TW202138914A - Radiation-sensitive resin composition, resist pattern formation method, and radiation-sensitive acid generator - Google Patents

Abstract

Provided are a radiation-sensitive resin composition, a resist pattern formation method, and a radiation-sensitive acid generator, with which it is possible to form a resist pattern having good sensitivity to light exposure and having excellent resolution and LWR performance. A radiation-sensitive resin composition containing: a polymer having a structural unit including an acid-dissociable group; and a radiation-sensitive acid generator including a compound represented by formula (1).

Description

Radiation-sensitive resin composition, resist pattern forming method, and radiation-sensitive acid generator

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

The radiation-sensitive resin composition used in microfabrication by lithography is made of ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), and other extreme ultraviolet and extreme ultraviolet light (wavelength 248 nm). , EUV) (wavelength 13.5 nm) and other electromagnetic waves, electron beams and other charged particle beams and other radioactive rays produce acid in the exposed part, and the exposed part and the non-exposed part are exposed to the developer by the chemical reaction with the acid as a catalyst The dissolving speed in the substrate is different, thereby forming a resist pattern on the substrate.

For the radiation-sensitive resin composition, in addition to having good sensitivity to exposure light such as extreme ultraviolet rays and electron beams, it is required to have excellent line width roughness (LWR) performance and resolution, which indicates the uniformity of line width.

In response to these requirements, the types and molecular structures of polymers, acid generators, and other components used in the radiation-sensitive resin composition have been studied, and their combinations have also been studied in detail (refer to 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 Literature]

[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

[The problem to be solved by the invention] At present, the miniaturization of resist patterns has advanced to a level below 40 nm in line width, and the required level of the performance is further improved, and the previous radiation-sensitive resin composition cannot meet the requirements.

The present invention has been completed based on the above circumstances, and its object is to provide a radiation-sensitive resin composition, a resist pattern forming method, and a resist pattern that can form a resist pattern with good sensitivity to exposure light, excellent LWR performance, and resolution. Radiation-sensitive acid generator. [Means to solve the problem]

（式（1）中，Ar¹ 為自環員數6～20的芳烴中去除（a+b+1）個的芳香環上的氫原子而成的基。Y為下述式（2）所表示的基。a為1～3的整數。於a為2以上的情況下，多個Y彼此相同或不同。b為0～5的整數。於b為1的情況下，R¹ 為碳數1～20的一價有機基、羥基、硝基或鹵素原子。於b為2以上的情況下，多個R¹ 彼此相同或不同，為碳數1～20的一價有機基、羥基、硝基或鹵素原子，或者為該些彼此結合並與該些所鍵結的碳原子一起構成的環員數4～20的脂環結構或環員數4～20的脂肪族雜環結構的一部分。n為1～3的整數。於n為1的情況下，多個R² 彼此相同或不同，為碳數1～20的一價有機基，或者為該些彼此結合並與該些所鍵結的硫原子一起構成的環員數5～20的芳香族雜環結構的一部分。於n為2的情況下，R² 為碳數1～20的一價有機基。於n為2以上的情況下，多個Ar¹ 彼此相同或不同，多個Y彼此相同或不同，多個R¹ 彼此相同或不同。X^- 為下述式（3）所表示的一價陰離子） [化2]

（式（2）中，*表示與所述式（1）中的Ar¹ 的鍵結部位。Z為-O-或-S-。L為單鍵或碳數1～20的二價有機基。Ar² 為自環員數6～20的芳烴中去除（c+1）個的芳香環上的氫原子而成的基。c為0～5的整數。於c為1的情況下，R³ 為碳數1～20的一價有機基、羥基、硝基或鹵素原子。於c為2以上的情況下，多個R³ 彼此相同或不同，為碳數1～20的一價有機基、羥基、硝基或鹵素原子，或者為該些彼此結合並與該些所鍵結的碳原子一起構成的環員數4～20的脂環結構或環員數4～20的脂肪族雜環結構的一部分） [化3]

（式（3）中，R^p1 為包含環員數5以上的環結構的一價基。R^p2 為二價連結基。R^p3 及R^p4 分別獨立地為氫原子、氟原子、碳數1～20的一價烴基或碳數1～20的一價氟化烴基。R^p5 及R^p6 分別獨立地為氟原子或碳數1～20的一價氟化烴基。n^p1 為0～10的整數。n^p2 為0～10的整數。n^p3 為0～10的整數。其中，n^p1 +n^p2 +n^p3 為1以上且30以下。於n^p1 為2以上的情況下，多個R^p2 彼此相同或不同。於n^p2 為2以上的情況下，多個R^p3 彼此相同或不同，多個R^p4 彼此相同或不同。於n^p3 為2以上的情況下，多個R^p5 彼此相同或不同，多個R^p6 彼此相同或不同）The invention completed to solve the above-mentioned problems is a radiation-sensitive resin composition containing: a polymer having a structural unit including an acid dissociable group (hereinafter, also referred to as "[A] polymer"); and The radiation-sensitive acid generator of the compound represented by the formula (1) (hereinafter, also referred to as "[B] acid generator"). [化1]

(In formula (1), Ar ¹ is a group obtained by removing (a+b+1) hydrogen atoms on an aromatic ring from an aromatic hydrocarbon with 6 to 20 ring members. Y is represented by the following formula (2) The group represented. a is an integer of 1 to 3. When a is 2 or more, a plurality of Ys are the same or different from each other. b is an integer of 0 to 5. When b is 1, R ¹ is the number of carbons A monovalent organic group of 1 to 20, a hydroxyl group, a nitro group or a halogen atom. When b is 2 or more, multiple R ¹ are the same or different from each other, and are a monovalent organic group of 1 to 20 carbons, a hydroxyl group, or a nitro group. A group or a halogen atom, or a part of an alicyclic structure having 4 to 20 ring members or an aliphatic heterocyclic structure having 4 to 20 ring members, which are bonded to each other and constituted together with the carbon atoms to which they are bonded. n is an integer of 1 to 3. When n is 1, a plurality of R ² are the same or different from each other and are a monovalent organic group having 1 to 20 carbons, or these are bonded to each other and bonded to these The sulfur atoms together constitute a part of an aromatic heterocyclic structure with 5-20 ring members. When n is 2, R ² is a monovalent organic group with 1-20 carbons. When n is 2 or more Below, a plurality of Ar ¹ are the same or different from each other, a plurality of Ys are the same or different from each other, and a plurality of R ¹ are the same or different from each other. X ^- is a monovalent anion represented by the following formula (3)) [化2]

(In formula (2), * represents ^{the bonding site with Ar 1} in the formula (1). Z is -O- or -S-. L is a single bond or a divalent organic group with 1 to 20 carbons 。 Ar ² is a group obtained by removing (c+1) hydrogen atoms on an aromatic ring from an aromatic hydrocarbon having 6 to 20 ring members. c is an integer of 0 to 5. When c is 1, R ³ is a monovalent organic group with 1 to 20 carbons, a hydroxyl group, a nitro group, or a halogen atom. When c is 2 or more, multiple R ³ are the same or different from each other, and are a monovalent organic group with 1 to 20 carbons , Hydroxy, nitro or halogen atoms, or these are bonded to each other and form an alicyclic structure with 4-20 ring members or aliphatic heterocyclic ring with 4-20 ring members together with the carbon atoms to which they are bonded Part of the structure) [化3]

(In formula (3), R ^p1 is a monovalent group including a ring structure with 5 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, and a carbon number of 1 A monovalent hydrocarbon group of -20 or a monovalent fluorinated hydrocarbon group of 1-20 carbons. R ^p5 and R ^p6 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group of 1-20 carbons. n ^p1 is 0-10 Integer. n ^p2 is an integer from 0 to 10. n ^p3 is an integer from 0 to 10. ^{Here, n p1} + n ^p2 + n ^p3 is 1 or more and 30 or less. When n ^p1 is 2 or more, a plurality of R ^{p2 is the} same or different from each other. When n ^p2 is 2 or more, multiple R ^p3 are the same or different from each other, and multiple R ^p4 are the same or different from each other. When n ^p3 is 2 or more, multiple R ^p5 are the same as each other Or different, multiple R ^p6 are the same or different from each other)

Another invention completed in order to solve the problem is a method of forming a resist pattern, including: directly or indirectly applying the radiation-sensitive resin composition to a substrate; And the step of exposing the formed resist film; and the step of developing the exposed resist film.

Another invention completed in order to solve the said subject is a radiation sensitive acid generator containing the compound represented by the said formula (1). [Effects of the invention]

According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, it is possible to form a resist pattern with good sensitivity to exposure light and excellent LWR performance and resolution. The radiation-sensitive acid generator of the present invention can be preferably used as a component of the radiation-sensitive resin composition. Therefore, the radiation-sensitive resin composition, the resist pattern forming method, and the radiation-sensitive acid generator can be preferably used in the processing process of semiconductor devices that are expected to be further miniaturized in the future.

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

＜Radiation-sensitive resin composition＞ This radiation-sensitive resin composition contains [A] a polymer and [B] an acid generator. This radiation-sensitive resin composition usually contains an organic solvent (hereinafter, also referred to as "[D] organic solvent"). The radiation-sensitive resin composition may also contain an acid diffusion control body (hereinafter, also referred to as "[C] acid diffusion control body") as a preferable component. This radiation sensitive resin composition may contain other arbitrary components within the range which does not impair the effect of this invention.

By containing the [A] polymer and [B] acid generator, the radiation-sensitive resin composition can form a resist pattern with good sensitivity to exposure light and excellent LWR performance and resolution. Although the reason why the radiation-sensitive resin composition exhibits the effect by including the structure is not necessarily clear, it can be estimated as follows, for example. That is, it is considered that when the [B] acid generator contained in the radiation-sensitive resin composition contains a specific compound, the acid generation efficiency caused by exposure is improved. As a result, the radiation-sensitive resin composition can be formed A resist pattern with good sensitivity to exposure light and excellent LWR performance and resolution.

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

＜[A] Polymer＞ [A] The polymer has a structural unit containing an acid-dissociable group (hereinafter, also referred to as "structural unit (I)").

[A] The polymer preferably further has a structural unit containing a phenolic hydroxyl group (hereinafter, also referred to as "structural unit (II)"). [A] The polymer preferably further has a structural unit (hereinafter referred to as "structural unit (III)") including a partial structure represented by the following formula (6) described later. [A] The polymer may further have other structural units (hereinafter, also simply referred to as "other structural units") other than the structural unit (I) to the structural unit (III). [A] The polymer may have one or two or more of each structural unit. The radiation-sensitive resin composition may contain one or two or more [A] polymers.

Hereinafter, each structural unit possessed by the [A] polymer will be described.

[Structural unit (I)] The structural unit (I) is a structural unit containing an acid-dissociable group. In the present specification, the "acid dissociable group" refers to a group that replaces a hydrogen atom in a carboxyl group, a hydroxyl group, and the like, and is a group that dissociates due to the action of an acid to provide a carboxyl group, a hydroxyl group, or the like. Due to the action of the acid generated by the [B] acid generator etc. by exposure, the acid dissociable group is dissociated, and the solubility of the [A] polymer in the developer between the exposed part and the non-exposed part is different, thereby A resist pattern can be formed.

As the structural unit (I), for example, structural units represented by the following formulas (4-1) to (4-3) (hereinafter, also referred to as "structural unit (I-1) to structural unit (I- 3)”) etc. In addition, for example, in the following formula (4-1), -C(R ^X )(R ^Y )(R ^Z ) bonded to an oxygen atom derived from a carboxyl group corresponds to an acid dissociable group.

[化4]

In the formula (4-1), formula (4-2), and formula (4-3), R ^{T is} each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

In the formula (4-1), R ^X is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^Y and R ^Z are each independently a monovalent hydrocarbon group having 1 to 20 carbons, or an alicyclic structure having 3 to 20 ring members formed by combining these groups with the carbon atoms to which they are bonded Part.

In the formula (4-2), 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. R ^D is a divalent hydrocarbon group having 1 to 20 carbons that forms an unsaturated alicyclic structure having 4 to 20 ring members together with the carbon atoms to which ^{R A} , R ^B and R ^{C are respectively bonded.}

In the formula (4-3), R ^U and R ^V are each independently a hydrogen atom or a monovalent hydrocarbon group with ^{1 to 20 carbons, and R W} is a monovalent hydrocarbon group with 1 to 20 carbons, or R ^U and R ^{V is} bonded to each other and forms part of an alicyclic structure with 3 to 20 ring members together with the bonded carbon atoms, or is a carbon atom where ^{R U} and R ^W are bonded to each other and bonded to R ^{U and} The oxygen atom to which R ^W is bonded together constitutes a part of an aliphatic heterocyclic structure having 4 to 20 ring members.

In this specification, the "carbon number" refers to the number of carbon atoms constituting the group. In addition, in this specification, the "number of ring members" refers to the number of atoms of the rings constituting the alicyclic structure, aromatic carbocyclic structure, aliphatic heterocyclic structure, and aromatic heterocyclic structure. In the case of polycyclic rings, Refers to the number of atoms constituting the polycyclic ring.

In this specification, 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 contain a cyclic structure but is composed of only a chain structure, and includes both a linear hydrocarbon group and a branched hydrocarbon group. The "alicyclic hydrocarbon group" refers to a hydrocarbon group containing only an alicyclic structure as a ring structure and not an aromatic ring structure, and includes both a monocyclic alicyclic hydrocarbon group and a polycyclic alicyclic hydrocarbon group. Among them, it is not necessary to include only an alicyclic structure, and a chain structure may be included in a part thereof. The "aromatic hydrocarbon group" refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. Among them, it is not necessary to include only an aromatic ring structure, and a chain structure or an alicyclic structure may be included in a part thereof.

Examples of the monovalent hydrocarbon group having 1 to 20 carbons represented by R ^X , R ^Y , R ^Z , R ^B , R ^C , R ^U , R ^V or R ^{W include: a monovalent chain having 1 to 20 carbons} Like hydrocarbon groups, monovalent alicyclic hydrocarbon groups with 3 to 20 carbons, monovalent aromatic hydrocarbon groups with 6 to 20 carbons, etc.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, second butyl, isobutyl, and tertiary butyl. Group; alkenyl groups such as vinyl, propenyl, butenyl; alkynyl groups such as ethynyl, propynyl, butynyl, etc.

Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include alicyclic saturated hydrocarbon groups such as cyclopentyl, cyclohexyl, norbornyl, adamantyl, tricyclodecyl, and tetracyclododecyl. ; Cyclopentenyl, cyclohexenyl, norbornenyl, tricyclodecenyl, tetracyclododecenyl and other alicyclic unsaturated hydrocarbon groups.

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

Examples of the alicyclic structure having 3 to 20 ring members formed by R ^Y and R ^Z bonded together with the carbon atoms to which they are bonded include: cyclopropane structure, cyclobutane structure, cyclopentane structure, Monocyclic saturated alicyclic structures such as cyclohexane structure; polycyclic saturated alicyclic structures such as norbornane structure and adamantane structure; cyclopropene structure, cyclobutene structure, cyclopentene structure, cyclohexene structure, etc. Unsaturated alicyclic structure of the ring; polycyclic unsaturated alicyclic structure such as norbornene structure, etc.

Examples of the divalent hydrocarbon group having 1 to 20 carbons represented by R ^{D include those represented by R X} , R ^Y , R ^Z , R ^B , R ^C , R ^U , R ^V or R ^W. -20 monovalent hydrocarbon groups, among the exemplified groups, a group obtained by removing one hydrogen atom, etc.

Examples of the unsaturated alicyclic structure having 4 to 20 ring members formed by the carbon atoms to which R ^D is bonded with each of R ^A , R ^B and R ^{C include: cyclobutene structure, cyclopentene structure, and ring} Monocyclic unsaturated alicyclic structures such as hexene structure; polycyclic unsaturated alicyclic structures such as norbornene structure, etc.

Examples of R ^U and R ^V are bonded to each other and form an alicyclic structure with 3 to 20 ring members together with the carbon atoms to which they are bonded. For example, R ^Y and R ^Z are bonded to each other and are bonded to each other. The exemplified structure is the same as an alicyclic structure having 3 to 20 ring members formed by the carbon atoms of the junction together.

Examples of an aliphatic heterocyclic structure with 4 to 20 ring members formed by R ^U and R ^W bonded together with the carbon atom ^{to which R U is bonded and the oxygen atom to which R W is bonded include: an oxygen heterocyclic ring} Heterocyclic structures containing saturated oxygen such as butane structure, oxolane structure, and oxane structure; oxetene structure, oxolene structure, and oxolene structure containing unsaturation The heterocyclic structure of oxygen, etc.

As R ^T , a hydrogen atom or a methyl group is preferable from the viewpoint of providing the copolymerizability of the monomer of the structural unit (I).

R ^{X is} preferably a chain hydrocarbon group or an aromatic hydrocarbon group, more preferably an alkyl group or an aryl group, and still more preferably a methyl group, an ethyl group, an isopropyl group, a tertiary butyl group, or a phenyl group.

R ^Y and R ^{Z are} preferably a part of an alicyclic structure having 3 to 20 ring members, which is bonded to each other and constitutes with the carbon atoms to which they are bonded. The alicyclic structure is preferably a saturated alicyclic structure, more preferably a monocyclic saturated alicyclic structure, and still more preferably a cyclopentane structure or a cyclohexane structure.

As R ^B , a hydrogen atom is preferred.

R ^{C is} preferably a hydrogen atom or a chain hydrocarbon group, more preferably a hydrogen atom or an alkyl group, and still more preferably a hydrogen atom or a methyl group.

As an unsaturated alicyclic structure having 4 to 20 ring members formed by the carbon atoms to which ^{R D} is bonded with each of R ^A , R ^B and R ^{C, a monocyclic unsaturated alicyclic structure is preferred, and more preferred is} Cycloheptane structure or cyclohexene structure.

As the structural unit (I), the structural unit (I-1) or the structural unit (I-2) is preferable.

The structural unit (I-1) is preferably a structural unit represented by the following formula (4-1-1) to formula (4-1-5) (hereinafter, also referred to as "structural unit (I-1- 1) ~ Structural unit (I-1-5)").

[化5]

In the formulas (4-1-1) to (4-1-5), R ^T has the same meaning as the formula (4-1).

The structural unit (I-2) is preferably a structural unit represented by the following formula (4-2-1) to formula (4-2-2) (hereinafter, also referred to as "structural unit (I-2- 1) ~ Structural unit (I-2-2)”).

[化6]

In the formula (4-2-1) and the formula (4-2-2), R ^T has the same meaning as the formula (4-2).

The lower limit of the content ratio of the structural unit (I) in the [A] polymer is preferably 30 mol%, more preferably 40 mol%, and still more preferably, relative to all the structural units constituting the [A] polymer It is 50 mol%. The upper limit of the content ratio is preferably 90 mol%, more preferably 80 mol%, and still more preferably 70 mol%. By setting the content ratio of the structural unit (I) in the above range, the sensitivity of the radiation-sensitive resin composition to exposure light, LWR performance, and resolution can be further improved.

[Structural unit (II)] The structural unit (II) is a structural unit 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.

In the case of KrF exposure, EUV exposure or electron beam exposure, the [A] polymer has the structural unit (II), which can further improve the sensitivity of the radiation-sensitive resin composition to exposure light. Therefore, the radiation-sensitive resin composition can be preferably 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 formulas (5-1) to (5-14) (hereinafter, also referred to as "structural unit (II-1) to structural unit (II- 14)”) etc.

[化7]

In the formulas (5-1) to (5-14), 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, and more preferably a hydrogen atom, from the viewpoint of providing the copolymerizability of the monomer of the structural unit (II).

As the structural unit (II), the structural unit (II-1), the structural unit (II-2), or a combination of these are preferred.

When the [A] polymer contains the structural unit (II), the lower limit of the content ratio of the structural unit (II) in the [A] polymer is preferably relative to all the structural units constituting the [A] polymer It is 10 mol%, more preferably 20 mol%, and still more preferably 25 mol%. The upper limit of the content ratio is preferably 80 mol%, more preferably 60 mol%, and still more preferably 50 mol%. By setting the content ratio of the structural unit (II) in the above range, the sensitivity of the radiation-sensitive resin composition to exposure light, LWR performance, and resolution can be further improved.

[Structural unit (III)] The structural unit (III) is a structural unit containing a group represented by the following formula (6). [A] Since the polymer has the structural unit (III), the solubility in the developer can be adjusted appropriately. In addition, the [A] polymer can improve the adhesion between the resist pattern and the substrate by having the structural unit (III).

[化8]

In the formula (6), R ¹² is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R ¹³ and R ¹⁴ are each independently a fluorine atom or a C 1-10 monovalent fluorinated hydrocarbon group. ** represents the bonding site to the part other than the group represented by the above formula (5).

In this specification, the "organic group" refers to a group containing at least one carbon atom.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹² include: a monovalent hydrocarbon group having 1 to 20 carbon atoms, and a group containing a divalent heteroatom-containing group between carbon and carbon of the hydrocarbon group (α ), a group (β) in which part or all of the hydrogen atoms of the hydrocarbon group or the group (α) are substituted with a monovalent heteroatom-containing group, the hydrocarbon group, the group (α) or A group (γ) formed by combining the group (β) and a divalent heteroatom-containing group, etc.

As the monovalent hydrocarbon group having 1 to 20 carbon atoms, for example, R ^X , R ^Y , R ^Z , R ^B , R ^C , R ^{U in the above-mentioned formulas (4-1) to (4-3)} The monovalent hydrocarbon group having 1 to 20 carbons represented by ^{R V} or R ^{W is the same as the exemplified groups.}

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. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned.

As a divalent heteroatom-containing group, for example, -O-, -CO-, -S-, -CS-, -NR'-, a group formed by combining two or more of these, and the like can be cited. R'is a hydrogen atom or a monovalent hydrocarbon group.

Examples of the monovalent fluorinated hydrocarbon group having 1 to 10 carbons represented by R ¹³ or R ¹⁴ include groups in which at least one hydrogen atom of the monovalent hydrocarbon group having 1 to 10 carbons is substituted with a fluorine atom. Specifically, examples include: partially fluorinated alkyl groups such as fluoromethyl, difluoromethyl, difluoroethyl, trifluoroethyl, and trifluoropropyl; trifluoromethyl, pentafluoroethyl, and hexafluoropropyl Perfluoroalkyl groups and the like.

As R ¹² , a hydrogen atom is preferred.

R ¹³ and R ^{14 are} preferably a monovalent fluorinated hydrocarbon group having 1 to 10 carbons, more preferably a monovalent perfluoroalkyl group having 1 to 10 carbons, and still more preferably a trifluoromethyl group.

The group represented by the formula (6) is preferably hydroxybis(perfluoroalkyl)methyl, and more preferably hydroxybis(trifluoromethyl)methyl.

As the structural unit (III), for example, structural units represented by the following formula (6-1) to formula (6-2) (hereinafter, also referred to as "structural unit (III-1) to structural unit (III- 2)").

[化9]

In the above formulas (6-1) and (6-2), R ^Q is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z ^f is a group represented by the above formula (6).

In the formula (6-1), L ¹ is a single bond or a divalent organic group having 1 to 20 carbons.

In the formula (6-2), L ² is a single bond or a divalent organic group having 1 to 20 carbon atoms. R ¹⁵ , R ¹⁶ and R ¹⁷ are each independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. s is an integer of 1-4. When s is 2 or more, a plurality of R ^{15 are the} same or different, a plurality of R ^{16 are the} same or different, and a plurality of R ^{17 are the} same or different.

The divalent organic group having 1 to 20 carbons represented by ^{L 1} and L ² includes, for example, the monovalent organic group having 1 to 20 carbons represented by ^{R 12 of the formula (6).} A group formed by removing a hydrogen atom from the group, etc.

Examples of the monovalent organic group having 1 to 20 carbons represented by R ¹⁵ , R ¹⁶ and R ¹⁷ include the monovalent organic group having 1 to 20 carbons represented by ^{R 12 as the formula (6).} The exemplified bases are the same bases and the like.

^{As R Q} in the formula (6-1), a hydrogen atom or a methyl group is preferable, and a methyl group is more preferable.

^{R Q} in the formula (6-2) is preferably a hydrogen atom.

As L ¹ , a divalent hydrocarbon group having 1 to 20 carbon atoms is preferred, and a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms is more preferred.

As L ² , a divalent hydrocarbon group having 1 to 20 carbons is preferred, and a divalent chain hydrocarbon group having 1 to 20 carbons is more preferred.

As R ¹⁵ and R ¹⁶ , a hydrogen atom is preferred.

As R ¹⁷ , a monovalent hydrocarbon group having 1 to 20 carbon atoms is preferred, and a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms is more preferred.

As s, 1 is preferable.

The structural unit (III-1) is preferably a structural unit represented by the following formula (6-1-1) (hereinafter, also referred to as "structural unit (III-1-1)") as the structural unit ( III-2) is preferably a structural unit represented by the following formula (6-2-1) (hereinafter, also referred to as "structural unit (III-2-1)").

[化10]

In the formula (6-1-1) and the formula (6-2-1), R ^Q and Z ^f have the same meaning as the formula (6-1) and (6-2), respectively.

When the [A] polymer has the structural unit (III), the lower limit of the content ratio of the structural unit (III) in the [A] polymer is preferably relative to all the structural units constituting the [A] polymer It is 1 mol%, more preferably 5 mol%. The upper limit of the content ratio is preferably 30 mol%, and more preferably 20 mol%. By setting the content ratio of the structural unit (III) in the above range, the sensitivity of the radiation-sensitive resin composition to exposure light, LWR performance, and resolution can be further improved.

[Other structural units] Examples of other structural units include structural units containing alcoholic hydroxyl groups other than the structural unit (III), structural units containing a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination of these structures, etc. .

In the case where the [A] polymer has other structural units, as the upper limit of the content ratio of the other structural units, relative to all the structural units constituting the [A] polymer, it is preferably 20 mol%, more preferably 10 mol%. Ear%.

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

[A] The lower limit of the polystyrene-converted weight average molecular weight (Mw) obtained by Gel Permeation Chromatography (GPC) of the polymer is preferably 1,000, more preferably 3,000, and still more preferably 4,000, especially 5,000. The upper limit of the Mw is preferably 50,000, more preferably 30,000, still more preferably 20,000, and particularly preferably 10,000. By setting the Mw of the polymer [A] in the above range, the coating property of the radiation-sensitive resin composition can be improved. As a result, the sensitivity and LWR of the radiation-sensitive resin composition to exposure light can be further improved. Performance and resolution.

As the upper limit of the ratio of the Mw of the polymer obtained by GPC to the polystyrene-converted number average molecular weight (Mn) (hereinafter, also referred to as "dispersion degree" or "Mw/Mn"), the upper limit is preferably 5, more preferably 3, further preferably 2, and particularly preferably 1.8. As the lower limit of the ratio, it is usually 1.0, preferably 1.1.

The Mw and Mn of the polymer in this specification are values measured using gel permeation chromatography (GPC) based on the following conditions. GPC string: 2 "G2000HXL", 1 "G3000HXL" and 1 "G4000HXL" of Tosoh (stock) Column temperature: 40℃ 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 monomers that provide each structural unit by a known method.

＜[B] Acid generator＞ [B] The acid generator includes a compound represented by the following formula (1) described later (hereinafter, also referred to as "compound (B)"). The compound (B) is a compound that generates an acid by irradiation with radiation. Examples of the radiation include the same radiation as those exemplified as the exposure light in the exposure step of the resist pattern forming method described later. By using the acid generated from the compound (B) by irradiation with radiation, the acid dissociable group contained in the structural unit (I) of the polymer is dissociated to generate a carboxyl group. There is a difference in the solubility of the resist film in the developer between them, whereby the resist pattern can be formed.

The lower limit of the temperature at which the acid generated from the compound (B) dissociates the acid-dissociable group contained in the structural unit (I) of the polymer [A] is preferably 80°C, more preferably 90°C, and further Preferably it is 100°C. The upper limit of the temperature is preferably 130°C, more preferably 120°C, and still more preferably 110°C. The lower limit of the time for the acid to dissociate the acid-dissociable group is preferably 10 seconds, more preferably 1 minute. The upper limit of the time is preferably 10 minutes, more preferably 2 minutes.

^{In this specification, the part represented by X-} in the compound represented by the following formula (1) (compound (B)) is also referred to as "anion (X)", and the part other than the part represented by ^{X-is also referred to as "anion (X)".} It is called "cation (T)".

[化11]

In the formula (1), Ar ¹ is a group obtained by removing (a+b+1) hydrogen atoms on an aromatic ring from an aromatic hydrocarbon having 6 to 20 ring members. Y is a group represented by the following formula (2) described later (hereinafter, also referred to as a group (Y)). a is an integer of 1-3. When a is 2 or more, a plurality of Ys are the same or different from each other. b is an integer of 0-5. When b is 1, R ¹ is a monovalent organic group having 1 to 20 carbons, a hydroxyl group, a nitro group, or a halogen atom. When b is 2 or more, a plurality of R ¹ are the same or different from each other and are a monovalent organic group with 1 to 20 carbons, a hydroxyl group, a nitro group, or a halogen atom, or these are bonded to each other and are bonded to these The bonded carbon atoms together constitute a part of an alicyclic structure with 4 to 20 ring members or an aliphatic heterocyclic structure with 4 to 20 ring members. n is an integer of 1-3. When n is 1, a plurality of R ² are the same or different from each other, and are a monovalent organic group having 1 to 20 carbons, or a ring member formed by bonding to each other and forming with the bonded sulfur atom Part of the aromatic heterocyclic structure of 5-20. When n is 2, R ² is a monovalent organic group having 1 to 20 carbons. When n is 2 or more, a plurality of Ar ¹ are the same or different from each other, a plurality of Ys are the same or different from each other, and a plurality of R ¹ are the same or different from each other. X ^- is a monovalent anion (anion (X)) represented by the following formula (3) described later.

Examples of aromatic hydrocarbons providing Ar ¹ with 6 to 20 ring members include benzene, naphthalene, anthracene, phenanthrene, fused tetrabenzene, and pyrene. Among these, in terms of further improving the sensitivity of the radiation-sensitive resin composition to exposure light, LWR performance, and resolution, benzene or naphthalene is preferred, and benzene is more preferred.

Examples of the monovalent organic group having 1 to 20 carbons represented by R ¹ or R ² include those exemplified as the monovalent organic group having 1 to 20 carbons represented by ^{R 12 in the formula (6).} The same base and so on.

Examples of an alicyclic structure having 4 to 20 ring members formed by bonding a plurality of R ^{1 to} each other and the bonded carbon atoms include a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, etc. Monocyclic saturated alicyclic structure; polycyclic saturated alicyclic structure such as norbornane structure and adamantane structure; monocyclic unsaturated aliphatic such as cyclopropene structure, cyclobutene structure, cyclopentene structure, and cyclohexene structure Ring structure; polycyclic unsaturated alicyclic structures such as norbornene structure.

Examples of the aliphatic heterocyclic structure having 4 to 20 ring members formed by bonding a plurality of R ^{1 to each other and the bonded carbon atoms include an azepane structure and an azetane structure} , Thiolane structure, thiolane structure, oxolane structure, oxane structure, dioxolane structure, etc.

As R ¹ , a monovalent organic group having 1 to 20 carbon atoms or a halogen atom is preferable, and an alkoxy group or a fluorine atom is more preferable. In addition, as R ¹ , it is also preferable that a plurality of R ¹ are bonded to each other and form an aliphatic heterocyclic structure having 4 to 20 ring members together with the bonded carbon atoms. The aliphatic heterocyclic structure is more preferably a dioxolane structure.

As a, 1 or 2 is preferable, and 1 is more preferable.

As b, 0-3 are preferable, and 0-2 are more preferable.

Examples of the aromatic heterocyclic structure having 5 to 20 ring members in which a plurality of R ² are bonded to each other and constituted together with the bonded sulfur atoms include a dibenzothiophene structure.

R ^{2 is} preferably a group represented by ^{-Ar 1} -(R ¹ ) _b in the formula (1). In addition, as R ² , it is also preferable that a plurality of R ² are bonded to each other and form an aromatic heterocyclic structure having 5 to 20 ring members together with the bonded sulfur atoms.

As n, 1 or 2 is preferable, and 1 is more preferable from the viewpoint that the sensitivity of the radiation-sensitive resin composition to exposure light, LWR performance, and resolution can be further improved.

[Base (Y)] The group (Y) is a group represented by the following formula (2). The compound (B) has the group (Y), so that the acid generation efficiency due to exposure is improved. As a result, the radiation-sensitive resin composition can form a resist pattern with good sensitivity to exposure light and excellent LWR performance and resolution.

[化12]

In the formula (2), * represents a bonding site ^{with Ar 1 in the formula (1).} Z is -O- or -S-. L is a single bond or a divalent organic group having 1 to 20 carbons. Ar ² is a group obtained by removing (c+1) hydrogen atoms on an aromatic ring from an aromatic hydrocarbon having 6 to 20 ring members. c is an integer of 0-5. When c is 1, R ³ is a monovalent organic group having 1 to 20 carbons, a hydroxyl group, a nitro group, or a halogen atom. When c is 2 or more, a plurality of R ³ are the same or different from each other, and are a monovalent organic group having 1 to 20 carbons, a hydroxyl group, a nitro group, or a halogen atom, or these groups are bonded to each other and are combined with these groups. The bonded carbon atoms together constitute a part of an alicyclic structure having 4 to 20 ring members or an aliphatic heterocyclic structure having 4 to 20 ring members.

As the divalent organic group having 1 to 20 carbons represented by L, for example, one may be removed from the groups exemplified as the monovalent organic group having 1 to 20 carbons represented by ^{R 12 of the formula (6).} Hydrogen atom base, etc.

As L, a single bond is preferable.

Examples of the aromatic hydrocarbon having 6 to 20 ring members that provide Ar ² include the same aromatic hydrocarbons as those exemplified as the aromatic hydrocarbon having 6 to 20 ring members that provides Ar ¹ of the formula (1). Among these, in terms of further improving the sensitivity of the radiation-sensitive resin composition to exposure light, LWR performance, and resolution, benzene or naphthalene is preferred, and benzene is more preferred.

In addition, Ar ^{2 is} preferably the same as ^{Ar 1 in} the above formula (1). In this case, the sensitivity, LWR performance, and resolution of the radiation-sensitive resin composition to exposure light can be further improved.

Examples of the monovalent organic group having 1 to 20 carbons represented by R ³ include the same groups as those exemplified as the monovalent organic group having 1 to 20 carbons represented by ^{R 12 in the formula (6).} Base and so on.

Examples of the alicyclic structure having 4 to 20 ring members formed by combining a plurality of R ³ with each other and the carbon atoms to which they are bonded include, for example, a combination with ^{a plurality of R 1 as the formula (1).} The alicyclic structure having 4 to 20 ring members constituted together with the carbon atoms to be bonded is the same alicyclic structure and the like as exemplified.

Examples of the aliphatic heterocyclic structure having 4 to 20 ring members in which a plurality of R ³ are bonded to each other and the carbon atoms to which they are bonded are combined with each other with a plurality of R ^{1 as the formula (1)} The aliphatic heterocyclic structure having 4 to 20 ring members combined with the carbon atoms to be bonded is exemplified by the same aliphatic heterocyclic structure and the like.

As R ³ , a monovalent organic group having 1 to 20 carbon atoms or a halogen atom is preferable, and an alkoxy group or a fluorine atom is more preferable. In addition, as R ³ , it is also preferable that a plurality of R ³ are bonded to each other and form an aliphatic heterocyclic structure having 4 to 20 ring members together with the bonded carbon atoms. The aliphatic heterocyclic structure is more preferably a dioxolane structure.

As c, 0-3 are preferable, and 0-2 are more preferable.

In addition, ^{the group represented by -Ar 2} -(R ³ ) _c is preferably the same group as the group represented by ^{-Ar 1} -(R ¹ ) _b in the above formula (1). In this case, the sensitivity to exposure light, LWR performance, and resolution can be further improved.

As Z, -O- is preferred.

Examples of the cation (T) include cations represented by the following formulas (1-1) to (1-9) (hereinafter also referred to as "cations (T-1) to cations (T-9)") Wait.

[化13]

As the cation (T), in this case, the cation (T-1), cation (T-5), and cation (T-1), cation (T-5), and cation ( T-8) or cation (T-9).

[Anion (X)] The anion (X) is a monovalent anion represented by the following formula (3).

[化14]

In the formula (3), R ^p1 is a monovalent group including a ring structure having 5 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 C 1-20 monovalent hydrocarbon group or a C 1-20 monovalent fluorinated hydrocarbon group. R ^p5 and R ^p6 are each independently a fluorine atom or a C 1-20 monovalent fluorinated hydrocarbon group. n ^p1 is an integer of 0-10. n ^p2 is an integer of 0-10. n ^p3 is an integer of 0-10. However, n ^p1 +n ^p2 +n ^p3 is 1 or more and 30 or less. When n ^p1 is 2 or more, a plurality of R ^p2 are the same as or different from each other. When n ^p2 is 2 or more, a plurality of R ^p3 are the same or different from each other, and a plurality of R ^p4 are the same or different from each other. When n ^p3 is 2 or more, a plurality of R ^p5 are the same or different from each other, and a plurality of R ^p6 are the same or different from each other.

Examples of the monovalent group including a ring structure having 5 or more ring members represented by R ^p1 include: a monovalent group including an alicyclic structure having 5 or more ring members, and an aliphatic heterocyclic ring having 5 or more ring members The monovalent group of the structure, the monovalent group including the aromatic carbocyclic structure with 5 or more ring members, the monovalent group including the aromatic heterocyclic structure with 5 or more ring members, and the like.

Examples of alicyclic structures having 5 or more ring members include cyclopentane structure, cyclohexane structure, cycloheptane structure, cyclooctane structure, cyclononane structure, cyclodecane structure, and cyclododecane structure. Monocyclic saturated alicyclic structures; cyclopentene structure, cyclohexene structure, cycloheptene structure, cyclooctene structure, cyclodecene structure and other monocyclic unsaturated alicyclic structures; norbornane structure, adamantane Structure, tricyclodecane structure, tetracyclododecane structure and other polycyclic saturated alicyclic structures; norbornene structure, tricyclodecene structure and other polycyclic unsaturated alicyclic structures, etc.

Examples of the aliphatic heterocyclic structure having 5 or more ring members include: caprolactone (hexanolactone) structure, norbornane lactone structure and other lactone structures; caprolactone structure, norbornane sultone structure, etc. Sultone structure; heterocyclic structures containing oxygen atoms such as oxepane structure and oxanorbornane structure; heterocyclic structures containing nitrogen atoms such as azacyclohexane structure and diazabicyclooctane structure; Heterocyclic structures containing sulfur atoms such as thiane structure and thianorbornane structure.

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

Examples of aromatic heterocyclic structures having 5 or more ring members include: furan structure, pyran structure, benzofuran structure, benzopyran structure, and other oxygen atom-containing heterocyclic structures; pyridine structure, pyrimidine structure, indole Heterocyclic structures containing nitrogen atoms such as indole structure.

The lower limit of the number of ring members of the ring structure of R ^p1 is preferably 6, more preferably 8, still more preferably 9, and particularly preferably 10. The upper limit of the number of ring members is preferably 15, more preferably 14, further preferably 13, and particularly preferably 12. By setting the number of ring members in the above range, the diffusion length of the acid can be shortened more appropriately.

Part or all of the hydrogen atoms contained in the ring structure of R ^{p1 may be substituted with substituents.} Examples of the substituent include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an alkoxy group, an alkoxycarbonyl group, and an alkoxycarbonyloxy group. , Acyl group, acyloxy group, etc. Among these, a hydroxyl group is preferred.

As R ^p1 , a monovalent group including an alicyclic structure with 5 or more ring members or a monovalent group including an aliphatic heterocyclic structure with 5 or more ring members is preferable, and a saturated alicyclic structure including a polycyclic ring is more preferable A monovalent group containing an oxygen atom-containing heterocyclic structure or a monovalent group containing a sulfur atom-containing heterocyclic structure.

Examples of the divalent linking group represented by R ^p2 include a carbonyl group, an ether group, a carbonyloxy group, a thioether group, a thiocarbonyl group, a sulfonyl group, and a divalent hydrocarbon group. Among these, a carbonyloxy group, a sulfonyl group, an alkanediyl group or a divalent alicyclic saturated hydrocarbon group is preferable, and a carbonyloxy group is more preferable.

Examples of the monovalent hydrocarbon group having 1 to 20 carbons represented by R ^p3 and R ^{p4 include an alkyl group having 1 to 20 carbons.} 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 or a fluorinated alkyl group, more preferably a fluorine atom or a perfluoroalkyl group, and still more preferably a fluorine atom or a trifluoromethyl group.

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

As n ^p1 , 0 to 5 are preferable, 0 to 2 are more preferable, and 0 or 1 is still more preferable.

As n ^p2 , 0-5 are preferable, 0-2 are more preferable, and 0 or 1 is still more preferable.

The lower limit of n ^p3 is preferably 1, and more preferably 2. By setting n ^p3 to 1 or more, the strength of the acid can be increased. As ^{the upper limit of n p3} , 4 is preferable, 3 is more preferable, and 2 is still more preferable.

The lower limit of n ^p1 +n ^p2 +n ^p3 is preferably 2, and more preferably 4. As ^{the upper limit of n p1} +n ^p2 +n ^p3 , 20 is preferable, and 10 is more preferable.

Examples of the anion (X) include anions represented by the following formulas (3-1) to (3-12) (hereinafter also referred to as "anions (X-1) to (X-12)") Wait.

[化15]

As the compound (B), a compound obtained by appropriately combining the cation (T) and the anion (X) can be used.

As the lower limit of the content of the [B] acid generator in the radiation-sensitive resin composition, relative to 100 parts by mass of the [A] polymer, it is preferably 0.1 part by mass, more preferably 1 part by mass, and still more preferably 5 Parts by mass, more preferably 10 parts by mass. The upper limit of the content is preferably 70 parts by mass, more preferably 60 parts by mass, still more preferably 50 parts by mass, and still more preferably 40 parts by mass. By setting the content of the [B] acid generator in the above range, the sensitivity to exposure light, LWR performance, and resolution of the resist pattern formed from the radiation-sensitive resin composition can be further improved.

＜[C] Acid diffusion control agent＞ [C] The acid diffusion control agent exerts an effect of controlling the diffusion phenomenon of acid generated by the [B] acid generator or the like in the resist film by exposure, and controlling the poor chemical reaction in the non-exposed area. By containing the [C] acid diffusion control agent, the radiation-sensitive resin composition can further improve the sensitivity of the radiation-sensitive resin composition to exposure light, LWR performance, and resolution. The radiation-sensitive resin composition may contain one or two or more [C] acid diffusion control agents.

[C] The acid diffusion control agent includes, for example, a nitrogen atom-containing compound, a photodegradable base that generates light by exposure to light and generates a weak acid, and the like.

Examples of the nitrogen atom-containing compound include amine compounds such as tripentylamine and trioctylamine, amide group-containing compounds such as formamide, N,N-dimethylacetamide, urea, 1, Urea compounds such as 1-dimethylurea, pyridine, N-(undecylcarbonyloxyethyl)morpholine, 1-(tertiary butoxycarbonyl)-4-hydroxypiperidine, N-tertiary pentyl Nitrogen-containing heterocyclic compounds such as oxycarbonyl-4-hydroxypiperidine, etc. Among these, an amine compound or a nitrogen-containing heterocyclic compound is preferable, and trioctylamine or 1-(tertiary butoxycarbonyl)-4-hydroxypiperidine is more preferable.

As the photodegradable base, for example, a compound containing an onium cation that is decomposed by exposure and an anion of a weak acid, and the like. The photodegradable base generates a weak acid by the proton generated by the decomposition of the onium cation and the anion of the weak acid in the exposed portion, so the acid diffusion controllability is reduced.

Examples of onium cations that are decomposed by exposure include alumium cations such as triphenylsulfonium cation, phenyldibenzothiophenium cation, and 4-fluorophenyldiphenylsulfonium cation.

Examples of the anion of the weak acid include an anion represented by the following formula.

[化16]

As the photodegradable base, a compound obtained by appropriately combining the onium cation decomposed by exposure and the anion of the weak acid can be used.

When the radiation-sensitive resin composition contains [C] acid diffusion control agent, the lower limit of the content ratio of [C] acid diffusion control agent in the radiation-sensitive resin composition is relative to [B] acid generation The dosage is 100 mol%, preferably 1 mol%, more preferably 5 mol%, and still more preferably 10 mol%. The upper limit of the content is preferably 100 mol%, more preferably 50 mol%, and still more preferably 30 mol%. By setting the content ratio of the [C] acid diffusion control agent in the above range, the sensitivity to exposure light, LWR performance, and resolution of the resist pattern formed from the radiation-sensitive resin composition can be further improved.

＜[D]Organic solvent＞ The radiation-sensitive resin composition usually contains [D] an organic solvent. [D] The organic solvent is not a solvent as long as it can dissolve or disperse at least [A] polymer, [B] acid generator, and optionally [C] acid diffusion control agent and other optional components. Specially limited.

[D] The organic solvent includes, for example, 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 or more [D] 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 Solvents; C2-C18 polyol solvents such as 1,2-propylene glycol; C3-C19 polyol partial ether solvents such as propylene glycol-1-monomethyl ether, etc.

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; tetrahydrofuran, tetrahydropyran Cyclic ether solvents; diphenyl ether, anisole and other aromatic ring-containing ether solvents.

Examples of ketone 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, trimethylnonanone and other chain ketone solvents; cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone , Cyclic ketone solvents such as methylcyclohexanone; 2,4-pentanedione, acetonylacetone, acetophenone, etc.

Examples of amide-based solvents include cyclic amide-based solvents such as N,N'-dimethylimidazolinone and N-methylpyrrolidone; N-methylmethamide, N,N-di Methylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylacetamide, etc. 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 carboxylates such as propylene glycol acetate. Solvents; Polyol partial ether carboxylate solvents such as propylene glycol monomethyl ether acetate; Diethyl oxalate and other polycarboxylic acid diester solvents; Carbonate solvents such as dimethyl carbonate and diethyl carbonate Wait.

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

[D] The organic solvent is preferably an alcohol-based solvent and/or an ester-based solvent, more preferably a C3-19 polyol partial ether solvent and/or a polyol partial ether carboxylate solvent, and more preferably It is propylene glycol 1-monomethyl ether and/or propylene glycol monomethyl ether acetate.

When the radiation-sensitive resin composition contains [D] an organic solvent, the lower limit of the content ratio of [D] the organic solvent is preferably 50 relative to all components contained in the radiation-sensitive resin composition. % By mass, more preferably 60% by mass, still more 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＞ As other optional components, for example, surfactants and the like can be cited. The radiation-sensitive resin composition may each contain one or two or more other optional components.

＜Preparation method of radiation-sensitive resin composition＞ The radiation-sensitive resin composition can be defined by, for example, [A] polymer, [B] acid generator, and optionally [C] acid diffusion control agent, [D] organic solvent, and other optional components. The mixture is mixed in a proportion, and it is preferably prepared by filtering the obtained mixture with a membrane filter with a pore size of 0.2 μm or less.

<Method of forming resist pattern> The resist pattern forming method includes a step of directly or indirectly applying the radiation-sensitive resin composition to 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"). In the coating step of the resist pattern forming method, the radiation-sensitive resin composition is used as the radiation-sensitive resin composition.

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 good sensitivity to exposure light, excellent LWR performance and resolution. Resist pattern.

Hereinafter, each step included in the resist pattern forming method will be described.

[Coating Step] In this step, the radiation-sensitive resin composition is directly or indirectly coated on the substrate. Thereby, a resist film is formed directly or indirectly 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 wafers such as silicon wafers, silicon dioxide, and aluminum-coated wafers. In addition, as a case where the radiation-sensitive resin composition is applied indirectly to the substrate, for example, the case where the radiation-sensitive resin composition is applied on an anti-reflection film formed on the substrate. As such an anti-reflection film, for example, an organic or inorganic anti-reflection film disclosed in Japanese Patent Publication No. 6-12452 or Japanese Patent Application Publication No. 59-93448, etc. can be cited.

Examples of the coating method include spin coating (spin coating), cast coating, roll coating, and the like. After coating, in order to volatilize the solvent in the coating film, soft bake (hereinafter, also referred to as "SB (Soft Bake)") may be carried out if necessary. The lower limit of the temperature of SB 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 SB time is preferably 5 seconds, and more preferably 10 seconds. The lower limit of the time is preferably 600 seconds, more preferably 300 seconds. The lower limit of the average thickness of the formed 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 500 nm.

[Exposure Step] In this step, the resist film formed by the coating step is exposed. This exposure is performed by irradiating exposure light through a photomask (water-proof and other liquid immersion medium as the case may be). As the exposure light, depending on the line width of the target pattern, for example, electromagnetic waves such as visible light, ultraviolet, extreme ultraviolet, extreme ultraviolet (EUV), X-rays, and gamma rays; and charged particle beams such as electron beams and alpha rays. Among these, it is preferably extreme ultraviolet, EUV or electron beam, more preferably ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), EUV (wavelength 13.5 nm) or electron beam, More preferably, it is ArF excimer laser light, EUV or electron beam.

Preferably, post-exposure bake (hereinafter, also referred to as "PEB (Post Exposure Bake)") is performed after the exposure, and the exposed part of the resist film is exposed to the [B] compound The generated acid promotes the dissociation of the acid dissociable group possessed by the polymer [A]. With this PEB, the difference in solubility in the developer can be increased between the exposed part and the non-exposed 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 step] In this step, the exposed resist film is developed. Thereby, a predetermined resist pattern can be formed. Generally, rinse with water or alcohol and other rinsing liquid after development and then dry. The development method in the development step may be alkaline development or organic solvent development.

In the case of alkali development, as the developer used for development, for example, dissolved sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, Diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (hereinafter, also referred to as "TMAH (Tetramethyl Ammonium Hydroxide)”), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, 1,5-diazabicyclo-[4.3.0]- An alkaline aqueous solution containing at least one of basic compounds such as 5-nonene. Among these, a TMAH aqueous solution is preferred, and a 2.38% by mass TMAH aqueous solution is more preferred.

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; solutions containing the organic solvents, and the like. Examples of the organic solvent include one or two or more of the solvents exemplified as [D] the organic solvent of the radiation-sensitive resin composition. Among these, ester-based solvents or ketone-based solvents are preferred. As the ester-based solvent, an acetate-based solvent is preferred, and n-butyl acetate is more preferred. As the ketone solvent, a chain ketone is preferred, and 2-heptanone is more preferred. The lower limit of the content of the organic solvent in the developer is preferably 80% by mass, more preferably 90% by mass, still more preferably 95% by mass, and particularly preferably 99% by mass. Examples of components other than the organic solvent in the developer include water and silicone oil.

Examples of the development method include: a method of immersing the substrate in a tank filled with a developer solution for a fixed period of time (dipping method); and a method of performing development by depositing the developer solution on the surface of the substrate using surface tension for a fixed period of time (coating method). Puddle method); method of spraying developer on the surface of the substrate (spray method); method of continuously spraying developer liquid on the substrate rotating at a fixed speed while scanning the developer spray nozzle at a fixed speed (dynamic distribution method) )Wait.

Examples of patterns formed by this resist pattern forming method include line and space patterns, hole patterns, and the like.

＜Radiation-sensitive acid generator＞ This radiation-sensitive acid generator contains the compound represented by the above formula (1). This radiation-sensitive acid generator has been described as the [B] acid generator in the above-mentioned radiation-sensitive resin composition. The radiation-sensitive acid generator can be preferably used as a radiation-sensitive acid generator in a radiation-sensitive resin composition. [Example]

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples. The physical property values in the examples were measured as follows.

[Weight average molecular weight (Mw), number average molecular weight (Mn) and degree of dispersion (Mw/Mn)] [A] The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer are obtained by gel permeation chromatography (GPC), using Tosoh (stock) GPC column ("G2000HXL" 2 The measurement is performed under the following conditions. In addition, the degree of dispersion (Mw/Mn) is calculated from the measurement results of Mw and Mn. Dissolution solvent: tetrahydrofuran Flow rate: 1.0 mL/min Sample concentration: 1.0% by mass Sample injection volume: 100 μL Column temperature: 40℃ Detector: Differential refractometer Standard material: monodisperse polystyrene

[Containing ratio of structural unit] [A] The content ratio of each structural unit in the polymer is determined by using a nuclear magnetic resonance device (Japan Electronics Corporation’s "JNM-Delta (JNM-Delta) 400") ¹³ C-nuclear magnetic resonance (Nuclear Magnetic Resonance, NMR) analysis and measurement.

＜[A] Synthesis of polymer＞ The monomers represented by the following formulas (M-1) to (M-11) (hereinafter also referred to as "monomers (M-1) to monomers) are used in the synthesis of the polymer [A] (M-11)”). In the following synthesis examples, unless otherwise specified, parts by mass refers to the value when the total mass of the monomers used is 100 parts by mass, and the molar% refers to the total of the monomers used The number of moles is set to the value at 100 mole%.

[化17]

[Synthesis Example 1] Synthesis of polymer (A-1) The monomer (M-1) and the monomer (M-3) are dissolved in 1-methoxy-2-propanol (200 parts by mass) so that the molar ratio becomes 40/60. Next, 6 mol% of azobisisobutyronitrile as a starter was added to prepare a monobody solution. On the other hand, 1-methoxy-2-propanol (100 parts by mass) was added to an empty reaction vessel and heated to 85°C while stirring. Next, the prepared single body solution was added dropwise over 3 hours, and then further heated at 85°C for 3 hours, and the polymerization reaction was performed for a total of 6 hours. After the completion of the polymerization reaction, the polymerization solution was cooled to room temperature.

The cooled polymerization solution was put into hexane (500 parts by mass with respect to the polymerization solution), and the precipitated white powder was separated by filtration. After washing the white powder separated by filtration twice with 100 parts by mass of hexane with respect to the polymerization solution, the white powder was separated by filtration and dissolved in 1-methoxy-2-propanol (300 parts by mass). Next, methanol (500 parts by mass), triethylamine (50 parts by mass), and ultrapure water (10 parts by mass) were added, and the hydrolysis reaction was carried out at 70° C. for 6 hours while stirring. After the hydrolysis reaction is completed, the residual solvent is distilled off, and the obtained solid is dissolved in acetone (100 parts by mass). It was added dropwise to 500 parts by mass of water to coagulate the resin, and the obtained solid was separated by filtration. It was dried at 50°C for 12 hours to obtain a white powdery polymer (A-1).

The Mw of the polymer (A-1) was 5,700, and the Mw/Mn was 1.61. In addition, as ^{a result of 13} C-NMR analysis, the content of each structural unit derived from the monomer (M-1) and the monomer (M-3) in the polymer (A-1) was 41.2 mol. % And 58.8 mol%.

[Synthesis example 2 to synthesis example 9] Synthesis of polymer (A-2) to polymer (A-9) The polymer (A-2) to the polymer (A-9) were synthesized in the same manner as in Synthesis Example 1, except that the monomers of the types and usage ratios shown in Table 1 below were used.

[Table 1] [A] Polymer Provide a single body of structural unit (I) Provide a single body of structural unit (II) Provide a single body of structural unit (III) Mw Mw/Mn type Usage (mol%) Containing ratio of structural unit (mol%) type Usage (mol%) Containing ratio of structural unit (mol%) type Usage (mol%) Containing ratio of structural unit (mol%) Synthesis example 1 A-1 M-1 ^a 40 41.2 M-3 60 58.8 - - - 5700 1.61 Synthesis Example 2 A-2 M-1 ^a 40 42.3 M-4 60 57.7 - - - 5800 1.64 Synthesis Example 3 A-3 M-1 ^a 30 33.1 M-5 60 56.8 - - - 6100 1.65 M-2 ^a 10 10.1 Synthesis Example 4 A-4 M-1 ^a 40 41.9 M-6 60 58.1 - - - 6200 1.50 Synthesis Example 5 A-5 M-1 ^a 40 39.9 M-7 60 60.1 - - - 5500 1.54 Synthesis Example 6 A-6 M-1 ^a 40 40.1 M-8 60 59.9 - - - 5400 1.53 Synthesis Example 7 A-7 M-1 ^a 40 43.2 M-9 60 56.8 - - - 6000 1.67 Synthesis Example 8 A-8 M-1 ^a 30 30.4 M-3 60 58.2 M-10 10 11.4 6900 1.70 Synthesis Example 9 A-9 M-1 ^a 30 30.2 M-3 60 59.1 M-11 10 10.7 6800 1.65 a: Exist as a hydroxystyrene unit

＜[B] Synthesis of acid generator＞ [Synthesis Example 10] Synthesis of acid generator (B-1) Add (2-phenoxyphenyl) synthesized according to the method described in "Org. Lett." 2017, 19, 838-841 (hereinafter, also referred to as "references") into the reaction vessel 20.0 mmol of phenyl sulfonate trifluoromethanesulfonate, 20.0 mmol of ammonium salt represented by the following formula (P-1), 150 g of dichloromethane, and 150 g of ultrapure water. After stirring at room temperature for 2 hours, the organic layer was separated. The obtained organic layer is washed with ultrapure water. After drying with sodium sulfate, the solvent was distilled off and purified by silica gel column chromatography to obtain a compound represented by the following formula (B-1) (hereinafter, also referred to as "acid generator (B- 1)”) (86% yield). The synthesis flow of the acid generator (B-1) is shown below.

[化18]

[Synthesis Example 11-Synthesis Example 29] Synthesis of acid generator (B-2)-acid generator (B-20) Except for appropriately changing the precursor, the compound represented by the following formula (B-2) to formula (B-20) was synthesized in the same manner as in Synthesis Example 10 (hereinafter, also referred to as "acid generator (B-2)-acid Generating agent (B-20)”).

[化19]

[化20]

[Synthesis Example 30] Synthesis of acid generator (b-1) 20.0 mmol of triphenyl sulfonium chloride, 20.0 mmol of ammonium salt represented by the following formula (P-2), 150 g of dichloromethane, and 150 g of ultrapure water were added to the reaction container. After stirring at room temperature for 2 hours, the organic layer was separated. The obtained organic layer is washed with ultrapure water. After drying with sodium sulfate, the solvent was distilled off and purified by silica gel column chromatography to obtain the compound represented by the following formula (b-1) (hereinafter, also referred to as "acid generator (b- 1)”) (91% yield). The synthesis flow of the acid generator (b-1) is shown below.

[化21]

<Preparation of Radiation Sensitive Resin Composition> The [C] acid diffusion control agent and [D] organic solvent used in the preparation of the radiation-sensitive resin composition are shown below. In addition, in the following examples and comparative examples, unless otherwise specified, parts by mass refers to the value when the mass of the polymer [A] used is 100 parts by mass, and mole% refers to [B] The number of moles of the acid generator used is a value at 100 mole%.

[[C] Acid Diffusion Control Agent] (C-1) to (C-6): Compounds represented by the following formulas (C-1) to (C-6)

[化22]

[[D]Organic solvent] (D-1): Propylene glycol monomethyl ether acetate (D-2): Propylene glycol-1-monomethyl ether

[Example 1] Preparation of radiation-sensitive resin composition (R-1) 100 parts by mass of (A-1) as [A] polymer, 20 parts by mass of (B-1) as [B] acid generator, and 20 mol% relative to (B-1) were taken as [C] (C-1) as an acid diffusion control agent and [D] 4,800 parts by mass and (D-2) 2,000 parts by mass as an organic solvent are mixed to prepare a radiation-sensitive resin composition (R-1).

[Example 2 to Example 33 and Comparative Example 1] Preparation of radiation sensitive resin composition (R-2) to radiation sensitive resin composition (R-33) and radiation sensitive resin composition (CR-1) Except that the types and contents of the components shown in Table 2 below were used, the radiation-sensitive resin composition (R-2) to the radiation-sensitive resin composition (R-33) and the radiation-sensitive resin composition (R-2) to the radiation-sensitive resin composition (R-33) were prepared in the same manner as in Example 1 Resin composition (CR-1).

[Table 2] Radiation-sensitive resin composition [A] Polymer [B] Acid generator [C] Acid diffusion control agent [D] Organic solvent type Content (parts by mass) type Content (parts by mass) type Containing ratio (mol%) type Content (parts by mass) Example 1 R-1 A-1 100 B-1 20 C-1 20 D-1/D-2 4800/2000 Example 2 R-2 A-1 100 B-2 20 C-1 20 D-1/D-2 4800/2000 Example 3 R-3 A-1 100 B-3 20 C-1 20 D-1/D-2 4800/2000 Example 4 R-4 A-1 100 B-4 20 C-1 20 D-1/D-2 4800/2000 Example 5 R-5 A-1 100 B-5 20 C-1 20 D-1/D-2 4800/2000 Example 6 R-6 A-1 100 B-6 20 C-1 20 D-1/D-2 4800/2000 Example 7 R-7 A-1 100 B-7 20 C-1 20 D-1/D-2 4800/2000 Example 8 R-8 A-1 100 B-8 20 C-1 20 D-1/D-2 4800/2000 Example 9 R-9 A-1 100 B-9 20 C-1 20 D-1/D-2 4800/2000 Example 10 R-10 A-1 100 B-10 20 C-1 20 D-1/D-2 4800/2000 Example 11 R-11 A-1 100 B-11 20 C-1 20 D-1/D-2 4800/2000 Example 12 R-12 A-1 100 B-12 20 C-1 20 D-1/D-2 4800/2000 Example 13 R-13 A-1 100 B-13 20 C-1 20 D-1/D-2 4800/2000 Example 14 R-14 A-1 100 B-14 20 C-1 20 D-1/D-2 4800/2000 Example 15 R-15 A-1 100 B-15 20 C-1 20 D-1/D-2 4800/2000 Example 16 R-16 A-1 100 B-16 20 C-1 20 D-1/D-2 4800/2000 Example 17 R-17 A-1 100 B-17 20 C-1 20 D-1/D-2 4800/2000 Example 18 R-18 A-1 100 B-18 20 C-1 20 D-1/D-2 4800/2000 Example 19 R-19 A-1 100 B-19 20 C-1 20 D-1/D-2 4800/2000 Example 20 R-20 A-1 100 B-20 20 C-1 20 D-1/D-2 4800/2000 Example 21 R-21 A-1 100 B-2 20 C-2 20 D-1/D-2 4800/2000 Example 22 R-22 A-1 100 B-2 20 C-3 20 D-1/D-2 4800/2000 Example 23 R-23 A-1 100 B-2 20 C-4 20 D-1/D-2 4800/2000 Example 24 R-24 A-1 100 B-2 20 C-5 20 D-1/D-2 4800/2000 Example 25 R-25 A-1 100 B-2 20 C-6 20 D-1/D-2 4800/2000 Example 26 R-26 A-2 100 B-2 20 C-1 20 D-1/D-2 4800/2000 Example 27 R-27 A-3 100 B-2 20 C-1 20 D-1/D-2 4800/2000 Example 28 R-28 A-4 100 B-2 20 C-1 20 D-1/D-2 4800/2000 Example 29 R-29 A-5 100 B-2 20 C-1 20 D-1/D-2 4800/2000 Example 30 R-30 A-6 100 B-2 20 C-1 20 D-1/D-2 4800/2000 Example 31 R-31 A-7 100 B-2 20 C-1 20 D-1/D-2 4800/2000 Example 32 R-32 A-8 100 B-2 20 C-1 20 D-1/D-2 4800/2000 Example 33 R-33 A-9 100 B-2 20 C-1 20 D-1/D-2 4800/2000 Comparative example 1 CR-1 A-1 100 b-1 20 C-1 20 D-1/D-2 4800/2000

＜Formation of resist pattern＞ Using a spin coater ("CLEAN TRACK ACT12" of Tokyo Electron (stock)), each of the prepared radiation-sensitive resin compositions was applied to an underlayer film (Brewer) with an average thickness of 20 nm. The surface of a 12-inch silicon wafer made by Brewer Science (“AL412” of Brewer Science) was subjected to a soft bake (SB) at 130°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a film thickness of 50 nm resist film. Secondly, use EUV exposure machine (model "NXE3300", manufactured by ASML, numerical aperture (NA)=0.33, lighting conditions: Conventional s=0.89, mask: imecDEFECT32FFR02) to irradiate the resist film EUV light. The resist film was subjected to post-exposure bake (PEB) at 130°C for 60 seconds. Then, a 2.38% by mass TMAH aqueous solution was used to perform development at 23° C. for 30 seconds to form a positive 32 nm line and space pattern.

＜Evaluation＞ Regarding each resist pattern formed as described above, the sensitivity, LWR performance, and resolution of each radiation-sensitive resin composition were evaluated in accordance with the following methods. Furthermore, for the length measurement of the resist pattern, a scanning electron microscope (“CG-4100” of Hitachi High-Technologies (stock)) is used. The evaluation results are shown in Table 3 below.

[Sensitivity] In the formation of the resist pattern, the exposure amount for forming the 32 nm line and space pattern was set as the optimal exposure amount, and the optimal exposure amount was set as Eop (unit: mJ/cm ² ). The smaller the value of Eop, the better the sensitivity. Regarding the sensitivity, the case where the Eop was 30 mJ/cm ² or less was evaluated as "good", and the case where the ^{Eop exceeded 30 mJ/cm 2} was evaluated as "bad".

[LWR performance] The formed resist pattern was observed from above using the scanning electron microscope. A total of 50 line widths are measured at an arbitrary location, and a 3 sigma value is obtained from the distribution of the measured values, and this is defined as LWR (unit: nm). The smaller the value of LWR, the smaller the sway of the line, which means that the LWR performance is better. Regarding the LWR performance, the case where the LWR was 4.0 nm or less was evaluated as "good", and the case where the LWR exceeded 4.0 nm was evaluated as "bad".

[Analysis] In the optimal exposure level, the size of the smallest resist pattern that can be analyzed is measured while changing the size of the mask pattern forming the line and space (1L/1S), and the measured value is used as the resolution (Unit: nm). The smaller the resolution value is, the finer the pattern can be formed, which means that the resolution is better. Regarding the resolution, the case where the resolution is 25 nm or less is evaluated as "good", and the case where the resolution exceeds 25 nm is evaluated as "bad".

[table 3] Radiation-sensitive resin composition Eop (mJ/cm ² ) LWR (nm) Resolution (nm) Example 1 R-1 25 3.6 twenty four Example 2 R-2 26 3.5 twenty three Example 3 R-3 27 3.6 twenty four Example 4 R-4 28 3.7 twenty four Example 5 R-5 28 3.5 twenty four Example 6 R-6 25 3.4 twenty three Example 7 R-7 27 3.4 twenty three Example 8 R-8 27 3.6 twenty four Example 9 R-9 twenty four 3.6 twenty four Example 10 R-10 twenty four 3.4 twenty three Example 11 R-11 twenty four 3.6 twenty four Example 12 R-12 25 3.4 twenty three Example 13 R-13 26 3.5 twenty four Example 14 R-14 twenty four 3.7 twenty four Example 15 R-15 25 3.8 twenty four Example 16 R-16 25 3.6 twenty four Example 17 R-17 25 3.5 twenty three Example 18 R-18 25 3.8 twenty four Example 19 R-19 27 3.8 twenty four Example 20 R-20 26 3.7 twenty four Example 21 R-22 25 3.5 twenty four Example 22 R-23 25 3.6 twenty four Example 23 R-24 twenty four 3.4 twenty four Example 24 R-25 26 3.7 twenty four Example 25 R-26 28 3.8 twenty four Example 26 R-27 26 3.4 twenty three Example 27 R-28 26 3.6 twenty three Example 28 R-29 27 3.6 twenty four Example 29 R-30 26 3.6 twenty four Example 30 R-31 27 3.7 twenty four Example 31 R-32 26 3.7 twenty four Example 32 R-33 26 3.7 twenty three Example 33 R-34 27 3.8 twenty four Comparative example 1 CR-1 32 4.0 28

As is clear from the results of Table 3, the radiation-sensitive resin composition of the examples has better sensitivity, LWR performance, and resolution than the radiation-sensitive resin composition of the comparative example. [Industrial availability]

According to the radiation-sensitive resin composition and the resist pattern forming method of the present invention, it is possible to form a resist pattern with good sensitivity to exposure light and excellent LWR performance and resolution. The radiation-sensitive acid generator of the present invention can be preferably used as a radiation-sensitive acid generator in a radiation-sensitive resin composition. Therefore, the radiation-sensitive resin composition, the resist pattern forming method, and the radiation-sensitive acid generator can be preferably used in the processing process of semiconductor devices that are expected to be further miniaturized in the future.

without

without

without.

Claims (9)

A radiation-sensitive resin composition comprising: a polymer having a structural unit containing an acid-dissociable group; and a radiation-sensitive acid generator containing a compound represented by the following formula (1),

In the formula (1), Ar ¹ is a group obtained by removing (a+b+1) hydrogen atoms on the aromatic ring from an aromatic hydrocarbon with 6 to 20 ring members; Y is represented by the following formula (2) A is an integer of 1 to 3; when a is 2 or more, multiple Ys are the same or different from each other; b is an integer of 0 to 5; when b is 1, R ¹ is carbon number 1. ～20 monovalent organic group, hydroxy group, nitro group or halogen atom; when b is 2 or more, multiple R ¹ are the same or different from each other and are monovalent organic group, hydroxy group, nitro group with 1-20 carbons Or a halogen atom, or a part of an alicyclic structure with 4-20 ring members or an aliphatic heterocyclic structure with 4-20 ring members formed by these bonded to each other and together with the carbon atoms to which they are bonded; n An integer of 1 to 3; when n is 1, a plurality of R ² are the same or different from each other, and are a monovalent organic group having 1 to 20 carbons, or these are bonded to each other and bonded to these Sulfur atoms together constitute part of an aromatic heterocyclic structure with 5-20 ring members; when n is 2, R ² is a monovalent organic group with 1-20 carbons; when n is 2 or more , Multiple Ar ¹ are the same or different from each other, multiple Ys are the same or different from each other, and multiple R ¹ are the same or different from each other; X ^- is a monovalent anion represented by the following formula (3),

In the formula (2), * represents ^{the bonding site with Ar 1} in the formula (1); Z is -O- or -S-; L is a single bond or a divalent organic group with 1-20 carbons; Ar ² is a group obtained by removing (c+1) hydrogen atoms on an aromatic ring from an aromatic hydrocarbon with 6 to 20 ring members; c is an integer of 0 to 5; when c is 1, R ³ It is a monovalent organic group with 1 to 20 carbons, a hydroxyl group, a nitro group or a halogen atom; when c is 2 or more, a plurality of R ³ are the same or different from each other, and are a monovalent organic group with 1 to 20 carbons, Hydroxyl group, nitro group or halogen atom, or alicyclic structure with 4 to 20 ring members or aliphatic heterocyclic structure with 4 to 20 ring members formed by these bonded to each other and together with the bonded carbon atoms a part of,

In formula (3), R ^p1 is a monovalent group including a ring structure having 5 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, and a carbon number of 1 to A 20 monovalent hydrocarbon group or a C 1-20 monovalent fluorinated hydrocarbon group; R ^p5 and R ^p6 are each independently a fluorine atom or a C 1-20 monovalent fluorinated hydrocarbon group; n ^p1 is an integer of 0-10 N ^p2 is an integer from 0 to 10; n ^p3 is an integer from 0 to 10; wherein, n ^p1 + n ^p2 + n ^p3 is 1 or more and 30 or less; when n ^p1 is 2 or more, multiple R ^p2 Are the same or different from each other; when n ^p2 is 2 or more, a plurality of R ^p3 are the same or different from each other, and a plurality of R ^p4 are the same or different from each other; when n ^p3 is 2 or more, a plurality of R ^p5 are the same or Different, a plurality of R ^p6 are the same or different from each other. The radiation-sensitive resin composition according to claim 1, wherein Y in the formula (1) is bonded to a carbon atom adjacent to the carbon atom to which the sulfur atom ^{in Ar 1 is bonded.} The radiation-sensitive resin composition according to claim 1 or 2, wherein n in the formula (1) is 1. The radiation-sensitive resin composition according to claim 1 or 2, wherein ^{the aromatic hydrocarbon providing Ar 1} in the formula (1) is benzene or naphthalene. The radiation-sensitive resin composition according to claim 1 or 2, wherein Ar ¹ in the formula (1) is the same as ^{Ar 2 in the formula (2).} The radiation-sensitive resin composition according to claim 1 or 2, wherein Z in the formula (2) is -O-. The radiation-sensitive resin composition according to claim 1 or 2, wherein L in the formula (2) is a single bond. A method for forming a resist pattern includes: a step of directly or indirectly coating a radiation-sensitive resin composition on a substrate; a step of exposing the resist film formed by the coating step; and In the step of developing the exposed resist film, the radiation-sensitive resin composition contains: a polymer having a structural unit containing an acid-dissociable group; and a compound containing a compound represented by the following formula (1) Radioactive acid generator,

In the formula (1), Ar ¹ is a group obtained by removing (a+b+1) hydrogen atoms on the aromatic ring from an aromatic hydrocarbon with 6 to 20 ring members; Y is represented by the following formula (2) A is an integer of 1 to 3; when a is 2 or more, multiple Ys are the same or different from each other; b is an integer of 0 to 5; when b is 1, R ¹ is carbon number 1. ～20 monovalent organic group, hydroxy group, nitro group or halogen atom; when b is 2 or more, multiple R ¹ are the same or different from each other and are monovalent organic group, hydroxy group, nitro group with 1-20 carbons Or a halogen atom, or a part of an alicyclic structure with 4-20 ring members or an aliphatic heterocyclic structure with 4-20 ring members formed by these bonded to each other and together with the carbon atoms to which they are bonded; n An integer of 1 to 3; when n is 1, a plurality of R ² are the same or different from each other, and are a monovalent organic group having 1 to 20 carbons, or these are bonded to each other and bonded to these Sulfur atoms together constitute part of an aromatic heterocyclic structure with 5-20 ring members; when n is 2, R ² is a monovalent organic group with 1-20 carbons; when n is 2 or more , Multiple Ar ¹ are the same or different from each other, multiple Ys are the same or different from each other, and multiple R ¹ are the same or different from each other; X ^- is a monovalent anion represented by the following formula (3),

In the formula (2), * represents ^{the bonding site with Ar 1} in the formula (1); Z is -O- or -S-; L is a single bond or a divalent organic group with 1-20 carbons; Ar ² is a group obtained by removing (c+1) hydrogen atoms on an aromatic ring from an aromatic hydrocarbon with 6 to 20 ring members; c is an integer of 0 to 5; when c is 1, R ³ It is a monovalent organic group with 1 to 20 carbons, a hydroxyl group, a nitro group or a halogen atom; when c is 2 or more, a plurality of R ³ are the same or different from each other, and are a monovalent organic group with 1 to 20 carbons, Hydroxyl group, nitro group or halogen atom, or alicyclic structure with 4 to 20 ring members or aliphatic heterocyclic structure with 4 to 20 ring members formed by these bonded to each other and together with the bonded carbon atoms a part of,

In formula (3), R ^p1 is a monovalent group including a ring structure having 5 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, and a carbon number of 1 to A 20 monovalent hydrocarbon group or a C 1-20 monovalent fluorinated hydrocarbon group; R ^p5 and R ^p6 are each independently a fluorine atom or a C 1-20 monovalent fluorinated hydrocarbon group; n ^p1 is an integer of 0-10 N ^p2 is an integer from 0 to 10; n ^p3 is an integer from 0 to 10; wherein, n ^p1 + n ^p2 + n ^p3 is 1 or more and 30 or less; when n ^p1 is 2 or more, multiple R ^p2 Are the same or different from each other; when n ^p2 is 2 or more, a plurality of R ^p3 are the same or different from each other, and a plurality of R ^p4 are the same or different from each other; when n ^p3 is 2 or more, a plurality of R ^p5 are the same or Different, a plurality of R ^p6 are the same or different from each other. A radiation-sensitive acid generator comprising a compound represented by the following formula (1);

In the formula (1), Ar ¹ is a group obtained by removing (a+b+1) hydrogen atoms on the aromatic ring from an aromatic hydrocarbon with 6 to 20 ring members; Y is represented by the following formula (2) A is an integer of 1 to 3; when a is 2 or more, multiple Ys are the same or different from each other; b is an integer of 0 to 5; when b is 1, R ¹ is carbon number 1. ～20 monovalent organic group, hydroxy group, nitro group or halogen atom; when b is 2 or more, multiple R ¹ are the same or different from each other and are monovalent organic group, hydroxy group, nitro group with 1-20 carbons Or a halogen atom, or a part of an alicyclic structure with 4-20 ring members or an aliphatic heterocyclic structure with 4-20 ring members formed by these bonded to each other and together with the carbon atoms to which they are bonded; n An integer of 1 to 3; when n is 1, a plurality of R ² are the same or different from each other, and are a monovalent organic group having 1 to 20 carbons, or these are bonded to each other and bonded to these Sulfur atoms together constitute part of an aromatic heterocyclic structure with 5-20 ring members; when n is 2, R ² is a monovalent organic group with 1-20 carbons; when n is 2 or more , Multiple Ar ¹ are the same or different from each other, multiple Ys are the same or different from each other, and multiple R ¹ are the same or different from each other; X ^- is a monovalent anion represented by the following formula (3),

In the formula (2), * represents ^{the bonding site with Ar 1} in the formula (1); Z is -O- or -S-; L is a single bond or a divalent organic group with 1-20 carbons; Ar ² is a group obtained by removing (c+1) hydrogen atoms on an aromatic ring from an aromatic hydrocarbon with 6 to 20 ring members; c is an integer of 0 to 5; when c is 1, R ³ It is a monovalent organic group with 1 to 20 carbons, a hydroxyl group, a nitro group or a halogen atom; when c is 2 or more, a plurality of R ³ are the same or different from each other, and are a monovalent organic group with 1 to 20 carbons, Hydroxyl group, nitro group or halogen atom, or alicyclic structure with 4 to 20 ring members or aliphatic heterocyclic structure with 4 to 20 ring members formed by these bonded to each other and together with the bonded carbon atoms a part of,

In formula (3), R ^p1 is a monovalent group including a ring structure having 5 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, and a carbon number of 1 to A 20 monovalent hydrocarbon group or a C 1-20 monovalent fluorinated hydrocarbon group; R ^p5 and R ^p6 are each independently a fluorine atom or a C 1-20 monovalent fluorinated hydrocarbon group; n ^p1 is an integer of 0-10 N ^p2 is an integer from 0 to 10; n ^p3 is an integer from 0 to 10; wherein, n ^p1 + n ^p2 + n ^p3 is 1 or more and 30 or less; when n ^p1 is 2 or more, multiple R ^p2 Are the same or different from each other; when n ^p2 is 2 or more, a plurality of R ^p3 are the same or different from each other, and a plurality of R ^p4 are the same or different from each other; when n ^p3 is 2 or more, a plurality of R ^p5 are the same or Different, a plurality of R ^p6 are the same or different from each other.