KR102341492B1 - Radiation-sensitive resin composition, process for forming resist pattern, radiation-sensitive acid generator, and compound - Google Patents

Abstract

[Problem] An object of the present invention is to provide a radiation-sensitive resin composition having excellent LWR performance and the like.
[Solutions] The present invention is a radiation-sensitive resin composition comprising a polymer having a first structural unit containing an acid-dissociable group, a compound represented by formula (1), and a solvent. In Formula (1), R<^1> and R<^2> are monovalent organic groups which do not contain a hydrogen atom or a C1-C20 fluorine atom. R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms. However, at least one of ^{R 1} , R ² , R ³ and R ⁴ represents a group represented by ^{OR Q .} R ^Q is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁵ , R ³ and R ⁴ , R ³ and R ⁵ , or R ⁵ and R ⁶ are taken together, and together with the carbon atom to which they are attached, reduce water 3 to You may comprise the ring structure of 20. Y ^- is SO ₃ ^- or COO ^- . X ⁺ is a monovalent radiation-sensitive onium cation.

Description

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

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

The radiation-sensitive resin composition used for microfabrication by lithography is KrF excimer laser light (wavelength 248 nm), ArF excimer laser light (wavelength 193 nm), extreme ultraviolet (EUV: Extreme Ultraviolet, wavelength 13.5 nm), etc. A resist pattern is formed on the substrate by generating an acid in the exposed portion by irradiation with a charged particle beam, such as, etc. to form At present, refinement|miniaturization of the processing technique of a resist pattern is aimed at by the use of a shorter wavelength laser beam, an electron beam, immersion exposure, etc.

Accordingly, the radiation-sensitive resin composition has excellent resist pattern resolution and cross-sectional rectangularity, as well as LWR (Line Width Roughness) performance, CDU (Critical Dimension Uniformity) performance, EL (Exposure Latitude) It is also requested|required that it is excellent also in performance, development defect suppression, film shrinkage suppression after PEB (post-exposure baking), etc. Moreover, it is also calculated|required that the radiation-sensitive resin composition has favorable storage stability. In response to these requirements, the types and molecular structures of acid generators, acid diffusion control agents, and other components used in the radiation-sensitive resin composition have been studied in detail (Japanese Patent Application Laid-Open No. 11-125907, Japan). See Japanese Patent Laid-Open No. Hei 8-146610 and Japanese Patent Laid-Open No. 2000-298347).

Japanese Patent Laid-Open No. 11-125907 Japanese Patent Laid-Open No. 8-146610 Japanese Patent Laid-Open No. 2000-298347

However, at the present time when the miniaturization of the resist pattern has progressed to a level of 45 nm or less in line width, the required level of the performance is higher, and the conventional radiation-sensitive resin composition cannot satisfy these requirements.

The present invention has been made on the basis of the above circumstances, and a radiation-sensitive resin excellent in LWR performance, CDU performance, EL performance, development defect suppression property, and film shrinkage suppression property after PEB (hereinafter also referred to as "LWR performance etc.") An object of the present invention is to provide a composition and a method for forming a resist pattern.

The invention made in order to solve the said subject is a polymer (hereinafter also referred to as "[A] polymer") having a first structural unit (hereinafter also referred to as "structural unit (I)") containing an acid-dissociable group; It is a radiation-sensitive resin composition containing the compound (henceforth "[B] compound") represented by following formula (1), and a solvent (henceforth "[C] solvent").

(in formula (1), R ¹ and R ² are each independently a monovalent organic group not containing a hydrogen atom or a fluorine atom having 1 to 20 carbon atoms, and R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represents a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms, with the proviso that at least one of ^{R 1} , R ² , R ³ and R ⁴ represents a group represented by ^{OR Q , and R Q} is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and when at least one of ^{R 1} and R ² represents a group represented by ^{OR Q , R Q} does not contain a fluorine atom, and R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁵ , R ³ and R ⁴ , R ³ and R ⁵ , or R ⁵ and R ⁶ are combined with each other to form a reduced number of 3 to 20 ring structures together with the carbon atom to which they are bonded may be configured, Y ^- is SO ₃ ^- or COO ^- , and X ⁺ is a monovalent radiation-sensitive onium cation)

Another invention made in order to solve the above problem includes a step of coating the radiation-sensitive resin composition on the surface side of a substrate, a step of exposing the resist film obtained by the coating, and a step of developing the exposed resist film A method of forming a resist pattern.

Another invention made in order to solve the said subject is a radiation-sensitive acid generator containing the compound represented by following formula (1).

(in formula (1), R ¹ and R ² are each independently a monovalent organic group not containing a hydrogen atom or a fluorine atom having 1 to 20 carbon atoms, and R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represents a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms, with the proviso that at least one of ^{R 1} , R ² , R ³ and R ⁴ represents a group represented by ^{OR Q , and R Q} is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and when at least one of ^{R 1} and R ² represents a group represented by ^{OR Q , R Q} does not contain a fluorine atom, and R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁵ , R ³ and R ⁴ , R ³ and R ⁵ , or R ⁵ and R ⁶ may be combined with each other to form a ring structure of 3 to 20 reduced numbers together with the carbon atom to which they are bonded, Y ^- is SO ₃ ^- or COO ^- , and X ⁺ is a monovalent radiation-sensitive onium cation)

Another invention made in order to solve the said subject is a compound represented by following formula (1).

(in formula (1), R ¹ and R ² are each independently a monovalent organic group not containing a hydrogen atom or a fluorine atom having 1 to 20 carbon atoms, and R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represents a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms, with the proviso that at least one of ^{R 1} , R ² , R ³ and R ⁴ represents a group represented by ^{OR Q , and R Q} is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and when at least one of ^{R 1} and R ² represents a group represented by ^{OR Q , R Q} does not contain a fluorine atom, and R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁵ , R ³ and R ⁴ , R ³ and R ⁵ , or R ⁵ and R ⁶ may be combined with each other to form a ring structure of 3 to 20 reduced numbers together with the carbon atom to which they are bonded, Y ^- is SO ₃ ^- or COO ^- , and X ⁺ is a monovalent radiation-sensitive onium cation)

Here, the "organic group" refers to a group containing at least one carbon atom. The "acid dissociable group" is a group which substitutes hydrogen atoms, such as a carboxy group and a hydroxyl group, and refers to the group which dissociates by the action of an acid. "Reduced number" refers to the number of atoms constituting the rings of the alicyclic structure, the aromatic ring structure, the aliphatic heterocyclic structure, and the aromatic heterocyclic structure. say the total

According to the radiation-sensitive resin composition and resist pattern formation method of the present invention, a resist pattern excellent in LWR performance, CDU performance, EL performance, development defect suppression property and film shrinkage suppression property after PEB can be formed. The radiation-sensitive acid generator and compound of the present invention can be suitably used as a component of the radiation-sensitive resin composition. Therefore, they can be suitably used for manufacturing a semiconductor device that is expected to be further miniaturized in the future.

<Radiation-sensitive resin composition>

The radiation-sensitive resin composition contains the polymer [A], the compound [B], and the solvent [C]. The radiation-sensitive resin composition is a suitable component as [D] another acid generator, [E] a nitrogen-containing compound, and a polymer having a higher fluorine atom mass content than the [A] polymer (hereinafter also referred to as "[F] polymer") ) may contain. Moreover, the said radiation-sensitive resin composition may contain other arbitrary components in the range which does not impair the effect of this invention. The said radiation-sensitive resin composition is excellent in LWR performance, CDU performance, EL performance, development defect suppression, and film|membrane shrinkage suppression after PEB by having the said structure. Hereinafter, each component is demonstrated.

<[A] Polymer>

[A] The polymer is a polymer having the structural unit (I). According to the radiation-sensitive resin composition, the acid-dissociable group of the polymer [A] in the exposed part is dissociated by the acid generated from the compound [B] or the like upon irradiation with radiation, and there is a difference in solubility in the developer between the exposed part and the unexposed part. , and as a result, a resist pattern can be formed. [A] A polymer becomes a base polymer in the said radiation-sensitive resin composition normally. The "base polymer" refers to a polymer having the highest content among polymers constituting the resist pattern, preferably 50% by mass or more, and more preferably 60% by mass or more.

[A] The polymer contains, in addition to the structural unit (I), a structural unit containing a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof (hereinafter also referred to as “structural unit (II)”), a phenolic hydroxyl group It is preferable to have a structural unit containing a structural unit (hereinafter also referred to as “structural unit (III)”) and/or a structural unit containing an alcoholic hydroxyl group (hereinafter also referred to as “structural unit (IV)”), and a structural unit ( You may have other structural units other than I)-(IV). [A] The polymer may have 1 type, or 2 or more types of these structural units.

[Structural unit (Ⅰ)]

Structural unit (I) is a structural unit containing an acid-dissociable group. Examples of the structural unit (I) include structural units represented by the following formulas (3) and (8). [A] The polymer may have a structural unit (I) 1 type, or 2 or more types. Hereinafter, structural unit (I) is demonstrated.

In the formula (3), R ^A1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^A2 is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ^A3 and R ^A4 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms, or these groups are combined to represent a ring structure having 3 to 20 reduced numbers constituted together with the carbon atom to which they are bonded.

In the formula (8), R ^{A1 has the same meaning as} in the formula (3). L ^p is a single bond, -COO- or -CONH-. R ^m is a monovalent organic group having 1 to 20 carbon atoms. c is an integer from 0 to 4. When c is 2 or more, a plurality of R ^m may be the same or different. R ^A5 , R ^A6 and R ^A7 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms or a monovalent oxy hydrocarbon group having 1 to 20 carbon atoms.

A "hydrocarbon group" includes a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group. This "hydrocarbon group" may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. The "chain hydrocarbon group" does not contain a cyclic structure, but refers to a hydrocarbon group composed only of a chain structure, and includes both a linear hydrocarbon group and a branched hydrocarbon group. The "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic structure as a ring structure and does not contain an aromatic ring structure, and includes both a monocyclic alicyclic hydrocarbon group and a polycyclic alicyclic hydrocarbon group. However, it does not need to be comprised only with an alicyclic structure, and the chain structure may be included in the part. An "aromatic hydrocarbon group" means a hydrocarbon group containing an aromatic ring structure as a ring structure. However, it is not necessary to be comprised only with the aromatic ring structure, and the chain structure and the alicyclic structure may be included in the part.

As R ^A1 , a hydrogen atom and a methyl group are preferable, and a methyl group is more preferable from the viewpoint of copolymerizability of the monomer giving the structural unit (I).

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^A2 , R ^A3 and R ^A4 include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and 6 carbon atoms. to 20 monovalent aromatic hydrocarbon groups; and the like.

As the monovalent chain hydrocarbon group having 1 to 20 carbon atoms, for example,

Alkyl groups, such as a methyl group, an ethyl group, n-propyl group, and i-propyl group;

Alkenyl groups, such as an ethenyl group, a propenyl group, and a butenyl group;

Alkynyl groups, such as an ethynyl group, a propynyl group, and a butynyl group, etc. are mentioned. Among these, an alkyl group is preferable, an alkyl group having 1 to 4 carbon atoms is more preferable, a methyl group, an ethyl group and an i-propyl group are still more preferable, and an ethyl group is particularly preferable.

As the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, for example,

monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group;

monocyclic cycloalkenyl groups such as a cyclopentenyl group and a cyclohexenyl group;

polycyclic cycloalkyl groups such as a norbornyl group, an adamantyl group, and a tricyclodecyl group;

Polycyclic cycloalkenyl groups, such as a norbornenyl group and a tricyclodecenyl group, etc. are mentioned. Among these, a monocyclic cycloalkyl group and a polycyclic cycloalkyl group are preferable, and a cyclopentyl group, a cyclohexyl group, a norbornyl group and an adamantyl group are more preferable.

As a C6-C20 monovalent|monohydric aromatic hydrocarbon group, for example,

Aryl groups, such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, a naphthyl group, a methylnaphthyl group, an anthryl group, and a methylanthryl group;

Aralkyl groups, such as a benzyl group, a phenethyl group, a naphthylmethyl group, and an anthryl methyl group, etc. are mentioned.

Examples of the alicyclic structure having 3 to 20 carbon atoms that R ^A3 and R ^A4 are combined with and constituted together with the carbon atom to which they are bonded include a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, and a norbornane structure. , alicyclic structures such as adamantane structure;

Aliphatic heterocyclic structures, such as an oxacyclopentane structure, a thiacyclopentane structure, and an azacyclopentane structure, etc. are mentioned. Among these, an alicyclic structure is preferable and a cyclohexane structure is more preferable.

As the structural unit (I), for example, structural units represented by the following formulas (3-1) to (3-6) and (8-1) (hereinafter, “structural units (I-1) to (I-7)” ') and the like.

In the formulas (3-1) to (3-6), R ^A1 to R ^{A4 have the same meanings as} in the formula (3).

In said formula (3-1), i is an integer of 1-4.

In said Formula (3-3), j is an integer of 1-4.

In the formula (3-6), R ^A2' , R ^A3' and R ^A4' are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms.

In the formula (8-1), R ^A1 , R ^A5 , R ^A6 and R ^{A7 have the same meaning as} in the formula (8).

As i and j, 1-3 are preferable and 1 and 2 are more preferable.

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

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

In the above formula, R ^{A1 has the same meaning as} in the above formula (3).

As the structural unit (I), a structural unit derived from 1-alkyl-monocyclic cycloalkan-1-yl (meth)acrylate, a structural unit derived from 2-alkyl-polycyclic cycloalkan-2-yl (meth)acrylate, and A structural unit derived from 2-(cycloalkan-yl)propan-2-yl (meth)acrylate is preferable, and a structural unit derived from 1-i-propylcyclopentan-1-yl (meth)acrylate, 1 -Structural unit derived from methylcyclohexan-1-yl (meth)acrylate, structural unit derived from 2-ethyl-adamantan-2-yl (meth)acrylate, 2-ethyl-tetracyclododecane- A structural unit derived from 2-yl (meth)acrylate, a structural unit derived from 2-(adamantan-1-yl)propan-2-yl (meth)acrylate, and 2-(cyclohexan-1-yl) ) A structural unit derived from propan-2-yl (meth)acrylate is more preferable.

The lower limit of the content of the structural unit (I) is preferably 10 mol%, more preferably 20 mol%, still more preferably 30 mol%, and more preferably 40 mol%, based on all the structural units constituting the polymer [A]. Especially preferred. As an upper limit of the said content rate, 80 mol% is preferable, 75 mol% is more preferable, 70 mol% is still more preferable, and its 60 mol% is especially preferable. By making the content rate of structural unit (I) into the said range, the LWR performance etc. of the said radiation-sensitive resin composition can be improved further.

[Structural unit (II)]

Structural unit (II) is a structural unit containing a lactone structure, a cyclic carbonate structure, a sultone structure, or a combination thereof. [A] Since the polymer further has a structural unit (II) in addition to the structural unit (I), the solubility in the developer can be more appropriately adjusted, and as a result, the LWR performance of the radiation-sensitive resin composition can be further improved. . Moreover, the adhesiveness of the resist pattern and board|substrate formed from the said radiation-sensitive resin composition can be improved.

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

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

As the structural unit (II), a structural unit derived from (meth)acrylate containing a lactone structure, a structural unit derived from (meth)acrylate containing a cyclic carbonate structure, and a structural unit derived from (meth)acrylate containing a sultone structure is preferably, a structural unit derived from norbornanlacton-yl (meth)acrylate, a structural unit derived from cyanonorbornanlacton-yl (meth)acrylate, norbornanlacton-yloxycarbonylmethyl A structural unit derived from (meth)acrylate, a structural unit derived from γ-butyrolacton-yl (meth)acrylate, a structural unit derived from ethylene carbonate-ylmethyl (meth)acrylate, and norbornane A structural unit derived from sulton-yl (meth)acrylate is more preferable.

[A] When the polymer has the structural unit (II), the lower limit of the content of the structural unit (II) is preferably 10 mol%, more preferably 20 mol%, based on all the structural units in the polymer [A]. and 30 mol% is more preferable, and 40 mol% is particularly preferable. As an upper limit of the said content rate, 80 mol% is preferable, 70 mol% is more preferable, 65 mol% is still more preferable, and its 60 mol% is especially preferable. By making the content ratio of the structural unit (II) within the above range, the solubility of the polymer [A] in a developer can be more appropriately adjusted, and as a result, the LWR performance and the like of the radiation-sensitive resin composition can be further improved. Moreover, the adhesiveness of the resist pattern obtained and a board|substrate can further be improved.

[Structural unit (III)]

The structural unit (III) is a structural unit containing a phenolic hydroxyl group. When KrF excimer laser light, EUV, electron beam or the like is used as the radiation irradiated in the exposure step in the resist pattern forming method, the [A] polymer has the structural unit (III), so that the sensitivity can be further increased.

Examples of the structural unit (III) include a structural unit represented by the following formula (4).

In the formula (4), R ¹⁴ is a hydrogen atom or a methyl group. R ¹⁵ is a monovalent organic group having 1 to 20 carbon atoms. p is an integer from 0 to 3. When p is 2 or 3, a plurality of R ¹⁵ may be the same or different. q is an integer from 1 to 3. However, p+q is 5 or less.

As said R ¹⁴ , a hydrogen atom is preferable from the viewpoint of copolymerizability of the monomer giving the structural unit (III).

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ¹⁵ include a monovalent hydrocarbon group having 1 to 20 carbon atoms, a carbon-carbon group of the hydrocarbon group, or a divalent hetero atom-containing group at the terminal on the bond side. and monovalent groups in which some or all of the hydrogen atoms in the hydrocarbon group and group (g) are substituted with a hetero atom-containing group.

As the monovalent hydrocarbon group having 1 to 20 carbon atoms, for example,

Alkyl groups, such as a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group;

Alkenyl groups, such as an ethenyl group, a propenyl group, and a butenyl group;

chain hydrocarbon groups such as alkynyl groups such as ethynyl group, propynyl group and butynyl group;

cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group;

Cycloalkenyl groups, such as a cyclopropenyl group, a cyclopentenyl group, and a cyclohexenyl group;

alicyclic hydrocarbon groups such as cross-linked hydrocarbon groups such as norbornyl group and adamantyl group;

Aryl groups, such as a phenyl group, a tolyl group, a xylyl group, and a naphthyl group;

Aralkyl groups, such as a benzyl group, a phenethyl group, and a naphthylmethyl group;

The group which has aromatic hydrocarbon groups, such as a styryl group, a styryl methyl group, an acenaphthyl group, and an acenaphthyl methyl group, etc. are mentioned.

Examples of the divalent hetero atom-containing group include -CO-, -CS-, -NH-, -O-, -S-, a group combining these, and the like.

As the monovalent group (g) containing a divalent hetero atom-containing group at the end of the carbon-carbon or bond-hand side of the hydrocarbon group, for example,

hetero atom-containing chain groups such as an oxoalkyl group, a thioalkyl group, an alkylaminoalkyl group, an alkoxyalkyl group, an alkylthioalkyl group, an alkoxy group, an alkenyloxy group, and an alkynyloxy group;

hetero atom-containing cyclic groups such as an oxocycloalkyl group, a thiocycloalkyl group, an azacycloalkyl group, an oxacycloalkyl group, a thiacycloalkyl group, an oxocycloalkenyl group, and an oxathiacycloalkyl group;

a hydrocarbyloxy group containing an aromatic hydrocarbon group such as a styryloxy group, a styrylmethyloxy group, an acenaphthyloxy group, and an acenaphthylmethyloxy group;

and aromatic heterocyclic groups such as heteroaryl groups such as pyrrolyl group, pyridyl group, quinolyl group, isoquinolyl group, furyl group, pyranyl group, thienyl group and benzothiophenyl group.

Examples of the monovalent hetero atom-containing group include a hydroxyl group, a sulfanyl group, a cyano group, a nitro group, and a halogen atom.

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

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

As the structural unit (III), for example, structural units represented by the following formulas (4-1) to (4-4) (hereinafter also referred to as “structural units (III-1) to (III-4)”) etc. can be heard

In the formulas (4-1) to (4-4), R ¹⁴ has the same meaning as in the formula (4).

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

[A] When the polymer has the structural unit (III), the lower limit of the content of the structural unit (III) is preferably 10 mol%, more preferably 20 mol%, based on all the structural units constituting the polymer [A]. and 30 mol% is more preferable, and 40 mol% is particularly preferable. As an upper limit of the said content rate, 90 mol% is preferable, 80 mol% is more preferable, 75 mol% is still more preferable, and 70 mol% is especially preferable. By making the content rate of structural unit (III) into the said range, the said radiation-sensitive resin composition can further improve the sensitivity.

Further, the structural unit (III) can be formed by, for example, polymerizing a styrene monomer having an acyloxy group such as an acetoxy group, and then subjecting the obtained polymer to a hydrolysis reaction in the presence of a base such as an amine.

[Structural unit (IV)]

The structural unit (IV) is a structural unit containing an alcoholic hydroxyl group. [A] By having the structural unit (IV), the polymer can be produced with more suitable solubility in a developer, and as a result, the LWR performance and the like of the radiation-sensitive resin composition can be further improved. Moreover, the adhesiveness to the board|substrate of a resist pattern can be improved further.

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

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

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

[A] When the polymer has the structural unit (IV), the lower limit of the content of the structural unit (IV) is preferably 5 mol%, more preferably 10 mol%, based on all the structural units constituting the polymer [A]. and 15 mol% is more preferable, and 20 mol% is particularly preferable. As an upper limit of the said content rate, 70 mol% is preferable, 65 mol% is more preferable, 60 mol% is still more preferable, and 50 mol% is especially preferable. By setting the content of the structural unit (IV) within the above range, the polymer [A] can be produced with more suitable solubility in a developer, and as a result, the LWR performance of the radiation-sensitive resin composition can be further improved. . Moreover, the adhesiveness with respect to the board|substrate of a resist pattern can be improved further.

[Other structural units]

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

[A] As a lower limit of content of a polymer, 70 mass % is preferable with respect to the total solid of the said radiation-sensitive resin composition, 80 mass % is more preferable, 85 mass % is still more preferable. "Total solid content" means the total of components other than the [C] solvent in the said radiation-sensitive resin composition. The said radiation-sensitive resin composition may contain the [A] polymer 1 type, or 2 or more types.

<[A] Polymer synthesis method>

[A] A polymer can be synthesize|combined by superposing|polymerizing, for example in a suitable solvent using a radical polymerization initiator etc. of the monomer which provides each structural unit.

[A] The lower limit of the polystyrene reduced weight average molecular weight (Mw) by gel permeation chromatography (GPC) of the polymer is preferably 1,000, more preferably 3,000, still more preferably 4,000, and particularly preferably 5,000. As an upper limit of the said Mw, 50,000 is preferable, 30,000 is more preferable, 20,000 is still more preferable, and 10,000 is especially preferable. [A] By making Mw of a polymer into the said range, coatability of the said radiation-sensitive resin composition improves, and development defect suppression property further improves.

[A] As a lower limit of ratio (Mw/Mn) of Mw with respect to polystyrene conversion number average molecular weight (Mn) by GPC of a polymer, it is 1 normally, and 1.1 is preferable. As an upper limit of the said ratio, 5 is preferable, 3 is more preferable, and 2 is still more preferable.

<[B] compound>

[B] The compound is a compound represented by the following formula (1). The said radiation-sensitive resin composition contains the [B] compound as an acid generator in addition to the [A] polymer. [B] The compound generates a weak acid upon exposure. The compound [B] is an acid diffusing agent that controls the diffusion phenomenon in the resist film of an acid generated from the following [D] other acid generator or the like upon exposure and suppresses an undesirable chemical reaction in an unexposed region. It works as yesterday.

In said formula (1), R<^1> and R<^2> are each independently a monovalent organic group which does not contain a hydrogen atom or a C1-C20 fluorine atom. R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms. However, at least one of ^{R 1} , R ² , R ³ and R ⁴ represents a group represented by ^{OR Q .} R ^Q is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and when at least one of ^{R 1} and R ² represents a group represented by ^{OR Q , R Q} does not contain a fluorine atom. R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁵ , R ³ and R ⁴ , R ³ and R ⁵ , or R ⁵ and R ⁶ are taken together, and together with the carbon atom to which they are attached, reduce water 3 to You may comprise the ring structure of 20. Y ^- is SO ₃ ^- or COO ^- . X ⁺ is a monovalent radiation-sensitive onium cation.

The said radiation-sensitive resin composition is excellent in LWR performance etc. by containing the compound [B] in addition to the polymer [A]. Although it is not necessarily clear about the reason why the said radiation-sensitive resin composition exhibits the said effect by having the said structure, for example, it can estimate as follows. That is, [B] is the anion of a compound, -SO ₃ ^- or COO ^- is bonded carbon atom or a -SO ₃ ^- or COO ^- by having a carbon atom adjacent to the oxygen with the carbon is to combine, in the [B] compound The polarity is changed, and diffusivity in the resist film is appropriately suppressed. In addition, the [B] compound has a monovalent organic group that does not contain a hydrogen atom or a fluorine atom having 1 to 20 carbon atoms at a position adjacent to _{-SO 3} ^- or COO ^{-, so that the acidity of the compound [B] is appropriately controlled.} do. As a result of these, the [B] compound functions well as an acid generator. Accordingly, it is considered that the LWR performance of the radiation-sensitive resin composition is improved.

As the ^{monovalent organic group not containing a fluorine atom having 1 to 20 carbon atoms represented by R 1} , for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, carbon-carbon of the hydrocarbon group, or fluorine at the end of the bond. 1 in which some or all of the hydrogen atoms of the monovalent group (g) containing a divalent hetero atom-containing group containing no atoms, the hydrocarbon group and the group (g) are substituted with a hetero atom-containing group containing no fluorine atoms A flag and the like are mentioned. Moreover, as a monovalent organic group which does not contain a C1-C20 fluorine atom represented by said R<^2> , the group similar to the group ^{mentioned for said R<1> is mentioned.} When at least one of ^{R 1} and R ² represents a group represented by ^{OR Q} , the monovalent organic group having 1 to 20 carbon atoms represented by ^{R Q} does not contain a fluorine atom having 1 to 20 carbon atoms represented by ^{R 1 .} The same group as the monovalent organic group which does not do is mentioned.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ³ include a monovalent hydrocarbon group having 1 to 20 carbon atoms, a carbon-carbon group of the hydrocarbon group, or a divalent hetero atom-containing group at the end of the bond. and monovalent groups in which some or all of the hydrogen atoms in the hydrocarbon group and group (g) are substituted with a hetero atom-containing group. Examples of the monovalent organic group having 1 to 20 carbon atoms represented by the R ⁴ groups may be mentioned any of the same groups in the above R ^3. When at least one of ^{R 3} and R ⁴ represents a group represented by ^{OR Q} , the monovalent organic group having 1 to 20 carbon atoms represented by ^{R Q} is the same as the monovalent organic group having 1 to 20 carbon atoms represented by ^{R 3 .} of can be lifted.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by ^{R 5} , R ⁶ and R ⁷ include the same groups as those ^{for R 3 .}

wherein R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁵ , R ³ and R ⁴ , R ³ and R ⁵ , or R ⁵ and R ⁶ are combined with each other to form together with the carbon atom to which they are attached As the ring structure having 3 to 20 reduced numbers, for example, an alicyclic structure having 3 to 20 reducing numbers, an aliphatic heterocyclic structure having 3 to 20 reducing numbers, an aromatic ring structure having 3 to 20 reducing numbers, an aromatic heterocyclic structure having 3 to 20 reducing numbers, etc. can be heard

Examples of the alicyclic structure having 3 to 20 reduced numbers include monocyclic saturated hydrocarbon structures such as cyclopropane structure, cyclobutane structure, cyclopentane structure, cyclohexane structure, cycloheptane structure and cyclooctane structure;

Polycyclic saturated hydrocarbon structures, such as a norbornane structure, etc. are mentioned.

Examples of the aliphatic heterocyclic structure having 3 to 20 reduced numbers include an oxacyclopentane structure, a thiacyclopentane structure, and an azacyclopentane structure.

Examples of the aromatic ring structure of the reduced water 3 to 20 include benzene, naphthalene, phenanthrene, and anthracene.

As the aromatic heterocyclic structure having 3 to 20 reduced numbers, for example,

monocyclic aromatic heterocyclic structures such as furan, pyran, pyridine and pyrimidine;

Polycyclic aromatic heterocyclic structures, such as benzopyran and an indole, etc. are mentioned.

As the ring structure having 3 to 20 reduced numbers, among these, an alicyclic structure having 3 to 20 reduced numbers or an aliphatic heterocyclic structure having 3 to 20 reduced numbers is preferable, a monocyclic saturated hydrocarbon structure having 5 to 8 carbon atoms and a polycyclic saturated structure having 7 to 12 carbon atoms. A hydrocarbon structure is more preferable, a cyclopentane structure, a cyclohexane structure, a cyclooctane structure, and a norbornane structure and an adamantane structure are still more preferable, and a cyclopentane structure and an adamantane structure are especially preferable.

Y ^- is SO ₃ ^- or COO ^- , more preferably _{SO 3} ^-.

The ^{monovalent radiation-sensitive onium cation represented by X +} is a cation decomposed by exposure light and/or irradiation with an electron beam. Taking an acid generator containing a sulfonate anion and a radiation-sensitive onium cation as an example, in the exposed portion, a sulfonic acid is produced from a proton generated by decomposition of the radiation-sensitive onium cation and the sulfonate anion.

As the ^{monovalent radiation-sensitive onium cation represented by X +} , for example, a cation represented by the following formula (ra) (hereinafter also referred to as “cation (ra)”), a cation represented by the following formula (rb) (hereinafter referred to as “cation (ra)”) , "cation (rb)"), a cation represented by the following formula (rc) (hereinafter also referred to as "cation (rc)"), etc. are mentioned.

In the formula (ra), R ^B3 and R ^B4 are each independently a monovalent organic group having 1 to 20 carbon atoms. R ^B5 is a monovalent organic group having 1 to 20 carbon atoms, a hydroxy group, a nitro group or a halogen atom. b3 is each independently an integer of 0 to 5; When ^{plural RB5} is plural, plural ^RB5 may be the same or different, and some ^RB5 may combine with each other and may comprise a ring structure. n _bb is an integer from 0 to 3.

As the ^{monovalent organic group having 1 to 20 carbon atoms represented by R B3} , R ^B4 and R ^B5 above, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, carbon-carbon of the hydrocarbon group, or 2 at the end of the bond loss side and a monovalent group (g) containing a valent hetero atom-containing group, and a monovalent group in which some or all of the hydrogen atoms of the hydrocarbon group and group (g) are substituted with a hetero atom-containing group.

As R ^B3 and R ^B4 , a monovalent unsubstituted hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon group in which a hydrogen atom is substituted by a substituent is preferable, and a monovalent unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms or a hydrogen atom is substituted by a substituent An aromatic hydrocarbon group is more preferable, and a phenyl group is still more preferable.

Examples of the substituent optionally substituted for a hydrogen atom in the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by ^{R B3} and R ^B4 _{include a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, -OSO 2} -R ^k , -SO ₂ -R ^k , -OR ^k , -COOR ^k , -O-CO-R ^k , -OR ^kk -COOR ^k , -R ^kk -CO-R ^k and -SR ^k are preferred. R ^k is a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^kk is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms.

R ^{B5 is a} substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, -OSO ₂ -R ^k , -SO ₂ -R ^k , -OR ^k , -COOR ^k , -O-CO-R ^k , -OR Preference is given to ^kk -COOR ^k , -R ^kk -CO-R ^k and -SR ^k. R ^k is a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^kk is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms.

In the formula (rb), R ^B6 and R ^B7 each independently represent a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group or a halogen atom. b4 is an integer from 0 to 7. When ^{plural RB6s} are plural, plural ^RB6s may be the same or different, and plural ^RB6s may be combined with each other to form a ring structure. b5 is an integer from 0 to 6. When ^{plural RB7s} are plural, plural ^RB7s may be the same or different, and plural ^RB7s may be combined with each other to constitute a ring structure. n _b2 is an integer from 0 to 3. R ^B8 is a single bond or a divalent organic group having 1 to 20 carbon atoms. n _b1 is an integer from 0 to 2.

As R ^B6 and R ^{B7, a} substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, -OR ^k , -COOR ^k , -O-CO-R ^k , -OR ^kk -COOR ^k and -R ^kk -CO -R ^k is preferred. R ^k is a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^kk is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms.

In the formula (rc), R ^B9 and R ^B10 are each independently a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group or a halogen atom. b6 and b7 are each independently an integer of 0 to 5; When ^{plural RB9s} are plural, plural ^RB9s may be the same or different, and plural ^RB9s may be combined with each other to form a ring structure. When there are a plurality of ^{RB10s , a plurality of RB10s} may be the same or different, and a plurality of ^RB10s may be combined with each other to constitute a ring structure.

As R ^B9 and R ^B10 , a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, -OSO ₂ -R ^k , -SO ₂ -R ^k , -OR ^k , -COOR ^k , -OR ^k -, - O-CO-R ^k , -OR ^kk -COOR ^k , -R ^kk -CO-R ^k , -SR ^k , and a ring structure constituted by combining two or more of these groups together are preferred. R ^k is a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^kk is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^B5 , R ^B6 , R ^B7 , R ^B9 and R ^{B10 include,}

linear alkyl groups such as a methyl group, an ethyl group, an n-propyl group, and an n-butyl group;

branched alkyl groups such as i-propyl group, i-butyl group, sec-butyl group and t-butyl group;

Aryl groups, such as a phenyl group, a tolyl group, a xylyl group, a mesityl group, and a naphthyl group;

Aralkyl groups, such as a benzyl group and a phenethyl group, etc. are mentioned.

Examples of the divalent organic group represented by R ^B8 include groups in which one hydrogen atom is removed from the monovalent organic group having 1 to 20 carbon atoms exemplified as ^{R B3} , R ^B4 and R ^{B5 in the formula (ra).} can

Examples of the substituent which may substitute a hydrogen atom in the hydrocarbon group represented by R ^B5 , R ^B6 , R ^B7 , R ^B9 and R ^B10 include, for example, a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom; and a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkoxy group, an alkoxycarbonyl group, an alkoxycarbonyloxy group, an acyl group, an acyloxy group, and the like. Among these, a halogen atom is preferable and a fluorine atom is more preferable.

R ^B5 , R ^B6 , R ^B7 , R ^B9 and R ^{B10 are an} unsubstituted linear or branched monovalent alkyl group, a monovalent fluorinated alkyl group, an unsubstituted monovalent aromatic hydrocarbon group, -OSO ₂ -R ^k and -SO _2- R ^k is preferable, a fluorinated alkyl group and an unsubstituted monovalent aromatic hydrocarbon group are more preferable, and a fluorinated alkyl group is still more preferable.

As b3 in Formula (ra), the integer of 0-2 is preferable, 0 and 1 are more preferable, and 0 is still more preferable. As n _bb, 0 and 1 are preferable and 0 is more preferable. As b4 in Formula (rb), the integer of 0-2 is preferable, 0 and 1 are more preferable, and 0 is still more preferable. As b5, the integer of 0-2 is preferable, 0 and 1 are more preferable, and 0 is still more preferable. As n _b2, 2 and 3 are preferable and 2 is more preferable. As n _b1, 0 and 1 are preferable and 0 is more preferable. As b6 and b7 in Formula (rc), the integer of 0-2 is preferable, 0 and 1 are more preferable, and 0 is still more preferable.

As X ^+, among these, cation (ra) and cation (rb) are preferable, triphenylsulfonium cation and 1-[2-(4-cyclohexylphenylcarbonyl)propan-2-yl]tetrahydrothiophenium cation This is more preferable.

[B] Examples of the compound include compounds represented by the following formulas (B-1) to (B-24) (hereinafter also referred to as “compounds (B-1) to (B-24)”). .

[B] As the compound, among these, compound (B-1), compound (B-2) and compound (B-5), compound (B-12) and compound (B-15) are preferable.

The compound [B] can be synthesized by various synthetic methods. For example, when the compound [B] is the compound (B-15), the compound represented by the following formula (b-2), which is a compound represented by the following formula (i) (also referred to as compound (i)) (hereinafter, Compound (B-15) can be synthesized from "compound (b-2)") according to the following scheme.

In the formula (i), R ¹ to R ⁷ , Y ⁻ have the same definitions as in the formula (1). M ⁺ is a monovalent metal cation.

Examples of the monovalent metal cation represented by M ^{+ include Na +} , Li ⁺ , K ⁺ , Cs ⁺ , Ag ⁺ and the like.

The intermediate compound (b-2) can be obtained by reacting the compound represented by the formula (b-1) with sodium sulfite. The compound (B-1) can be obtained by reacting the compound (b-2) with triphenylsulfonium chloride. Compounds [B] other than these can also be synthesized using a known method.

[B] The lower limit of the content of the compound is preferably 0.1% by mass, more preferably 0.5% by mass, still more preferably 1% by mass, and particularly preferably 3% by mass relative to the total solid content of the radiation-sensitive resin composition. . As an upper limit of the said content, in total solid, 30 mass % is preferable, 20 mass % is more preferable, 15 mass % is still more preferable, 10 mass % is especially preferable. [B] Lithography performance, such as resolution, of the said radiation-sensitive resin composition as content of a compound is less than the said lower limit may fall. [B] When content of a compound exceeds the said upper limit, the sensitivity of the said radiation-sensitive resin composition may fall.

Moreover, as a lower limit of content of [B] compound, 0.1 mass part is preferable with respect to 100 mass parts of [A] polymers, 0.5 mass part is more preferable, 1 mass part is still more preferable, 2 mass parts is especially preferable. Moreover, as an upper limit of content, 30 mass parts is preferable with respect to 100 mass parts of [A] polymer, 20 mass parts is more preferable, 15 mass parts is still more preferable, 10 mass parts is especially preferable. [B] By making content of the compound into the said range, the LWR performance etc. of the said radiation-sensitive resin composition can be improved further.

<[C] solvent>

The said radiation-sensitive resin composition contains the solvent [C] normally. [C] The solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least the polymer [A], the compound [B], and the [E] nitrogen-containing compound contained as necessary. The said radiation-sensitive resin composition may contain the [C] solvent 1 type, or 2 or more types.

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

[C] As the solvent, an ester solvent and a ketone solvent are preferable, a polyhydric alcohol partial ether carboxylate solvent and a cyclic ketone solvent are more preferable, and a polyhydric alcohol partial alkyl ether acetate and a cycloalkanone are more preferable; Propylene glycol monomethyl ether acetate and cyclohexanone are particularly preferred.

<[D] Another acid generator>

The said radiation-sensitive resin composition may contain [D] other acid generators other than the [B] compound in the range which does not impair the effect of this invention. [D] Another acid generator is a substance that generates an acid by exposure. With this generated acid, the acid-dissociable group of the polymer [A] is dissociated to generate a carboxy group, a hydroxyl group, etc., and the solubility of the polymer [A] in a developer is changed. pattern can be formed. As a content form of another acid generator in the said radiation-sensitive resin composition, even if it is a free compound form (henceforth "[D] another acid generator" as appropriate), it is a form incorporated as a part of a polymer. Either these or both of these forms may be sufficient.

As another acid generator, it has an anion and a radiation-sensitive onium cation, The acid generator etc. which an anion does not have the structure represented by said Formula (1) are mentioned.

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

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

[D] As a specific example of another acid generator, the compound etc. which are described in Paragraph [0080] of Unexamined-Japanese-Patent No. 2009-134088 - [0113] are mentioned, for example.

[D] As another acid generator, the acid generator represented by a following formula (r) is preferable. [D] Since the other acid generator has the following structure, the diffusion length of the acid generated by exposure in the resist film due to the interaction with the structural unit (I) of the polymer [A] or the compound [B], etc. in the resist film is more appropriate It is thought that the LWR performance and depth of focus of the radiation-sensitive resin composition can be further improved as a result.

In the formula (r), R ^p1 is a monovalent group including a ring structure having 5 or more reduced numbers. R ^p2 is a divalent linking group. R ^p3 and R ^p4 are each independently a hydrogen atom, a fluorine atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. R ^p5 and R ^p6 are each independently a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. n ^p1 is an integer from 0 to 10. n ^p2 is an integer from 0 to 10; n ^p3 is an integer from 1 to 10; When n ^p1 is 2 or more, a plurality of R ^p2 may be the same or different. When n ^p2 is 2 or more, a plurality of R ^p3 may be the same or different, and a plurality of R ^p4 may be the same or different. When n ^p3 is 2 or more, a plurality of R ^p5 may be the same or different, and a plurality of R ^p6 may be the same or different. X ⁺ is a monovalent radiation-sensitive onium cation.

Examples of the monovalent group including a ring structure with 5 or more reduced numbers represented by R ^p1 include a monovalent group including an alicyclic structure with 5 or more reduced numbers, a monovalent group including an aliphatic heterocyclic structure with 5 or more reduced numbers, or a direction with 5 or more reduced numbers. The monovalent group containing a ring structure, the monovalent group containing the aromatic heterocyclic structure of 5 or more reduced numbers, etc. are mentioned.

As an alicyclic structure of 5 or more reduced numbers, for example,

monocyclic cycloalkane structures such as a cyclohexane structure, a cycloheptane structure, a cyclooctane structure, a cyclononane structure, a cyclodecane structure, and a cyclododecane structure;

monocyclic cycloalkene structures such as a cyclohexene structure, a cycloheptene structure, a cyclooctene structure, and a cyclodecene structure;

polycyclic cycloalkane structures such as norbornane structure, adamantane structure, tricyclodecane structure and tetracyclododecane structure;

Polycyclic cycloalkene structures, such as a norbornene structure and a tricyclodecene structure, etc. are mentioned.

As the aliphatic heterocyclic structure of 5 or more reduced numbers, for example,

Lactone structures, such as a hexanolactone structure and a norbornanlactone structure;

Sultone structures, such as a hexano sultone structure and a norbornan sultone structure;

oxygen atom-containing heterocyclic structures such as an oxacycloheptane structure and an oxa norbornane structure;

nitrogen atom-containing heterocyclic structures such as an azacyclohexane structure and a diazabicyclooctane structure;

The sulfur atom-containing heterocyclic structure of a thiacyclohexane structure and a thianorbornane structure, etc. are mentioned.

As said aromatic ring structure of 5 or more reduced numbers, a benzene structure, a naphthalene structure, a phenanthrene structure, anthracene structure, etc. are mentioned, for example.

Examples of the aromatic heterocyclic structure having 5 or more reduced numbers include oxygen atom-containing heterocyclic structures such as furan structure, pyran structure and benzopyran structure, nitrogen atom-containing heterocyclic structures such as pyridine structure, pyrimidine structure and indole structure. can

The lower limit of the number of reductions in the ring structure of R ^p1 is preferably 7, more preferably 8, still more preferably 9, and particularly preferably 10. On the other hand, as an upper limit of the said reduced water, 15 is preferable, 14 is more preferable, 13 is still more preferable, and 12 is especially preferable. By setting the reduced water to the above range, the diffusion length of the above-described acid can be shortened more appropriately, and as a result, the LWR performance of the radiation-sensitive resin composition can be further improved.

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

R ^p1 is preferably a monovalent group containing an alicyclic structure with a reduced number of 5 or more and a monovalent group containing an aliphatic heterocyclic structure with a reduced number of 5 or more, among them, a monovalent group containing an alicyclic structure with a reduced number of 9 or more, and an aliphatic group with a reduced number of 9 or more A monovalent group containing a heterocyclic structure is more preferable, and an adamantyl group, a hydroxyadamantyl group, a norbornanlacton-yl group, a norbornansulton-yl group and 5-oxo-4-oxatricyclo[4.3.1.1 ^{3, 8} ]undecan-yl group is more preferred, and adamantyl group is particularly preferred.

Examples of the divalent linking group represented by R ^p2 include a carbonyl group, an ether group, a carbonyloxy group, a sulfide group, a thiocarbonyl group, a sulfonyl group, and a divalent hydrocarbon group. As the ^{divalent linking group represented by R p2} , a carbonyloxy group, a sulfonyl group, an alkanediyl group and a cycloalkanediyl group are preferable, a carbonyloxy group and a cycloalkanediyl group are more preferable, a carbonyloxy group and a norbor group A nadiyl group is more preferable, and a carbonyloxy group is especially preferable.

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

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

As n ^p1, the integer of 0-5 is preferable, the integer of 0-3 is more preferable, the integer of 0-2 is still more preferable, 0 and 1 are especially preferable.

As n ^p2, the integer of 0-5 is preferable, the integer of 0-2 is more preferable, 0 and 1 are still more preferable, and 0 is especially preferable.

As n ^p3 , the integer of 1-5 is preferable, the integer of 1-4 is more preferable, the integer of 1-3 is still more preferable, 1 and 2 are especially preferable.

Monovalent radiation sensitive onium cation represented by X ⁺ X ⁺ is synonymous with the above equation (1).

As the acid generator represented by the formula (r), for example, a compound represented by the following formulas (r-1) to (r-15) (hereinafter also referred to as “compounds (r-1) to (r-15)” ) and the like.

In the formulas (r-1) to (r-15), X ⁺ is a monovalent radiation-sensitive onium cation.

[D] As another acid generator, an onium salt compound is preferable, and the compounds (r-5), (r-14) and (r-15) are more preferable.

Moreover, as another acid generator [D], the polymer which has a structural unit represented by following formula (7) is also preferable.

In the formula (7), R' is a hydrogen atom or a methyl group. X ⁺ is a monovalent radiation-sensitive onium cation.

[D] As a lower limit of content of another acid generator, 0.1 mass part is preferable with respect to 100 mass parts of [A] polymer, 0.5 mass part is more preferable, 1 mass part is still more preferable. As an upper limit of the said content, 35 mass parts is preferable, 30 mass parts is more preferable, and 25 mass parts is still more preferable. [D] By making content of another acid generator into the said range, the sensitivity and developability of the said radiation-sensitive resin composition can improve, As a result, LWR performance and depth of focus can be improved. [D] The other acid generator can use 1 type, or 2 or more types.

Moreover, in the range which does not impair the effect of this invention, the said radiation-sensitive resin composition can also use the photodegradable base which sensitizes by exposure and generate|occur|produces a weak acid as another acid generator [D]. The photodegradable base functions as an acid diffusion control agent. Examples of the photodegradable base include an onium salt compound that decomposes upon exposure and loses acid diffusion controllability (however, except for compounds [B]). For example, the sulfonium salt compound represented by the following formula (6-1), the iodonium salt compound represented by the following formula (6-2), etc. are mentioned.

In the formula (6-1), R ²³ and R ²⁴ are each independently a monovalent organic group having 1 to 20 carbon atoms. R ³⁰ is a monovalent organic group having 1 to 20 carbon atoms, a hydroxy group, a nitro group, or a halogen atom. b8 is each independently an integer of 0 to 5; When ^{plural R 30} is plural, plural R ³⁰ may be the same or different, and plural R ³⁰ may be combined with each other to constitute a ring structure. n _b3 is an integer from 0 to 3.

As the ^{monovalent organic group having 1 to 20 carbon atoms represented by R 23} , R ²⁴ and R ³⁰ , for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms, or 2 at the end of the carbon-carbon or bond side of the hydrocarbon group and a monovalent group (g) containing a valent hetero atom-containing group, and a monovalent group in which some or all of the hydrogen atoms of the hydrocarbon group and group (g) are substituted with a hetero atom-containing group.

R ²³ and R ²⁴ are preferably a monovalent unsubstituted hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon group in which a hydrogen atom is substituted by a substituent, and a monovalent unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms or a hydrogen atom in which a substituent is substituted. An aromatic hydrocarbon group is more preferable, and a phenyl group is still more preferable.

Examples of the substituent optionally substituted for the hydrogen atom of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by ^{R 23} and R ²⁴ _{include a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, -OSO 2} -R ^q ; -SO ₂ -R ^q , -OR ^q , -COOR ^q , -O-CO-R ^q , -OR ^qq -COOR ^q , -R ^qq -CO-R ^q and -SR ^q are preferred. R ^q is a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^qq is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms.

R ^{30 is a} substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, -OSO ₂ -R ^q , -SO ₂ -R ^q , -OR ^q , -COOR ^q , -O-CO-R ^q , -OR Preference is given to ^qq -COOR ^q , -R ^qq -CO-R ^q and -SR ^{q .} R ^q is a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^qq is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms.

In the formula (6-2), R ²⁶ to R ²⁷ each independently represent a monovalent organic group having 1 to 20 carbon atoms, a hydroxyl group, a nitro group, or a halogen atom.

As R ²⁶ and R ^{27 , a} substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, -OSO ₂ -R ^q , -SO ₂ -R ^q , -OR ^q , -COOR ^q , -OCR ^q , -OR ^{Preferred are qq} -COOR ^q , -R ^qq -CO-R ^q , -SR ^q , and a ring structure constituted by combining two or more of these groups together. R ^q is a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^qq is a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by ^{R 30} , R ²⁶ and R ²⁷ include groups similar to those exemplified as ^{R B5 in the formula (ra).}

Examples of the substituent optionally substituted for the hydrogen atom of the hydrocarbon group represented by ^{R 30} , R ²⁶ and R ²⁷ include groups similar to those exemplified for ^{RB5 in the formula (ra).}

As R ³⁰ , R ²⁶ and R ^{27 , an} unsubstituted linear or branched monovalent alkyl group, a monovalent fluorinated alkyl group, an unsubstituted monovalent aromatic hydrocarbon group, -OSO ₂ -R ^q and -SO ₂ -R ^q are Preferably, a fluorinated alkyl group and an unsubstituted monovalent aromatic hydrocarbon group are more preferable, and a fluorinated alkyl group is still more preferable.

In the above formulas (6-1) and (6-2), E ^- and Q ^- are each independently OH ^- , R ^β -COO ^- , R ^γ -SO ₃ ^- or represented by the following formula (6-3) is an anion. R ^β is an alkyl group, an aryl group or an aralkyl group. R ^γ is an alkyl group or an aralkyl group.

In the formula (6-3), R ²⁸ is a C1-C12 linear or branched alkyl group, a C1-C12 linear or branched fluorinated alkyl group, or a C1-C12 linear or branched alkyl group. It is an alkoxy group. u is an integer from 0 to 2. When u is 2, two R ²⁸ may be the same or different.

[D] As another acid generator, the compound etc. which are represented by a following formula are mentioned, for example.

[D] As another acid generator, triphenylsulfonium salicylate and triphenylsulfonium 10-camphorsulfonate are preferable among these.

In addition, although it does not correspond to the above-mentioned [B] compound, as a compound similar to the above-mentioned [B] compound, for example, a compound represented by the following formulas (H-1) to (H-4) (hereinafter referred to as “Compound (H-1)” ) to (H-4)”).

[D] When a photodegradable base is included as another acid generator, as a lower limit of content of a photodegradable base, 0 mass parts is preferable with respect to 100 mass parts of [A] polymer, 0.1 mass parts is more preferable, 0.3 mass addition is more preferable, and 0.5 mass part is especially preferable. As an upper limit of the said content, 15 mass parts is preferable with respect to 100 mass parts of [A] polymer, 10 mass parts is more preferable, 8 mass parts is still more preferable. When content of another acid diffusion control body exceeds the said upper limit, the sensitivity of the said radiation-sensitive resin composition may fall.

<[E] Nitrogen-containing compound>

The said radiation-sensitive resin composition may contain [E] nitrogen-containing compound in the range which does not impair the effect of this invention. [E] The nitrogen-containing compound controls the diffusion phenomenon in the resist film of [D] acid generated from other acid generators or the like upon exposure and suppresses an undesirable chemical reaction in an unexposed region. It exerts an effect as a control agent. In addition, while the storage stability of the radiation-sensitive resin composition is improved, the resolution as a resist is further improved. In addition, it is possible to suppress the change in the line width of the resist pattern due to the fluctuation of the post-exposure delay time from exposure to development, and a radiation-sensitive resin composition excellent in process stability can be obtained.

[E] As the nitrogen-containing compound, for example, a compound represented by the following formula (5) (hereinafter also referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule (hereinafter referred to as “nitrogen-containing compound”) compound (II)"), a compound having three nitrogen atoms (hereinafter also referred to as "nitrogen-containing compound (III)"), an amide group-containing compound, a urea compound, a nitrogen-containing heterocyclic compound, and the like.

In the formula (5), R ²⁰ , R ²¹ and R ²² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group.

Examples of the nitrogen-containing compound (I) include monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine; and aromatic amines such as aniline and 2,6-dii-propylaniline.

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

Examples of the nitrogen-containing compound (III) include polyamine compounds such as polyethyleneimine and polyallylamine; Polymers, such as dimethylamino ethyl acrylamide, etc. are mentioned.

Examples of the amide group-containing compound include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, and pyrroly. Don, N-methylpyrrolidone, etc. are mentioned.

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

Examples of the nitrogen-containing heterocyclic compound include pyridines such as pyridine and 2-methylpyridine; morpholines such as N-propyl morpholine and N-(undecylcarbonyloxyethyl)morpholine; and imidazoles such as pyrazine, pyrazole, benzimidazole and 2-phenylbenzimidazole.

As the nitrogen-containing organic compound, a compound having an acid dissociable group may also be used. Examples of the nitrogen-containing organic compound having an acid-dissociable group include Nt-butoxycarbonylpiperidine, Nt-butoxycarbonylimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarp. Bornyl-2-phenylbenzimidazole, N-(t-butoxycarbonyl)di-n-octylamine, N-(t-butoxycarbonyl)diethanolamine, N-(t-butoxycarbonyl) dicyclohexylamine, N-(t-butoxycarbonyl)diphenylamine, Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-amyloxycarbonyl-4-hydroxypiperidine, etc. can be heard

When the radiation-sensitive resin composition contains the [E] nitrogen-containing compound, the lower limit of the content of the [E] nitrogen-containing compound is preferably 0.1 parts by mass, more preferably 0.3 parts by mass, with respect to 100 parts by mass of the polymer [A], , 1 part by mass is more preferable. As an upper limit of the said content, 15 mass parts is preferable, 10 mass parts is more preferable, 5 mass parts is still more preferable.

<[F] Polymer>

The polymer [F] is a polymer having a higher fluorine atom mass content than the polymer [A]. Since the polymer [F] has a higher mass content of fluorine atoms than the polymer [A], due to its oil repellency characteristic, when a resist film is formed, its distribution tends to be localized in the resist film surface layer. As a result, according to the radiation-sensitive resin composition, it is possible to suppress elution of the acid generator, the acid diffusion controller, and the like into the immersion exposure solution during immersion exposure. In addition, according to the radiation-sensitive resin composition, the advancing contact angle between the resist film and the immersion exposure solution can be controlled within a desired range due to the water repellency characteristics of the polymer [F], and the occurrence of bubble defects can be suppressed. In addition, according to the radiation-sensitive resin composition, the receding contact angle between the resist film and the immersion exposure solution is increased, so that no water droplets remain, and high-speed scanning exposure becomes possible. The said radiation-sensitive resin composition can form the resist film suitable for the liquid immersion exposure method by containing [F] polymer in this way.

[F] The lower limit of the mass content of fluorine atoms in the polymer is preferably 1% by mass, more preferably 2% by mass, still more preferably 4% by mass, and particularly preferably 7% by mass. As an upper limit of the said mass content, 60 mass % is preferable, 50 mass % is more preferable, 40 mass % is still more preferable, 30 mass % is especially preferable. By setting the mass content of fluorine atoms in the above range, localization of the polymer [F] in the resist film can be more appropriately adjusted. In addition, the mass content rate of the fluorine atom of a ^{polymer can calculate|require the structure of a polymer by 13} C-NMR spectrum measurement, and can compute it from the structure.

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

Further, the [F] polymer preferably has an alkali dissociable group. [F] When the polymer has an alkali dissociable group, the surface of the resist film can be effectively changed from hydrophobicity to hydrophilicity during alkali development, and the defect suppression property of the radiation-sensitive resin composition is further improved. An "alkali dissociable group" is a group which substitutes hydrogen atoms, such as a carboxy group and a hydroxyl group, and refers to the group which dissociates in aqueous alkali solution (for example, 23 degreeC 2.38 mass % tetramethylammonium hydroxide aqueous solution).

As the structural unit (F), a structural unit represented by the following formula (f-1) (hereinafter also referred to as “structural unit (F-1)”) and a structural unit represented by the following formula (f-2) (hereinafter, "Structural unit (F-2)") is preferred. The structural unit (F) may have a structural unit (F-1) and a structural unit (F-2) 1 type, or 2 or more types, respectively.

[Structural unit (F-1)]

The structural unit (F-1) is a structural unit represented by the following formula (f-1). [F] By having the structural unit (F-1), the mass content of fluorine atoms can be adjusted in the polymer.

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

As R ^A , a hydrogen atom and a methyl group are preferable, and a methyl group is more preferable from the viewpoint of copolymerizability of the monomer giving the structural unit (F-1).

As G, -COO-, -SO ₂ NH-, -CONH-, and -OCONH- are preferable, and -COO- is more preferable.

Examples of the monovalent fluorinated chain hydrocarbon group having 1 to 6 carbon atoms represented by R ^{B include trifluoromethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 2,2,3,3,3} -Pentafluoropropyl group, 1,1,1,3,3,3-hexafluoropropyl group, perfluoro-n-propyl group, perfluoro-i-propyl group, perfluoro-n-butyl group group, perfluoro-i-butyl group, perfluoro-t-butyl group, 2,2,3,3,4,4,5,5-octafluoropentyl group, perfluorohexyl group, etc. can

Examples ^{of the monovalent fluorinated alicyclic hydrocarbon group having 4 to 20 carbon atoms represented by R B} include a monofluorocyclopentyl group, a difluorocyclopentyl group, a perfluorocyclopentyl group, a monofluorocyclohexyl group, Difluorocyclopentyl group, perfluorocyclohexylmethyl group, fluoronorbornyl group, fluoroadamantyl group, fluorobornyl group, fluoroisobornyl group, fluorotricyclodecyl group, fluorotetracyclodecyl group, etc. can be heard

R ^B as the preferred fluorinated chain hydrocarbon group, and 2-2,2,2-trifluoro-ethyl group, and 1,1,1,3,3,3-hexafluoro-propyl group is more preferable, and 2,2,2 - A trifluoroethyl group is more preferable.

[F] When the polymer has a structural unit (F-1), the lower limit of the content rate of the structural unit (F-1) is preferably 10 mol% with respect to all structural units constituting the [F] polymer, and 20 mol % is more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 70 mol% is more preferable, and 50 mol% is still more preferable. By making the content rate of a structural unit (F-1) into the said range, the mass content rate of the fluorine atom of the polymer [F] can be adjusted more suitably.

[Structural unit (F-2)]

The structural unit (F-2) is a structural unit represented by the following formula (f-2). [F] When the polymer has the structural unit (F-2), solubility in an alkali developer is improved, and the occurrence of development defects can be suppressed. Structural unit (F-2) has (x) an alkali-soluble group and (y) a group (hereinafter also referred to as an "alkali dissociable group") that dissociates by the action of alkali to increase solubility in an alkali developer It is broadly divided into two cases.

It is common to both (x) and (y), and in said Formula (f-2), R ^C is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ^D is a single bond, a hydrocarbon group having 1 to 20 carbon atoms (s+1), an oxygen atom, a sulfur atom, -NR'-, a carbonyl group, -COO- or -CONH- at the terminal of ^{the R E side of the hydrocarbon group} This bonded structure or a structure in which a part of the hydrogen atoms of the hydrocarbon group are substituted with an organic group having a hetero atom. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. s is an integer from 1 to 3.

When the structural unit (F-2) has (x) an alkali-soluble group, R ^F is a hydrogen atom and A ¹ is an oxygen atom, -COO-* or -SO ₂ O-*. * indicates a site binding to ^{R F .} W ¹ is a single bond, a hydrocarbon group having 1 to 20 carbon atoms, or a divalent fluorinated hydrocarbon group. When A ¹ is an oxygen atom, W ¹ is a fluorinated hydrocarbon group having a fluorine atom or a fluoroalkyl group at the carbon atom to which ^{A 1 is bonded.} R ^E is a single bond or a divalent organic group having 1 to 20 carbon atoms. When s is 2 or 3, a plurality of ^RE , W ¹ , A ¹ and R ^F may be the same or different, respectively. When the structural unit (F-2) has (x) an alkali-soluble group, affinity to an alkali developer can be improved, and development defects can be suppressed. (x) As the structural unit (F-2) having an alkali-soluble group ^{, the case where A 1} is an oxygen atom and W ¹ is a 1,1,1,3,3,3-hexafluoro-2,2-propanediyl group Especially preferred.

When the structural unit (F-2) has (y) an alkali dissociable group, R ^F is a monovalent organic group having 1 to 30 carbon atoms, A ¹ is an oxygen atom, -NR ^aa -, -COO-* or -SO ₂ O-*. R ^aa is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. * indicates a site binding to ^{R F .} W ¹ is a single bond or a divalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. R ^E is a single bond or a divalent organic group having 1 to 20 carbon atoms. When A ¹ is -COO-* or -SO ₂ O-*, W ¹ or R ^F has a fluorine atom on a carbon atom bonded to ^{A 1 or a carbon atom adjacent thereto.} When A ¹ is an oxygen atom, W ¹ , R ^E are a single bond, R ^D is a structure in which a carbonyl group is bonded to a terminal on the side of a hydrocarbon group having 1 to 20 carbon atoms RE ^{E , and R F} is an organic group having a fluorine atom to be. When s is 2 or 3, a plurality of ^RE , W ¹ , A ¹ and R ^F may be the same or different, respectively. When the structural unit (F-2) has (y) an alkali dissociable group, the hydrophilicity of the resist film surface in the alkali developing step is improved. As a result, the affinity to the developer can be greatly improved, and development defects can be more effectively suppressed. (y) As the structural unit (F-2) having an alkali dissociable group ^{, it is particularly preferable that A 1} is -COO-* and R ^F or W ¹ or both of them have a fluorine atom.

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

As the (s+1) valent hydrocarbon group having 1 to 20 carbon atoms represented by ^{R D} , for example, s hydrogen atoms from the monovalent hydrocarbon group having 1 to 20 carbon atoms exemplified as ^{R 6} to R ^{8 in the formula (2).} and groups other than .

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

As R ^D , when s is 1, a single bond and a divalent hydrocarbon group are preferable, a single bond and an alkanediyl group are more preferable, a single bond and an alkanediyl group having 1 to 4 carbon atoms are still more preferable, a single bond and a methane group A diyl group and a propanediyl group are particularly preferred.

Examples of the divalent organic group having 1 to 20 carbon atoms represented by R ^E include groups in which one hydrogen atom is removed from the monovalent organic group exemplified as ^{R 15 in the formula (4).}

As R ^E , a group having a single bond and a lactone structure is preferable, a group having a single bond and a polycyclic lactone structure is more preferable, and a group having a single bond and a norbornanlactone structure is more preferable.

Examples of the divalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms represented by W ^{1 include a fluoromethanediyl group, difluoromethanediyl group, fluoroethanediyl group, difluoroethanediyl group, tetrafluoro} fluorinated alkanediyl groups such as an ethanediyl group, a hexafluoropropanediyl group and an octafluorobutanediyl group;

A fluorinated alkene diyl group, such as a fluoroethene diyl group and a difluoroethene diyl group, etc. are mentioned. Among these, a fluorinated alkanediyl group is preferable, and a difluoromethanediyl group is more preferable.

As A ^{1, an} oxygen atom, -COO-*, or -SO ₂ O-* is preferable, and -COO-* is more preferable.

Examples of the monovalent organic group having 1 to 30 carbon atoms represented by R ^F include an alkali dissociable group, an acid dissociable group, and a hydrocarbon group having 1 to 30 carbon atoms. As R ^{F ,} among these, an alkali dissociable group is preferable. The R ^F group by alkali dissociable, it is possible to improve the hydrophilicity of the surface of the resist film at the time of alkali development, a defective inhibitory in the art the radiation-sensitive resin composition is further improved.

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

In the formula (iii), R ^5a and R ^5b are each independently a monovalent organic group having 1 to 20 carbon atoms, or these groups combine with each other to form an alicyclic structure having 3 to 20 reduced numbers formed together with the carbon atom to which they are bonded indicates.

In the formula (iv), R ^5c and R ^5d are each independently a monovalent organic group having 1 to 20 carbon atoms, or a heterocyclic structure having 3 to 20 reduced numbers formed together with the nitrogen atom to which these groups are bonded together. indicates

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

Examples of the monovalent organic group having 1 to 20 carbon atoms and the monovalent hydrocarbon group having 1 to 20 carbon atoms include groups similar to those exemplified as ^{R 15 in the formula (4).}

Examples of the monovalent fluorinated hydrocarbon group having 1 to 20 carbon atoms include groups in which some or all of the hydrogen atoms of the groups exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms are substituted with fluorine atoms.

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

Among these, groups (v-3) and (v-5) are preferred.

Further, ^{it is preferable that R F} is a hydrogen atom because the affinity of the polymer [F] to an alkaline developer is improved. In this case, if A ¹ is an oxygen atom and W ¹ is a 1,1,1,3,3,3-hexafluoro-2,2-propanediyl group, the affinity is further improved.

[F] When the polymer has a structural unit (F-2), the lower limit of the content of the structural unit (F-2) is preferably 10 mol%, and 20 mol% based on the total structural units constituting the [F] polymer. % is more preferable, and 40 mol% is still more preferable. As an upper limit of the said content rate, 90 mol% is preferable, 85 mol% is more preferable, and its 80 mol% is still more preferable. By making the content rate of the structural unit (F-2) into the above range, the hydrophilicity of the surface of the resist film formed from the radiation-sensitive resin composition can be further improved before and after alkali development.

The lower limit of the content of the structural unit (F) is preferably 10 mol%, more preferably 20 mol%, and still more preferably 25 mol%, based on all the structural units constituting the polymer [F]. As an upper limit of the said content rate, 90 mol% is preferable, 85 mol% is more preferable, and its 80 mol% is still more preferable.

[F] The lower limit of the structural unit containing an acid-dissociable group in the polymer is preferably 10 mol%, more preferably 20 mol%, further 50 mol%, based on all the structural units constituting the [F] polymer. desirable. As an upper limit of the said content rate, 90 mol% is preferable, 80 mol% is more preferable, and its 75 mol% is still more preferable. By making the content rate of the structural unit containing an acid-dissociable group into the said range, the development defect suppression property of the said radiation-sensitive resin composition can be improved further.

When the said radiation-sensitive resin composition contains the [F] polymer, as a lower limit of content of [F] polymer, 0.1 mass part is preferable with respect to 100 mass parts of [A] polymer, 0.5 mass part is more preferable, 1 mass part It is more preferable, and 2 mass parts is especially preferable. As an upper limit of the said content, 30 mass parts is preferable, 20 mass parts is more preferable, 15 mass parts is still more preferable, and 10 mass parts is especially preferable. The said radiation-sensitive resin composition may contain the [F] polymer 1 type, or 2 or more types.

The polymer [F] can be synthesized in the same manner as the polymer [A] described above.

[F] The lower limit of Mw by GPC of the polymer is preferably 1,000, more preferably 3,000, still more preferably 4,000, and particularly preferably 5,000. As an upper limit of the said Mw, 50,000 is preferable, 30,000 is more preferable, 20,000 is still more preferable, and 10,000 is especially preferable. [F] By making Mw of a polymer into the said range, the coatability and development defect suppression property of the said radiation-sensitive resin composition improve.

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

<Other optional ingredients>

The said radiation-sensitive resin composition may contain other arbitrary components other than the said [A] - [F] component. As another optional component, surfactant, an alicyclic skeleton containing compound, a sensitizer, etc. are mentioned, for example. You may use these other arbitrary components individually by 1 type or in combination of 2 or more type, respectively.

[Surfactants]

Surfactant exhibits the effect of improving coatability, striation, developability, etc. As the surfactant, for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate and nonionic surfactants such as polyethylene glycol distearate. As an upper limit of content of surfactant, 2 mass parts is preferable with respect to 100 mass parts of [A] polymer, and 1 mass part is more preferable.

[Compound containing alicyclic skeleton]

The alicyclic skeleton-containing compound exhibits an effect of improving dry etching resistance, pattern shape, adhesion to a substrate, and the like. Examples of the alicyclic skeleton-containing compound include adamantane derivatives such as 1-adamantanecarboxylic acid, deoxycholic acid esters such as deoxycholic acid t-butyl, and lithocholic acid such as lithocholic acid t-butyl. Esters etc. are mentioned.

[sensitizer]

A sensitizer exhibits the effect|action which increases the production amount of the acid from the [B] acid generator etc., and exhibits the effect of improving the "apparent sensitivity" of the said radiation-sensitive resin composition.

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

<Method for producing radiation-sensitive resin composition>

The radiation-sensitive resin composition is, for example, [A] polymer, [B] compound, [C] solvent, and [D] other acid generators, [E] nitrogen-containing compound, [F] polymer contained as necessary. and other optional components are mixed in a predetermined ratio, and preferably, the obtained liquid mixture can be produced by filtering, for example, with a filter having a pore diameter of about 0.2 µm. As a lower limit of the solid content concentration of the said radiation-sensitive resin composition, 0.1 mass % is preferable, 0.5 mass parts is more preferable, and its 1 mass % is still more preferable. As an upper limit of the said solid content concentration, 50 mass % is preferable, 30 mass % is more preferable, and its 20 mass % is still more preferable.

The said radiation-sensitive resin composition can be used also for the object for the positive pattern formation using an alkaline developing solution, and the object for the negative pattern formation using the developing solution containing an organic solvent. Among these, when using for negative pattern formation using the developing solution containing an organic solvent, the said radiation-sensitive resin composition can exhibit higher resolution.

<Resist pattern formation method>

The resist pattern forming method includes a step of coating the radiation-sensitive resin composition on the surface side of the substrate (hereinafter also referred to as a “coating step”), and a step of exposing the resist film obtained by the coating (hereinafter “exposure step”). '), and a step of developing the exposed resist film (hereinafter, also referred to as a “developing step”).

According to the resist pattern forming method, since the above-mentioned radiation-sensitive resin composition is used, a resist pattern excellent in LWR performance, CDU performance, EL performance, development defect suppression property and film shrinkage suppression property after PEB can be formed. have. Hereinafter, each process is demonstrated.

[coating process]

In this process, the said radiation-sensitive resin composition is coated on the surface side of a board|substrate. Thereby, a resist film is formed. As a board|substrate to which the said radiation-sensitive resin composition is coated, a silicon wafer, the wafer coat|covered with aluminum, etc. are mentioned, for example. Although it does not specifically limit as a coating method of the said radiation-sensitive resin composition, For example, well-known methods, such as a spin coating method, etc. are mentioned. When coating the radiation-sensitive resin composition, the amount of the radiation-sensitive resin composition to be coated is adjusted so that the resist film to be formed has a desired thickness. Moreover, after coating the said radiation-sensitive resin composition on a board|substrate, in order to volatilize a solvent, you may perform prebaking (henceforth "PB"). As a lower limit of the temperature of PB, 30 degreeC is preferable and 50 degreeC is more preferable. As an upper limit of the said temperature, 200 degreeC is preferable and 150 degreeC is more preferable. As a lower limit of the time of PB, 10 second is preferable and 30 second is more preferable. As an upper limit of the said time, 600 second is preferable and 300 second is more preferable. The lower limit of the average thickness of the resist film is preferably 10 nm, more preferably 20 nm, still more preferably 50 nm. As an upper limit of the said average thickness, 1,000 nm is preferable, 200 nm is more preferable, and 150 nm is still more preferable.

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

[Exposure process]

In this step, the resist film obtained by the above coating is exposed. This exposure is performed by irradiating radiation through an immersion exposure liquid such as water in some cases and through a mask having a predetermined pattern.

As the liquid immersion exposure liquid, a liquid having a refractive index greater than that of air is usually used. Specific examples thereof include pure water, long-chain or cyclic aliphatic compounds. Radiation is irradiated from the exposure apparatus with the immersion exposure liquid interposed therebetween, that is, the immersion exposure liquid is filled between the lens and the resist film, and the resist film is exposed through a mask having a predetermined pattern.

Examples of the radiation include, depending on the type of the radiation-sensitive acid generator used, deep ultraviolet rays such as visible light, ultraviolet light, ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), EUV (wavelength 13.5 nm); Electromagnetic waves such as X-rays, electron beams, charged particle beams such as α-rays, etc. are appropriately selected and used, but among these, ArF excimer laser beams, KrF excimer laser beams, EUV, X-rays and electron beams are preferable. and electron beams are more preferable. In addition, exposure conditions, such as an exposure amount, can be suitably selected according to the compounding composition of the said radiation-sensitive resin composition, the kind of additive, etc.

It is preferable to heat-process the resist film after exposure (hereinafter also referred to as "post-exposure heating (PEB)"). By this PEB, the dissociation reaction of the acid-dissociable group, such as polymer [A], can advance smoothly. Although the heating conditions of PEB are suitably adjusted by the compounding composition of the radiation-sensitive resin composition, as a lower limit of the temperature of PEB, 30 degreeC is preferable, 50 degreeC is more preferable, and 70 degreeC is still more preferable. As an upper limit of the said temperature, 200 degreeC is preferable, 150 degreeC is more preferable, and 120 degreeC is still more preferable. As a lower limit of the time of PEB, 10 second is preferable and 30 second is more preferable. As an upper limit of the said time, 600 second is preferable and 300 second is more preferable.

[Development process]

In this step, the resist film exposed in the exposure step is developed. As a developing solution used for this image development, the liquid containing an aqueous alkali solution (alkali developing solution), an organic solvent (organic solvent developing solution), etc. are mentioned, for example. Thereby, a predetermined resist pattern is formed.

Examples of the alkali developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, and methyldiethylamine. , ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabi The aqueous alkali solution etc. which melt|dissolved at least 1 sort(s) of alkaline compounds, such as cyclo[4.3.0]-5- nonene, are mentioned. Among these, TMAH aqueous solution is preferable, and 2.38 mass % TMAH aqueous solution is more preferable.

As an organic solvent developing solution, organic solvents, such as a hydrocarbon solvent, an ether solvent, an ester solvent, a ketone solvent, and an alcohol solvent, or the liquid containing an organic solvent is mentioned, for example. As an organic solvent, 1 type, 2 or more types, etc. of the solvent illustrated as [C] solvent of the above-mentioned radiation-sensitive resin composition are mentioned, for example. Among these, ester solvents and ketone solvents are preferable. As an ester solvent, an acetate ester solvent is preferable, and n-butyl acetate is more preferable. As the ketone solvent, a chain ketone is preferable, and 2-heptanone is more preferable. As a lower limit of content of the organic solvent in an organic solvent developing solution, 80 mass % is preferable, 90 mass % is more preferable, 95 mass % is still more preferable, and 99 mass % is especially preferable. As components other than the organic solvent in an organic solvent developing solution, water, silicone oil, etc. are mentioned, for example.

You may use these developing solutions individually or in combination of 2 or more types. In addition, it is common to wash|clean with water etc. and to dry after image development.

<Radiation sensitive acid generator>

The said radiation-sensitive acid generator contains the compound represented by said Formula (1). Since the radiation-sensitive acid generator has the above-described properties, it can be suitably used as a radiation-sensitive acid generator component of the radiation-sensitive resin composition, and can improve the LWR performance of the radiation-sensitive resin composition. have.

<Compound>

The said compound is a compound represented by said Formula (1). The compound can be suitably used as the above-mentioned radiation-sensitive acid generator.

[Example]

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

[Measurement of weight average molecular weight (Mw), number average molecular weight (Mn) and dispersion degree (Mw/Mn)]

Mw and Mn of the polymer are measured by gel permeation chromatography (GPC) under the following conditions using GPC columns ("G2000HXL" 2, "G3000HXL" 1, "G4000HXL" 1) manufactured by Tosoh Corporation by gel permeation chromatography (GPC). did In addition, the dispersion degree (Mw/Mn) was computed from the measurement result of Mw and Mn.

Elution solvent: tetrahydrofuran

Flow rate: 1.0 mL/min

Sample injection volume: 100 μL

Column temperature: 40°C

Detector: Differential Refractometer

Standard material: monodisperse polystyrene

[ ¹³ C-NMR analysis]

¹³ C-NMR analysis for determining the content ratio of each structural unit of the polymer was measured using a nuclear magnetic resonance apparatus ("JNM-Delta400" manufactured by Nippon Denshi Corporation).

<Synthesis of [A] polymer and [F] polymer>

The monomers used by the synthesis|combination of each polymer in each Example and a comparative example are shown below.

In addition, the compounds (M-1), (M-4), (M-5), (M-7), (M-10), (M-11), (M-18) and (M-20) ) represents the structural unit (I), and the compounds (M-2), (M-6), (M-8), (M-9), (M-12) to (M-17) represent the structural unit (II ), (M-19) is a structural unit (III), (M-3) is a structural unit (IV), and (M-21) is a structural unit as an acid generator (represented by the formula (7) above structural unit), and (M-22) gives a structural unit (F), respectively.

[Synthesis Example 1] (Synthesis of Polymer (A-1))

7.97 g (35 mol%) of compound (M-1), 7.44 g (45 mol%) of compound (M-2), and 4.49 g (20 mol%) of compound (M-3) were dissolved in 40 g of 2-butanone and 0.80 g of AIBN (5 mol% based on the total monomer) as an initiator to prepare a monomer solution. Subsequently, a 100 mL three-necked flask containing 20 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80° C. while stirring, and the prepared monomer solution was added dropwise over 3 hours with a dropping funnel. The initiation of dripping was made into the start time of a polymerization reaction, and the polymerization reaction was performed for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water to 30°C or less. The polymerization solution cooled in 400 g of methanol was thrown in, and the white powder which precipitated was separated by filtration. The white powder separated by filtration was washed twice with 80 g of methanol, then filtered and dried at 50°C for 17 hours to synthesize a white powdery polymer (A-1) (15.2 g, yield 76%). Polymer (A-1) had Mw of 7,300 and Mw/Mn of 1.53. ^As a result of 13 C-NMR analysis, the content ratio of each structural unit derived from (M-1), (M-2) and (M-3) was 34.3 mol%, 45.1 mol%, and 20.6 mol%, respectively.

[Synthesis Examples 2 to 11, 13 to 14] (Synthesis of Polymers (A-2) to (A-11), (A-13) to (A-14)

Polymers (A-2) to (A-11) and (A-13) to (A-14) were respectively synthesized in the same manner as in Synthesis Example 1 except that the types and amounts of the monomers shown in Table 1 were used. In addition, "-" in a table|surface shows that the applicable component is not used. Table 1 shows the content ratio of each structural unit of the obtained polymer, the yield, and the values of Mw and Mw/Mn.

[Synthesis Example 12] (Synthesis of Polymer (A-12))

After dissolving 55.0 g (65 mol%) of compound (M-19) and 45.0 g (35 mol%) of compound (M-18), 4 g of AIBN as an initiator, and 1 g of t-dodecyl mercaptan in 100 g of propylene glycol monomethyl ether , was copolymerized for 16 hours by maintaining the reaction temperature at 70 °C under a nitrogen atmosphere. After completion of the polymerization reaction, the polymerization solution was added dropwise into 1,000 g of n-hexane to coagulate and purify the polymer. Subsequently, 150 g of propylene glycol monomethyl ether was added to the polymer again, followed by further addition of 150 g of methanol, 34 g of triethylamine, and 6 g of water, followed by a hydrolysis reaction for 8 hours while refluxing at a boiling point. After completion of the reaction, the solvent and triethylamine were distilled off under reduced pressure, and the obtained polymer was dissolved in 150 g of acetone, and then it was added dropwise to 2,000 g of water to coagulate, and the resulting white powder was filtered, dried at 50° C. for 17 hours, and white A powdery polymer (A-12) was obtained (65.7 g, yield 77%). Polymer (A-12) had Mw of 7500 and Mw/Mn of 1.90. ^As a result of 13 C-NMR analysis, the content of each structural unit derived from (M-19) and (M-18) was 65.4 mol% and 34.6 mol%, respectively.

[Synthesis Example 15] (Synthesis of Polymer (F-1))

82.2 g (70 mol%) of compound (M-22) and 17.8 g (30 mol%) of compound (M-10) were dissolved in 200 g of 2-butanone, and 0.46 g of AIBN as an initiator (1 mol% based on all monomers) ) was added to prepare a monomer solution. Subsequently, a 500 mL three-neck flask containing 100 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated at 80° C. while stirring, and the prepared monomer solution was added dropwise over 3 hours with a dropping funnel. The initiation of dripping was made into the start time of a polymerization reaction, and the polymerization reaction was performed for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water to 30°C or less. After substituting the solvent in 400 g of acetonitrile, 100 g of hexane was added and stirred to recover the acetonitrile layer three times. By substituting the solvent for propylene glycol monomethyl ether acetate, a solution containing 60.1 g of the polymer (F-1) was obtained (yield: 60%). Polymer (F-1) had Mw of 15000 and Mw/Mn of 1.90. ^As a result of 13 C-NMR analysis, the content of each structural unit derived from (M-22) and (M-10) was 70.3 mol% and 29.7 mol%, respectively.

<Synthesis of [B] compound>

[Synthesis Example 16] (Synthesis of Compound (B-1))

6.00 g (61.1 mmol) of the compound represented by the following formula (b-3), 38.5 g (305 mmol) of sodium sulfite, and 100 mL of water were added to a 300 mL round bottom flask, immersed in an oil bath at 115 ° C., and heated and stirred for 36 hours. A compound represented by the following formula (b-4) was synthesized. After cooling to room temperature, without isolating compound (b-4), 19.2 g (64.2 mmol) of triphenylsulfonium chloride, 200 mL of dichloromethane, and 100 mL of water were added, and the mixture was stirred at room temperature for 10 hours. After fractionating the organic layer, washing with water was repeated twice to obtain a crude compound represented by the following formula (b-5). Without further purification, triethylamine 7.42 g (73.3 mmol), 1,4-diazabicyclo [2.2.2] octane 2.05 g (18.3 mmol) and acetonitrile 100 mL were added, and stirring was started at room temperature. . A solution in which 14.6 g (73.3 mmol) of adamantane carbonyl chloride was dissolved in 50 mL of acetonitrile was slowly added dropwise thereto. After stirring at room temperature for 12 hours, the solvent was distilled off, dichloromethane was added, and washing with water was repeated 4 times. Purification by column chromatography gave 14.0 g (yield 38%) of a compound represented by the following formula (B-1) (hereinafter also referred to as “compound (B-1)”).

[Synthesis Examples 17 to 29] (Synthesis of Compounds (B-2) to (B-14))

The compounds represented by the following formulas (B-2) to (B-14) were synthesized by appropriately selecting a precursor and performing the same operation as in Synthesis Example 1.

[Synthesis Example 30] (Synthesis of Compound (B-15))

To a 300 mL round-bottom flask, 7.28 g (19.4 mmol) of the compound represented by the following formula (b-1), 19.5 g (155 mmol) of sodium sulfite, and 50 mL of water were added, immersed in an oil bath at 115 ° C., and heated and stirred for 36 hours. A compound represented by the following formula (b-2) was synthesized. After cooling to room temperature, without isolating the compound represented by the following formula (b-2), 6.07 g (20.3 mmol) of triphenylsulfonium chloride, 100 mL of dichloromethane, and 100 mL of water were added, and the mixture was stirred at room temperature for 10 hours. . After the organic layer was separated, washing with water was repeated 4 times. By purification by column chromatography, 6.02 g (yield 43%) of a compound represented by the following formula (B-15) (hereinafter also referred to as “compound (B-15)”) was obtained.

[Synthesis Example 31] (Synthesis of Compound (B-16))

In a 100 mL round bottom flask, 3.00 g (4.16 mmol) of compound (B-15), 0.505 g (4.99 mmol) of triethylamine, 0.140 g (1.25 mmol) of 1,4-diazabicyclo[2.2.2]octane, aceto Stirring in a water bath was initiated by addition of 10 mL of nitrile. A solution in which 0.991 g (4.99 mmol) of adamantane carbonyl chloride was dissolved in 10 mL of acetonitrile was slowly added dropwise thereto. After completion of the dropwise addition, the mixture was stirred at room temperature for 2 hours, and then stirred at 50°C for 8 hours. After addition of dichloromethane, the mixture was washed three times with a saturated aqueous sodium hydrogen carbonate solution and twice with a saturated aqueous ammonium chloride solution. After drying over anhydrous sodium sulfate and distilling off the solvent, the compound represented by the following formula (B-16) (hereinafter also referred to as “compound (B-16)”) was purified by column chromatography to obtain 2.53 g (yield 69%). ) was obtained.

[Synthesis Examples 32 to 39] (Synthesis of Compounds (B-17) to (B-24))

The compounds represented by the following formulas (B-17) to (B-24) were synthesized by appropriately selecting a precursor and performing the same operation as in Synthesis Example 30.

[Synthesis Examples 40 to 44] (Synthesis of Reference Example Compounds (H-1) to (H-4))

In addition, the compounds represented by the following formulas (H-1) to (H-4) were synthesized as reference examples by appropriately selecting precursors and performing the same operation as in Synthesis Example 30.

<Preparation of radiation-sensitive resin composition>

Components other than the [A] polymer constituting the radiation-sensitive resin composition are shown.

[[C] solvent]

C-1: propylene glycol monomethyl ether acetate

C-2: cyclohexanone

C-3: γ-butyrolactone

[[D] other acid generators]

[D] As other acid generators, [D1] acid generator containing sulfonate and [D2] acid generator containing photodegradable base were used.

[[D1] acid generator]

[D1] As the acid generator, compounds represented by the following formulas (D1-1) to (D1-9) were used.

[[D2] acid generator]

[D2] As the acid generator, compounds represented by the following formulas (D2-1) to (D2-5) were used.

[[E] Nitrogen-containing compounds]

[E] As the nitrogen-containing compound, compounds represented by the following formulas (E-1) to (E-4) were used.

[Example 1]

[A] 100 parts by mass of (A-1) as a polymer, 7 parts by mass of (B-1) as a [B] compound, 2,427 parts by mass of (C-1) as a solvent, 1,040 parts by mass of (C-2) as a solvent and (C-3) 200 parts by mass, [D] 10 parts by mass of (D-1) as another acid generator, and 3 parts by mass of (F-1) as a polymer [F] containing a fluorine atom, 0.2 µm A radiation-sensitive resin composition (J-1) was prepared by filtration with a membrane filter of

[Examples 2 to 30, Comparative Examples 1 to 17 and Reference Examples 1 to 4]

The radiation-sensitive resin compositions (J-2) to (J-30), (CJ-1) to (CJ-) were carried out in the same manner as in Example 1, except that each component of the type and content shown in Tables 2 and 3 was used. 17) and (S-1) to (S-4) were prepared.

<Formation of resist pattern (1): ArF excimer laser immersion exposure, alkali development>

A composition for forming a lower layer anti-reflection film (“ARC66” by Brewer Sciences) was coated on the surface of a 12-inch silicon wafer using a spin coater (“CLEAN TRACK ACT12” by Tokyo Electron Corporation), and then the film was heated at 205°C for 60 seconds. A 105 nm-thick lower layer anti-reflection film was formed. Each radiation-sensitive resin composition was apply|coated on this underlayer antireflection film using the said spin coater, and PB was performed at 100 degreeC for 50 second. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with a film thickness of 90 nm. Next, using an ArF excimer laser immersion exposure apparatus ("TWINSCAN XT-1900i" manufactured by ASML), the coating film was 38 nm line and space (1L/1S) under optical conditions of NA = 1.35 and Dipole35X (σ = 0.97/0.77). was exposed through a mask pattern for forming a resist pattern. After exposure, PEB was performed at 90 degreeC for 50 second. Then, puddle development was performed at 23 degreeC for 30 second using the 2.38 mass % TMAH aqueous solution. Subsequently, after rinsing for 7 seconds using ultrapure water, a 38 nm line and space (1L/1S) resist pattern was formed by spin-drying at 2,000 rpm for 15 seconds. At this time, the exposure amount at which the portion exposed through the mask pattern for forming a 38 nm line (line) 100 nm Pitch pattern forms a line having a line width (38 nm) was set as the optimum exposure amount (Eop).

<Formation of resist pattern (2): ArF excimer laser immersion exposure, organic solvent development>

A negative resist pattern was formed in the same manner as in the formation of the resist pattern (1) except that organic solvent development was performed using n-butyl acetate instead of the TMAH aqueous solution, and washing with water was not performed.

<Evaluation>

Each radiation-sensitive resin composition was evaluated by measuring according to the following method about the formed resist pattern. The evaluation results are shown in Tables 4 and 5 below. In addition, the scanning electron microscope ("CG-4100" by Hitachi High Technologies) was used for the lengthening of a resist pattern.

[LWR Performance]

The resist pattern formed by irradiating the Eop exposure obtained above was observed from the top of the pattern using the scanning electron microscope. A total of 500 variations in line width were measured, and a 3-sigma value was obtained from the distribution of the measured values, and this was defined as the LWR performance (nm). The smaller the LWR performance, the better the line fluctuation is. LWR performance can be evaluated as "good" when it is 2.5 nm or less, and "bad" when it exceeds 2.5 nm.

[Critical Dimension Uniformity (CDU) Performance]

The resist pattern formed by irradiating the Eop exposure obtained above was observed from the top of the pattern using the scanning electron microscope. The line width was measured at 20 points in the range of 400 nm to obtain the average value, and the average value was measured for 500 points in total at any point, and the three sigma value was obtained from the distribution of the measured values, and this was defined as the CDU performance (nm). The CDU performance is better as the value of the CDU is smaller, the variation of the line width in a long period is small. When the CDU performance is 1.5 nm or less, it can be evaluated as "good", and when it exceeds 2.0 nm, it can be evaluated as "poor".

[EL (ExposureLatitude) Performance]

The EL performance of the radiation-sensitive resin composition was evaluated by each value of 10% EL, Bridge limit, and Collapse limit measured by the following method.

(10% EL)

In the case of using a 38 nm line and space (1L/1S) mask pattern for forming a resist pattern, the range of exposure dose when the size of the resolved resist pattern is within ±10% of the design dimension of the mask The ratio to Eop is 10% EL (%). As for 10% EL, the larger the value, the smaller the amount of change in the patterning performance with respect to the change in exposure amount is good.

(Bridge limit)

In the formation of the resist pattern, from the above Eop, the minimum pattern width (Bridge limit) at which a bridge occurs when the exposure amount is decreased in the case of alkali development and when the exposure amount is increased in the case of organic solvent development. (nm) was calculated, and this value was used as an index of the bridge limit. The larger the bridge limit value, the less likely it is to cause a bridge defect, which is better.

(Collapse limit)

In the formation of the resist pattern, the minimum pattern width (Collapse limit) at which pattern collapse occurs when the exposure amount is increased from Eop in the case of alkali development and when the exposure amount is decreased in the case of organic solvent development. ) (nm) was calculated, and this value was used as an index of the collapse limit. The smaller the value of the Collapse limit, the more difficult it is to cause the resist pattern to collapse, which is better.

[developing defect suppression property]

A coating film is formed with a radiation-sensitive resin composition on a 12-inch silicon wafer on which an anti-reflection film is formed with a lower layer of the composition for forming an anti-reflection film ("ARC66" manufactured by Nissan Chemical Corporation), and SB (Soft Bake at 120° C. for 50 seconds) ) to form a resist film with a film thickness of 110 nm. Next, an ArF excimer laser immersion exposure apparatus ("NSR-S610C" manufactured by NIKON) was used for this resist film, and a line and space (1L) having a target size of 38 nm in width under the conditions of NA = 1.3, ratio = 0.800, and Dipole. /1S) It exposed through the mask pattern for formation. After exposure, PEB was performed at 95 degreeC for 50 second. Then, with the GP nozzle of a developing apparatus ("Clean Track ACT8" by Tokyo Electron Corporation), it developed for 10 second with 2.38 mass % of tetramethylammonium hydroxide aqueous solution or butyl acetate. In addition, in the case of tetramethylammonium hydroxide aqueous solution development, it rinsed with pure water continuously for 15 second, and spin-dried at 2,000 rpm. At this time, the exposure amount for forming 1L/1S with a width of 38 nm was set as the optimal exposure amount. At this optimum exposure dose, 1L/1S having a line width of 38 nm was formed on the entire surface of the wafer to obtain a wafer for defect inspection. In addition, a scanning electron microscope (Hitachi High Technologies, CC-4000) was used for length measurement. The number of defects on the wafer for defect inspection was measured using a defect inspection apparatus ("KLA2810" manufactured by KLA-Tencor). Then, the measured defects were classified as those judged to be resist film-derived defects and external foreign substances, and the number of defects judged to be resist film-derived defects was calculated. The development defect suppression property is so good that the number of defects judged to be derived from the resist film is small.

[Membrane shrinkage inhibition after PEB]

On the surface of a 12-inch silicon wafer, using a spin coater (CLEAN TRACK AT12, manufactured by Tokyo Electron), a composition for forming an antireflection layer (ARC66, manufactured by Brewer Sciences) was applied, followed by heating at 205°C for 60 seconds to have a film thickness of 105 nm of the lower anti-reflection film was formed. Each of the radiation-sensitive resin compositions prepared above was applied on the lower antireflection film using the spin coater, and PB was performed at 90° C. for 60 seconds. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with a film thickness of 90 nm. Next, this resist film was subjected to full surface exposure at 70 mJ using an ArF excimer laser immersion exposure apparatus (NSR-S610C, manufactured by NIKON), and then the film thickness was measured to determine the film thickness A. Then, after performing PEB for 60 second at 90 degreeC, the film thickness measurement was performed again and the film thickness B was calculated|required. At this time, 100x(A-B)/A(%) was calculated|required, and this was made into the film|membrane contraction rate after PEB. It shows that the film|membrane shrinkage suppression after PEB is so good that a measured value is small. The evaluation results are shown in Table 6 below.

[Example 31]

[A] 100 parts by mass of (A-1) as a polymer, 3.6 parts by mass of (B-1) as a compound [B], 4280 parts by mass of (C-1) as a solvent, 1830 parts by mass of (C-2) as a solvent , [D] A radiation-sensitive resin composition (J-31) was prepared by mixing 20 parts by mass of (D-1) as another acid generator and filtering with a 0.2 µm membrane filter.

[Examples 32 to 38, Comparative Examples 18 to 22 and Reference Examples 5 to 6]

The radiation-sensitive resin compositions (J-31) to (J-38), (CJ-18) to (CJ-22) and (CJ-22) and (S-5) to (S-6) were prepared.

<Formation of resist pattern (3): electron beam exposure, alkali development>

Each of the radiation-sensitive resin compositions described in Table 5 above was applied to the surface of an 8-inch silicon wafer using a spin coater (CLEAN TRACK ACT8, manufactured by Tokyo Electron), and PB was performed at 90° C. for 60 seconds. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with a film thickness of 50 nm. Next, the resist film was irradiated with an electron beam using a simple electron beam drawing apparatus (manufactured by Hitachi, Ltd., model "HL800D", output: 50 KeV, current density: 5.0 A/cm ^{2 ).} After irradiation, PEB was performed at 120°C for 60 seconds. Then, using the 2.38 mass % TMAH aqueous solution as an alkaline developing solution, it developed at 23 degreeC for 30 second, wash|cleaned with water, and dried, and formed the positive resist pattern.

<Formation of resist pattern (4): electron beam exposure, organic solvent development>

A negative resist pattern was formed in the same manner as in formation (1) of the resist pattern, except that organic solvent development was performed using n-butyl acetate instead of the TMAH aqueous solution, and washing with water was not performed.

<Evaluation>

The same evaluation as in the said Example was performed about the resist pattern formed using each said radiation-sensitive resin composition. The results are shown in Table 8 below.

From the results of Tables 4, 5 and 8, the radiation-sensitive resin composition was excellent in LWR performance, CDU performance, EL performance and development defect suppression in all cases of alkali development and organic solvent development in ArF exposure and electron beam exposure. thing appeared In addition, from the results in Table 6, it was also shown that the film shrinkage suppression property after PEB in ArF exposure was excellent. On the other hand, it was shown that the radiation-sensitive resin composition of Comparative Example was inferior in all of the above performance compared to that of Example.

According to the radiation-sensitive resin composition and resist pattern formation method of the present invention, a resist pattern having excellent LWR performance, CDU performance, EL performance, development defect suppression property and film shrinkage suppression property after PEB can be formed. The compound of the present invention can be suitably used as a component of the radiation-sensitive resin composition. Therefore, they can be suitably used for pattern formation in the manufacture of semiconductor devices etc. which are expected to advance further refinement|miniaturization in the future.

Claims (6)

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

(in formula (1), R ¹ and R ² are each independently a monovalent organic group not containing a hydrogen atom or a fluorine atom having 1 to 20 carbon atoms, and R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represents a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms, with the proviso that at least one of ^{R 1} , R ² , R ³ and R ⁴ represents a group represented by ^{OR Q , and R Q} is a carbon number 1 to 20, and when at least one of ^{R 1} and R ² represents a group represented by ^{OR Q , R Q} does not contain a fluorine atom, and R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁵ , R ³ and R ⁴ , R ³ and R ⁵ , or R ⁵ and R ⁶ may be combined with each other to form a ring structure of 3 to 20 reduced numbers together with the carbon atom to which they are bonded , Y ^- is SO ₃ ^- or COO ^- , and X ⁺ is a monovalent radiation-sensitive onium cation) The radiation-sensitive resin composition according to claim 1, wherein the ring structure having 3 to 20 reduced numbers of the formula (1) is an alicyclic structure having 3 to 20 reduced numbers or an aliphatic heterocyclic structure having 3 to 20 reduced numbers. The radiation-sensitive resin composition according to claim 1 or 2, wherein the first structural unit is represented by the following formula (3).

(In formula (3), R ^A1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R ^A2 is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and R ^A3 and R ^A4 are each independently 20 is a monovalent hydrocarbon group, or these groups combine with each other to represent a ring structure having 3 to 20 reduced numbers constituted together with the carbon atom to which they are bonded) A step of coating the radiation-sensitive resin composition according to claim 1 or 2 on the surface side of the substrate;
exposing the resist film obtained by the coating;
Process of developing the exposed resist film
A resist pattern forming method comprising a. A radiation-sensitive acid generator represented by the following formula (1).

(in formula (1), R ¹ and R ² are each independently a monovalent organic group not containing a hydrogen atom or a fluorine atom having 1 to 20 carbon atoms, and R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represents a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms, with the proviso that at least one of ^{R 1} , R ² , R ³ and R ⁴ represents a group represented by ^{OR Q , and R Q} is a carbon number 1 to 20, and when at least one of ^{R 1} and R ² represents a group represented by ^{OR Q , R Q} does not contain a fluorine atom, and R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁵ , R ³ and R ⁴ , R ³ and R ⁵ , or R ⁵ and R ⁶ may be combined with each other to form a reduced number of 3 to 20 ring structure together with the carbon atom to which they are bonded, and Y ^- is SO ₃ ^- or COO ^- , and X ⁺ is a monovalent radiation-sensitive onium cation) A compound represented by the following formula (1).

(in formula (1), R ¹ and R ² are each independently a monovalent organic group not containing a hydrogen atom or a fluorine atom having 1 to 20 carbon atoms, and R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represents a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms, with the proviso that at least one of ^{R 1} , R ² , R ³ and R ⁴ represents a group represented by ^{OR Q , and R Q} is a carbon number 1 to 20, and when at least one of ^{R 1} and R ² represents a group represented by ^{OR Q , R Q} does not contain a fluorine atom, and R ¹ and R ² , R ¹ and R ³ , R ¹ and R ⁵ , R ³ and R ⁴ , R ³ and R ⁵ , or R ⁵ and R ⁶ may be combined with each other to form a reduced number of 3 to 20 ring structure together with the carbon atom to which they are bonded, and Y ^- is SO ₃ ^- or COO ^- , and X ⁺ is a monovalent radiation-sensitive onium cation)