sensitive resin compositions was applied using the spin coater, and PB was performed at 90 ° C. for 60 seconds. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with an average thickness of 90 nm. Next, this resist film was subjected to an optical condition of NA = 1.3 and dipole (Sigma 0.977 / 0.782) using an ArF excimer laser immersion exposure apparatus (“NSR-S610C” manufactured by NIKON). , Exposed through a 40 nm line and space (1L1S) mask pattern. After the exposure, PEB was performed at 90 ° C. for 60 seconds. Thereafter, the resist was alkali-developed using a 2.38 mass% TMAH aqueous solution as an alkali developer, washed with water, and dried to form a positive resist pattern. When this resist pattern is formed, the exposure amount when the pattern formed through a one-to-one line and space mask with a target dimension of 40 nm is formed into a one-to-one line and space with a line width of 40 nm is the optimum exposure amount. It was.

<Formation of resist pattern (2)>
A negative resist pattern was prepared in the same manner as in the above resist pattern formation (1) except that n-butyl acetate was used instead of the TMAH aqueous solution and the organic solvent was developed, and washing with water was not performed. Formed.

<Evaluation>
About each formed said resist pattern, the LWR performance of the radiation sensitive resin composition, the resolution, the rectangularity of a cross-sectional shape, the depth of focus, and defect inhibitory property were evaluated by measuring. Moreover, the storage stability of the radiation sensitive resin composition was evaluated by the following method. A scanning electron microscope (Hitachi High-Technologies “CG-4100”) was used for measuring the resist pattern. The evaluation results are shown in Table 4 and Table 5 below.

[LWR performance]
The resist pattern was observed from above using the scanning electron microscope. A total of 50 line widths were measured at arbitrary points, and a 3-sigma value was obtained from the distribution of the measured values, and this was defined as LWR performance (nm). The LWR performance indicates that the smaller the value, the better. The LWR performance can be evaluated as good when it is 4.9 nm or less, and poor when it exceeds 4.9 nm.

[Resolution]
At the optimum exposure amount, the dimension of the minimum resist pattern that is resolved when the size of the mask pattern forming the line and space (1L / 1S) is changed is measured, and the measured value is determined as the resolution (nm). It was. The smaller the value, the better the resolution. The resolution can be evaluated as good when it is 36 nm or less, and as poor when it exceeds 36 nm.

[Rectangularity of the cross-sectional shape]
Observe the cross-sectional shape of the resist pattern resolved at the optimum exposure amount, measure the line width Lb in the middle of the resist pattern and the line width La at the top of the film, calculate La / Lb, and calculate the cross-sectional shape A rectangularity index. The rectangular shape of the cross-sectional shape is good when 0.95 ≦ (La / Lb) ≦ 1.05, and when (La / Lb) <0.95 or 1.05 <(La / Lb). Can be evaluated as bad.

[Depth of focus]
In the resist pattern resolved at the above optimum exposure amount, the dimension when the focus is changed in the depth direction is observed, and the depth direction in which the pattern dimension falls within 90% to 110% of the standard without any bridge or residue. Was measured, and the measurement result was defined as the depth of focus. When the depth of focus exceeds 50 nm, it can be evaluated as good, and when it is 50 nm or less, it can be evaluated as defective.

[Defect suppression]
In the resist pattern resolved at the optimum exposure amount, the number of defects was measured using a defect inspection apparatus (“KLA2810” manufactured by KLA-Tencor). The defect suppression is better as the number of defects per unit area is smaller. Defect suppression can be evaluated as good when it is 0.1 piece / cm ² or less, and defective when it exceeds 0.1 piece / cm ² .

[Storage stability]
About the radiation sensitive resin composition immediately after the preparation and the radiation sensitive resin composition after being stored at 25 ° C. for 3 months after the preparation, the pattern formed through a 40 nm one-to-one line and space mask is a line. Measure the exposure amount (optimal exposure amount) when formed in a one-to-one line and space with a width of 40 nm, calculate Ea and Eb, and calculate (Ea−Eb) × 100 / Ea. It was used as an index. The storage stability is good when -1.00 ≦ [(Ea−Eb) × 100 / Ea] ≦ 1.00, and [(Ea−Eb) × 100 / Ea] <− 1.00 or 1 When .00 <[(Ea−Eb) × 100 / Ea], it can be evaluated as defective.

[Preparation of radiation-sensitive resin composition for electron beam exposure]
[Example 31]
[A] 100 parts by mass of (A-8) as a polymer, [B] 20 parts by mass of (B-3) as an acid generator, [C] (C-1) 3.2 as an acid diffusion controller Radiation sensitivity by mixing (E-1) 4,280 parts by mass and (E-2) 1,830 parts by mass as [E] solvent and filtering through a membrane filter with a pore size of 0.2 μm. Resin composition (J-31) was prepared.

[Examples 32-34 and Comparative Examples 9 and 10]
Except having used each component of the kind and content shown in the following Table 6, it operated similarly to Example 31, and radiation sensitive resin composition (J-31)-(J-34) and (CJ-9) ) And (CJ-10) were prepared.

<Formation of resist pattern (3)>
Using a spin coater (“CLEAN TRACK ACT8” manufactured by Tokyo Electron) on the surface of an 8-inch silicon wafer, each radiation-sensitive resin composition shown in Table 7 was applied, and PB was performed at 90 ° C. for 60 seconds. It was. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with an average thickness of 50 nm. Next, the resist film was irradiated with an electron beam by using a simple electron beam drawing apparatus (“HL800D” manufactured by Hitachi, Ltd., output: 50 KeV, current density: 5.0 A / cm ² ). After irradiation, PEB was performed at 120 ° C. for 60 seconds. Thereafter, development was performed at 23 ° C. for 30 seconds using a 2.38 mass% TMAH aqueous solution as an alkali developer, washed with water, and dried to form a positive resist pattern.

<Formation of resist pattern (4)>
A negative resist pattern was prepared in the same manner as in the above resist pattern formation (3) except that n-butyl acetate was used instead of the TMAH aqueous solution and the organic solvent was developed. Formed.

<Evaluation>
The resist pattern formed by the electron beam exposure was evaluated for the LWR performance, the resolution, the rectangular shape of the cross-sectional shape, the depth of focus, and the storage stability in the same manner as in the ArF exposure. The evaluation results are shown in Table 7 below. In the case of electron beam exposure, the LWR performance can be evaluated as good when it is 5.2 nm or less, and poor when it exceeds 5.2 nm.

  As is clear from the results of Tables 4, 5 and 7, the radiation-sensitive resin compositions of the examples have the LWR performance, the solution in the case of ArF exposure and electron beam exposure, and in the case of alkali development and organic solvent development. Excellent image quality, rectangular cross-section, depth of focus and storage stability. In the comparative example, each of these characteristics was inferior to the example. Generally, according to electron beam exposure, it is known to show the same tendency as in the case of EUV exposure. Therefore, according to the radiation-sensitive resin composition of the example, even in the case of EUV exposure, It is estimated that the LWR performance is excellent.

According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, while exhibiting excellent storage stability and depth of focus, LWR is small, resolution is high, cross-sectional rectangularity is excellent, and there are few defects. A resist pattern can be formed. The acid diffusion controlling agent of the present invention can be suitably used as an acid diffusion controlling agent component of the radiation sensitive resin composition. The compound of the present invention can be suitably used as the acid diffusion controller. Therefore, they can be suitably used for pattern formation in semiconductor device manufacturing or the like where further miniaturization is expected.

Claims (7)

A polymer having a first structural unit containing an acid-dissociable group,
A radiation sensitive acid generator, and
An acid diffusion controller which is a compound represented by the following formula (1-1), (1-2) or (1-3) or a combination thereof (provided that the formulas (S-6), (S-7) and (Excluding those represented by (S-8))
The radiation-sensitive resin composition containing a.

(In Formula (1-1), R ¹ and R ² are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. X ⁺ is a monovalent radiation-sensitive onium cation. L ² is a single bond or a divalent organic group having 1 to 10 carbon atoms, and R ³ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, a hydroxy group, a sulfanyl group, or an amino group. there .n, when it .n is 2 or an integer from 0 to 4, a plurality of ^{R 3} may optionally be the same or different ^{.R 1,} of R 2, ^{L 2} and one or more of ^{R 3} May be combined with each other to form a ring structure having 3 to 20 ring members together with an atom or an atomic chain to which they are bonded, provided that when n is 0, R ¹ and R ² are each Independently, they are monovalent organic groups having 1 to 20 carbon atoms, or they are combined with each other To form a ring structure ring members 3 to 20 together with that atom or chain of atoms.)

(In the formula (1-2), R ¹ , R ² and X ⁺ have the same meanings as the formula (1-1). L ³ is a single bond or a divalent organic group having 1 to 20 carbon atoms. And two or more of R ¹ , R ² and L ³ may be combined with each other to form a ring structure having 3 to 20 ring members together with the nitrogen atom to which they are bonded.

(In formula (1-3), X ⁺ has the same meaning as in formula (1-1). R ⁴ represents a monovalent hydrocarbon group having 1 to 8 carbon atoms, a hydroxy group, a sulfanyl group, or an amino group. M is an integer of 1 to 4. When m is 2 or more, the plurality of R ⁴ may be the same or different, and two or more of the plurality of R ⁴ are combined with each other. A ring structure having 4 to 20 ring members may be formed together with the carbon chain to be bonded.)

The radiation sensitive resin composition according to claim 1, wherein the radiation sensitive acid generator is represented by the following formula (2-1).

(In formula (2-1), R ^p1 is a monovalent group containing a ring structure having 6 or more ring members. R ^p2 is a divalent linking group. R ^p3 and R ^p4 are independent of each other. A hydrogen atom, a fluorine atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms, wherein R ^p5 and R ^p6 are each independently , A fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms, n ^p1 is an integer of 0 to 10. n ^p2 is an integer of 0 to 10. n ^p3 is 1 When n ^p1 is 2 or more, the plurality of R ^p2 may be the same or different, and when n ^p2 is 2 or more, the plurality of R ^p3 may be the same or different. R ^p4 may be the same or different, and when n ^p3 is 2 or more, a plurality of R ^p5 may be the same or different. And a plurality of R ^p6 may be the same or different. Z ⁺ is a monovalent radiation-sensitive onium cation.) The first structural unit, the radiation-sensitive resin composition according to claim 1 or claim 2 represented by the following formula (a-1).

(In formula (a-1), R ⁵ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y ¹ is a monovalent acid dissociation represented by the following formula (Y-1). Group.)

(In formula (Y-1), R ^e1 is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^e2 and R ^e3 are each independently monovalent carbon atoms having 1 to 20 carbon atoms. It is a hydrogen group or represents an alicyclic structure having 3 to 20 ring members composed of these groups together with the carbon atom to which they are bonded.) The radiation-sensitive resin composition according to claim 1, wherein the polymer further has a second structural unit containing a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof. Forming a resist film;
A step of exposing the resist film, and a step of developing the exposed resist film,
The resist pattern formation method which forms the said resist film with the radiation sensitive resin composition of any one of Claims 1-4 . An acid diffusion controller which is a compound represented by the following formula (1-1), (1-2) or (1-3) or a combination thereof (provided that the formula (s-6), (s-7), (Excluding those represented by (s-8) and (s-12)) .

(In Formula (1-1), R ¹ and R ² are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. X ⁺ is a monovalent radiation-sensitive onium cation. L ² is a single bond or a divalent organic group having 1 to 10 carbon atoms, and R ³ is a monovalent hydrocarbon group having 1 to 6 carbon atoms, a hydroxy group, a sulfanyl group, or an amino group. there .n, when it .n is 2 or an integer from 0 to 4, a plurality of ^{R 3} may optionally be the same or different ^{.R 1,} of R 2, ^{L 2} and one or more of ^{R 3} May be combined with each other to form a ring structure having 3 to 20 ring members together with an atom or an atomic chain to which they are bonded, provided that when n is 0, R ¹ and R ² are each Independently, they are monovalent organic groups having 1 to 20 carbon atoms, or they are combined with each other To form a ring structure ring members 3 to 20 together with that atom or chain of atoms.)

(In the formula (1-2), R ¹ , R ² and X ⁺ have the same meanings as the formula (1-1). L ³ is a single bond or a divalent organic group having 1 to 20 carbon atoms. And two or more of R ¹ , R ² and L ³ may be combined with each other to form a ring structure having 3 to 20 ring members together with the nitrogen atom to which they are bonded.

(In formula (1-3), X ⁺ has the same meaning as in formula (1-1). R ⁴ represents a monovalent hydrocarbon group having 1 to 8 carbon atoms, a hydroxy group, a sulfanyl group, or an amino group. M is an integer of 1 to 4. When m is 2 or more, the plurality of R ⁴ may be the same or different, and two or more of the plurality of R ⁴ are combined with each other. A ring structure having 4 to 20 ring members may be formed together with the carbon chain to be bonded.)

(In Formula (1-3-1) and Formula (1-3-2), X ⁺ has the same meaning as in Formula (1-1) above.)

(In formulas (s-6), (s-7), (s-8) and (s-12), X ⁺ has the same meaning as in formula (1-1) above.) A compound represented by the following formula (1-1), (1-2), (1-3), (1-3-1) or (1-3-2) (provided that the formula (s-6), (Excluding those represented by (s-7), (s-8) and (s-12)) .

(In formula (1-1), R ¹ and R ² are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. X ⁺ represents the following formula (Z-1) to L ² is a single bond or a divalent organic group having 1 to 10 carbon atoms, and R ³ is a monovalent hydrocarbon group having 1 to 6 carbon atoms. , A hydroxy group, a sulfanyl group, or an amino group, n is an integer of 0 to 4. When n is 2 or more, a plurality of R ³ may be the same or different from each other R ¹ , R ² , L ^Two or more of ² and 1 or a plurality of R ³ may be combined with each other to form a ring structure having 3 to 20 ring members together with an atom or an atomic chain to which they are bonded, provided that n is 0. If, ^{R 1} and ^{R 2} are each independently a monovalent organic group having 1 to 20 carbon atoms, or together combined et al To form a ring structure ring members 3 to 20 together with the atoms or atomic chain they are attached.)

(In the formula (1-2), R ¹ and R ² have the same meaning as the above formula (1-1). X ⁺ represents a cation represented by the following formulas (Z-1) to (Z-3). L ³ is a single bond or a divalent organic group having 1 to 20 carbon atoms , and two or more of R ¹ , R ² and L ³ are combined with each other to form a ring together with the nitrogen atom to which they are bonded. A ring structure having 3 to 20 members may be formed.)

(In formula (1-3), X ⁺ is a cation represented by the following formulas (Z-1) to (Z-3). R ⁴ is a monovalent hydrocarbon group having 1 to 8 carbon atoms. , A sulfanyl group or an amino group, m is an integer of 1 to 4. When m is 2 or more, the plurality of R ⁴ may be the same or different, and two or more of the plurality of R ⁴ May be combined with each other to form a ring structure having 4 to 20 ring members together with the carbon chain to which they are bonded.)

(In Formula (1-3-1) and Formula (1-3-2), X ⁺ has the same meaning as in Formula (1-1) above.)

(In formula (Z-1), R ^a1 , R ^a2 and R ^a3 each independently represent a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic group having 6 to 12 carbon atoms. family hydrocarbon group, or an -OSO ₂ -R ^P or _-SO 2 -R ^Q, or .R ^P and ^{R Q} or two represents a keyed configured ring structure of these groups is Each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted aromatic group having 6 to 12 carbon atoms. group is a hydrocarbon group .K1, k2 and k3 are each independently an integer of 0 to 5 ^.R a1 ^{to R a3} and ^R when ^P and ^{R Q} are a plurality each of the plurality of ^R a1 ^{to R a3} And R ^P and R ^Q are the same May be different.
In formula (Z-2), R ^a4 represents a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms. k4 is an integer of 0 to 7. If R ^a4 is plural, the plurality of R ^a4 may be the same or different, and plural R ^a4 may represent a constructed ring aligned with each other. R ^a5 is a substituted or unsubstituted alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms. k5 is an integer of 0-6. If R ^a5 is plural, the plurality of R ^a5 may be the same or different, and plural R ^a5 may represent a keyed configured ring structure. r is an integer of 0-3. R ^a6 is a single bond or a divalent organic group having 1 to 20 carbon atoms. t is an integer of 0-2.
In formula (Z-3), R ^a7 and R ^a8 each independently represent a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. represents either a -OSO ₂ -R ^R or _-SO 2 -R ^S, or two or more are combined with each other configured ring of these groups. R ^R and R ^S are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted carbon. It is an aromatic hydrocarbon group of formula 6-12. k6 and k7 are each independently an integer of 0 to 5. R ^{a7, R} a8, ^R when ^R and ^{R S} is plural respective plurality of ^{R a7,} R a8, ^{R R} and ^{R S} may be the same as or different from each other. )

(In formulas (s-6), (s-7), (s-8) and (s-12), X ⁺ is a cation represented by the above formulas (Z-1) to (Z-3). is there.)