WO2010119910A1

WO2010119910A1 - Radiation-sensitive resin composition, polymer used therein, and compound used therein

Info

Publication number: WO2010119910A1
Application number: PCT/JP2010/056718
Authority: WO
Inventors: 信司松村; 幸生西村; 晃雅征矢野; 龍一芹澤; 昇大塚; 寛冨岡
Original assignee: Jsr株式会社
Priority date: 2009-04-15
Filing date: 2010-04-14
Publication date: 2010-10-21

Abstract

Disclosed is a radiation-sensitive resin composition which is capable of forming a resist pattern that has low LWR and excellent pattern shape. The radiation-sensitive resin composition contains (A) a polymer that has a repeating unit represented by formula (I). In formula (I), X+ is preferably at least one onium cation selected from the group consisting of onium cations represented by formula (1-1) and formula (1-2).

Description

Radiation sensitive resin composition, polymer used therefor and compound used therefor

The present invention relates to a radiation-sensitive resin composition used in a semiconductor manufacturing process such as an IC, a circuit board such as a liquid crystal or a thermal head, and other photolithography processes, a polymer suitably used for the composition, and the polymer. It relates to the compound used for.

The chemically amplified radiation-sensitive resin composition generates an acid in an exposed area by irradiation with far ultraviolet light or the like typified by a KrF excimer laser or an ArF excimer laser, and reacts with the acid as a catalyst to react with the exposed area. It is a composition that changes the dissolution rate of the unexposed portion with respect to the developer to form a resist pattern on the substrate.

When more precise line width control is performed, for example, when the device design dimension is sub-half micron or less, the chemically amplified resist not only has excellent resolution performance but also resist pattern line. It has become important that LWR (Line Width Roughness), which is an index of variation in width, is small and the pattern shape is rectangular.
In order to control such a fine shape, a technique of adding a basic compound as an acid diffusion control agent for adjusting the diffusion rate of the generated acid is known. In particular, an acid diffusion controller that loses acid diffusion controllability by being dissociated by an acid is attracting attention in terms of excellent contrast between an exposed area and an unexposed area, but the LWR characteristics and pattern shape are still insufficient. .

Japanese Patent Publication No. 2-27660 JP 2009-53688 A

An object of the present invention is to provide a radiation-sensitive resin composition capable of forming a resist pattern having a small LWR and an excellent pattern shape.

The invention made to solve the above problems is
(A) Radiation sensitivity containing a polymer (hereinafter also referred to as “polymer (A)”) having a repeating unit represented by the following formula (I) (hereinafter also referred to as “repeating unit (I)”). It is a resin composition.

(In formula (I), R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group.
R ² and R ⁴ are each independently a single bond, a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, or a divalent having a cyclic or cyclic partial structure having 3 to 20 carbon atoms. Or a group in which some or all of these hydrogen atoms are substituted with fluorine atoms.
R ³ is a single bond, —O—, —C (═O) — group, —O—C (═O) — group, —C (═O) —O— group or sulfinyl group.
A ⁻ is —N ⁻ —SO ₂ —R ^D , —COO ⁻ , —O 2 ^— or SO ₃ ^— .
^RD is a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or one of these hydrogen atoms. Part or all is a group substituted with a fluorine atom.
X ⁺ is an onium cation.
a is 0 or 1;
However, when A is SO ₃ ^— , the end of R ^{4 on} the SO ₃ ⁻ side may not be —CF ₂ —. A ^- is -COO ^- ^when, not if all of R 2, ^{R 3} and ^{R 4} is a single bond. When a is 1, A ⁻ is not —O 2 ^— . )

The polymer (A) of the radiation-sensitive resin composition acts as a base with respect to the acid generated by exposure when it contains a radiation-sensitive acid generator, but decomposes upon irradiation with actinic rays or radiation and becomes basic. Disappear. As a result, in the radiation-sensitive resin composition containing the polymer (A), acid is diffused in the exposed area, while acid diffusion in the unexposed area is controlled, and a good contrast is obtained. Furthermore, since a structure having acid diffusion controllability is present in the polymer, uniform acid diffusion controllability in the unexposed area is expressed, so that good LWR characteristics and pattern shapes can be obtained.

In the polymer (A), X ⁺ in the above formula (I) is at least one selected from the group consisting of onium cations represented by the following formula (1-1) and the following formula (1-2), respectively. Preferably there is.

(In the formulas (1-1) and (1-2), R ⁵ to R ⁹ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, or a substituent having 1 to 10 carbon atoms. An alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.)

When each polymer has the specific onium cation, the radiation-sensitive resin composition can exhibit good radiation sensitivity.

The radiation-sensitive resin composition is (B1) a polymer (hereinafter referred to as “polymer (B1)” having a repeating unit represented by the following formula (3) (hereinafter also referred to as “repeating unit (3)”). It is preferable to further contain.

(In the formula (3), R ¹ , R ² and X ⁺ are as defined in the above formula (1). N is an integer of 1 to 4.)

The polymer (B1) is a polymer having a function as a radiation-sensitive acid generator that generates an acid upon irradiation with radiation, whereby uniform acid diffusion in an exposed area is achieved and good pattern formation is achieved. Can demonstrate its sexuality.

X ⁺ in the above formula (3) is preferably at least one selected from the group consisting of onium cations represented by the following formula (1-1) and the following formula (1-2).

When the polymer (B1) has the specific onium cation, the polymer (B1) exhibits good radiation sensitivity and can efficiently generate an acid.

The polymer (B1) preferably further has a repeating unit represented by the following formula (2) (hereinafter also referred to as “repeating unit (2)”).

(In the formula (2), the definition of ^{R 1} are as defined in the above formula (3).
R ¹⁰ is an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms.
R ¹¹ is each independently an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or two R ¹¹ 's are bonded to each other so that both are bonded. A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms is formed together with the carbon atoms. )

Since the repeating unit (2) has a protecting group (acid-dissociable group) that can be removed by the action of an acid, the protecting group is removed by the action of an acid to cause the polymer (B1) to exhibit alkali solubility. And developability can be improved.

The radiation-sensitive resin composition comprises (B2) a radiation-sensitive acid generator (hereinafter also referred to as “acid generator (B2)”) instead of the polymer (B1) or together with the polymer (B1). Furthermore, you may contain.

In the radiation-sensitive resin composition of the present invention, the polymer (A) is also referred to as a repeating unit represented by the following formula (1) as the repeating unit (I) (hereinafter also referred to as “repeating unit (1)”). (Hereinafter, the polymer having the repeating unit (1) is also referred to as “polymer (A1)”).

(In the formula (1), R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group.
R ² represents a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, a divalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or a hydrogen atom thereof. It is a group partially or entirely substituted with a fluorine atom.
R ³ is a single bond, —C (═O) — group, —O—C (═O) — group or sulfinyl group.
R ^D is a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or a hydrogen atom thereof. It is a group partially or entirely substituted with a fluorine atom.
X ⁺ is an onium cation. )

In the radiation-sensitive resin composition of the present invention, it is preferable that the polymer (A) further has at least one selected from the group consisting of the repeating unit (2) and the repeating unit (3) (hereinafter, A polymer having the repeating unit (I) and the repeating unit (3) is also referred to as “polymer (A11)”). In addition, this polymer (A11) is a polymer having a function as a radiation-sensitive acid generator that generates an acid upon irradiation with radiation, thereby achieving uniform acid diffusion in the exposed area, which is favorable. Pattern forming ability can be exhibited.

The polymer of the present invention has the above repeating unit (I). For this reason, although it acts as a base for the acid generated by exposure, it decomposes itself upon irradiation with actinic rays or radiation and loses basicity. Thereby, when the said polymer is used for a radiation sensitive resin composition, while an acid diffuses in an exposed part, the acid diffusion in an unexposed part will be controlled and favorable contrast will be obtained. Furthermore, since a structure having acid diffusion controllability is present in the polymer, uniform acid diffusion controllability in the unexposed area is expressed, so that good LWR characteristics and pattern shapes can be obtained. Therefore, the polymer of the present invention is suitable for the radiation sensitive resin composition.

The polymer of the present invention preferably contains the above repeating unit (1) as the repeating unit (I).

The polymer of the present invention preferably further has the repeating unit (2). Since it has a protecting group (acid dissociable group) that can be removed by the action of an acid, the protecting group is removed by the action of an acid, and the polymer can exhibit alkali solubility.

In the polymer of the present invention, X ⁺ in the above formula (I) is at least one selected from the group consisting of onium cations represented by the above formula (1-1) and the above formula (1-2), respectively. Is preferred. Thereby, the radiation sensitivity of the said polymer can be improved.

The polymer of the present invention can function as a radiation-sensitive acid generator that generates an acid upon irradiation with radiation by further including the repeating unit (3).

In the polymer, X ⁺ in formula (3) is preferably at least one selected from the group consisting of onium cations represented by formula (1-1) and formula (1-2), respectively. . Also by this, the radiation sensitivity for acid generation from the polymer can be improved.

The compound of the present invention is a compound represented by the following formula (i) (hereinafter also referred to as “compound (i)”) or a compound represented by the following formula (ii) (hereinafter also referred to as “compound (ii)”). ).

(In formula (i), R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group.
R ² represents a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, a divalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or a hydrogen atom thereof. It is a group partially or entirely substituted with a fluorine atom.
R ³ is a single bond, —C (═O) — group, —O—C (═O) — group or sulfinyl group.
R ^D is a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or a hydrogen atom thereof. It is a group partially or entirely substituted with a fluorine atom.
X ⁺ is an onium cation. )

(In formula (ii), R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group.
R ² and R ⁴ are each independently a single bond, a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, or a divalent having a cyclic or cyclic partial structure having 3 to 20 carbon atoms. Or a group in which some or all of these hydrogen atoms are substituted with fluorine atoms.
R ³ is a single bond, —O—, —C (═O) —, —C (═O) —O— or —O—C (═O) — group, provided that R ² , R ³ and R Not all ⁴ are single bonds).
X ⁺ is an onium cation. )

The sulfonamide structure or carboxylic acid anion structure of the compound decomposes when irradiated with radiation and loses basicity, and maintains basicity when not irradiated. When a polymer formed of such a compound is used in the radiation-sensitive resin composition, the acid diffuses in the exposed area, while the acid diffusion in the unexposed area is controlled. Contrast can be obtained. Furthermore, since a structure having acid diffusion controllability is present in the polymer, homogeneous acid diffusion controllability in unexposed areas is expressed, and good LWR characteristics and pattern shapes are obtained. Therefore, the compound of this invention is suitable for manufacture of the said polymer.

The radiation sensitive resin composition of the present invention has an effect that a resist pattern having a small LWR and an excellent pattern shape can be formed.
The polymer and compound of the present invention are suitably used as a raw material for the radiation-sensitive resin composition of the present invention.

Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that modifications, improvements, and the like appropriately added to the embodiments described above fall within the scope of the present invention.

<Radiation sensitive resin composition>
The radiation sensitive resin composition of the present invention contains a polymer (A) having a repeating unit (I), and preferably a polymer (B1) having a repeating unit (3) and an acid generator (B2). At least one selected from the group consisting of: The repeating unit (3) has a function similar to that of the acid generator (B2) that generates an acid upon irradiation with radiation. Preferred embodiments of the polymer (A) include a polymer (A1) having the repeating unit (1) as the repeating unit (I), and a copolymer having the repeating unit (I) and the repeating unit (3). A polymer (A11) is mentioned. The radiation-sensitive resin composition of the present invention includes a radiation-sensitive resin composition containing the polymer (A1) and the polymer (A11) in addition to the composition containing these polymers. It is. Hereinafter, polymer (A), polymer (B1) as acid generator and acid generator (B2), polymer (A11) which is a preferred embodiment of polymer (A), and other suitable polymers Will be described.

<Polymer (A)>
The polymer (A) constituting the radiation-sensitive resin composition of the present invention has the repeating unit (I) and corresponds to the polymer of the present invention. The repeating unit (I) has a sulfonamide structure, a carboxylate anion structure and a sulfonate anion structure each having an onium salt as a cation. In any structure, when the radiation-sensitive resin composition contains at least one selected from the group consisting of the polymer (B1) and the acid generator (B), it is a base for the acid generated in the exposure step. However, it decomposes upon irradiation with actinic rays or radiation, and loses basicity. Thereby, as for the radiation sensitive resin composition containing a polymer (A), an acid diffuses in an exposed part, acid diffusion in an unexposed part is controlled, and favorable contrast is obtained. Furthermore, since the structure having acid diffusion controllability is present in the polymer, homogeneous acid diffusion controllability in the unexposed area is expressed, so that particularly excellent LWR characteristics and pattern shapes can be obtained. The effect is obtained.

The polymer (A) is preferably a polymer that exhibits alkali insolubility or alkali insolubility, but has a protecting group (acid dissociable group) that can be removed by the action of an acid, and the protection by the action of an acid. A polymer in which a group is eliminated and exhibits alkali solubility (hereinafter also referred to as “acid-dissociable polymer”). Preferred examples of the repeating unit having an acid dissociable group include the repeating unit (2).

The repeating unit (1) in the polymer (A) preferably generates a weak acid having a pKa of 3 to 8 by exposure, and the acid dissociable group in the polymer (A), preferably the acid in the repeating unit (2). The dissociable group has a structure in which the protecting group is not dissociated by such a weak acid. On the other hand, the acid generated by exposure of the above-described acid generator (B2) and repeating unit (3) preferably has a pKa2 or less, and when the acid diffuses, in the undecomposed polymer (A) Diffusion is suppressed by ion exchange with the repeating unit (1). That is, in the irradiated part of actinic rays or radiation, the repeating unit (I) in the polymer (A) is decomposed so that the basicity against the acid generated from the acid generator (B2) or the repeating unit (3) Although it loses, it has a diffusion suppressing function with respect to the acid generated from the acid generator (B2) or the repeating unit (3) by ion exchange in the non-irradiated part, and as a result, it is good in the irradiated part and non-irradiated part Contrast is obtained.

(Repeating unit (I))
In the above formula (I), R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group, preferably a hydrogen atom or a methyl group. Examples of the group represented by R ² and R ⁴ include a methylene group, an ethylene group, an i-propylene group, an n-butylene group, an n-pentylene group, an n-hexylene group, an n-heptylene group, and an n-octylene group. A linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms; from hydrocarbons such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, dicyclopentane, norbornane, tricyclodecane, tetracyclododecane, adamantane, etc. A divalent hydrocarbon group having two or more hydrogen atoms and having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, and part or all of the hydrogen atoms in these groups are substituted with fluorine atoms Group. R ³ is a single bond, —C (═O) — group, —O—C (═O) — group or sulfinyl group. Examples of the group represented by R ⁴ include a methyl group, an ethyl group, an i-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. To 10 linear or branched monovalent hydrocarbon groups; a hydrogen atom from a hydrocarbon such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, dicyclopentane, norbornane, tricyclodecane, tetracyclododecane, adamantane, etc. And a monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms and a group in which some or all of the hydrogen atoms in these groups are substituted with fluorine atoms Is mentioned. Among them, a fluorinated alkyl group, particularly a perfluoroalkyl group such as a trifluoromethyl group, a pentafluoroethyl group, and a heptafluoropropyl group, is preferably used.

Specific examples of the repeating unit (I) include a repeating unit (1), a repeating unit (21) and a repeating unit (31) described later, and among them, the repeating unit (1) is particularly preferable.

(Repeating unit (1))
In the above formula (1), R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group, preferably a hydrogen atom or a methyl group. Examples of the group represented by R ² include a methylene group, an ethylene group, an i-propylene group, an n-butylene group, an n-pentylene group, an n-hexylene group, an n-heptylene group, and an n-octylene group. To 10 linear or branched divalent hydrocarbon groups; from a hydrocarbon such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, dicyclopentane, norbornane, tricyclodecane, tetracyclododecane, adamantane, etc. to a hydrogen atom 2 And a divalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms and a group in which part or all of the hydrogen atoms in these groups are substituted with fluorine atoms Is mentioned. R ³ is a single bond, —C (═O) — group, —O—C (═O) — group or sulfinyl group. Examples of the group represented by R ⁴ include a methyl group, an ethyl group, an i-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. To 10 linear or branched monovalent hydrocarbon groups; a hydrogen atom from a hydrocarbon such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, dicyclopentane, norbornane, tricyclodecane, tetracyclododecane, adamantane, etc. And a monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms and a group in which part or all of the hydrogen atoms in these groups are substituted with fluorine atoms Is mentioned. Among them, a fluorinated alkyl group, particularly a perfluoroalkyl group such as a trifluoromethyl group, a pentafluoroethyl group, and a heptafluoropropyl group, is preferably used.

As the monomer used for obtaining the repeating unit (1), the compound of the present invention represented by the above formula (i) is used. Preferable specific examples of the compound include compounds represented by the following formulas (i-1) to (i-14). Of these, compounds in which R ¹ is a hydrogen atom or a methyl group are preferably used.

(In the formula, R ¹ and X ⁺ are as defined in the above formula (1).)

The onium cation represented by X ⁺ is preferably at least one selected from the above formula (1-1) and the above formula (1-2).

Examples of the sulfonium cation represented by the above formula (1-1) include cations represented by the following formulas (j-1) to (j-22). Examples of the iodonium cation represented by the above formula (1-2) include cations represented by the following formulas (k-1) to (k-25).

The monovalent onium cation represented by X ⁺ in the above formula (1) is described in, for example, Advances in Polymer Science, Vol. 62, p. 1-48 (1984).
The compound of the present invention can be synthesized generally by exchanging the active proton of the sulfonamide compound with an onium cation by ion exchange.

(Repeating unit (21))
The polymer (A) includes a repeating unit represented by the following formula (21-1) (hereinafter also referred to as “repeating unit (21-1)”) and a repeating unit represented by the above formula (I) and At least one selected from the group consisting of repeating units represented by the formula (21-2) (hereinafter also referred to as “repeating units (21-2)”) (hereinafter referred to as repeating units (21-1) and (21- 2) may be collectively referred to as “repeating unit (21)” (hereinafter, the polymer having the repeating unit (21) is also referred to as “polymer (A21)”).

(In the formulas (21-1) and (21-2), R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group.
R ² and R ⁴ are each independently a single bond, a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, or a divalent having a cyclic or cyclic partial structure having 3 to 20 carbon atoms. Or a group in which some or all of these hydrogen atoms are substituted with fluorine atoms.
R ³ is a single bond, —O—, —C (═O) —, —C (═O) —O— or —O—C (═O) — group, provided that R ² , R ³ and R Not all ⁴ are single bonds).
X ⁺ is an onium cation. )

In the above formulas (21-1) and (21-2), R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group, preferably a hydrogen atom or a methyl group. The groups represented by R ² and R ⁴ in the formula (21-1) include a single bond; a methylene group, an ethylene group, an i-propylene group, an n-butylene group, an n-pentylene group, an n-hexylene group, n A linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms such as a heptylene group or an n-octylene group; cyclopropane, cyclobutane, cyclopentane, cyclohexane, dicyclopentane, norbornane, tricyclodecane, A divalent hydrocarbon group having a cyclic or cyclic partial structure of 3 to 20 carbon atoms in the form of removing two hydrogen atoms from a hydrocarbon such as tetracyclododecane or adamantane, and one of the hydrogen atoms in these groups Examples thereof include groups in which part or all are substituted with fluorine atoms. Of these, a linear alkylene group having 1 to 4 carbon atoms and a cyclic hydrocarbon group in which two hydrogen atoms are removed from cyclohexane, norbornane and adamantane are preferred. R ³ in the above formula (1-1) represents a single bond, —O—, —C (═O) —, —C (═O) —O— or —O—C (═O) — group. However, the case where R ² , R ³ and R ⁴ are all single bonds is excluded.

As the monomer used for obtaining the repeating unit (21-1), the compound of the present invention represented by the following formula (ii) is used, and the monomer used for obtaining the repeating unit (21-1) is used. As the monomer, acrylic acid is used.

(In the formula (ii), R ¹ to R ⁴ and X ⁺ have the same meaning as in the above formula (21-1).)

Preferable specific examples of the compound (ii) include, for example, compounds represented by the following formulas (ii-1) to (ii-17). Of these, compounds in which R ¹ is a hydrogen atom or a methyl group are preferably used.

(Wherein R ¹ and X ⁺ are as defined in the above formula (21-1).)

As the sulfonium cation represented by the above formula (1-1), cations represented by the above formulas (j-1) to (j-22) can be preferably used. As the iodonium cation represented by the above formula (1-2), cations represented by the above formulas (k-1) to (k-25) can be preferably used.

In addition, the compound (ii) can be generally synthesized by exchanging the active proton at the carboxylic acid site with an onium cation by ion exchange.

The polymer (A21) usually has other repeating units. As other repeating units, a repeating unit (2) described later and other repeating units can be mentioned as suitable ones.

The ratio of the repeating unit (21) in the polymer (A21) is preferably 0.1 to 20 mol%, particularly preferably 0.1 to 10 mol%, based on all repeating units. When the ratio of the repeating unit (21) is less than 0.1 mol%, the effect of reducing the pattern shape or LWR may be insufficient. Moreover, when it exceeds 20 mol%, there exists a possibility that the problem of the shape defect by low sensitivity or the deterioration of the transmittance | permeability may arise.

Further, the ratio when the polymer (A21) has the repeating unit (2) is preferably 20 to 80 mol%, particularly preferably 25 to 75 mol% in all repeating units. If this ratio is less than 20 mol%, sufficient solubility may not be obtained and resolution may deteriorate. Moreover, when it exceeds 80 mol%, there exists a possibility that adhesiveness with a board | substrate may deteriorate.

In the radiation sensitive resin composition containing the polymer (A21), at least one polymer selected from the group consisting of the polymer (A1), the polymer (A11) and the polymer (B1) is a repeating unit. (21) may be further included, and the polymer (A21) is used together with at least one polymer selected from the group consisting of the polymer (A1), the polymer (A11) and the polymer (B1). May be.

(Repeating unit (31))
The polymer (A) may have a repeating unit represented by the following formula (31) (hereinafter also referred to as “repeating unit (31)”) as the repeating unit represented by the above formula (I). Good (hereinafter, the polymer having the repeating unit (31) is also referred to as “polymer (A31)”).

(In formula (31), R ¹ represents a hydrogen atom, a methyl group or a trifluoromethyl group.
R ² represents a single bond, a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, a divalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or these A group in which part or all of the hydrogen atoms are substituted with fluorine atoms.
R ³ is a single bond or a divalent group represented by —O—, —C (═O) —, —C (═O) —O— or —O—C (═O) —.
R ⁴ is a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, or a divalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms.
X ⁺ is an onium cation. )

In the above formula (31), R ¹ is a hydrogen atom, a methyl group or a trifluoromethyl group, among them preferably a hydrogen atom or a methyl group. Examples of the linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms represented by R ² and R ⁴ in the above formula (1) include, for example, a methylene group, an ethylene group, an i-propylene group, Examples thereof include an n-butylene group, an n-pentylene group, an n-hexylene group, an n-heptylene group, and an n-octylene group. Examples of the divalent hydrocarbon group having a cyclic structure having 3 to 20 carbon atoms or a cyclic partial structure. Is, for example, a group in which two hydrogen atoms are removed from an alicyclic hydrocarbon such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, dicyclopentane, norbornane, tricyclodecane, tetracyclododecane, adamantane and the like. . Of these, a linear alkylene group having 1 to 4 carbon atoms and a cyclic hydrocarbon group in which two hydrogen atoms are removed from cyclohexane, norbornane or adamantane are preferred. In addition, the group represented by R ² may be a group in which some or all of the hydrogen atoms are substituted with fluorine atoms.

As the monomer used to obtain the repeating unit (31), a compound represented by the following formula (iii) (hereinafter also referred to as “compound (iii)”) is used.

(In the formula (iii), R ¹ to R ⁴ and X ⁺ have the same meanings as in the above formula (31).)

Preferable specific examples of the compound include compounds represented by the following formulas (iii-1) to (iii-11). Of these, compounds in which R ¹ is a hydrogen atom or a methyl group are preferably used.

(In the formula, R ¹ and X ⁺ have the same meanings as in the above formula (31).)

In addition, the compound of the present invention can be generally synthesized by exchanging an active proton at a carboxylic acid site to an onium cation by ion exchange.

The ratio of the repeating unit (31) in the polymer (A31) is preferably from 0.1 to 20 mol%, particularly preferably from 0.1 to 10 mol%, based on all repeating units. When the ratio of the repeating unit (31) is less than 0.1 mol%, the effect of reducing the pattern shape or LWR may be insufficient. Moreover, when it exceeds 20 mol%, there exists a possibility that the problem of the shape defect by low sensitivity or the deterioration of the transmittance | permeability may arise.
Further, the ratio when the polymer (A31) has the repeating unit (2) is preferably 20 to 80 mol%, particularly preferably 25 to 75 mol% in all repeating units. If this ratio is less than 20 mol%, sufficient solubility may not be obtained and resolution may deteriorate. Moreover, when it exceeds 80 mol%, there exists a possibility that adhesiveness with a board | substrate may deteriorate.

In the radiation sensitive resin composition containing the polymer (31), at least one polymer selected from the group consisting of the polymer (A1), the polymer (A11) and the polymer (B1) is a repeating unit. (31) may be further included, and the polymer (A31) is used in combination with at least one polymer selected from the group consisting of the polymer (A1), the polymer (A11) and the polymer (B1). May be.

<Polymer (A11)>
The polymer (A11) is a copolymer having the repeating unit (I) and the repeating unit (3). That is, the polymer of the present invention is a polymer having both an acid diffusion suppressing function by the repeating unit (I) and a radiation-sensitive acid generating function by the repeating unit (3). Therefore, the polymer (B1) and the acid generator (B2) are not essential components in the radiation-sensitive resin composition containing the polymer (A11).

The ratio of the repeating unit (3) in the polymer (A11) is preferably 0.1 to 20 mol%, particularly preferably 0.1%, based on all repeating units in the acid dissociable polymer contained in the radiation-sensitive resin composition. 1 to 10 mol%. If this ratio is less than 0.1 mol%, effects such as pattern shape and LWR reduction may be insufficient. Moreover, when the said ratio exceeds 20 mol%, there exists a possibility that the problem of the shape defect by the exposure amount margin insufficient (EL margin shortage) or the deterioration of the transmittance | permeability may arise.

The polymer (A11) usually has other repeating units. As other repeating units, a repeating unit (2) described later and other repeating units can be mentioned as suitable ones.

As described above, the polymer (A) usually has other repeating units. As another repeating unit, the repeating unit (2) in the polymer (B1) described later and other repeating units can be mentioned as suitable ones.

In addition, the radiation sensitive resin composition of this invention may contain 2 or more types of polymers (A) from which a copolymerization ratio and molecular weight differ, a polymer (B1), or another acid dissociable polymer. May be contained. Examples of the repeating unit constituting the other acid dissociable polymer include the repeating unit (2) described later and other repeating units.

The ratio of the repeating unit (1) in the polymer (A) is preferably from 0.1 to 20 mol%, particularly preferably from 0.1 to 20 mol% in all repeating units in the acid dissociable polymer contained in the radiation-sensitive resin composition. 1 to 10 mol%. If this ratio is less than 0.1 mol%, effects such as pattern shape and LWR reduction may be insufficient. Moreover, when the said ratio exceeds 20 mol%, there exists a possibility that the problem of the shape defect by low sensitivity or the deterioration of the transmittance | permeability may arise.

The proportion of the polymer (A) having the repeating unit (2) is preferably 20 to 80 mol%, particularly preferably in all repeating units in the acid dissociable polymer contained in the radiation sensitive resin composition. Is 25 to 75 mol%. If this ratio is less than 20 mol%, sufficient solubility may not be obtained and resolution may deteriorate. Moreover, when it exceeds 80 mol%, there exists a possibility that adhesiveness with a board | substrate may deteriorate.

<Polymer (B1)>
The polymer (B1) is a polymer having a repeating unit (3). The polymer (B1) is a polymer having a function as a radiation-sensitive acid generator that generates an acid upon irradiation with radiation. Therefore, when the radiation-sensitive resin composition contains the polymer (B1), The acid generator (B2) is not an essential component.

(Repeating unit (3))
In the above formula (3), the definitions of R ¹ , R ² and X ⁺ are the same as in the above formula (1). X ⁺ is the same as in the repeating unit (1), and the above formula (1-1) and It is preferably at least one selected from the formula (1-2). N is an integer of 1 to 4, and is preferably 2.

Preferred examples of the monomer used for obtaining the repeating unit (3) include the following formulas (3-1) to (3-7). Of these, compounds in which R ¹ is a hydrogen atom or a methyl group are preferably used.

(Repeating unit (2))
The polymer (B1) preferably further contains a repeating unit (2). The repeating unit (2) has a protecting group (acid-dissociable group) that can be removed by the action of an acid, and the protecting group is released by the action of an acid to cause the polymer (B1) to exhibit alkali solubility. Have

In the above formula (2), the alkyl group having 1 to 4 carbon atoms in R ¹⁰ and R ¹¹ is methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group. , 1-methylpropyl group, t-butyl group and the like. Examples of the monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms in R ¹⁰ and R ¹¹ include cycloalkyl groups such as a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; Examples include a group having a bridged alicyclic skeleton such as a pentanyl group, a dicyclopentenyl group, a tricyclodecyl group, a tetracyclododecyl group, and an adamantyl group. Further, the divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms formed by bonding two R ¹¹ together with the carbon atom to which both are bonded includes the above-described monovalent alicyclic hydrocarbon group. A group obtained by removing one hydrogen atom from a hydrocarbon group can be exemplified.

Preferred examples of the repeating unit (2) include the following formulas (2-1) to (2-9).

(In the formula, R ¹ has the same definition as the above formula (1).)

The polymer (B1) may further have other repeating units. Preferably, it further contains at least one selected from the group consisting of a repeating unit having a lactone skeleton and a repeating unit having a cyclic carbonate structure.

Examples of the repeating unit having a lactone skeleton include (meth) acrylic acid-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (meth) acrylic acid. -9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] non-2-yl ester, (meth) acrylic acid-5-oxo-4-oxa-tricyclo [ 5.2.1.0 ^3,8 ] dec-2-yl ester, (meth) acrylic acid-10-methoxycarbonyl-5-oxo-4-oxa-tricyclo [5.2.1.0 ^3,8 ] Non-2-yl ester, (meth) acrylic acid-6-oxo-7-oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-4-methoxycarbonyl-6-oxo -7- Oxa-bicyclo [3.2.1] oct-2-yl ester, (meth) acrylic acid-7-oxo-8-oxa-bicyclo [3.3.1] non-2-yl ester, (meth) acrylic Acid-4-methoxycarbonyl-7-oxo-8-oxa-bicyclo [3.3.1] non-2-yl ester, (meth) acrylic acid-2-oxotetrahydropyran-4-yl ester, (meth) Acrylic acid-4-methyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-ethyl-2-oxotetrahydropyran-4-yl ester, (meth) acrylic acid-4-propyl-2 -Oxotetrahydropyran-4-yl ester, (meth) acrylic acid-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-2,2-di Methyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-4,4-dimethyl-5-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-2-oxotetrahydrofuran-3-yl ester, (Meth) acrylic acid-4,4-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid-5,5-dimethyl-2-oxotetrahydrofuran-3-yl ester, (meth) acrylic acid- 5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid-3,3-dimethyl-5-oxotetrahydrofuran-2-ylmethyl ester, (meth) acrylic acid-4,4-dimethyl-5-oxotetrahydrofuran A repeating unit derived from a compound such as -2-ylmethyl ester It can be mentioned.

Examples of the repeating unit having a cyclic carbonate structure include a repeating unit represented by the following formula.

(In the formula, R ¹ has the same definition as the above formula (1).)

Other repeating units include other repeating units derived from (meth) acrylic acid esters, such as hydroxyl group-containing (meth) acrylic acid esters and carboxyl group-containing (meth) acrylic acid esters.

The ratio of the repeating unit (3) in the polymer (B1) is preferably 0.1 to 20 mol%, particularly preferably 0.1%, based on all repeating units in the acid dissociable polymer contained in the radiation-sensitive resin composition. 1 to 10 mol%. If this ratio is less than 0.1 mol%, effects such as pattern shape and LWR reduction may be insufficient. On the other hand, if it exceeds 20 mol%, there is a possibility that a problem of shape defect due to insufficient exposure margin (EL margin shortage) or deterioration of transmittance may occur.

Further, the content ratio when the polymer (B1) contains the repeating unit (2) is preferably 20 to 80 mol%, particularly in all repeating units in the acid dissociable polymer contained in the radiation-sensitive resin composition. Preferably, it is 25 to 75 mol%. If this ratio is less than 20 mol%, sufficient solubility may not be obtained and resolution may deteriorate. Moreover, when it exceeds 80 mol%, there exists a possibility that adhesiveness with a board | substrate may deteriorate. It is preferable to adjust the copolymerization ratio and the mixing ratio of the polymer (A) and the polymer (B1) so as to achieve such a ratio.

<Acid generator (B2)>
Examples of the acid generator (B2) include onium salts such as sulfonium salts and iodonium salts, organic halogen compounds, sulfone compounds such as disulfones and diazomethane sulfones, and dicarboximide compounds.

Specific preferred examples of the acid generator (B2) include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] Triphenylsulfonium salt compounds such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium camphorsulfonate;

4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2. 2.1] 4-cyclohexylphenyldiphenylsulfonium salt compounds such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate and 4-cyclohexylphenyldiphenylsulfonium camphorsulfonate;

4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2- 4-methanesulfonylphenyl diphenylsulfonium salt compounds such as bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate and 4-methanesulfonylphenyldiphenylsulfonium camphorsulfonate;

Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2, Diphenyliodonium salt compounds such as 2-tetrafluoroethanesulfonate and diphenyliodonium camphorsulfonate;

Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, Bis (4-tert-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-tert-butylphenyl) iodonium camphor Bis (4-tert-butylphenyl) iodonium salt compounds such as sulfonate;

1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (4-n-Butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium 2-bicyclo [2.2. 1] 1- (4-n-) such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium camphorsulfonate Butoxynaphthalen-1-yl) tetrahydrothiophenium salt compound;

1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (6-n-Butoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium 2-bicyclo [2.2. 1] 1- (4-n-) such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium camphorsulfonate Butoxynaphthalen-1-yl) tetrahydrothiophenium salt compound;

1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (3,5-Dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2. 1] 1- (3,5- such as hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium camphorsulfonate Dimethyl-4-hydroxyphenyl) tetrahydrothio Eniumu salt compound;

N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept -5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- ( 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxy imide, N- (2- (3- tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethane-sulfonyloxy) bicyclo [2.2.1] hept Bicyclo [2.2.1] such as -5-ene-2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide And hept-5-ene-2,3-dicarboximide compounds.

The acid generator (B2) can be used alone or in admixture of two or more. The blending amount of the acid generator (B2) is preferably 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymer (A) from the viewpoint of ensuring the sensitivity and developability as a resist. More preferably, it is 1 to 20 parts by mass. In this case, if the blending amount of the acid generator is less than 0.1 parts by mass, the sensitivity and developability tend to decrease. On the other hand, if it exceeds 30 parts by mass, the transparency to radiation decreases and a rectangular resist is produced. It tends to be difficult to obtain a pattern. The acid generator (B2) is not an essential component of the radiation sensitive resin composition, but may be used as an optional component.

<Production method of polymer (A) and polymer (B1)>
The method for producing each polymer of the present invention and the polymer (A) and polymer (B1) used in the radiation-sensitive resin composition is not particularly limited. For example, the polymer has a desired molecular composition. The polymerizable unsaturated monomer corresponding to each repeating unit can be produced by polymerizing in a suitable solvent in the presence of a radical polymerization initiator, a chain transfer agent or the like. The radical polymerization initiator is preferably added so as to have a sufficiently high concentration in order to realize a sufficient polymerization rate. However, if the ratio of the amount of radical polymerization initiator to the amount of chain transfer agent is too high, a radical-radical coupling reaction occurs and an undesirable non-living radical polymer is formed. Therefore, the obtained polymer has a molecular weight and molecular weight. The part which has the characteristic which is not controlled in polymer characteristics, such as distribution, will be contained. The molar ratio between the amount of radical polymerization initiator and the amount of chain transfer agent is preferably (1: 1) to (0.005: 1).

Although it does not specifically limit as said radical polymerization initiator, A thermal polymerization initiator, a redox polymerization initiator, and a photoinitiator are mentioned. Specific examples include polymerization initiators such as peroxides and azo compounds. More specific radical polymerization initiators include t-butyl hydroperoxide, t-butyl perbenzoate, benzoyl peroxide, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azo. Examples thereof include bisisobutyronitrile (AIBN), 1,1′-azobis (cyclohexanecarbonitrile), dimethyl-2,2′-azobisisobutyrate (MAIB), dimethylazobisisobutyronitrile and the like.
Examples of the chain transfer agent include pyrazole derivatives and alkylthiols.

Polymerization can be carried out by a method such as ordinary batch polymerization or dropping polymerization. For example, for the monomers that form each of the above repeating units (1), (2) and other repeating units, necessary types and amounts are dissolved in an organic solvent, and in the presence of a radical polymerization initiator and a chain transfer agent. The polymer (A1) is obtained by polymerizing with. As the polymerization solvent, an organic solvent capable of dissolving the monomer, radical polymerization initiator and chain transfer agent is generally used. Examples of the organic solvent include ketone solvents, ether solvents, aprotic polar solvents, ester solvents, aromatic solvents, and chain or cyclic aliphatic solvents. Examples of ketone solvents include methyl ethyl ketone and acetone. Examples of ether solvents include alkoxyalkyl ethers such as methoxymethyl ether, ethyl ether, tetrahydrofuran, 1,4-dioxane and the like. Examples of the aprotic polar solvent include dimethylformamide and dimethylsulfoxide. Examples of ester solvents include alkyl acetates such as ethyl acetate and methyl acetate. Aromatic solvents include alkylaryl solvents such as toluene, xylene, and halogenated aromatic solvents such as chlorobenzene. Examples of the aliphatic solvent include hexane and cyclohexane.

The polymerization temperature is generally 20 to 120 ° C., preferably 50 to 110 ° C., more preferably 60 to 100 ° C. Although polymerization may be performed even in a normal air atmosphere, polymerization in an inert gas atmosphere such as nitrogen or argon is preferable. The molecular weight of the polymer (A) can be adjusted by controlling the ratio between the monomer amount and the chain transfer agent amount. The polymerization time is generally 0.5 to 144 hours, preferably 1 to 72 hours, more preferably 2 to 24 hours.

The polymer (A) and the polymer (B1) may have a residue derived from a chain transfer agent at the molecular chain end, and may not have a residue derived from the chain transfer agent at the molecular chain end. Moreover, the state which a part of residue derived from a chain transfer agent remains in the molecular chain terminal may be sufficient.

The polymer used in the radiation-sensitive resin composition of the present invention is naturally low in impurities such as halogen and metal, and the residual monomer and oligomer components are below the predetermined values, for example, 0. It is preferable that it is 1 mass% or less. As a result, not only can the sensitivity, resolution, process stability, pattern shape, etc. as a resist be further improved, but also a radiation-sensitive resin composition that can be used as a resist with little change over time such as foreign matter in liquid or sensitivity can be obtained. .

Examples of the polymer purification method include the following methods. (1) As a method for removing impurities such as metal, a metal is adsorbed by using a zeta potential filter or by washing the polymer solution with an acidic aqueous solution such as oxalic acid or sulfonic acid. For example, a method of removing in a chelated state can be mentioned. In addition, (2) methods for removing residual monomers and oligomer components below specified values include liquid-liquid extraction methods that remove residual monomers and oligomer components by combining water washing and an appropriate solvent, and specific molecular weights. A purification method in the form of a solution such as ultrafiltration that extracts and removes only the following, and residual monomers are removed by coagulating the polymer in the poor solvent by dropping the polymer solution into the poor solvent. There are a reprecipitation method and a purification method in a solid state such as washing the filtered polymer slurry with a poor solvent. Moreover, these methods can also be combined. The poor solvent used in the reprecipitation method depends on the physical properties of the polymer to be purified and cannot be generally exemplified. However, those skilled in the art can appropriately select the poor solvent according to the physical properties of the polymer. it can.

The weight average molecular weight (hereinafter abbreviated as “Mw”) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer of the present invention and the polymer used in the radiation sensitive resin composition of the present invention is usually 1, 000 to 300,000, preferably 2,000 to 300,000, more preferably 2,000 to 12,000. If the Mw of the polymer is less than 1,000, the heat resistance as a resist tends to decrease, while if it exceeds 300,000, the developability as a resist tends to decrease.
Further, the ratio (Mw / Mn) of the polymer Mw to the polystyrene-equivalent number average molecular weight (hereinafter abbreviated as “Mn”) by gel permeation chromatography (GPC) is preferably 1 to 5, more preferably 1 To 3, particularly preferably 1 to 1.6.

<Other ingredients>
In the radiation sensitive resin composition of the present invention, various additives such as an acid diffusion controller, an alicyclic additive, a surfactant, and a sensitizer can be blended as necessary.
Since the polymer (A) used in the present invention itself has acid diffusion controllability, good resolution, pattern shape, and LWR characteristics can be obtained without using any other acid diffusion control agent. , You may use together. As other acid diffusion control agents, nitrogen-containing organic compounds excluding the polymer (A) are preferably used.

Examples of the nitrogen-containing organic compound include a compound represented by the following formula (4) (hereinafter sometimes referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule (hereinafter referred to as “nitrogen-containing compound (I)”). “Nitrogen-containing compound (II)”), polyamino compounds having three or more nitrogen atoms in the same molecule and polymers thereof (hereinafter sometimes collectively referred to as “nitrogen-containing compound (III)”) And amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.

(In the formula (4), R ¹² are independently of each other a hydrogen atom, an optionally substituted linear, branched or cyclic alkyl group, aryl group, or aralkyl group.)

Examples of the nitrogen-containing compound (I) include mono (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; di-n- Butylamine, di-n-pentylamine, di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n-decylamine, cyclohexylmethylamine, dicyclohexylamine, etc. Di (cyclo) alkylamines; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine , Tri-n-nonylamine, tri-n-decylamine, cyclohex Tri (cyclo) alkylamines such as dimethylamine, methyldicyclohexylamine, tricyclohexylamine; substituted alkylamines such as 2,2 ′, 2 ″ -nitrotriethanol; aniline, N-methylaniline, N, N— Dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenylamine, naphthylamine, 2,4,6-tri-tert-butyl-N-methylaniline, N- Aromatic amines such as phenyldiethanolamine and 2,6-diisopropylaniline can be mentioned.

Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenyl ether. 4,4′-diaminobenzophenone, 4,4′-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2, -(4-aminophenyl) -2- (3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis [1- (4-aminophenyl) ) -1-Methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methyl Til] benzene, bis (2-dimethylaminoethyl) ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′ , N′-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N ′, N ″, N ″ -pentamethyldiethylenetriamine and the like.

Examples of the nitrogen-containing compound (III) include polymers of polyethyleneimine, polyallylamine, 2-dimethylaminoethylacrylamide, and the like.

Examples of the amide group-containing compound include Nt-butoxycarbonyldi-n-octylamine, Nt-butoxycarbonyldi-n-nonylamine, Nt-butoxycarbonyldi-n-decylamine, and Nt-butoxy. Carbonyldicyclohexylamine, Nt-butoxycarbonyl-1-adamantylamine, Nt-butoxycarbonyl-2-adamantylamine, Nt-butoxycarbonyl-N-methyl-1-adamantylamine, (S)-(- ) -1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, (R)-(+)-1- (t-butoxycarbonyl) -2-pyrrolidinemethanol, Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonylpyrrolidine, Nt-butoxycarbonyl Perazine, N, N-di-t-butoxycarbonyl-1-adamantylamine, N, N-di-t-butoxycarbonyl-N-methyl-1-adamantylamine, Nt-butoxycarbonyl-4,4′- Diaminodiphenylmethane, N, N′-di-t-butoxycarbonylhexamethylenediamine, N, N, N′N′-tetra-t-butoxycarbonylhexamethylenediamine,

N, N′-di-t-butoxycarbonyl-1,7-diaminoheptane, N, N′-di-t-butoxycarbonyl-1,8-diaminooctane, N, N′-di-t-butoxycarbonyl- 1,9-diaminononane, N, N′-di-t-butoxycarbonyl-1,10-diaminodecane, N, N′-di-t-butoxycarbonyl-1,12-diaminododecane, N, N′-di -T-butoxycarbonyl-4,4'-diaminodiphenylmethane, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-methylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole, N In addition to Nt-butoxycarbonyl group-containing amino compounds such as -t-butoxycarbonylpyrrolidine, formamide, -Methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine, isocyanuric acid tris ( 2-hydroxyethyl) and the like.

Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea. Etc.

Examples of the nitrogen-containing heterocyclic compound include imidazole, 4-methylimidazole, 4-methyl-2-phenylimidazole, benzimidazole, 2-phenylbenzimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-methyl. Imidazoles such as -1H-imidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, 2-methyl-4-phenylpyridine, Pyridines such as nicotine, nicotinic acid, nicotinamide, quinoline, 4-hydroxyquinoline, 8-oxyquinoline, acridine, 2,2 ′: 6 ′, 2 ″ -terpyridine; piperazine, 1- (2-hydroxyethyl ) In addition to piperazines such as piperazine, Razine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-piperidino-1,2-propanediol, morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3 -(N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane and the like.

The compounding amount of the nitrogen-containing organic compound is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less with respect to 100 parts by mass of the polymer. If the amount is more than 15 parts by mass, the sensitivity as a resist and the developability of the exposed area may be reduced. If the amount of the nitrogen-containing organic compound is less than 0.001 part by mass, the pattern shape and dimensional fidelity as a resist may be lowered depending on the process conditions.

Next, the alicyclic additive may have an acid-dissociable group, and is a component that exhibits an action of further improving dry etching resistance, pattern shape, adhesion to the substrate, and the like.

Examples of the alicyclic additive include 1-adamantanecarboxylic acid t-butyl, 1-adamantanecarboxylic acid t-butoxycarbonylmethyl, 1-adamantanecarboxylic acid α-butyrolactone ester, 1,3-adamantane dicarboxylic acid di-t- Butyl, 1-adamantane acetate t-butyl, 1-adamantane acetate t-butoxycarbonylmethyl, 1,3-adamantanediacetate di-t-butyl, 2,5-dimethyl-2,5-di (adamantylcarbonyloxy) hexane Adamantane derivatives such as;

T-butyl deoxycholate, t-butoxycarbonylmethyl deoxycholate, 2-ethoxyethyl deoxycholate, 2-cyclohexyloxyethyl deoxycholate, 3-oxocyclohexyl deoxycholate, tetrahydropyranyl deoxycholate, deoxychol Deoxycholic acid esters such as acid mevalonolactone ester; t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid, 2-cyclohexyloxyethyl lithocholic acid, 3-oxocyclohexyl lithocholic acid, lithocholic acid Examples thereof include lithocholic acid esters such as tetrahydropyranyl acid acid and mevalonolactone ester of lithocholic acid. In addition, the said alicyclic additive can be used individually by 1 type or 2 or more types.

Surfactant is a component having an action of improving coatability, striation, developability and the like. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene In addition to nonionic surfactants such as glycol distearate, the following are all trade names: KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (manufactured by Tochem Products), Megafuck F171, F173 (manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (Sumitomo 3M) Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (Asahi Glass Co., Ltd.) Can do. In addition, the said surfactant can be used individually by 1 type or 2 types or more. It is preferable that the compounding quantity of surfactant is 2 mass parts or less with respect to 100 mass parts of polymers (A).

The sensitizer absorbs radiation energy and transmits the energy to the photoacid generator, for example, in the form of radicals or electrons, thereby increasing the amount of acid produced. It has the effect of improving sensitivity. Examples of the sensitizer include carbazoles, benzophenones, rose bengals, anthracenes, phenols and the like. In addition, the said sensitizer can be used individually by 1 type or 2 types or more. It is preferable that the compounding quantity of a sensitizer is 50 mass parts or less with respect to 100 mass parts of polymers (A).

<Preparation of radiation-sensitive resin composition>
When the radiation-sensitive resin composition of the present invention is used, it is usually dissolved in a solvent so that the total solid concentration is 1 to 50% by mass, preferably 3 to 25% by mass. It is filtered through a filter of about 2 μm and prepared as a radiation sensitive resin composition solution. Examples of the solvent used for the preparation of the radiation sensitive resin composition solution include linear or branched ketones such as 2-pentanone, 2-hexanone, 2-heptanone, and 2-octanone; cyclopentanone, Cyclic ketones such as cyclohexanone; propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; 2-hydroxypropionic acids such as methyl 2-hydroxypropionate and ethyl 2-hydroxypropionate Alkyls: 3-alkoxypropionates such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, etc. Coal monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, n-butyl acetate, methyl pyruvate, Examples include ethyl pyruvate, N-methylpyrrolidone, and γ-butyrolactone.

These solvents can be used alone or in admixture of two or more. Propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclohexanone, γ-butyrolactone, ethyl 2-hydroxypropionate, 3-ethoxy It is preferable to contain at least one selected from ethyl propionate.

<Method for forming photoresist pattern>
The radiation sensitive resin composition of the present invention is useful as a chemically amplified resist. In a positive chemically amplified resist, a resin component, mainly an acid dissociable group in the polymer (A) is dissociated by the action of an acid generated from an acid generator by exposure, and is represented by a carboxyl group. This produces a polar group. As a result, the solubility of the exposed portion of the resist in the alkaline developer is increased, and the exposed portion is dissolved and removed by the alkaline developer to obtain a positive photoresist pattern.

Further, in the case of the negative type, the crosslinking reaction between the alkali-soluble resin component and the crosslinking agent easily occurs by the action of the acid generated from the acid generator by exposure by containing a crosslinking agent or the like. As a result, the solubility of the exposed portion of the resist in the alkaline developer is lowered, and the undeposed rear portion is dissolved and removed by the alkaline developer to obtain a resist pattern.

Hereinafter, a method for forming a photoresist pattern using a positive radiation sensitive resin composition will be described in detail.

The photoresist pattern forming method is generally performed according to the following procedure, for example. (1) After forming a photoresist film on the substrate using the radiation-sensitive resin composition (step (1)), (2) the formed photoresist film (with an immersion medium if necessary) ), Exposing by exposure to radiation through a mask having a predetermined pattern (step (2)), heating the substrate (exposed photoresist film) (step (3)), and then (4) developing ( Step (4)), a photoresist pattern can be formed.

In the step (1), a radiation sensitive resin composition or a composition solution obtained by dissolving it in a solvent is applied to a substrate (silicon wafer) by an appropriate application means such as spin coating, cast coating, roll coating or the like. , Silicon dioxide, a wafer coated with an antireflection film, etc.) to form a photoresist film. Specifically, after applying the resin composition solution so that the obtained resist film has a predetermined thickness, the solvent in the coating film is vaporized by pre-baking (PB) to form a resist film.

In step (2), the photoresist film formed in step (1) is irradiated with radiation (possibly through an immersion medium such as water) and exposed. In this case, radiation is irradiated through a mask having a predetermined pattern. As the radiation, irradiation is performed by appropriately selecting from visible light, ultraviolet light, far ultraviolet light, X-rays, charged particle beams and the like according to the line width of the target pattern. Among these, far ultraviolet rays represented by ArF excimer laser (wavelength 193 nm) and KrF excimer laser (wavelength 248 nm) are preferable, and ArF excimer laser is particularly preferable.

Step (3) is called post-exposure bake (PEB), and is a step in which the acid generated from the acid generator deprotects the polymer in the exposed portion of the photoresist film in step (2). There is a difference in the solubility of the exposed portion (exposed portion) and the unexposed portion (unexposed portion) in the alkaline developer. PEB is usually carried out by appropriately selecting in the range of 50 ° C to 180 ° C.

In step (4), the exposed photoresist film is developed with a developer to form a predetermined photoresist pattern. After development, it is common to wash with water and dry. Examples of the developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine , Ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4.3. [0] An aqueous alkali solution in which at least one alkaline compound such as 5-nonene is dissolved is preferable.

Also, when performing immersion exposure, before the step (2), in order to protect the direct contact between the immersion liquid and the resist film, an immersion liquid insoluble immersion protective film is formed on the resist film. It may be provided. As the immersion protective film, a solvent peeling type protective film (see, for example, JP-A-2006-227632) which is peeled off by a solvent before the step (4), a development which is peeled off simultaneously with the development in the step (4) Any of liquid-removable protective films (see, for example, WO 2005-069096 and WO 2006-035790) may be used. However, from the viewpoint of throughput, it is preferable to use a developer peeling type immersion protective film.

The resist pattern obtained in this way has good rectangularity and LWR is suppressed, so that it is suitable for fine processing using a lithography technique.

Hereinafter, the embodiments of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Here, the part is based on mass unless otherwise specified.

Each measurement and evaluation in each of the following synthesis examples was performed in the following manner.
(1) Mw and Mn
Gel permeation based on monodisperse polystyrene using GPC columns (2 G2000HXL, 1 G3000HXL, 1 G4000HXL) manufactured by Tosoh Corporation under the analysis conditions of flow rate 1.0 ml / min, elution solvent tetrahydrofuran, column temperature 40 ° C. It was measured by an association chromatography (GPC). Further, the degree of dispersion Mw / Mn was calculated from the measurement results.
⁽²⁾ 13 ^C-NMR, 1 H-NMR analysis of ¹³ C-NMR analysis and of the resin, ¹ H-NMR of the monomers, using a Nippon Denshi Co. "JNM-EX270", was measured.

<Synthesis of Compound (i)>
Hereinafter, a synthesis example of an onium salt compound having a polymerizable unsaturated bond and having a sulfonamide as an anion (that is, compound (i)) will be described.

20 g of ion exchange resin (QAE Sephadex A-25) manufactured by GE Healthcare Biosciences was swollen all day and night in ultrapure water and filled into a column tube. A solution in which 28 g of a sodium salt represented by the following formula (X-1) obtained by deprotonation of a (X-1) derivative made by Central Glass Co. with a metal base such as sodium hydrogen carbonate was dissolved in methanol was poured. The sulfonamide anion was supported on the resin. After flashing back with a sufficient amount of methanol, a solution of 5.2 g of triphenylsulfonium chloride dissolved in methanol was passed through the column tube to perform anion exchange. The solvent of the obtained solution was removed with an evaporator and then dried overnight at room temperature to obtain 8.1 g of the following compound (M-5).

With respect to the synthesized (M-5), the compound was identified by ¹ H-NMR. The peak intensity and chemical shift are shown below.
¹ H-NMR: 1.94 (s, 3H, CC H ₃ ), 3.59 (t, 2H, J = 5.2 Hz, OCH ₂ C H ₂ ), 4.31 (t, 2H, J = 5.2, OC H ₂ CH ₂ ), 5.61 (s, 1 H, CC H ₂ ), 6.16 (s, 1 H, CC H ₂ ), 7.67-7.80 (m, 15 H, Ar H)

Hereinafter, each synthesis example of the polymers (A1), (A11) and (B1) will be described. As the polymers (A1), (A11) and (B1), the monomers used in the synthesis of the polymers (A-1) to (A-9) are represented by the formulas (M-1) to (M-7). ) As shown below.

<Synthesis of Polymer (A-1)>
(Synthesis Example 1)
Monomer (M-1) 8.0 g (35 mol%), monomer (M-2) 5.0 g (15 mol%), monomer (M-4) 13.5 g (45 mol%) ) And 3.5 g (5 mol%) of monomer (M-5) were dissolved in 60 g of 2-butanone, and 1.1 g (5 mol%) of dimethylazobisisobutyronitrile was added. A solution was prepared. On the other hand, a 200 ml three-necked flask charged with 30 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reactor was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise. It was dripped using a funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured into 600 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice with 150 g of methanol in the form of a slurry and then filtered and dried at 50 ° C. for 17 hours to obtain a white powder copolymer (hereinafter referred to as “polymer (A-1)”. ) "). The obtained polymer was measured for Mw, Mw / Mn (molecular weight dispersity), yield (mass%), and the ratio (mol%) of each repeating unit in the polymer. The results are shown in Table 2. Moreover, the content rate of the low molecular weight component with a molecular weight of less than 1,000 of the obtained polymer was less than 0.1 mass% as a result of measuring by GPC.

(Synthesis Examples 2 to 9)
Polymers (A-2) to (A-9) were obtained in the same manner as in Synthesis Example 1 except that the monomers shown in Table 1 were used in the proportions shown in Table 1. The obtained polymer was measured for Mw, Mw / Mn (molecular weight dispersity), yield (mass%), and the ratio (mol%) of each repeating unit in the polymer. The results are shown in Table 2.

* The percentages in parentheses for monomers 1 to 4 are used (mol%)

<Preparation of radiation-sensitive resin composition>
Polymers (A), acid generator (B), nitrogen-containing compound (D), and solvent (C) were mixed in the proportions shown in parentheses in Table 3. Examples 1 to 8 and Comparative Example 1 Radiation sensitive resin compositions (3) to (3) were prepared.

Details of the acid generator (B), nitrogen-containing compound (D) and solvent (C) shown in Table 3 are shown below. In the table, “part” is based on mass unless otherwise specified.
<Acid generator (B)>
(B-1): Triphenylsulfonium nonafluoro-n-butanesulfonate (B-2): Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate (B-3): Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2′-yl) -1,1,2,2-tetrafluoroethanesulfonate,
<Nitrogen-containing compound (D)>
(D-1): Nt-butoxycarbonyl-4-hydroxypiperidine <Solvent (C)>
(C-1): Propylene glycol monomethyl ether acetate (C-2): Cyclohexanone (C-3): γ-butyrolactone

<Evaluation of radiation-sensitive resin composition>
Each of the radiation sensitive resin compositions of Examples 1 to 8 and Comparative Examples 1 to 3 was subjected to various evaluations as follows. These evaluation results are shown in Table 4.

<Sensitivity>
Using a silicon wafer having an ARC29 (Nissan Chemical Industries Co., Ltd.) film with a film thickness of 770 mm on the wafer surface, each composition solution was applied onto the substrate by spin coating using a clean track ACT8 (manufactured by Tokyo Electron). Then, PB was performed on the hot plate under the conditions shown in Table 4 to form a resist film having a thickness of 0.09 μm. The resist film formed as described above was exposed through a mask pattern using a Nikon ArF excimer laser exposure apparatus “S306C” (numerical aperture 0.78). After performing PEB under the conditions shown in Table 4, a positive resist pattern was formed by developing with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds, washing with water, and drying. . At this time, an exposure amount such that a line and space pattern (1L / 1S) having a diameter of 0.090 μm in the mask has a diameter of 0.090 μm was set as the optimum exposure amount, and this optimum exposure amount was set as the sensitivity.

<Cross-sectional shape of pattern (pattern shape)
The cross-sectional shape of the 0.075 μm line and space pattern in the sensitivity measurement as described above was observed with “S-4800” manufactured by Hitachi High-Technologies Corporation, and showed a T-top shape (ie, a shape other than a rectangle). The case was “bad”, and the case of a rectangular shape was “good”.

<LWR (Line Widness Roughness)>
At the optimum exposure amount, a 0.090 μm (1L / 1S) pattern formed on the resist film on the substrate was observed from the top of the pattern using a length measurement SEM (manufactured by Hitachi, Ltd., model number “S9380”), The diameter is measured at an arbitrary point, and the measurement variation is expressed by 3 sigma.
In addition, this value is so preferable that it is small, and the case where it was 9.0 nm or less was made favorable.

The radiation-sensitive resin compositions according to Examples 1 to 8 had sufficient sensitivity, and had a good shape and a low LWR pattern. On the other hand, the LWR was poor in the compositions of Comparative Examples 1 and 2, and the pattern shape was defective in the composition of Comparative Example 3.

<Synthesis of Compound (ii)>
Hereinafter, a synthesis example of an onium salt compound having a polymerizable unsaturated bond and having a carboxylate anion (that is, compound (ii)) will be described.

<Synthesis of Compound (M-21)>
20 g of ion exchange resin (QAE Sephadex A-25) manufactured by GE Healthcare Biosciences was swollen with ultrapure water all day and night, and filled into a column tube. A solution in which 31 g of a sodium salt obtained by deprotonation of a compound represented by the following formula (X-21) manufactured by Mitsubishi Rayon Co., Ltd. with a metal base such as sodium hydrogen carbonate was dissolved in methanol was poured. Anions were supported on the resin. After flashing back with a sufficient amount of methanol, a solution of 5.2 g of triphenylsulfonium chloride dissolved in methanol was passed through the column tube to perform anion exchange. The solvent of the obtained solution was removed with an evaporator and then dried overnight at room temperature to obtain 8.4 g of the following compound (M-21).

With respect to the synthesized compound (M-21), the compound was identified by ¹ H-NMR. The peak intensity and chemical shift are shown below.
¹ H-NMR: 1.92 (s, 3H, CC H ₃ ), 1.04-1.92 (m, 8H, CH ₂ ), 2.23-2.25 (m, 2H, COC H ) 4 .01-4.02 (m, 1 H, OC H ₂ ) 422-4.23 (m, 3 H, OC H ₂ ) 5.55 (s, 1 H, CC H ₂ ), 6.10 (s, 1 H, CC H ₂ ), 7.65-7.89 (m, 15H, Ar H )

<Synthesis of Compound (M-22)>
20 g of ion exchange resin (QAE Sephadex A-25) manufactured by GE Healthcare Biosciences was swollen with ultrapure water all day and night, and filled into a column tube. A solution in which 12 g of a sodium salt obtained by deprotonation of a compound represented by the following formula (X-22) manufactured by Aldrich with a metal base such as sodium hydrogencarbonate was dissolved in methanol was poured, and the carboxylate anion was converted into a resin. It was made to carry on. After flashing back with a sufficient amount of methanol, a solution of 5.2 g of triphenylsulfonium chloride dissolved in methanol was passed through the column tube to perform anion exchange. The solvent of the obtained solution was removed with an evaporator and then dried overnight at room temperature to obtain 5.6 g of the following compound (M-22).

With respect to the synthesized compound (M-22), the compound was identified by ¹ H-NMR. The peak intensity and chemical shift are shown below.
^{_{1 H-NMR: 1.86 (s}} , 3H, CC H 3), 5.05 (s, 1H, CC H 2), 5.73 (s, 1H, CC H 2), 7.69-7. 84 (m, 15H, Ar H )

Hereinafter, each synthesis example of the polymer (A21) will be described. The monomers used for the synthesis of the polymer (A21) are shown below as formulas (M-21) to (M-24).

<Synthesis of Polymer (A-21)>
(Synthesis Example 10)
1.6 g (3 mol%) of the monomer (M-21), 8.4 g (50 mol%) of the monomer (M-23), and 10.4 g (47 mol) of the monomer (M-24) %) Was dissolved in 60 g of 2-butanone, and a monomer solution charged with 1.1 g of dimethylazobisisobutyronitrile was prepared. On the other hand, a 200 ml three-necked flask charged with 30 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reactor was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added to the dropping funnel. Was added dropwise over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured into 600 g of methanol, and the precipitated white powder was filtered off. The filtered white powder was washed twice in a slurry with 150 g of methanol, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder copolymer. Mw, Mw / Mn (molecular weight dispersity), yield (mass%) of the obtained polymer, and the ratio (mol%) of each repeating unit in the polymer were measured. The results are shown in Table 6.

<Synthesis of Polymers (A-22) to (A-23)>
(Synthesis Examples 11 to 12)
The polymers (A-22) to (A-23) were prepared in the same manner as the synthesis of the resin (A-21) except that the combinations shown in Table 5 and monomers having a mass of charge mol% were used. Was synthesized. Mw, Mw / Mn (molecular weight dispersity), yield (mass%) of the obtained polymer, and the ratio (mol%) of each repeating unit in the polymer were measured. The results are shown in Table 6.

* The percentages in parentheses for monomers 1 to 3 are used (mol%)

<Preparation of radiation-sensitive resin composition>
Polymers (A), an acid generator (B), a nitrogen-containing compound (D) and a solvent (C) were mixed in the proportions shown in parentheses in Table 7. The examples 9 to 12 and comparative examples 4 to A radiation sensitive resin composition of No. 5 was prepared.

Details of the acid generator (B), nitrogen-containing compound (D) and solvent (C) shown in Table 7 are shown below. In the table, “part” is based on mass unless otherwise specified.
<Acid generator (B)>
(B-1): Triphenylsulfonium nonafluoro-n-butanesulfonate (B-2): Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2'-yl) -1,1-difluoroethanesulfonate (B-3): Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2′-yl) -1,1,2,2-tetrafluoroethanesulfonate,
<Nitrogen-containing compound (D)>
(D-1): Nt-butoxycarbonyl-4-hydroxypiperidine <Solvent (C)>
(C-1): Propylene glycol monomethyl ether acetate (C-2): Cyclohexanone (C-3): γ-butyrolactone

<Evaluation of radiation-sensitive resin composition>
Each of the radiation sensitive resin compositions of Examples 9 to 12 and Comparative Examples 4 to 5 was subjected to various evaluations as follows. These evaluation results are shown in Table 8.

<Sensitivity>
When exposure is performed with an ArF light source, a silicon wafer having an ARC29 (Nissan Chemical Industries Co., Ltd.) film having a film thickness of 770 mm is formed on the wafer surface, and each composition solution is placed on a substrate on a clean track ACT8 (Tokyo Electron). ) Was applied by spin coating, and PB was performed on a hot plate under the conditions shown in Table 8 to form a resist film having a thickness of 0.09 μm. The resist film formed as described above was exposed through a mask pattern using a Nikon ArF excimer laser exposure apparatus “S306C” (numerical aperture 0.78). After performing PEB under the conditions shown in Table 4, it was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds, washed with water, and dried to form a positive resist pattern. At this time, an exposure amount such that a line and space pattern (1L / 1S) having a diameter of 0.090 μm in the mask has a diameter of 0.090 μm was set as the optimum exposure amount, and this optimum exposure amount was set as the sensitivity.

<Cross-sectional shape of pattern (pattern shape)
The cross-sectional shape of the 0.090 μm line and space pattern in the sensitivity measurement as described above was observed with SEM “S-4800” manufactured by Hitachi High-Technologies Corporation, and the T-top shape (ie, a shape other than a rectangle) was obtained. The case where it was shown was “bad”, and the case where it was a rectangular shape was “good”.

The radiation-sensitive resin compositions according to Examples 9 to 12 were able to form a pattern having a good shape and a low LWR while having sufficient sensitivity. On the other hand, the LWR was poor in the composition of Comparative Example 4, and the pattern shape was defective in the composition of Comparative Example 5.

<Synthesis of Compound (iii)>
Hereinafter, a synthesis example of an onium salt compound having a polymerizable unsaturated bond and having a sulfonate anion (that is, compound (iii)) will be described.

<Synthesis of Compound (M-31)>
20 g of ion exchange resin (QAE Sephadex A-25) manufactured by GE Healthcare Biosciences was swollen with ultrapure water all day and night, and filled into a column tube. A solution in which 25 g of a compound represented by the following formula (X-31) manufactured by Asahi Kasei Finechem Co., Ltd. was dissolved in water was passed therethrough to support the sulfonate anion on the resin. After flashing back with a sufficient amount of methanol, a solution of 5.2 g of triphenylsulfonium chloride dissolved in methanol was passed through the column tube to perform anion exchange. The solvent of the obtained solution was removed with an evaporator and then dried overnight at room temperature to obtain 5.9 g of a compound (M-31) represented by the following formula (M-31).

With respect to the synthesized compound (M-31), the compound was identified by ¹ H-NMR. The peak intensity and chemical shift are shown below.
^{_{_{1 H-NMR: 1.91 (m}}} , 2H, O-CH 2 - CH 2 -), 1.92 (s, 3H, CC H 3), 1.99 (m, 2H, - CH 2 -CH 2 —SO3) 2.85 (t, 2H, —CH ₂ —SO3), 4.11 (t, 2H, O— CH ₂ —), 5.55 (s, 1H, CC H ₂ ), 6.10 ( s, 1H, CC H ₂ ), 7.6-7.9 (m, 15H, Ar H )

Hereinafter, each synthesis example of the polymer (A31) will be described. The monomers used for the synthesis of the polymer (A31) are shown below as formulas (M-31) to (M-34).

<Synthesis of Polymer (A-31)>
(Synthesis Example 13)
Monomer (M-31) 1.8 g (4 mol%), monomer (M-32) 6.3 g (40 mol%), monomer (M-33) 2.3 g (10 mol%) ) And 9.6 g (46 mol%) of monomer (M-34) were dissolved in 40 g of 2-butanone, and a monomer solution was further charged with 0.8 g of dimethylazobisisobutyronitrile. . On the other hand, a 200 ml three-necked flask charged with 20 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction vessel was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise. It was dripped using a funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured into 400 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 100 g of methanol in the form of a slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder copolymer. Mw, Mw / Mn (molecular weight dispersity), yield (mass%) of the obtained polymer, and the ratio (mol%) of each repeating unit in the polymer were measured. The results are shown in Table 10.

<Synthesis of Polymer (A-32)>
(Synthesis Example 14)
6.6 g (40 mol%) of the monomer (M-32), 2.4 g (10 mol%) of the monomer (M-33), and 10.3 g (50 mol) of the monomer (M-34) %) Was dissolved in 40 g of 2-butanone, and a monomer solution was prepared by adding 0.8 g of dimethylazobisisobutyronitrile. On the other hand, a 200 ml three-necked flask charged with 20 g of 2-butanone was purged with nitrogen for 30 minutes. After purging with nitrogen, the reaction vessel was heated to 80 ° C. with stirring, and the monomer solution prepared in advance was added dropwise. It was dripped using a funnel over 3 hours. The polymerization start was carried out for 6 hours with the start of dropping as the polymerization start time. After completion of the polymerization, the polymerization solution was cooled with water to 30 ° C. or less, poured into 400 g of methanol, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 100 g of methanol in the form of a slurry, filtered, and dried at 50 ° C. for 17 hours to obtain a white powder copolymer. Mw, Mw / Mn (molecular weight dispersity), yield (mass%) of the obtained polymer, and the ratio (mol%) of each repeating unit in the polymer were measured. The results are shown in Table 10.

* The percentages in parentheses for monomers 1 to 4 are used (mol%)

<Preparation of radiation-sensitive resin composition>
(Examples 13 to 14, Comparative Examples 6 to 7)
Polymers (A), acid generator (B), nitrogen-containing compound (D), and solvent (C) were mixed in the proportions shown in parentheses in Table 11, and Examples 13-14 and Comparative Examples 6- A radiation sensitive resin composition of No. 7 was prepared.

Details of the acid generator (B), nitrogen-containing compound (D) and solvent (C) shown in Table 11 are shown below. In the table, “part” is based on mass unless otherwise specified.
<Acid generator (B)>
(B-1): Triphenylsulfonium 2- (bicyclo [2.2.1] hepta-2′-yl) -1,1,2,2-tetrafluoroethanesulfonate,
<Nitrogen-containing compound (D)>
(D-1): Nt-butoxycarbonyl-4-hydroxypiperidine <Solvent (C)>
(C-1): Propylene glycol monomethyl ether acetate (C-2): Cyclohexanone (C-3): γ-butyrolactone

<Evaluation of radiation-sensitive resin composition>
Each of the radiation sensitive resin compositions of Examples 13 to 14 and Comparative Examples 6 to 7 was subjected to various evaluations as follows. These evaluation results are shown in Table 12.

<Sensitivity>
When exposure is performed with an ArF light source, a silicon wafer having an ARC29 (Nissan Chemical Industries Co., Ltd.) film having a film thickness of 770 mm is formed on the wafer surface, and each composition solution is placed on a substrate on a clean track ACT8 (Tokyo Electron). ) Was applied by spin coating, and PB was performed on a hot plate under the conditions shown in Table 4 to form a resist film having a thickness of 0.09 μm. The resist film formed as described above was exposed through a mask pattern using a Nikon ArF excimer laser exposure apparatus “S306C” (numerical aperture 0.78). After performing PEB under the conditions shown in Table 4, it was developed with a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds, washed with water, and dried to form a positive resist pattern. At this time, an exposure amount such that a line and space pattern (1L / 1S) having a diameter of 0.090 μm in the mask has a diameter of 0.090 μm was set as the optimum exposure amount, and this optimum exposure amount was set as the sensitivity.

<Cross-sectional shape of pattern (pattern shape)
As described above, the cross-sectional shape of the 0.090 μm line and space pattern in the sensitivity measurement is observed with SEM “S-4800” manufactured by Hitachi High-Technologies Corporation, and the T-top shape (ie, a shape other than a rectangle) is obtained. The case where it was shown was “bad”, and the case where it was a rectangular shape was “good”.

The radiation-sensitive resin compositions according to Examples 13 to 14 had sufficient sensitivity, and had a good shape and a low LWR pattern. On the other hand, the LWR was poor in the composition of Comparative Example 6, and the pattern shape was defective in the composition of Comparative Example 7.

Since the radiation-sensitive resin composition of the present invention has a sufficient radiation sensitivity, has a good pattern rectangularity, and can form a resist pattern in which LWR is suppressed, a KrF excimer laser or an ArF excimer laser is used. It can be suitably used as a lithography material for a light source.

This application claims the benefit of priority based on Japanese Patent Application Nos. 2009-098982, 2009-191426, 2009-129665, and 2010-28339, the contents of which are incorporated herein by reference. Is done.

Claims

(A) A radiation-sensitive resin composition containing a polymer having a repeating unit represented by the following formula (I).

(In formula (I), R 1 is a hydrogen atom, a methyl group or a trifluoromethyl group.
R 2 and R 4 are each independently a single bond, a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, or a divalent having a cyclic or cyclic partial structure having 3 to 20 carbon atoms. Or a group in which some or all of these hydrogen atoms are substituted with fluorine atoms.
R 3 is a single bond, —O—, —C (═O) — group, —O—C (═O) — group, —C (═O) —O— group or sulfinyl group.
A − is —N − —SO 2 —R D , —COO − , —O 2 — or —SO 3 — .
RD is a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or one of these hydrogen atoms. Part or all is a group substituted with a fluorine atom.
X + is an onium cation.
a is 0 or 1;
However, when A − is —SO 3 — , the end of R 4 on the SO 3 − side may not be —CF 2 —. A - is -COO - when, not if all of R 2, R 3 and R 4 is a single bond. When a is 1, A − is not —O 2 — . )
2. The sensation according to claim 1, wherein X + in the formula (I) is at least one selected from the group consisting of onium cations represented by the following formula (1-1) and the following formula (1-2), respectively. Radiation resin composition.

(In the formulas (1-1) and (1-2), R 5 to R 9 each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, or a substituent having 1 to 10 carbon atoms. An alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.)
(B1) The radiation sensitive resin composition of Claim 1 or Claim 2 which further contains the polymer which has a repeating unit represented by following formula (3).

(In the formula (3), R 1 , R 2 and X + are as defined in the above formula (1). N is an integer of 1 to 4.)
4. The sensation according to claim 3, wherein X + in the above formula (3) is at least one selected from the group consisting of onium cations represented by the following formula (1-1) and the following formula (1-2), respectively. Radiation resin composition.

(In the formulas (1-1) and (1-2), R 5 to R 9 each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, or a substituent having 1 to 10 carbon atoms. An alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.)
(B1) The radiation sensitive resin composition of Claim 3 or Claim 4 in which a polymer further has a repeating unit represented by following formula (2).

(In the formula (2), the definition of R 1 are as defined in the above formula (3).
R 10 is an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms.
R 11 is each independently an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or two R 11 's are bonded to each other so that both are bonded. A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms is formed together with the carbon atoms. )
(B2) The radiation sensitive resin composition according to any one of claims 1 to 5, further comprising a radiation sensitive acid generator.
The radiation sensitive resin composition according to any one of claims 1 to 6, wherein the polymer (A) further has a repeating unit represented by the following formula (3).

(In the formula (3), R 1 , R 2 and X + are as defined in the above formula (1). N is an integer of 1 to 4.)
X + in at least one formula selected from the group consisting of the above formula (I) and the above formula (3) is an onium cation represented by the following formula (1-1) and the following formula (1-2), respectively. The radiation sensitive resin composition according to claim 7, which is at least one selected from the group consisting of:

(In the formulas (1-1) and (1-2), R 5 to R 9 each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, or a substituent having 1 to 10 carbon atoms. An alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.)
The radiation sensitive resin composition according to any one of claims 1 to 8, wherein the polymer (A) further has a repeating unit represented by the following formula (2).

(In the formula (2), the definition of R 1 are as defined in the above formula (1).
R 10 is an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms.
R 11 is each independently an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or two R 11 's are bonded to each other so that both are bonded. A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms is formed together with the carbon atoms. )
The radiation sensitive substance according to any one of claims 1 to 9, wherein the polymer (A) has a repeating unit represented by the following formula (1) as the repeating unit represented by the formula (I). Resin composition.

(In the formula (1), R 1 is a hydrogen atom, a methyl group or a trifluoromethyl group.
R 2 represents a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, a divalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or a hydrogen atom thereof. It is a group partially or entirely substituted with a fluorine atom.
R 3 is a single bond, —C (═O) — group, —O—C (═O) — group or sulfinyl group.
R D is a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or a hydrogen atom thereof. It is a group partially or entirely substituted with a fluorine atom.
X + is an onium cation. )
The polymer which has a repeating unit represented by following formula (I).

(In formula (I), R 1 is a hydrogen atom, a methyl group or a trifluoromethyl group.
R 2 and R 4 are each independently a single bond, a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, or a divalent having a cyclic or cyclic partial structure having 3 to 20 carbon atoms. Or a group in which some or all of these hydrogen atoms are substituted with fluorine atoms.
R 3 is a single bond, —O—, —C (═O) — group, —O—C (═O) — group, —C (═O) —O— group or sulfinyl group.
A − is —N − —SO 2 —R D , —COO − , —O 2 — or —SO 3 — .
RD is a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or one of these hydrogen atoms. Part or all is a group substituted with a fluorine atom.
X + is an onium cation.
a is 0 or 1;
However, when A − is —SO 3 — , the end of R 4 on the SO 3 − side may not be —CF 2 —. A - is -COO - when, not if all of R 2, R 3 and R 4 is a single bond. When a is 1, A − is not —O 2 — . )
The polymer according to claim 11, comprising a repeating unit represented by the following formula (1) as the repeating unit represented by the formula (I).

(In the formula (1), R 1 is a hydrogen atom, a methyl group or a trifluoromethyl group.
R 2 represents a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, a divalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or a hydrogen atom thereof. It is a group partially or entirely substituted with a fluorine atom.
R 3 is a single bond, —C (═O) — group, —O—C (═O) — group or sulfinyl group.
R D is a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or a hydrogen atom thereof. It is a group partially or entirely substituted with a fluorine atom.
X + is an onium cation. )
The polymer according to claim 11 or 12, further comprising a repeating unit represented by the following formula (2).

(In the formula (2), the definition of R 1 are as defined in the above formula (1).
R 10 is an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms.
R 11 is each independently an alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or two R 11 's are bonded to each other so that both are bonded. A divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms is formed together with the carbon atoms. )
X + in the formula (I) is at least one selected from the group consisting of onium cations represented by the following formula (1-1) and the following formula (1-2), respectively. The polymer according to claim 13.

(In the formulas (1-1) and (1-2), R 5 to R 9 each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, or a substituent having 1 to 10 carbon atoms. An alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.)
The polymer according to any one of claims 11 to 14, further comprising a repeating unit represented by the following formula (3).

(In the formula (3), R 1 , R 2 and X + are as defined in the above formula (1). N is an integer of 1 to 4.)
16. The polymer according to claim 15, wherein X + in the formula (3) is at least one selected from the group consisting of onium cations represented by the following formula (1-1) and the following formula (1-2), respectively. .

(In the formulas (1-1) and (1-2), R 5 to R 9 each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, or a substituent having 1 to 10 carbon atoms. An alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.)
A compound represented by the following formula (i).

(In formula (i), R 1 is a hydrogen atom, a methyl group or a trifluoromethyl group.
R 2 represents a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, a divalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or a hydrogen atom thereof. It is a group partially or entirely substituted with a fluorine atom.
R 3 is a single bond, —C (═O) — group, —O—C (═O) — group or sulfinyl group.
R D is a linear or branched monovalent hydrocarbon group having 1 to 10 carbon atoms, a monovalent hydrocarbon group having a cyclic or cyclic partial structure having 3 to 20 carbon atoms, or a hydrogen atom thereof. It is a group partially or entirely substituted with a fluorine atom.
X + is an onium cation. )
A compound represented by the following formula (ii).

(In formula (ii), R 1 is a hydrogen atom, a methyl group or a trifluoromethyl group.
R 2 and R 4 are each independently a single bond, a linear or branched divalent hydrocarbon group having 1 to 10 carbon atoms, or a divalent having a cyclic or cyclic partial structure having 3 to 20 carbon atoms. Or a group in which some or all of these hydrogen atoms are substituted with fluorine atoms.
R 3 is a single bond, —O—, —C (═O) —, —C (═O) —O— or —O—C (═O) — group, provided that R 2 , R 3 and R Not all 4 are single bonds).
X + is an onium cation. )