TW202330488A - Radiation-sensitive resin composition, method of forming resist pattern, and compound - Google Patents

Abstract

A radiation-sensitive resin composition includes: a polymer, solubility of which in a developer solution is capable of being altered by an action of an acid; a radiation-sensitive acid generator; and a compound represented by formula (1).

Description

Radiation sensitive resin composition, resist pattern forming method and compound

The invention relates to a radiation-sensitive resin composition, a resist pattern forming method and a compound.

Radiation-sensitive resin compositions used in microfabrication using lithography are produced by ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm) and other far-ultraviolet, extreme ultraviolet (Extreme Ultraviolet) rays. , EUV) (wavelength 13.5 nm) and other electromagnetic waves, charged particle beams such as electron beams, etc., generate acid in the exposed part, and the exposed part and the non-exposed part are relatively developed by the chemical reaction using the acid as a catalyst. The dissolution rate of the liquid is different, thereby forming a resist pattern on the substrate.

For radiation-sensitive resin compositions, in addition to good sensitivity to exposure light such as extreme ultraviolet rays and electron beams, excellent critical dimension uniformity (Critical Dimension Uniformity, CDU) performance and resolution are also required.

In response to these requirements, the types and molecular structures of polymers, acid generators, and other components used in the radiation-sensitive resin composition were studied, and their combinations were also studied in detail (see Japanese Patent Laid-Open No. 2010- 134279, Japanese Patent Laid-Open No. 2014-224984, and Japanese Patent Laid-Open No. 2016-047815). [Prior art literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2010-134279 [Patent Document 2] Japanese Patent Laid-Open No. 2014-224984 [Patent Document 3] Japanese Patent Laid-Open No. 2016-047815

[Problem to be Solved by the Invention] With the further miniaturization of the resist pattern, the required level of the above-mentioned performance is further increased, and a radiation-sensitive resin composition satisfying these requirements is demanded.

The present invention is based on the above circumstances, and an object of the present invention is to provide a radiation-sensitive resin composition capable of forming a resist pattern having good sensitivity to exposure light and excellent CDU performance and resolution, and a resist pattern forming methods and compounds. [Means to solve the problem]

The invention made to solve the above-mentioned problems is a radiation-sensitive resin composition containing: a polymer whose solubility in a developer is changed by the action of an acid (hereinafter, also referred to as “[A] polymer substances"), radiation-sensitive acid generators (hereinafter also referred to as "[C] acid generators"), and compounds represented by the following formula (1) (hereinafter also referred to as "[D] compounds") . [chemical 1] (In formula (1), Ar ¹ is a group obtained by removing (a+b+2) hydrogen atoms from an aromatic hydrocarbon ring with 6 to 30 ring members; R ¹ is a monovalent group with 1 to 20 carbons Organic group or halogen atom; L ¹ is a divalent linking group; R ² is a substituted or unsubstituted monovalent aromatic hydrocarbon group with 6-20 carbons; a is an integer of 0-10; b is 1-10 Integer; wherein, a+b is 10 or less; when a is more than 2, multiple ^R1s are the same or different from each other; when b is more than 2, multiple ^L1s are the same or different from each other, and multiple R1s are the same or different from each other. ² are the same or different from each other; X ⁺ is a monovalent radioactive onium cation)

Another invention to solve the above-mentioned problem is a resist pattern forming method, which includes: the step of directly or indirectly applying the above-mentioned radiation-sensitive resin composition on a substrate; a step of exposing the resist film formed in the applying step; and a step of developing the exposed resist film.

Still another invention made in order to solve the said subject is [D] compound. [Effect of the invention]

According to the radiation-sensitive resin composition and resist pattern forming method of the present invention, a resist pattern having good sensitivity to exposure light and excellent CDU performance and resolution can be formed. The compound of the present invention can be suitably used as a component of the radiation-sensitive resin composition. Therefore, these can be suitably used in the manufacturing process of the semiconductor element which is expected to be further miniaturized in the future, etc.

Hereinafter, the radiation-sensitive resin composition, resist pattern forming method, and compound of the present invention will be described in detail.

＜Radiation sensitive resin composition＞ This radiation-sensitive resin composition contains [A] a polymer, [C] an acid generator, and [D] a compound. The radiation-sensitive resin composition usually contains an organic solvent (hereinafter also referred to as “[E] organic solvent”). The radiation-sensitive resin composition may contain a polymer having a higher fluorine atom content than the [A] polymer (hereinafter also referred to as “[B] polymer”) as a suitable component. This radiation sensitive resin composition may contain other arbitrary components in the range which does not impair the effect of this invention.

When this radiation-sensitive resin composition contains [A] polymer, [C] acid generator, and [D] compound, it is possible to form a resist pattern with good sensitivity to exposure light and excellent CDU performance and resolution. Although not necessarily clear about the reason why the said structure is exhibited by this radiation sensitive resin composition including the said structure, it can guess as follows, for example. That is, it is considered that the [D] compound has a bulky (bulky) structure, and the diffusion length of acid generated by exposure can be moderately shortened, and as a result, the sensitivity to exposure light, CDU performance, and resolution can be improved.

The radiation-sensitive resin composition can be prepared, for example, by mixing [A] polymer, [C] acid generator and [D] compound, and optionally [B] polymer, [E] organic solvent and other optional components are mixed in a prescribed ratio, and the obtained mixture is preferably filtered through a membrane filter having a pore size of 0.20 μm or less.

Hereinafter, each component contained in this radiation sensitive resin composition is demonstrated.

＜[A] Polymer＞ [A] The polymer is a polymer whose solubility in a developer is changed by the action of an acid. Usually, when [A] polymer has an acid dissociative group, the property which changes the solubility to a developing solution by the action of an acid is exhibited. Therefore, the [A] polymer preferably has a structural unit (hereinafter also referred to as "structural unit (I)") containing an acid-dissociative group. The radiation-sensitive resin composition may contain one kind or two or more kinds of [A] polymers.

[A] The polymer further preferably has a structural unit containing a phenolic hydroxyl group (hereinafter also referred to as "structural unit (II)"). [A] The polymer may further have structural units other than the structural unit (I) and the structural unit (II) (hereinafter also simply referred to as "other structural units"). [A] The polymer may have one kind or two or more kinds of each structural unit.

The lower limit of the content ratio of the [A] polymer in the radiation-sensitive resin composition is preferably 50% by mass relative to all components other than the [E] organic solvent contained in the radiation-sensitive resin composition, More preferably, it is 70 mass %, More preferably, it is 80 mass %. The upper limit of the content ratio is preferably 99% by mass, more preferably 95% by mass.

The lower limit of the polystyrene-equivalent weight average molecular weight (Mw) of the polymer [A] obtained by gel permeation chromatography (Gel Permeation Chromatography, GPC) is preferably 1,000, more preferably 3,000, still more preferably 4,000. The upper limit of the Mw is preferably 50,000, more preferably 30,000, still more preferably 20,000, still more preferably 15,000, and most preferably 10,000. By making Mw of [A] polymer into the said range, the applicability of this radiation sensitive resin composition can be improved. [A] The Mw of the polymer can be adjusted by, for example, adjusting the type of polymerization initiator used for synthesis, its usage amount, and the like.

[A] The upper limit of the ratio of Mw of the polymer to the polystyrene-equivalent number average molecular weight (Mn) obtained by GPC (hereinafter also referred to as "dispersion" or "Mw/Mn") is preferably 2.5, more preferably 2.0, further preferably 1.7. The lower limit of the ratio is usually 1.0, preferably 1.1, more preferably 1.2, still more preferably 1.3.

[Measuring method of Mw and Mn] The Mw and Mn of the polymer in this specification are the values measured using the gel permeation chromatography (GPC) under the following conditions. GPC column: 2 "G2000HXL", 1 "G3000HXL" and 1 "G4000HXL" of Tosoh Column temperature: 40°C Dissolution 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

[A] The polymer can be synthesized by, for example, polymerizing a monomer providing each structural unit by a known method.

Each structural unit contained in the [A] polymer will be described below.

[Structural unit (I)] The structural unit (I) is a structural unit containing an acid dissociative group. The term "acid dissociative group" refers to a group that substitutes a hydrogen atom in a carboxyl group, a hydroxyl group, etc., and dissociates by the action of an acid to provide a carboxyl group, a hydroxyl group, or the like. The acid dissociative group is dissociated by the action of the acid generated from the [C] acid generator or the like due to exposure, and the solubility of the [A] polymer in the developer is different between the exposed part and the non-exposed part. This can form a resist pattern. [A] The polymer may have one type or two or more types of structural units (I).

As a structural unit (I), the structural unit represented by following formula (2-1) - a formula (2-2), etc. are mentioned, for example.

[Chem 2]

In the formula (2-1) and formula (2-2), R ³ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Z is an acid dissociative group (hereinafter also referred to as "acid dissociative group (Z)").

In the formula (2-2), L ² is a single bond, -COO-, -CONH- or -O-. Ar ² is a group obtained by removing (s+t+u+1) hydrogen atoms from an aromatic hydrocarbon ring having 6 to 20 ring members. s is an integer of 0-10, and t is an integer of 0-10. Wherein, s+t is an integer of 1-10. When s is 2 or more, several Z are mutually same or different. When s is 1 or more, R ⁴ is a hydrogen atom or a monovalent organic group having 1 to 20 carbons. When t is 2 or more, a plurality of R ⁴ are the same or different from each other. When s is 0 and t is 1, R ⁴ is an acid dissociative group. When s is 0 and t is 2 or more, at least one of the plurality of R ⁴ is an acid dissociative group. R ⁵ is a monovalent organic group having 1 to 20 carbon atoms or a halogen atom. u is an integer of 0-10. When u is 2 or more, a plurality of R ⁵ are the same or different from each other. Among them, s+t+u is 10 or less.

The "number of ring members" refers to the number of atoms constituting a ring structure, and in the case of a polycyclic ring, refers to the number of atoms constituting the polycyclic ring. "Aromatic ring" includes "aromatic hydrocarbon ring" and "aromatic heterocycle". The "aromatic ring" includes a "monocyclic aromatic ring" and a "polycyclic aromatic ring". The "polycyclic aromatic ring" includes not only condensed polycyclic rings in which two rings have two atoms in common, but also ring-set polycyclic rings in which two rings do not have common atoms but are connected by a single bond.

The "carbon number" means the number of carbon atoms constituting a group. By "organic group" is meant a group comprising at least one carbon atom. "Hydrocarbon group" includes chain hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group. The "hydrocarbon group" may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The term "chain hydrocarbon group" refers to a hydrocarbon group that does not contain a ring structure but only has a chain structure, and includes both straight-chain hydrocarbon groups and branched hydrocarbon groups. The term "alicyclic hydrocarbon group" refers to a hydrocarbon group containing only an alicyclic ring as a ring structure without an aromatic ring, and includes both monocyclic alicyclic hydrocarbon groups and polycyclic alicyclic hydrocarbon groups. However, it is not necessary to consist only of alicyclic rings, and a chain structure may be contained in a part thereof. The term "aromatic hydrocarbon group" refers to a hydrocarbon group including an aromatic ring as a ring structure. However, it does not need to consist only of an aromatic ring, and may contain a chain structure or an alicyclic ring in a part thereof. "Aliphatic hydrocarbon group" refers to a chain hydrocarbon group and an alicyclic hydrocarbon group.

R ³ is preferably a hydrogen atom or a methyl group, more preferably a hydrogen atom, from the viewpoint of providing copolymerizability of the monomer of the structural unit (I).

L ² is preferably a single bond.

Examples of aromatic hydrocarbon rings providing Ar ² with ring members of 6 to 20 include: benzene rings; condensed polycyclic aromatic hydrocarbon rings such as naphthalene rings, phenanthrene rings, anthracene rings, and fluorene rings; biphenyl rings, Terbiphenyl rings, binaphthyl rings, phenylnaphthalene rings, and other ring-set aromatic hydrocarbon rings, etc.

The aromatic hydrocarbon ring having 6 to 20 ring members providing Ar ² is preferably a benzene ring.

As s, 0-3 are preferable, 0-2 are more preferable, and 1 is still more preferable.

Examples of the monovalent organic group having 1 to 20 carbons represented by ^R4 when s is 1 or more include: a monovalent hydrocarbon group having 1 to 20 carbons; A group (α) of a heteroatom-containing group; a group (β) obtained by substituting a part or all of the hydrogen atoms of the hydrocarbon group or the group (α) with a monovalent heteroatom-containing group; A group (γ) obtained by combining the above-mentioned hydrocarbon group, the above-mentioned group (α), and the above-mentioned group (β) with a divalent heteroatom-containing group, and the like. In addition, the organic group in this case may be an acid dissociative group (Z) described later.

Examples of the monovalent hydrocarbon group having 1 to 20 carbons include: a monovalent chain hydrocarbon group having 1 to 20 carbons, a monovalent alicyclic hydrocarbon group having 3 to 20 carbons, and a monovalent aromatic group having 6 to 20 carbons. Hydrocarbyl etc.

Examples of monovalent chain hydrocarbon groups having 1 to 20 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, and isopropyl, alkenyl groups such as vinyl, propenyl, and butenyl, ethynyl, Alkynyl groups such as propynyl and butynyl, etc.

Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include monocyclic saturated alicyclic hydrocarbon groups such as cyclopentyl and cyclohexyl, norbornyl, adamantyl, tricyclodecanyl, tetracyclodeca Polycyclic alicyclic saturated hydrocarbon groups such as diradicals, monocyclic alicyclic unsaturated hydrocarbon groups such as cyclopentenyl and cyclohexenyl, norbornenyl, tricyclodecenyl, tetracyclododecenyl, etc. Polycyclic alicyclic unsaturated hydrocarbon groups, etc.

Examples of monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include aryl groups such as phenyl, tolyl, xylyl, naphthyl, and anthracenyl, benzyl, phenethyl, naphthylmethyl, and anthracenyl. Methyl and other aralkyl groups, etc.

Examples of the heteroatom constituting the monovalent or divalent heteroatom-containing group include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, and a halogen atom. The halogen atom is a fluorine atom, chlorine atom, bromine atom or iodine atom.

Examples of divalent heteroatom-containing groups include: -O-, -CO-, -S-, -CS-, -NR'-, and combinations of two or more of these (e.g. , -COO-, -CONR'-, etc.) etc. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R′ include groups having 1 to 10 carbon atoms among the groups exemplified as the “monovalent hydrocarbon group having 1 to 20 carbon atoms”.

When s is 1 or more, R ⁴ is preferably a monovalent organic group having 1 to 20 carbons, more preferably a combination of a monovalent hydrocarbon group having 1 to 20 carbons and a divalent heteroatom-containing group. group, more preferably a group composed of a monovalent chain hydrocarbon group having 1 to 20 carbon atoms and -CO-, and more preferably an acyl group.

Examples of R ⁴ when s is 0 include the same groups as the acid-dissociating group (Z) described later.

As t, 0-2 are preferable, and 1 is more preferable.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ⁵ include the same groups as those exemplified as the monovalent organic group having 1 to 20 carbon atoms represented by R ⁴ .

The halogen atom represented by R ⁵ is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

As u, 0 or 1 is preferable, and 0 is more preferable.

(acid dissociative group (Z)) The acid dissociative group (Z) is a group that substitutes a hydrogen atom in a carboxyl group and dissociates by the action of an acid to provide a carboxyl group. As an acid dissociative group (Z), the group etc. which are represented by following formula (3-1) - a formula (3-2) etc. are mentioned, for example.

[Chem 3]

In the formula (3-1), R ^X is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^Y and R ^Z are each independently a monovalent hydrocarbon group with 1 to 20 carbon atoms, or a saturated alicyclic ring with 3 to 20 ring members formed by combining these groups with the carbon atoms to which they are bonded. part.

In the formula (3-2), R ^A is a hydrogen atom. R ^B and R ^C are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbons. ^RD is a divalent hydrocarbon group having 1 to 20 carbons constituting an unsaturated alicyclic ring having 4 to 20 ring members together with carbon atoms to which ^RA , ^RB, and R ^C are bonded.

As the monovalent hydrocarbon group having 1 to 20 carbons represented by R ^X , ^RY , R ^Z , R ^B or R ^C , for example, the same as the carbon number of 1 to 20 in R ⁴ in the above formula (2-2) can be mentioned. Among the 20 monovalent organic groups, the same groups as the monovalent hydrocarbon groups having 1 to 20 carbon atoms are exemplified.

Examples of substituents that the hydrocarbon group represented by R ^X may have include halogen atoms such as fluorine atoms and iodine atoms, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, alkoxy groups, alkoxycarbonyl groups, and alkoxy groups. Carbonyloxy, acyl, acyloxy, etc.

Examples of saturated alicyclic rings having 3 to 20 ring members that RY and R ^Z are bonded to each other and constitute with these bonded carbon atoms include cyclopropane ring ^, cyclobutane ring, cyclopentane ring, Monocyclic saturated alicyclic rings such as cyclohexane rings, polycyclic saturated alicyclic rings such as norbornane rings and adamantane rings, and the like.

As the divalent hydrocarbon group having 1 to 20 carbons represented by R ^D , for example, those selected from the monovalent organic groups having 1 to 20 carbons in R ⁴ in the above formula (2-2) have 1 to 20 carbons. A group obtained by removing one hydrogen atom from the exemplified group as a monovalent hydrocarbon group of 20, and the like.

Examples of unsaturated alicyclic rings having 4 to 20 ring ^members composed of three carbon atoms to which R ^D is bonded to RA, R ^B and R ^C include cyclobutene rings, cyclopentene rings, Monocyclic unsaturated alicyclic rings such as cyclohexene rings, polycyclic unsaturated alicyclic rings such as norbornene rings, and the like.

R ^X is preferably a substituted or unsubstituted chain hydrocarbon group or a substituted or unsubstituted aromatic hydrocarbon group, more preferably an unsubstituted chain hydrocarbon group or an unsubstituted aromatic hydrocarbon group, more preferably is an unsubstituted alkyl group or an unsubstituted aryl group, more preferably a methyl group, an ethyl group or a phenyl group.

R ^Y is preferably a chain hydrocarbon group or an alicyclic hydrocarbon group, more preferably an alkyl group or a polycyclic alicyclic saturated hydrocarbon group, and still more preferably a methyl group or a norbornyl group.

R ^Z is preferably a chain hydrocarbon group, more preferably an alkyl group, and still more preferably a methyl group.

In addition, RY ^and R ^Z are also preferably a part of a saturated alicyclic ring having 3 to 20 ring members that are bonded to each other and constituted together with the carbon atoms to which they are bonded. The saturated alicyclic ring is preferably a monocyclic saturated alicyclic ring, more preferably a cyclopentane ring or a cyclohexane ring.

The structural unit (I) is preferably a structural unit represented by the following formula (2-1-1) to formula (2-1-3) or formula (2-2-1).

[chemical 4]

In the formula (2-1-1) ~ formula (2-1-3) and formula (2-2-1), R ³ is the same as the formula (2-1) ~ formula (2-2) meaning.

The lower limit of the content ratio of the structural unit (I) in the [A] polymer is preferably 20 mol %, more preferably 25 mol %, and still more preferably It is 30 mol%, and more preferably 35 mol%. The upper limit of the content ratio is preferably 90 mol%, more preferably 80 mol%, and still more preferably 75 mol%. By setting the content ratio of the structural unit (I) within the above-mentioned range, the sensitivity to exposure light, CDU performance, and resolution of the radiation-sensitive resin composition can be further improved. In addition, unless otherwise specified, the upper limit and the lower limit of the numerical range described in this specification may be "less than" or "less than", and the lower limit may be "more than" or "exceed". In addition, the upper limit and the lower limit can be combined arbitrarily.

In addition, it may be considered that the structural unit of the [A] polymer corresponds to the repetition of classification of two or more structural units. For example, a structural unit considered to correspond not only to the structural unit (I) but also to a structural unit other than the structural unit (I) may be included. If a specific example is used for illustration, it is also considered that the structural unit represented by the following formula not only conforms to the structural unit (I) as "a structural unit having an acid dissociative group", but also corresponds to the "containing alcoholic group" described later. The structural unit (III) of the structural unit of the hydroxyl group is consistent. Regarding such a structural unit, in this specification, it is handled so as to correspond to the smaller number in parentheses of the structural unit. That is, although the structural unit represented by the following formula is a structural unit having an alcoholic hydroxyl group, it is treated as corresponding to the structural unit (I) as "a structural unit having an acid dissociative group".

[chemical 5]

In the formula, R ³ has the same meaning as the formula (2-1) to formula (2-2).

[Structural unit (II)] The structural unit (II) is a group containing a phenolic hydroxyl group. The "phenolic hydroxyl group" is not limited to the hydroxyl group directly bonded to the benzene ring, but refers to all the hydroxyl groups directly bonded to the aromatic ring. The structural unit (II) is a structural unit different from the structural unit (I). A structural unit including both a phenolic hydroxyl group and an acid dissociative group is classified as a structural unit (I). That is, the structural unit (II) does not contain an acid dissociative group. [A] The polymer may contain one kind or two or more kinds of structural units (II).

In the case of KrF exposure, EUV exposure, or electron beam exposure, since [A] the polymer has the structural unit (II), the sensitivity of the radiation-sensitive resin composition to exposure light can be further increased. Therefore, when [A] the polymer has a structural unit (II), the radiation-sensitive resin composition can be suitably used as a radiation-sensitive resin composition for KrF exposure, EUV exposure, or electron beam exposure.

As the structural unit (II), for example, structural units represented by the following formula (II-1) to formula (II-17) (hereinafter also referred to as "structural unit (II-1) to structural unit (II- 17)") etc.

[chemical 6]

In the formulas (II-1) to (II-17), R ^P is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

R ^P is preferably a hydrogen atom or a methyl group from the viewpoint of copolymerizability of a monomeric body providing the structural unit (II).

As the structural unit (II), preferably structural unit (II-1) to structural unit (II-3), structural unit (II-6) to structural unit (II-8), structural unit (II-11), Structural units (II-12) or combinations of these.

When the [A] polymer has a structural unit (II), the lower limit of the content ratio of the structural unit (II) in the [A] polymer is preferably relative to all structural units constituting the [A] polymer It is 15 mol%, more preferably 20 mol%, and even more preferably 25 mol%. The upper limit of the content ratio is preferably 60 mol%, more preferably 50 mol%, still more preferably 40 mol%, and most preferably 35 mol%.

[Other structural units] Examples of other structural units include: a structural unit containing an alcoholic hydroxyl group (hereinafter also referred to as "structural unit (III)"), a structural unit containing an alkoxyalkyl group (hereinafter also referred to as "structural unit (IV) )"), a structural unit including a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof (hereinafter also referred to as "structural unit (V)"), and the like.

(structural unit (III)) The structural unit (III) is a structural unit containing an alcoholic hydroxyl group. By further having the structural unit (III), the solubility in a developing solution can be further moderately adjusted.

As a structural unit (III), the structural unit etc. which are represented by the following formula are mentioned, for example.

[chemical 7]

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

(structural unit (IV)) The structural unit (IV) is a structural unit containing an alkoxyalkyl group. By further having a structural unit (IV), the adhesiveness with a board|substrate can be improved.

As an alkoxyalkyl group, the group which combined the alkanediyl group which has 2-5 carbons, and the alkoxyl group which has 1-5 carbons, etc. are mentioned, for example methoxyethyl group and ethoxyethyl group. In other words, groups represented by -R ⁴¹ -OR ⁴² (R ⁴¹ is an alkanediyl group having 2 to 5 carbons, and R ⁴² is an alkyl group having 1 to 5 carbons) and the like can be mentioned.

As a structural unit (IV), the structural unit etc. which are represented by the following formula are mentioned, for example. [chemical 8]

In the above formula, R ^L3 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

When the [A] polymer has other structural units, the lower limit of the content ratio of the other structural units is preferably 1 mol %, more preferably 5 mol %, based on all the structural units in the [A] polymer. Ear%. The upper limit of the content ratio is preferably 30 mol%, more preferably 20 mol%.

＜[B] Polymer＞ The [B] polymer is different from the [A] polymer, and has a higher fluorine atom content than the [A] polymer. In general, a polymer having higher hydrophobicity than the polymer used as the base polymer tends to exist in the surface layer of the resist film. [B] The polymer has a higher fluorine atom content than the [A] polymer, so it tends to exist in the surface layer of the resist film due to the characteristic of hydrophobicity. As a result, when the radiation-sensitive resin composition contains the [B] polymer, it can be expected that the cross-sectional shape of the formed resist pattern becomes favorable. This radiation-sensitive resin composition may contain [B] polymer as a surface conditioner of a resist film, for example. The radiation-sensitive resin composition may contain one kind or two or more kinds of [B] polymers.

＜[C] Acid producer＞ [C] The acid generator is a substance that generates acid by exposure. As exposure light, the light similar to the light etc. which were illustrated as exposure light in the exposure process of this resist pattern formation method mentioned later, for example is mentioned. [A] The acid dissociative group in the structural unit (I) of the polymer is dissociated by the acid generated by exposure, and is dissolved in the developing solution between the exposed part and the non-exposed part of the resist film There is a difference in properties, whereby a resist pattern can be formed.

Examples of the acid generated from the [C] acid generator include sulfonic acid, imidic acid, and the like.

The content form of the [C] acid generator in the radiation-sensitive resin composition may be, for example, the form of a low-molecular compound (hereinafter, also referred to as "[C] acid generator") described later, or may be a sensitive The form of the radioactive acid-generating polymer (hereinafter also referred to as “[C] acid-generating polymer”) may be both forms. The term "low molecular weight compound" refers to a compound having a molecular weight of 1,000 or less that does not have a molecular weight distribution. The "radiation-sensitive acid-generating polymer" refers to a polymer having a structural unit that generates acid upon exposure. In other words, the [C]acid generating polymer can also be said to be a form in which the [C]acid generating body is incorporated as a part of the polymer. The [C] acid-generating polymer may be a different polymer from the [A] polymer and the [B] polymer. The radiation-sensitive resin composition may contain one or more [C] acid generators.

The [C] acid generator is preferably a [C] acid generator. Examples of the [C] acid generator include onium salt compounds, N-sulfonyloxyimide compounds, sulfonimide compounds, halogen-containing compounds, diazoketone compounds, and the like.

Examples of the onium salt compound include periumium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, and pyridinium salts.

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

As [C] acid generator, the [C] acid generator which generate|occur|produces a sulfonic acid by exposure is preferable. As [C] acid generator which generate|occur|produces a sulfonic acid by exposure, the compound etc. which are represented by following formula (4) are mentioned, for example. [chemical 9]

In the formula (4), R ^a1 is a monovalent organic group having 1 to 30 carbon atoms. L ^a is a divalent linking group. n _a1 is an integer of 0-10. When n _a1 is 2 or more, a plurality of L ^a are mutually the same or different. R ^a2 and R ^a3 are each independently a hydrogen atom, a fluorine atom, a monovalent hydrocarbon group having 1 to 20 carbons, or a monovalent fluorinated hydrocarbon group having 1 to 20 carbons. n _a2 is an integer of 0-10. When n _a2 is 2 or more, a plurality of R ^a2 are the same or different from each other, and a plurality of R ^a3 are the same or different from each other. Y ⁺ is a monovalent radiation sensitive onium cation.

Examples of the monovalent organic group having 1 to 30 carbon atoms represented by R ^a1 include those exemplified as the monovalent organic group having 1 to 20 carbon atoms represented by R ⁴ in the formula (2-2). The group with the same valence as the organic group, etc.

The monovalent organic group having 1 to 30 carbons represented by R ^a1 is preferably a monovalent group having 1 to 30 carbons including a ring structure having 5 or more ring members. Examples of ring structures having 5 or more ring members include alicyclic rings with 5 or more ring members, aliphatic heterocycles with 5 or more ring members, aromatic hydrocarbon rings with 5 or more ring members, Aromatic heterocycles or combinations thereof.

A part or all of the hydrogen atoms contained in the ring structure may be substituted with a substituent. Examples of substituents include halogen atoms such as fluorine atoms and iodine atoms, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, alkyl groups, alkoxy groups, alkoxycarbonyl groups, alkoxycarbonyloxy groups, acyl groups, acyl groups Oxygen, side oxygen (=O), etc.

Examples of the alicyclic ring having 5 or more ring members include cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring, cyclononane ring, cyclodecane ring, cyclododecane ring, etc. Monocyclic saturated alicyclic rings, monocyclic unsaturated alicyclic rings such as cyclopentene rings, cyclohexene rings, cycloheptene rings, cyclooctene rings, and cyclodecene rings, norbornane rings, adamantane rings, tricyclic Polycyclic saturated alicyclic rings such as cyclodecane ring and tetracyclododecane ring, polycyclic unsaturated alicyclic rings such as norbornene ring and tricyclodecene, and the like.

Examples of the aliphatic heterocyclic ring having 5 or more ring members include lactone structures such as a hexanolactone ring and a norbornane sultone ring, hexanosultone ring, norbornane sultone ring and other sultone structures, heterocyclic rings containing oxygen atoms such as oxepane ring and oxanorbornane ring, heterocyclic rings containing nitrogen atoms such as azacyclohexane ring and diazabicyclooctane ring, A heterocyclic ring containing a sulfur atom such as a thiane ring, a thianorbornane ring, and the like.

Examples of the aromatic hydrocarbon ring having 5 or more ring members include a benzene ring, a naphthalene ring, a phenanthrene ring, an anthracene ring, and the like.

Examples of aromatic heterocyclic rings having 5 or more ring members include heterocyclic rings containing oxygen atoms such as furan rings, pyran rings, benzofuran rings, and benzopyran rings; pyridine rings, pyrimidine rings, and indole rings. Heterocyclic rings containing nitrogen atoms such as nitrogen atoms, heterocyclic rings containing sulfur atoms such as thiophene rings, etc.

The lower limit of the number of ring members of the ring structure is preferably 6, more preferably 8, still more preferably 9, particularly preferably 10. The upper limit of the number of ring members is preferably 25.

Examples of the divalent linking group represented by ^L include: carbonyl, ether, carbonyloxy (-COO-), oxycarbonyl (-OCO-), thioether, thiocarbonyl, sulfonyl, or A base formed by combining these. Among these, an ether group, a carbonyloxy group or an oxycarbonyl group is preferable.

As n _a1 , 0 or 1 is preferable.

As the monovalent hydrocarbon group having 1 to 20 carbons represented by R ^a2 or R ^a3 , for example, the carbon in the monovalent organic group having 1 to 20 carbons in R ⁴ in the above formula (2-2) can be mentioned. The same groups as the exemplified groups are monovalent hydrocarbon groups having a number of 1 to 20, and the like.

Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbons represented by R ^a2 or R ^a3 include groups in which some or all of the hydrogen atoms of the monovalent hydrocarbon group having 1 to 20 carbons are substituted with fluorine atoms, etc. .

R ^a2 and R ^a3 are preferably a hydrogen atom, a fluorine atom, an alkyl group or a fluorinated alkyl group, more preferably a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

As n _a2 , preferably 0-5, more preferably 0-4.

Examples of monovalent radiation-sensitive onium cations represented by Y ⁺ include monovalent cations represented by the following formulas (ra) to (rc) (hereinafter also referred to as "cations (ra) to cations (rc) ")wait.

[chemical 10]

In the formula (ra), R ^B1 and R ^B2 are each independently a group obtained by removing one hydrogen atom from a substituted or unsubstituted aromatic hydrocarbon ring with ring members of 6 to 20, or R ^B1 and R ^B2 are combined with each other and constitute a part of a substituted or unsubstituted polycyclic aromatic ring having 9 to 30 ring members together with these bonded sulfur atoms. R ^B3 is a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group or a halogen atom. b1 is an integer of 0-9. When b1 is 2 or more, a plurality of R ^B3 are the same as or different from each other. n _b1 is an integer of 0-3.

In the formula (rb), R ^B4 and R ^B5 are each independently a monovalent organic group having 1 to 20 carbons, a hydroxyl group, a nitro group or a halogen atom. b2 is an integer of 0-9. When b2 is 2 or more, a plurality of R ^B4 are the same as or different from each other. b3 is an integer of 0-10. When b3 is 2 or more, a plurality of R ^B5 are the same or different from each other. It is a monovalent organic group with 1 to 20 carbons, a hydroxyl group, a nitro group or a halogen atom. R ^B6 is a single bond or a divalent organic group having 1 to 20 carbon atoms. n _b2 is an integer of 0-2. n _b3 is an integer of 0-3.

In the formula (rc), R ^B7 and R ^B8 are each independently a monovalent organic group having 1 to 20 carbons, a hydroxyl group, a nitro group or a halogen atom. b4 is an integer of 0-5. When b4 is 2 or more, a plurality of R ^B7 are the same or different from each other. b5 is an integer of 0-5. When b5 is 2 or more, a plurality of R ^B8 are the same or different from each other.

As the aromatic hydrocarbon ring having 6 to 20 ring members providing ^RB1 and ^RB2 , for example, the same as the aromatic hydrocarbon ring having 6 to 20 ring members providing Ar ² of the above formula (2-2) and The exemplified rings are the same as the rings and the like. The aromatic hydrocarbon ring having 6 to 20 ring members providing R ^B1 and R ^B2 is preferably a benzene ring or a naphthalene ring, more preferably a benzene ring.

As a polycyclic aromatic ring with 9 to 30 ring members formed by combining R ^B1 and R ^B2 together with the bonded sulfur atoms, it is preferably a benzothiophene ring, a dibenzothiophene ring, or a thioxanthene ring. ring, thioxanthone ring or phenoxathione ring, etc.

In the aromatic hydrocarbon ring or the polycyclic aromatic ring, some or all of hydrogen atoms bonded to atoms constituting the ring structure may be substituted with a substituent. Examples of substituents include halogen atoms such as fluorine atoms and iodine atoms, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, alkyl groups, fluorinated alkyl groups, alkoxy groups, alkoxycarbonyl groups, and alkoxycarbonyloxy groups. , acyl group, acyloxy group, pendant oxygen group (=O) or a combination of these, etc. Among these, a fluorine atom, a hydroxyl group, a trifluoromethyl group, a cyano group, a methyl group or a tert-butyl group is preferable.

Examples of monovalent organic groups having 1 to 20 carbon atoms represented by R ^B3 , R ^B4 , R ^B5 , R ^B7 , and R ^B8 include those having the same carbon number as that represented by R ⁴ in the above formula (2-2). 1 to 20 monovalent organic groups and the same groups as exemplified.

Examples of the divalent organic group represented by R ^B6 include those obtained by removing one hydrogen atom from the groups exemplified as ^the monovalent organic group having 1 to 20 carbon atoms represented by R in the formula (2-2). Cheng's base and so on.

As b1, 0-2 are preferable, 0 or 1 is more preferable, and 0 is still more preferable. As n _b1 , 0 or 1 is preferable.

The monovalent radiation-sensitive onium cation represented by Y ⁺ is preferably a cation (ra).

The cation (r-a) is preferably a cation represented by the following formula (r-a-1) to formula (r-a-13).

[chemical 11]

The [C] acid generator is preferably a compound represented by the following formula (4-1) to formula (4-10).

[chemical 12]

In the formula (4-1) to formula (4-10), Y ⁺ has the same meaning as the formula (4).

The lower limit of the content of the [C] acid generator in the radiation-sensitive resin composition is preferably 5 parts by mass, more preferably 10 parts by mass, and still more preferably 15 parts by mass relative to 100 parts by mass of the [A] polymer. parts by mass. The upper limit of the content is preferably 50 parts by mass, more preferably 40 parts by mass, and still more preferably 30 parts by mass. By setting content of [C] acid generator into the said range, the sensitivity to exposure light of this radiation sensitive resin composition, CDU performance, and resolution can be improved further.

＜[D] compound＞ [D] The compound is a compound represented by the following formula (1). The [D] compound acts as an acid diffusion controller (quencher). The acid diffusion control agent controls the diffusion phenomenon in the resist film of the acid generated from the [C] acid generator, etc. by exposure, thereby controlling undesirable chemical reactions in the non-exposed area (for example, the formation of acid dissociative groups). dissociation reaction). When the radiation-sensitive resin composition contains the [D] compound, it is possible to form a resist pattern having good sensitivity to exposure light and excellent CDU performance and resolving power.

[chemical 13]

In the formula (1), Ar ¹ is a group obtained by removing (a+b+2) hydrogen atoms from an aromatic hydrocarbon ring having 6 to 30 ring members. R ¹ is a monovalent organic group having 1 to 20 carbon atoms or a halogen atom. L ¹ is a divalent linking group. R ² is a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms. a is an integer of 0-10. b is an integer of 1-10. However, a+b is 10 or less. When a is 2 or more, a plurality of R ¹ are the same or different from each other. When b is 2 or more, a plurality of L ¹ are the same or different from each other, and a plurality of R ² are the same or different from each other. X ⁺ is a monovalent radiation-sensitive onium cation.

Examples of the aromatic hydrocarbon ring having 6 to 30 ring members providing Ar ¹ include the rings exemplified as the aromatic hydrocarbon ring having 6 to 20 ring members providing Ar ² of the above formula (2-2). Same ring etc. The aromatic hydrocarbon ring having 6 to 30 ring members providing Ar ¹ is preferably a benzene ring or a naphthalene ring.

The carboxylate group (—COO ⁻ ) and the hydroxyl group in the formula (1) are preferably respectively bonded to adjacent carbon atoms constituting Ar ¹ . In other words, the carboxylate group and the hydroxyl group are preferably bonded at the ortho positions of the same benzene ring in Ar ¹ . Furthermore, in other words, it is preferable that the carbon atom on Ar ¹ to which the carboxylate group is bonded is directly bonded to the carbon atom on Ar ¹ to which the hydroxyl group is bonded. In this case, the storage stability of the radiation sensitive resin composition can be improved.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹ include those exemplified as the monovalent organic group having 1 to 20 carbon atoms represented by R ⁴ in the formula (2-2). Same basis etc.

The halogen atom represented by ^R1 is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

R ¹ is preferably a halogen atom, more preferably an iodine atom.

As a, 0-2 are preferable, 0 or 1 is more preferable, and 0 is still more preferable.

Examples of the divalent linking group represented by ^L include: ether group (-O-), carbonyloxy group (-CO-O-), oxycarbonyl group (-O-CO-), carbonyl sulfide group ( -CO-S-), thioether group (-S-), thiocarbonyl group (-CS-), sulfonyl group (-SO ₂ -), alkanediyl group with 1 to 5 carbon atoms, or a combination of these base etc.

L ¹ is preferably a carbonyloxy group, an oxycarbonyl group, an ether group, a thioether group, an alkanediyl group having 1 to 5 carbon atoms, or a combination thereof, and is more preferably a carbonyloxy group or a methanediyl group. oxy (-CH ₂ -O-), methanediylsulfide (-CH ₂ -S-) or oxycarbonylmethanediyloxy (-O-CO-CH ₂ -O-).

Moreover, when combining the said divalent linking group, it may be preferable not to combine the same kind of group. In other words, as L ¹ , carbonyloxy group, oxycarbonyl group, ether group, thioether group, alkanediyl group having 1 to 5 carbon atoms, or a combination thereof (wherein the combination Except for the case of two or more bases of the same kind). Furthermore, for example, the oxycarbonylmethanediyloxy group can also be understood as a group formed by combining two ether groups, carbonyl groups, and methanediyl groups. However, "carbonyl" is not contained in the above-mentioned exemplary divalent linking group. Therefore, it is considered that a combination of an oxycarbonyl group, a methanediyl group, and an ether group is treated as inconsistent with a combination of two or more groups of the same type. On the other hand, for example, an oxymethanediyloxy group (—O—CH ₂ —O—) is a group formed by combining two ether groups, so it is treated as a combination of two or more groups of the same type.

As the monovalent aromatic hydrocarbon group having 6 to 20 carbons in R ² , for example, the carbon number 6 in the monovalent organic group having 1 to 20 carbons in R ⁴ in the formula (2-2) can be mentioned. The groups exemplified are the same groups as monovalent aromatic hydrocarbon groups of ~20.

R ² is preferably a substituted or unsubstituted aryl group, more preferably a substituted or unsubstituted phenyl group or a substituted or unsubstituted naphthyl group.

Examples of substituents that the aromatic hydrocarbon group represented by R ² may include: halogen atoms such as fluorine atoms and iodine atoms, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, alkoxy groups, alkoxycarbonyl groups, Alkoxycarbonyloxy, acyl, acyloxy, etc. Among these, a fluorine atom, an iodine atom, or an alkoxy group is preferable, and an iodine atom is more preferable.

R ² is more preferably a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms in which at least one hydrogen atom on the aromatic ring is replaced by an iodine atom. In this case, the sensitivity to exposure light can be further improved.

Examples of the monovalent radiation-sensitive onium cation represented by X ⁺ include the monovalent radiation-sensitive onium cation exemplified as Y ⁺ in the formula (4), and the like. X ⁺ is preferably the above-mentioned cation (ra), more preferably a cation (ra-1) to a cation (ra-13).

The compound [D] is preferably a compound represented by the following formula (1-1) to formula (1-14).

[chemical 14]

In the formula (1-1) to formula (1-13), X ⁺ has the same meaning as the formula (1).

The lower limit of the content ratio of the [D] compound in the radiation sensitive resin composition is preferably 1 mol %, more preferably 5 mol % with respect to 100 mol % of the [C] acid generator, and further Preferably it is 10 mole%. The upper limit of the content ratio is preferably 200 mol%, more preferably 100 mol%, still more preferably 50 mol%, and most preferably 25 mol%. By making the content ratio of [D] compound into the said range, the sensitivity to exposure light of the resist pattern formed from this radiation sensitive resin composition, CDU performance, and resolution can be improved further.

＜[E]Organic solvent＞ The radiation-sensitive resin composition usually contains [E] an organic solvent. [E] The organic solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least [A] polymer, [C] acid generator, [D] compound, and optionally other optional components.

Examples of the [E] organic solvent include alcohol-based solvents, ether-based solvents, ketone-based solvents, amide-based solvents, ester-based solvents, and hydrocarbon-based solvents. The radiation sensitive resin composition may contain one kind or two or more kinds of [E] organic solvents.

Examples of alcohol-based solvents include aliphatic monoalcohol-based solvents having 1 to 18 carbon atoms such as 4-methyl-2-pentanol and n-hexanol, and alicyclic monoalcohols having 3 to 18 carbon atoms such as cyclohexanol. 1,2-propanediol and other polyol-based solvents with 2 to 18 carbon atoms, propylene glycol monomethyl ether and other polyol-based partial ether solvents with 3-19 carbon atoms, etc.

Examples of ether solvents include dialkyl ether solvents such as diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, diisopentyl ether, dihexyl ether, diheptyl ether, tetrahydrofuran, tetrahydropyran Cyclic ether-based solvents such as diphenyl ether, anisole and other aromatic ring-containing ether-based solvents, etc.

Examples of ketone-based solvents include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-isobutyl ketone, and 2-heptanone , ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-isobutyl ketone, trimethyl nonanone and other chain ketone solvents, cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone , Methylcyclohexanone and other cyclic ketone solvents, 2,4-pentanedione, acetonylacetone, acetophenone, etc.

Examples of amide-based solvents include cyclic amide-based solvents such as N,N'-dimethylimidazolidone and N-methylpyrrolidone, N-methylformamide, N,N-di Methylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylacrylamide and other chains Amide-based solvents, etc.

Examples of ester-based solvents include monocarboxylic acid ester-based solvents such as n-butyl acetate and ethyl lactate, lactone-based solvents such as γ-butyrolactone and valerolactone, and polyhydric alcohol carboxylic acid esters such as propylene glycol acetate. Polyol partial ether carboxylate-based solvents such as propylene glycol monomethyl ether acetate, polycarboxylic acid diester-based solvents such as diethyl oxalate, and carbonate-based solvents such as dimethyl carbonate and diethyl carbonate wait.

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

[E] The organic solvent is preferably an alcohol-based solvent, an ester-based solvent, or a combination thereof, more preferably a polyol partial ether-based solvent having 3 to 19 carbon atoms, a polyol partial ether carboxylate-based solvent, or the like. Some combinations, and then preferably propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate or these combinations.

When the radiation-sensitive resin composition contains [E] organic solvent, the lower limit of the content ratio of [E] organic solvent is preferably 50% with respect to all components contained in the radiation-sensitive resin composition. % by mass, more preferably 60% by mass, further preferably 70% by mass, particularly preferably 80% by mass. The upper limit of the content ratio is preferably 99.9% by mass, more preferably 99.5% by mass, and still more preferably 99.0% by mass.

＜Other optional ingredients＞ Examples of other optional components include acid diffusion controllers, surfactants, and the like other than the above-mentioned [D] compound. The radiation-sensitive resin composition may contain one or two or more other optional components.

＜Resist pattern formation method＞ The resist pattern forming method includes: a step of directly or indirectly coating a radiation-sensitive resin composition on a substrate (hereinafter also referred to as "coating step"); The step of exposing the resist film (hereinafter also referred to as "exposure step"); and the step of developing the exposed resist film (hereinafter also referred to as "development step").

According to the resist pattern forming method, by using the radiation-sensitive resin composition as the radiation-sensitive resin composition in the coating step, it is possible to form a resist pattern with good sensitivity to exposure light, CDU performance, and resolving power. Excellent resist patterning.

Each step included in this resist pattern forming method will be described below.

[Coating procedure] In this step, the radiation-sensitive resin composition is directly or indirectly coated on the substrate. Thereby, a resist film can be directly or indirectly formed on the substrate.

In this step, the radiation-sensitive resin composition is used as the radiation-sensitive resin composition.

Examples of the substrate include conventionally known ones such as silicon wafers, silicon dioxide, and aluminum-coated wafers.

As an application method, for example, spin coating (spin coating), cast coating, roll coating, etc. are mentioned. After coating, in order to volatilize the solvent in the coating film, prebake (hereinafter, also referred to as "PB") may be performed if necessary. The lower limit of the temperature of PB is preferably 60°C, more preferably 80°C. The upper limit of the temperature is preferably 150°C, more preferably 140°C. The lower limit of the PB time is preferably 5 seconds, more preferably 10 seconds. The upper limit of the time is preferably 600 seconds, more preferably 300 seconds. The lower limit of the average thickness of the resist film to be formed is preferably 10 nm, more preferably 20 nm. The upper limit of the average thickness is preferably 1,000 nm, more preferably 500 nm.

[Exposure steps] In this step, the resist film formed in the coating step is exposed. This exposure is performed by irradiating exposure light through a photomask (if necessary, through a liquid immersion medium such as water). As exposure light, far ultraviolet light, EUV or electron beam is preferable, ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), EUV (wavelength 13.5 nm) or electron beam is more preferable, Further preferred is KrF excimer laser light, EUV or electron beam, particularly preferably EUV or electron beam.

It is preferable to perform a post-exposure bake (Post Exposure Bake) (hereinafter also referred to as "PEB") after the exposure. According to this PEB, the difference in solubility with respect to a developing solution can be enlarged between an exposed part and an unexposed part. The lower limit of the temperature of PEB is preferably 50°C, more preferably 80°C, and still more preferably 100°C. The upper limit of the temperature is preferably 180°C, more preferably 130°C. The lower limit of the PEB time is preferably 5 seconds, more preferably 10 seconds, and still more preferably 30 seconds. The upper limit of the time is preferably 600 seconds, more preferably 300 seconds, and still more preferably 100 seconds.

[Development procedure] In this step, the exposed resist film is developed. Thereby, a predetermined resist pattern can be formed. The developing method in the developing step may be alkali developing or organic solvent developing.

In the case of alkali development, examples of the developer used for development include dissolving sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, ethylamine, n-propylamine, Diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (Tetramethyl Ammonium Hydroxide) (hereinafter, also known as is "TMAH"), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, 1,5-diazabicyclo-[4.3.0]- An alkaline aqueous solution or the like of at least one basic compound such as 5-nonene. Among these, TMAH aqueous solution is preferable, and 2.38 mass % TMAH aqueous solution is more preferable.

In the case of organic solvent development, examples of the developer include organic solvents such as hydrocarbon-based solvents, ether-based solvents, ester-based solvents, ketone-based solvents, and alcohol-based solvents, and solutions containing the organic solvents. As said organic solvent, the solvent etc. which were illustrated as [D] organic solvent of the said radiation sensitive resin composition are mentioned, for example.

＜Compound＞ This compound is demonstrated as [D] compound in the said radiation sensitive resin composition. This compound can be suitably used as a component of a radiation sensitive resin composition. In addition, this compound can be suitably used as an acid diffusion controller. [Example]

Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The measurement method of each physical property value is shown below.

[Weight average molecular weight (Mw), number average molecular weight (Mn) and degree of dispersion (Mw/Mn)] The Mw and Mn of the polymer are measured according to the conditions described in the section of [Measuring method of Mw and Mn]. The degree of dispersion (Mw/Mn) of the polymer was calculated from the measurement results of Mw and Mn.

＜Synthesis of [D] compound＞ [Synthesis Example 1-1] Synthesis of Compound (D-1) Disperse sodium hydroxide (41.6 mmol) in a container with N,N-dimethylformamide (10 mL). A solution of 2,4-dihydroxybenzoic acid (10.0 mmol) in N,N-dimethylformamide (7.5 mL) was added dropwise to the vessel at room temperature over 1 hour. Then, a solution of 2-(bromomethyl)naphthalene (10.0 mmol) in N,N-dimethylformamide (7.5 mL) was added dropwise over 1 hour at room temperature. After completion of the dropwise addition, the mixture was further stirred at room temperature for 2 hours. After cooling to below 10°C, add 1 mol/L hydrochloric acid (100 mL) to stop the reaction. The precipitated solid is filtered, washed with distilled water and dichloromethane respectively, and the compound (2-hydroxyl-4-(naphthalene-2-ylmethoxy)benzoic acid represented by the following formula (pD-1) is obtained ; hereinafter, also referred to as "compound (pD-1)").

Mix compound (pD-1) (8.20 mmol), sodium bicarbonate (16.4 mmol), triphenylcaldium chloride (12.3 mmol), dichloromethane (82 mL) and distilled water (82 mmol), at room temperature Stir for 3 hours. After completion of the reaction, liquid separation was performed, and the organic layer was dried with anhydrous sodium sulfate and filtered. The solvent was distilled off to obtain a compound represented by the following formula (D-1) (hereinafter also referred to as "compound (D-1)").

The synthesis scheme of compound (D-1) is shown below.

[chemical 15]

[Synthesis Example 1-2 to Synthesis Example 1-14] Synthesis of Compound (D-2) to Compound (D-14) Compounds represented by the following formula (D-2) to formula (D-14) (hereinafter also referred to as "compound (D-2) to compound (D -14)").

[chemical 16]

＜Synthesis of [A] Polymer＞ In the synthesis of the [A] polymer, monomers represented by the following formula (M-1) to formula (M-11) (hereinafter also referred to as "monomer (M-1) to monomer Body (M-11)"). In the following synthesis examples, unless otherwise specified, "parts by mass" means the value when the total mass of the monomers used is 100 parts by mass, and "mole%" means the value when the total mass of the monomers used is 100 parts by mass. The value when the total molar number of the measuring body is 100 mole %.

[chemical 17]

[Synthesis Example 2-1] Synthesis of Polymer (A-1) Monomer (M-1), monomer (M-5) and monomer (M-8) were dissolved in propylene glycol-1-monomethyl ether (200 parts by mass). 7 mol % of 2,2'-azobis(methyl isobutyrate) was added as an initiator to prepare a monomer solution. On the other hand, propylene glycol monomethyl ether (100 parts by mass relative to the total amount of monomers) was put into an empty container, and it heated to 85 degreeC, stirring. The monomer solution was added dropwise to the container over a period of 3 hours. After completion of the dropwise addition, the polymerization solution was cooled to room temperature after further heating at 85° C. for 3 hours. The polymerization solution was added dropwise to n-hexane (1,000 parts by mass) to coagulate and refine the polymer.

The polymer was again added and dissolved in propylene glycol monomethyl ether (150 parts by mass). Methanol (150 parts by mass), triethylamine (1.5 molar equivalents relative to the amount of compound (M-1) used) and water (1.5 molar equivalents relative to the amount of compound (M-1) used) were added thereto. molar equivalent). Reflux at the boiling point for 8 hours to carry out the hydrolysis reaction. After completion of the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the obtained polymer was dissolved in acetone (150 parts by mass). This was added dropwise to water (2,000 parts by mass) to solidify, and the generated white powder was separated by filtration. After drying at 50° C. for 17 hours, a white powdery polymer (A-1) was obtained in good yield. Mw of the polymer (A-1) was 7,200, and Mw/Mn was 1.5.

[Synthesis Example 2-2 to Synthesis Example 2-8] Synthesis of Polymer (A-2) to Polymer (A-8) Polymer (A-2) to polymer (A-8) were synthesized in the same manner as in Synthesis Example 1, except that monomers of the types and blending ratios shown in Table 1 below were used.

[Table 1] [A] polymer Provides the monomer of the structural unit (I) Monomer providing structural unit (II) Monomers that provide other building blocks mw Mw/Mn type Dosage (mole%) type Dosage (mole%) type Dosage (mole%) Synthesis Example 2-1 A-1 M-5 45 M-1 45 M-8 10 7200 1.5 Synthesis example 2-2 A-2 M-5 55 M-1 25 - - 5300 1.4 M-2 20 Synthesis example 2-3 A-3 M-6 55 M-2 45 - - 4200 1.3 Synthesis Example 2-4 A-4 M-7 40 M-2 30 - - 6800 1.6 M-3 30 Synthesis example 2-5 A-5 M-7 70 M-1 30 - - 5700 1.5 Synthesis Example 2-6 A-6 M-6 50 M-1 35 M-9 15 8500 1.5 Synthesis Example 2-7 A-7 M-4 60 M-1 30 M-10 10 6300 1.5 Synthesis Example 2-8 A-8 M-4 30 M-1 35 - - 4800 1.4 M-7 35

＜Synthesis of [B] Polymer＞ [Synthesis Example 3-1] Synthesis of Polymer (B-1) The monomer (M-7) and the monomer (M-11) were dissolved in 2-butanone (100 parts by mass) so that the molar ratio became 70/30. 5 mol% of azobisisobutyronitrile was added as a starter to prepare a monomer solution. On the other hand, 2-butanone (50 parts by mass) was put into an empty container, and nitrogen flushing was performed for 30 minutes. The inside of the container was heated to 80° C., and the monomer solution was added dropwise over 3 hours while stirring. After completion|finish of dripping, after heating at 80 degreeC for 3 hours, the polymerization solution was water-cooled and cooled to 30 degreeC or less. After transferring the polymerization solution to a separatory funnel, hexane (150 parts by mass) was added to uniformly dilute the polymerization solution, and methanol (600 parts by mass) and water (30 parts by mass) were added and mixed. After standing still for 30 minutes, the lower layer was recovered, and the solvent was replaced with propylene glycol monomethyl ether acetate. In this way, a propylene glycol monomethyl ether acetate solution containing the polymer (B-1) was obtained. Mw of the polymer (B-1) was 7,800, and Mw/Mn was 1.8.

＜Preparation of radiation-sensitive resin composition＞ The [C] acid generator, [D] acid diffusion controller, and [E] organic solvent used in the preparation of the radiation-sensitive resin composition are shown below. In the following examples and comparative examples, unless otherwise specified, "parts by mass" refers to the value when the mass of the [A] polymer used is 100 parts by mass, and "mol %" refers to the The number of moles of the [C] acid generator to be used is a value when 100 mol % is used.

[[C] acid generator] As the [C] acid generator, compounds represented by the following formula (C-1) to formula (C-10) (hereinafter also referred to as "acid generator (C-1) to acid generator (C- 10)").

[chemical 18]

[[D] Acid Diffusion Control Agent] As the [D] acid diffusion control agent, compounds represented by the above-mentioned compound (D-1) to compound (D-14) and the following formula (d-1) to formula (d-2) (hereinafter also referred to as as "compound (d-1) to compound (d-2)").

[chemical 19]

[[E]organic solvent] As [E] the organic solvent, the following (E-1) and (E-2) were used. (E-1): Propylene glycol monomethyl ether acetate (E-2): Propylene glycol monomethyl ether

[Example 1] Preparation of radiation-sensitive resin composition (R-1) 100 parts by mass of (A-1) as [A] polymer, 1 part by mass of (B-1) as [B] polymer, 22 parts by mass of (C-1) as [C] acid generator, 5,500 parts by mass of (E-1) and (E-2) as [D] acid diffusion control agent and [E] organic solvent at 20 mol % relative to (C-1) 1,500 parts by mass are mixed. The obtained mixed solution was filtered through a membrane filter with a pore size of 0.20 μm, thereby preparing a radiation-sensitive resin composition (R-1).

[Example 2 to Example 30 and Comparative Example 1 to Comparative Example 2] Radiation sensitive resin composition (R-2) to radiation sensitive resin composition (R-30) and radiation sensitive resin composition (CR- 1) ~Preparation of radiation-sensitive resin composition (CR-2) The radiation sensitive resin composition (R-2) to the radiation sensitive resin composition (R-30) and the radiation sensitive Sexual resin composition (CR-1) ~ radiation sensitive resin composition (CR-2).

[Table 2] Radiation Sensitive Resin Composition [A] polymer [B] polymer [C] acid generator [D] Acid diffusion control agent [E] solvent type Content (parts by mass) type Content (parts by mass) type Content (parts by mass) type Content (mole%) type Content (parts by mass) Example 1 R-1 A-1 100 B-1 1 C-1 twenty two D-1 20 E-1/E-2 5500/1500 Example 2 R-2 A-1 100 B-1 1 C-1 twenty two D-2 20 E-1/E-2 5500/1500 Example 3 R-3 A-1 100 B-1 1 C-1 twenty two D-3 20 E-1/E-2 5500/1500 Example 4 R-4 A-1 100 B-1 1 C-1 twenty two D-4 20 E-1/E-2 5500/1500 Example 5 R-5 A-1 100 B-1 1 C-1 twenty two D-5 20 E-1/E-2 5500/1500 Example 6 R-6 A-1 100 B-1 1 C-1 twenty two D-6 20 E-1/E-2 5500/1500 Example 7 R-7 A-1 100 B-1 1 C-1 twenty two D-7 20 E-1/E-2 5500/1500 Example 8 R-8 A-1 100 B-1 1 C-1 twenty two D-8 20 E-1/E-2 5500/1500 Example 9 R-9 A-1 100 B-1 1 C-1 twenty two D-9 20 E-1/E-2 5500/1500 Example 10 R-10 A-1 100 B-1 1 C-1 twenty two D-10 20 E-1/E-2 5500/1500 Example 11 R-11 A-1 100 B-1 1 C-1 twenty two D-11 20 E-1/E-2 5500/1500 Example 12 R-12 A-1 100 B-1 1 C-1 twenty two D-12 20 E-1/E-2 5500/1500 Example 13 R-13 A-1 100 B-1 1 C-1 twenty two D-13 20 E-1/E-2 5500/1500 Example 14 R-14 A-1 100 B-1 1 C-1 twenty two D-14 20 E-1/E-2 5500/1500 Example 15 R-15 A-2 100 B-1 1 C-1 twenty two D-4 20 E-1/E-2 5500/1500 Example 16 R-16 A-3 100 B-1 1 C-1 twenty two D-4 20 E-1/E-2 5500/1500 Example 17 R-17 A-4 100 B-1 1 C-1 twenty two D-4 20 E-1/E-2 5500/1500 Example 18 R-18 A-5 100 B-1 1 C-1 twenty two D-4 20 E-1/E-2 5500/1500 Example 19 R-19 A-6 100 B-1 1 C-1 twenty two D-4 20 E-1/E-2 5500/1500 Example 20 R-20 A-7 100 B-1 1 C-1 twenty two D-4 20 E-1/E-2 5500/1500 Example 21 R-21 A-8 100 B-1 1 C-1 twenty two D-4 20 E-1/E-2 5500/1500 Example 22 R-22 A-1 100 B-1 1 C-2 twenty two D-4 20 E-1/E-2 5500/1500 Example 23 R-23 A-1 100 B-1 1 C-3 twenty two D-4 20 E-1/E-2 5500/1500 Example 24 R-24 A-1 100 B-1 1 C-4 twenty two D-4 20 E-1/E-2 5500/1500 Example 25 R-25 A-1 100 B-1 1 C-5 twenty two D-4 20 E-1/E-2 5500/1500 Example 26 R-26 A-1 100 B-1 1 C-6 twenty two D-4 20 E-1/E-2 5500/1500 Example 27 R-27 A-1 100 B-1 1 C-7 twenty two D-4 20 E-1/E-2 5500/1500 Example 28 R-28 A-1 100 B-1 1 C-8 twenty two D-4 20 E-1/E-2 5500/1500 Example 29 R-29 A-1 100 B-1 1 C-9 twenty two D-4 20 E-1/E-2 5500/1500 Example 30 R-30 A-1 100 B-1 1 C-10 twenty two D-4 20 E-1/E-2 5500/1500 Comparative example 1 CR-1 A-1 100 B-1 1 C-1 twenty two d-1 20 E-1/E-2 5500/1500 Comparative example 2 CR-2 A-1 100 B-1 1 C-1 twenty two d-2 20 E-1/E-2 5500/1500

＜Formation of resist pattern＞ Using a spin coater ("CLEAN TRACK ACT12" of Tokyo Electron Co., Ltd.), each of the prepared radiation-sensitive resin compositions was coated on a surface with an average thickness of 20 nm. The underlayer film ("AL412" from Brewer Science) was placed on the surface of a 12-inch silicon wafer. After pre-baking (PB) at 130° C. for 60 seconds, it was cooled at 23° C. for 30 seconds to form a resist film with an average thickness of 30 nm. Next, use an EUV exposure machine (ASML's "NXE3300", numerical aperture (NA) = 0.33, lighting conditions: conventional (Conventional) s = 0.89, mask imecDEFECT32FFR02) to the antibody The etchant film is irradiated with EUV light. After irradiation, the resist film was subjected to a post-exposure bake (PEB) at 130° C. for 60 seconds. Next, development was performed at 23° C. for 30 seconds using a 2.38% by mass TMAH aqueous solution to form a positive contact hole pattern (diameter: 25 nm, pitch: 50 nm).

＜Evaluation＞ About each resist pattern formed above, sensitivity, CDU performance, and resolution were evaluated according to the following method. For the length measurement of the resist pattern, a scanning electron microscope ("CG-4100" of Hitachi High-Tech Co., Ltd.) was used. The evaluation results are shown in Table 3 below.

[Sensitivity] In the formation of the resist pattern, the exposure dose for forming a contact hole pattern with a diameter of 25 nm was taken as the optimum exposure dose, and the optimum exposure dose was defined as Eop (mJ/cm ² ). Regarding the sensitivity, the case where Eop was 60 mJ/cm ² or less was judged as "good", and the case where Eop was more than 60 mJ/cm ² was judged as "poor".

[CDU performance] The resist pattern was observed from above using the scanning electron microscope, and the diameters of a total of 800 contact hole patterns were measured at arbitrary locations, and a 3-sigma value was obtained from the distribution of the measured values, which was defined as CDU (unit: nm ). With regard to the CDU performance, the smaller the value of the CDU, the smaller the variation in the aperture diameter in the long period is, and the better it is. Regarding the CDU performance, the case where the CDU was 4.5 nm or less was evaluated as "good", and the case where the CDU exceeded 4.5 nm was evaluated as "poor".

[analytic] In the formation of the resist pattern, the diameter of the smallest contact hole pattern resolved when the exposure amount was changed was measured, and the measured value was defined as the resolution (unit: nm). Regarding resolution, the smaller the value of the resolution, the better it is. Regarding the resolution, the case where the resolution was 22 nm or less was evaluated as "good", and the case where the resolution exceeded 22 nm was evaluated as "poor".

[table 3] Radiation Sensitive Resin Composition Eop (mJ/cm ² ) CDU (nm) Resolution (nm) Example 1 R-1 55 4.2 twenty two Example 2 R-2 58 4.3 twenty one Example 3 R-3 52 3.7 19 Example 4 R-4 45 3.9 19 Example 5 R-5 48 4.2 18 Example 6 R-6 55 3.7 18 Example 7 R-7 57 3.8 19 Example 8 R-8 53 3.9 20 Example 9 R-9 48 4.1 18 Example 10 R-10 47 4.1 19 Example 11 R-11 40 3.6 17 Example 12 R-12 43 4.0 19 Example 13 R-13 49 3.9 18 Example 14 R-14 50 3.9 19 Example 15 R-15 51 3.9 19 Example 16 R-16 53 3.7 20 Example 17 R-17 47 4.0 20 Example 18 R-18 57 3.7 18 Example 19 R-19 49 3.9 19 Example 20 R-20 46 4.0 18 Example 21 R-21 50 3.9 18 Example 22 R-22 53 3.8 19 Example 23 R-23 51 3.9 20 Example 24 R-24 49 3.9 19 Example 25 R-25 50 3.8 20 Example 26 R-26 48 4.0 20 Example 27 R-27 52 4.0 18 Example 28 R-28 44 4.1 18 Example 29 R-29 48 4.2 18 Example 30 R-30 50 4.0 19 Comparative example 1 CR-1 65 5.0 25 Comparative example 2 CR-2 83 6.2 twenty three

Claims (8)

A radiation-sensitive resin composition comprising: a polymer whose solubility with respect to a developer is changed by the action of an acid, a radiation-sensitive acid generator, and a compound represented by the following formula (1), In formula (1), Ar ¹ is a group obtained by removing (a+b+2) hydrogen atoms from an aromatic hydrocarbon ring with 6 to 30 ring members; R ¹ is a monovalent organic compound with 1 to 20 carbons. group or halogen atom; L ¹ is a divalent linking group; R ² is a substituted or unsubstituted monovalent aromatic hydrocarbon group with 6 to 20 carbons; a is an integer of 0 to 10; b is an integer of 1 to 10 ; wherein, a+b is 10 or less; when a is more than 2, a plurality of R ¹ are the same or different; when b is more than 2, a plurality of L ¹ are the same or different, and a plurality of R ² The same or different from each other; X ⁺ is a monovalent radiation-sensitive onium cation. The radiation-sensitive resin composition according to claim 1, wherein ^R in the formula (1) is a monovalent aromatic hydrocarbon group with 6 to 20 carbons substituted by an iodine atom for at least one hydrogen atom on the aromatic ring . The radiation-sensitive resin composition according to Claim 1 or Claim 2, wherein ^L in the formula (1) is carbonyloxy, oxycarbonyl, ether, thioether, or carbon number 1 to 5 alkanediyl or a combination of these. The radiation-sensitive resin composition according to Claim 1, Claim 2 or Claim 3, wherein the carboxylate group and the hydroxyl group in the formula (1) are respectively bonded to adjacent carbon atoms constituting Ar ¹ . The radiation-sensitive resin composition according to any one of claims 1 to 4, wherein the polymer has a structural unit containing an acid-dissociative group. The radiation-sensitive resin composition according to claim 5, wherein the structural unit is represented by the following formula (2-1) or formula (2-2), In formula (2-1) and formula (2-2), R ³ is a hydrogen atom, fluorine atom, methyl or trifluoromethyl; Z is an acid dissociative group; in formula (2-2), L ² is Single bond, -COO-, -CONH- or -O-; Ar ² is a group formed by removing (s+t+u+1) hydrogen atoms from an aromatic hydrocarbon ring with 6 to 20 ring members; s is an integer of 0 to 10, t is an integer of 0 to 10; among them, s+t is an integer of 1 to 10; when s is 2 or more, multiple Zs are the same or different from each other; when s is 1 or more In this case, R ⁴ is a hydrogen atom or a monovalent organic group with 1 to 20 carbons; when t is 2 or more, multiple R ⁴ are the same or different from each other; when s is 0 and t is 1, R ⁴ is an acid dissociative group; when s is 0 and t is 2 or more, at least one of the multiple R ⁴ is an acid dissociative group; R ⁵ is a monovalent organic group with 1 to 20 carbons or a halogen atom ; u is an integer of 0 to 10; when u is 2 or more, a plurality of R ⁵ are the same or different from each other; wherein, s+t+u is 10 or less. A resist pattern forming method, comprising: A coating step of directly or indirectly coating the radiation-sensitive resin composition as described in any one of claim 1 to claim 6 on the substrate; a step of exposing the resist film formed by the applying step; and and developing the exposed resist film. A compound represented by the following formula (1), In formula (1), Ar ¹ is a group obtained by removing (a+b+2) hydrogen atoms from an aromatic hydrocarbon ring with 6 to 30 ring members; R ¹ is a monovalent organic compound with 1 to 20 carbons. group or halogen atom; L ¹ is a divalent linking group; R ² is a substituted or unsubstituted monovalent aromatic hydrocarbon group with 6 to 20 carbons; a is an integer of 0 to 10; b is an integer of 1 to 10 ; wherein, a+b is 10 or less; when a is more than 2, a plurality of R ¹ are the same or different; when b is more than 2, a plurality of L ¹ are the same or different, and a plurality of R ² The same or different from each other; X ⁺ is a monovalent radiation-sensitive onium cation.