JP2015055868A - Resin composition and method for forming resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition excellent in LWR (line width roughness), CDU (critical dimension uniformity), resolution, rectangularity, depth of focus, exposure latitude and MEEF (mask error enhancement factor).SOLUTION: The resin composition to be used for forming a resist pattern comprises: a first polymer having a first structural unit including one or two COO groups, one OH group, and a fluorine atom or a fluorinated alkyl group in a side chain of a resin; and an organic solvent.

Description

  The present invention relates to a resin composition and a resist pattern forming method.

  For forming various electronic device structures such as semiconductor devices and liquid crystal devices, a resist pattern forming method by photolithography is used. In this resist pattern forming method, for example, a radiation sensitive resin composition for forming a resist pattern on a substrate, and immersion exposure for forming a protective film on the resist film formed by the radiation sensitive resin composition Various resin compositions such as a protective film-forming resin composition are used. The radiation-sensitive resin composition generates an acid in an exposed portion by irradiation with exposure light such as far ultraviolet rays such as an ArF excimer laser and an electron beam, and the catalytic action of this acid causes the developer in the exposed portion and the unexposed portion to be developed. A difference is caused in the dissolution rate to form a resist pattern on the substrate. In addition, the protective film-forming resin composition for immersion exposure can form a resist pattern by facilitating high-speed scanning in immersion exposure because the surface of the protective film to be formed exhibits water repellency. .

  In such a resin composition, not only the resolution of the resist pattern to be formed is high and the rectangular shape of the cross-sectional shape is excellent, but also the LWR (Line Width Roughness) and CDU (Critical Dimension Uniformity) are small, the depth of focus, An exposure margin and MEEF (Mask Error Enhancement Factor) performance are also excellent, and it is required to obtain a highly accurate pattern with a high yield. In response to this requirement, various studies have been made on the structure of the polymer contained in the resin composition, and since the polymer has a hydroxy group and a fluorine atom-containing group, the hydrophilicity of the hydroxy group and the repellency of the fluorine atom are observed. It is known that by adjusting the balance of aqueous properties, the resin composition can improve the above-mentioned performance as well as having water repellency while improving the solubility in a developer (JP-A-2006-243264 and JP-A-2004). -2119822 publication).

  However, at present, when the miniaturization of the resist pattern is progressing to a level of 45 nm or less, the required level of the performance is further increased, and the conventional resin composition does not satisfy these requirements. Not done.

JP 2006-243264 A Japanese Patent Laid-Open No. 2004-21882

  The present invention has been made based on the circumstances as described above, and its purpose is to exhibit excellent depth of focus, exposure margin and MEEF performance, and LWR performance, CDU performance, resolution, and cross-sectional shape. An object of the present invention is to provide a resin composition capable of forming a resist pattern having excellent rectangularity.

The invention made to solve the above problems is
A resin composition for use in a resist pattern forming method by photolithography, comprising at least one selected from the group consisting of a group represented by the following formula (1) and a group represented by the following formula (2) It contains a first polymer having units and an organic solvent.

（式（１）及び（２）中、Ｒ^１及びＲ^２は、それぞれ独立して、水素原子、フッ素原子又は炭素数１〜２０の１価の有機基である。これらの基が互いに合わせられ構成される環構造を形成してもよい。Ｒ^３は、それぞれ独立して、炭素数１〜３０の１価の有機基である。Ｒ^ｆ２及びＲ^ｆ３は、それぞれ独立して、水素原子、フッ素原子、炭素数１〜１０のアルキル基又は炭素数１〜１０のフッ素化アルキル基である。１又は複数のＲ^ｆ２及びＲ^ｆ３並びにＲ^３のうちの２つ以上は、互いに合わせられ構成される環員数４〜３０の環構造を形成してもよい。但し、Ｒ^ｆ１、Ｒ^ｆ２及びＲ^ｆ３のうちの少なくとも１つはフッ素原子又はフッ素化アルキル基である。ｍ及びｎは、それぞれ独立して、１〜３の整数である。Ｒ^１、Ｒ^２、Ｒ^ｆ２及びＲ^ｆ３がそれぞれ複数の場合、複数のＲ^１、Ｒ^２、Ｒ^ｆ２及びＲ^ｆ３はそれぞれ同一でも異なっていてもよい。＊は、上記構造単位の他の部分に結合する部位を示す。
式（１）中、Ｒ^ｆ１は、炭素数１〜１０のアルキル基、炭素数５〜２０のシクロアルキル基、炭素数６〜２０の芳香族炭化水素基又は炭素数１〜１０のフッ素化アルキル基である。１又は複数のＲ^１及びＲ^２並びにＲ^ｆ１のうちの２つ以上は、互いに合わせられ構成される環員数３〜３０の環構造を形成してもよい。）

(In Formulas (1) and (2), R ¹ and R ² are each independently a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms. These groups are combined with each other. R ³ is each independently a monovalent organic group having 1 to 30 carbon atoms, and R ^f2 and R ^f3 are each independently a hydrogen atom, fluorine atom, two or more of .1 or ^{R f2} and ^{R f3} and ^{R 3} is an alkyl group or a fluorinated alkyl group having 1 to 10 carbon atoms having 1 to 10 carbon atoms is constructed aligned with one another A ring structure having 4 to 30 ring members, provided that at least one of R ^f1 , R ^f2 and R ^f3 is a fluorine atom or a fluorinated alkyl group, and m and n are each independently And R ¹ , R ² , R ^When there are a plurality of ^f2 and ^Rf3 , the plurality of R ¹ , R ² , R ^f2 and R ^f3 may be the same or different from each other, and * represents a site bonded to the other part of the structural unit.
In formula (1), R ^f1 is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or a fluorinated alkyl having 1 to 10 carbon atoms. It is a group. ^Two or more of one or more of R ¹ and R ² and R ^f1 may form a ring structure having 3 to 30 ring members that are combined with each other. )

Another invention made to solve the above problems is as follows:
A resist pattern forming method comprising: forming a resist film; exposing the resist film; and developing the exposed resist film; and forming the resist film from the resin composition.

Yet another invention made to solve the above problems is as follows:
A step of forming a resist film, a step of laminating a protective film on the resist film, a step of immersion exposure of the resist film on which the protective film is laminated, and a step of developing the resist film subjected to the immersion exposure And a resist pattern forming method in which the protective film is formed of the resin composition.

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

  According to the resin composition and resist pattern forming method of the present invention, a resist pattern that exhibits excellent depth of focus, exposure margin, and MEEF performance, and is excellent in LWR performance, CDU performance, resolution, and cross-sectional shape rectangularity. Can be formed. Therefore, these can be suitably used for pattern formation in semiconductor device manufacturing or the like, where miniaturization is expected to progress further in the future.

<Resin composition>
The said resin composition is a resin composition used for the resist pattern formation method by photolithography, Comprising: It contains the [A] polymer and the [B] solvent.

  Preferred embodiments of the resin composition include a radiation-sensitive resin composition (hereinafter also referred to as “resin composition (A)”), a protective film-forming resin composition for immersion exposure (hereinafter referred to as “resin composition”). (B) ") and the like.

<Resin composition (A)>
When the resin composition is a resin composition (A) (radiation sensitive resin composition), it contains a [A] polymer and a [B] solvent, and a radiation sensitive acid generator (hereinafter referred to as “[C] acid”). Generator ") and a fluorine-containing polymer other than [D] acid diffusion controller and [E] [A] polymer (hereinafter also referred to as" [E] polymer "). ) May be contained, and other optional components may be contained within a range not impairing the effects of the present invention.

  The resin composition (A) may contain only the base polymer as a polymer component, and may contain a water-repellent polymer additive in addition to the base polymer. The “base polymer” refers to a polymer that is a main component of the resist film formed from the resin composition (A), and preferably occupies 50% by mass or more based on the total polymer constituting the resist film. Refers to a polymer. Further, the “water-repellent polymer additive” is a polymer that tends to be unevenly distributed in the surface layer of the resist film to be formed by being contained in the resin composition (A). A polymer having higher hydrophobicity than the polymer serving as the base polymer tends to be unevenly distributed in the resist film surface layer, and can function as a water-repellent polymer additive. Since the resin composition (A) contains a water-repellent polymer additive, elution of the acid generator and the like from the resist film can be suppressed, and the formed resist film surface exhibits a high dynamic contact angle. The resist film surface can exhibit excellent water drainage characteristics. Accordingly, in the immersion exposure process, high-speed scan exposure can be performed without the necessity of separately forming an upper layer film for blocking the resist film surface and the immersion medium. When the resin composition (A) contains a water-repellent polymer additive, the content of the water-repellent polymer additive is 0.1 to 20 parts by mass with respect to 100 parts by mass of the base polymer. Preferably, 0.3 parts by mass to 15 parts by mass is more preferable, and 0.5 parts by mass to 10 parts by mass is more preferable. As content of the base polymer in a resin composition (A), 70 mass% or more is preferable with respect to the total solid in a resin composition (A), 80 mass% or more is more preferable, 85 mass% or more Is more preferable.

In the resin composition (A), in order for the polymer to function well as a water-repellent polymer additive, the polymer constituting the water-repellent polymer additive is preferably a polymer having a fluorine atom, Further, the fluorine atom content is more preferably larger than the fluorine atom content of the base polymer. If the fluorine atom content of the water-repellent polymer additive is larger than the fluorine atom content of the base polymer, the tendency of the water-repellent polymer additive to be unevenly distributed on the surface layer is further increased in the formed resist film. In addition, the characteristics resulting from the hydrophobicity of the water-repellent polymer additive such as high water drainage on the resist film surface are more effectively exhibited. The fluorine atom content of the polymer constituting the water-repellent polymer additive is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, and particularly preferably 7% by mass or more. In addition, this fluorine atom content rate (mass%) is computable from the structure of the polymer calculated | required by the measurement of < ¹³ > C-NMR.

  As an aspect of the polymer component in the resin composition (A), (1) [A] polymer as the base polymer, (2) [A] polymer and water-repellent polymer additive as the base polymer [A] polymer, (3) [A] polymer as base polymer and [E] polymer as water repellent polymer additive, (4) [F] polymer and repellent as base polymer The case where each contains the [A] polymer as an aqueous polymer additive is mentioned.

<Resin composition (B)>
When the resin composition is a resin composition (B) (a protective film-forming resin composition for immersion exposure), it contains a [A] polymer and a [B] solvent, and will be described later as preferred components [E] [E] [ A] A fluorine atom-containing polymer other than the polymer (hereinafter also referred to as “[E] polymer”) may be contained, and other optional components may be contained as long as the effects of the present invention are not impaired. Also good.
As content of the polymer component in a resin composition (B), 80 mass% or more is preferable with respect to the total solid in a resin composition (B), 90 mass% or more is more preferable, 95 mass% or more Is more preferable.
Hereinafter, each component will be described.

<[A] polymer>
[A] The polymer is a polymer having the structural unit (I). In the resin composition, the [A] polymer has the structural unit (I), thereby exhibiting excellent depth of focus, exposure margin and MEEF performance, LWR performance, CDU performance, resolution, and cross-sectional shape. A resist pattern having excellent rectangularity can be formed (these performances are hereinafter also referred to as “lithographic performances”). Although it is not necessarily clear why the resin composition has the above-described configuration, the following can be inferred, for example. That is, the structural unit (I) has a hydroxy group, a fluorine atom, and a —COOR group as in the above formula (1), and has water repellency due to the fluorine atom and the like and hydrophilicity due to the hydroxy group and the like. Can be adjusted more appropriately. As a result, according to the said resin composition, it is thought that the lithography performance of the resist pattern formed can be improved.

  In addition to the above-mentioned lithography performance, the resin composition (B) (protective film forming resin composition for immersion exposure) is excellent in composition stability and upper layer film removability, elution amount, peeling resistance, blob defect In addition, a resist pattern in which bridge defects are suppressed can be formed.

The [A] polymer (hereinafter also referred to as “[A1] polymer”) as the base polymer in the resin composition (A) is a structural unit containing an acid dissociable group in addition to the structural unit (I) ( II) and a structural unit other than the structural unit (I), preferably having a structural unit (III) containing at least one selected from the group consisting of a lactone structure, a cyclic carbonate structure and a sultone structure, The structural unit (VI) may be included, and structural units other than the structural units (I) to (III) and (VI) may be included.
The [A] polymer (hereinafter also referred to as “[A2] polymer”) as the water-repellent polymer additive in the resin composition (A) is not limited to the structural unit (I), but the structural unit (I). It is preferable to have a structural unit containing a fluorine atom, and may have a structural unit (VI) containing a hydroxy group, other than the above structural units (I) to (III) and (VI) It may have a structural unit of
The [A] polymer (hereinafter also referred to as “[A3] polymer”) in the resin composition (B) has a hydroxy group at the terminal and is adjacent to the hydroxy group in addition to the structural unit (I). It is preferable that the atom has a structural unit (IV) containing a group (z) having at least one fluorine atom or a fluorinated alkyl group, and may have a structural unit (V) containing a sulfo group. It may have a structural unit of
[A] The polymer may have one or more of the above structural units.
Hereinafter, each structural unit will be described.
[Structural unit (I)]
The structural unit (I) is a structural unit containing a group represented by the following formula (1) or the following formula (2). (Hereinafter also referred to as “structural unit (I-1)” and “structural unit (I-2)”)

In the above formula (1) and (2), ^{R 1} and ^{R 2} are each independently a hydrogen atom, a monovalent organic group fluorine atom or having 1 to 20 carbon atoms. You may form the ring structure comprised by combining these groups mutually. R ³ is each independently a monovalent organic group having 1 to 30 carbon atoms. R ^f2 and R ^f3 are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 10 carbon atoms, or a fluorinated alkyl group having 1 to 10 carbon atoms. 1 or more of the plurality of ^{R f2} and ^{R f3} and ^{R 3} may form a ring structure composed of ring members 4-30 are combined with each other. However, at least one of R ^f1 , R ^f2 and R ^f3 is a fluorine atom or a fluorinated alkyl group. m and n are each independently an integer of 1 to 3. R ^{1, R 2, R} when ^f2 and ^{R f3} is plural respective plurality of ^{R 1,} R ^{2, R f2} and ^{R f3} may have respectively the same or different. * Indicates a site that binds to another part of the structural unit.
In formula (1), R ^f1 is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or a fluorinated alkyl having 1 to 10 carbon atoms. It is a group. ^Two or more of one or more of R ¹ and R ² and R ^f1 may form a ring structure having 3 to 30 ring members that are combined with each other.

The monovalent organic group represented by R ¹ , R ² and R ³ is, for example, a monovalent hydrocarbon group having 1 to 20 carbon atoms. A group containing a divalent heteroatom-containing group at the carbon-carbon or bond-end side of the hydrocarbon group, a part or all of the hydrogen atoms of the hydrocarbon group and the group containing the heteroatom-containing group And a group substituted with a monovalent heteroatom-containing group.

  Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a chain hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, and an aromatic having 6 to 20 carbon atoms. Group hydrocarbon group and the like. Examples of the monovalent hydrocarbon group having 1 to 30 carbon atoms include a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, and an aromatic having 6 to 30 carbon atoms. Group hydrocarbon group and the like.

Examples of the chain hydrocarbon group include:
Alkyl groups such as methyl, ethyl, propyl, butyl, and pentyl groups;
Alkenyl groups such as ethenyl group, propenyl group, butenyl group, pentenyl group;
Examples thereof include alkynyl groups such as ethynyl group, propynyl group, butynyl group, and pentynyl group.

Examples of the alicyclic hydrocarbon group include:
Monocyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group;
A polycyclic cycloalkyl group such as a norbornyl group, an adamantyl group, a tricyclodecyl group, a tetracyclododecyl group;
A monocyclic cycloalkenyl group such as a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group;
Examples thereof include polycyclic cycloalkenyl groups such as norbornenyl group and tricyclodecenyl group.

Examples of the aromatic hydrocarbon group include:
Aryl groups such as phenyl, tolyl, xylyl, naphthyl and anthryl;
Examples thereof include aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group and anthrylmethyl group.

  Examples of the hetero atom contained in the monovalent and divalent heteroatom-containing group include an oxygen atom, a sulfur atom, a nitrogen atom, a silicon atom, and a phosphorus atom. In these, an oxygen atom, a sulfur atom, and a nitrogen atom are preferable, and an oxygen atom is more preferable.

  Examples of the divalent heteroatom-containing group include —O—, —CO—, —CS—, —NR′—, and a combination thereof. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

  Examples of the monovalent heteroatom-containing group include a hydroxy group, a carboxy group, a sulfanyl group (—SH), an amino group, and a cyano group.

Examples of the ring structure formed by combining the groups of R ¹ and R ² with each other include, for example:
Monocyclic cycloalkane structures such as cyclopropane structure, cyclobutane structure, cyclopentane structure, cyclohexane structure, cyclooctane structure;
Polycyclic cycloalkane structures such as norbornane structure, adamantane structure, tricyclodecane structure and tetracyclododecane structure;
Monocyclic cycloalkene structures such as cyclopropene structure, cyclobutene structure, cyclopentene structure, cyclohexene structure, cyclooctene structure;
Polycyclic cycloalkene structures such as norbornene structure, tricyclodecene structure, tetracyclododecene structure;
Examples include a lactone structure such as a butyrolactone structure.

Examples of the alkyl group represented by R ^f1 , R ^f2 and R ^f3 include, for example,
Examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group.

Examples of the cycloalkyl group represented by R ^f1 , R ^f2 and R ^f3 include, for example,
Monocyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group;
And polycyclic cycloalkyl groups such as a norbornyl group, an adamantyl group, a tricyclodecyl group, and a tetracyclododecyl group.

Examples of the fluorinated alkyl group represented by R ^f1 , R ^f2 and R ^f3 include, for example,
Trifluoromethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, 1,1,1,3,3,3-hexafluoro Propyl group, perfluoro n-propyl group, perfluoro i-propyl group, perfluoro n-butyl group, perfluoro i-butyl group, perfluoro t-butyl group, 2,2,3,3,4,4, Examples include 5,5-octafluoropentyl group and perfluorohexyl group.

Examples of the ring structure in which R ^f2, R ^f3 , and R ³ are combined with each other include the same groups as the ring structure in which the groups R ¹ and R ² are combined with each other.

Examples of the ring structure formed by combining R ¹ and R ² and R ^f1 with each other include the same groups as the ring structure formed by combining the groups R ¹ and R ² with each other.

R ¹ and R ² are preferably a hydrogen atom, a methyl group, an ethyl group, or a trifluoromethyl group, and more preferably a hydrogen atom. The ring structure constituted by combining these groups is preferably a cycloalkane structure, and more preferably a cyclohexane structure.
R ³ is preferably a methyl group, an ethyl group, a group having a lactone structure, a fluorinated alkyl group, a monocyclic cycloalkane structure, or a polycyclic cycloalkane structure, such as a pentafluoroethyl group, a trifluoromethyl group, or a butyrolactone. A group having a structure, an adamantyl group, a cyclohexyl group, and a phenyl group are preferred.

When R ³ contains a fluorine atom, a fluorinated alkyl group, —COO— and a group containing a fluorine atom are more preferable, and a perfluoroalkyl group, a hydrocarbon oxycarbonyldifluoromethyl group, and a fluorinated alkoxycarbonyldifluoromethyl group are further included. A trifluoromethyl group, an alkoxycarbonyldifluoromethyl group, and a fluorinated alkoxycarbonyldifluoromethyl group are particularly preferable.

If any of the above ^{R f2} and ^{R f3} contains a fluorine ^atom, it is preferable that at least one of ^{R f2} and ^{R f3} is a fluorine atom, a fluorinated alkyl ^group, both fluorine atoms ^{R f2} and ^{R f3,} More preferably, it is a fluorinated alkyl group, both R ^f2 and R ^f3 are more preferably a fluorine atom and a perfluoroalkyl group, and both R ^f2 and R ^f3 are a fluorine atom and a trifluoromethyl group. It is particularly preferable that both R ^f2 and R ^f3 are more preferably fluorine atoms.

The ring structure constituted by combining R ^f2 or R ^f3 and R ³ is preferably a lactone structure, more preferably a butyrolactone structure.
R ^f1 is preferably a difluoromethyl group, a trifluoromethyl group, a cyclohexyl group, or a phenyl group, and more preferably a trifluoromethyl group.

In the structural unit (I), it is preferable that at least one of R ^f2, R ^f3 , and R ^f1 bonded to the carbon atom adjacent to —COH in the above formula (1) contains a fluorine atom. Thereby, the acidity of OH group can be raised and a [A] polymer can exhibit higher affinity with respect to an alkali developing solution. In addition, it is preferable that at least one of R ^f2 , R ^f3, and R ³ bonded to the carbon atom adjacent to —COO— in the above formula (1) contains a fluorine atom. By doing in this way, the property to hydrolyze by the effect | action of an alkali improves. When this —COOR ³ — is hydrolyzed, it gives a carboxy group and a hydroxy group. Therefore, the [A] polymer has higher hydrophilicity during alkali development, so that an alkaline developer of the resin composition can be obtained. The affinity for is further increased. As a result, according to the resin composition, the lithography performance of the formed resist pattern can be further improved.

  m and n are each independently an integer of 1 to 3. m is preferably 1 or 2, and more preferably 1. n is preferably 1 or 2, and more preferably 1.

  Examples of the structural unit (I) include structural units represented by the following formulas (1-1) to (1-3) (hereinafter also referred to as “structural units (I-1) to (I-3)”). ) And the like.

In the above formulas (1-1) to (1-3), Z is a group represented by the above formula (1). R ⁴ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

  As the structural unit (I-1), structural units represented by the following formulas (1-1-1) to (1-3-1) (hereinafter referred to as “structural units (I-1-1) to (I— 3-1) ") is preferred.

In the above formulas (1-1-1) to (1-3-1), R ¹ , R ² , R ³ , R ^f1 , R ^f2 and R ^f3 have the same ^{meanings as} the respective groups in the above formula (1). is there.

  Examples of the monomer that gives the structural unit (I) (hereinafter also referred to as “compound (i)”) include, for example, the following formulas (i-1-1) to (i-1-17), (i-2- 1), (i-2-2), (i-3-1) and compounds represented by (i-3-2) (hereinafter, “compounds (i-1-1) to (i-1-17)”. ), (I-2-1), (i-2-2), (i-3-1) and (i-3-2) ").

  Among these, the compounds (i-1-1) to (i-1-17) are preferable.

  [A1] The content ratio of the structural unit (I) of the polymer is preferably 2 mol% to 30 mol%, and preferably 3 mol% to 20 mol% with respect to all the structural units constituting the [A1] polymer. More preferably, 5 mol% to 15 mol% is more preferable. [A2] The content ratio of the structural unit (I) of the polymer is preferably 5 mol% to 60 mol%, and preferably 10 mol% to 50 mol%, based on all structural units constituting the [A2] polymer. More preferably, it is more preferably 20 mol% to 45 mol%. [A3] The content of the structural unit (I) of the polymer is preferably 30 mol% to 100 mol%, and 40 mol% to 99 mol% with respect to all the structural units constituting the [A3] polymer. More preferably, 45 mol% to 98 mol% is more preferable. By making the said content rate into the said range, the lithography performance of the said resin composition improves more.

  For example, when compound (i) is represented by the following formulas (1-1A) to (1-3A), compound (i) can be easily synthesized according to the following scheme.

In the above formula, R ¹ and R ² are each independently a hydrogen atom, a monovalent organic group fluorine atom or having 1 to 20 carbon atoms. You may form the ring structure comprised by combining these groups mutually. R ³ is a monovalent organic group having 1 to 30 carbon atoms. R ^f2 and R ^f3 are each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 10 carbon atoms, or a fluorinated alkyl group having 1 to 10 carbon atoms. 1 or more of the plurality of ^{R f2} and ^{R f3} and ^{R 3} may form a ring structure composed of ring members 4-30 are combined with each other. However, at least one of R ^f1 , R ^f2 and R ^f3 is a fluorine atom or a fluorinated alkyl group. m and n are each independently an integer of 1 to 3. R ^{1, R 2, R} when ^f2 and ^{R f3} is plural respective plurality of ^{R 1,} R ^{2, R f2} and ^{R f3} may have respectively the same or different. R ^f1 is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or a fluorinated alkyl group having 1 to 10 carbon atoms. ^Two or more of one or more of R ¹ and R ² and R ^f1 may form a ring structure having 3 to 30 ring members that are combined with each other. R ⁴ is each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Y is a halogen atom.

  Y is preferably a chlorine atom or a bromine atom, more preferably a bromine atom.

  By reacting the compound represented by the formulas (1-1a) to (1-3a) with the compound represented by the formula (b) in a solvent in the presence of zinc, the formula (1- The compounds represented by 1A) to (1-3A) can be obtained. This compound can be isolated by purification by solvent washing, column chromatography, recrystallization, distillation or the like. Moreover, it can synthesize | combine by the same scheme also about the compound which has group represented by Formula (2).

[Structural unit (II)]
The structural unit (II) is a structural unit represented by the following formula (3). The group represented by —CR ⁶ R ⁷ R ⁸ in the structural unit (II) is an acid dissociable group. The “acid-dissociable group” refers to a group that substitutes a hydrogen atom of a carboxy group and is dissociated by the action of an acid. The said resin composition can improve a sensitivity because the [A] polymer has structural unit (II), As a result, lithography performance etc. can be improved.

In the above formula (2), R ⁵ represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ⁶ is a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. R ⁷ and R ⁸ are each independently a monovalent chain hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or these groups. Represents an alicyclic structure having 3 to 20 carbon atoms that is configured together with the carbon atoms to which they are bonded to each other. However, when the alicyclic structure formed by combining R ⁷ and R ⁸ with each other includes a double bond between the carbon atom adjacent to the carbon atom to which they are bonded and the carbon atom adjacent to the carbon atom, R ⁶ may be a hydrogen atom.

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

Examples of the monovalent chain hydrocarbon group having 1 to 10 carbon atoms represented by R ⁶ , R ⁷ and R ⁸ include, for example,
Alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group;
An alkenyl group such as an ethenyl group, a propenyl group, a butenyl group;
Examples thereof include alkynyl groups such as ethynyl group, propynyl group, and butynyl group.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ⁶ , R ⁷ and R ⁸ include, for example,
Monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group;
A monocyclic cycloalkenyl group such as a cyclopentenyl group and a cyclohexenyl group;
A polycyclic cycloalkyl group such as a norbornyl group, an adamantyl group and a tricyclodecyl group;
And polycyclic cycloalkenyl groups such as a norbornenyl group and a tricyclodecenyl group.

Examples of the alicyclic structure having 3 to 20 carbon atoms constituted and represented together with the carbon atom to which these groups are combined with each other include, for example,
Monocyclic cycloalkane structures such as cyclopropane structure, cyclobutane structure, cyclopentane structure, cyclohexane structure, cycloheptane structure, cyclooctane structure;
Examples thereof include polycyclic cycloalkane structures such as a norbornane structure, an adamantane structure, a tricyclodecane structure, and a tetracyclododecane structure.

  As the structural unit (II), structural units represented by the following formulas (3-1) to (3-5) (hereinafter also referred to as “structural units (II-1) to (II-5)”) are preferable. .

In the above formula ^{(3-1) ~ (3-5),} R 5 ~R 8 is as defined in the above formula (3). R ⁶ ′ is a hydrogen atom, a monovalent chain hydrocarbon group having 1 to 10 carbon atoms, or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. i and j are each independently an integer of 1 to 4. R ^X and R ^Y are each independently a hydrogen atom or a monovalent chain hydrocarbon group having 1 to 10 carbon atoms. R ^Z is a tetravalent alicyclic carbon atom having 3 to 20 carbon atoms including a carbon atom to which R 6 ′ is bonded and a double bond between the carbon atom to which R ^X is bonded and the carbon atom to which R ^Y is bonded. It is a hydrogen group.

  Examples of the structural units (II-1) to (II-5) include structural units represented by the following formulas.

In said formula, R < ⁵ > is synonymous with the said Formula (3).

  As structural unit (II), structural unit derived from 1-alkyl-1-cyclopentyl (meth) acrylate, structural unit derived from 2-alkyl-2-adamantyl (meth) acrylate, 2- (adamantan-1-yl ) A structural unit derived from propan-2-yl (meth) acrylate and a structural unit derived from 2-cyclohexylpropan-2-yl (meth) acrylate are preferred.

  [A1] The content ratio of the structural unit (II) of the polymer is preferably 10 mol% to 80 mol%, and 20 mol% to 70 mol% with respect to all the structural units constituting the [A1] polymer. More preferably, it is more preferably 30 mol% to 65 mol%. [A2] The content ratio of the structural unit (II) of the polymer is preferably 30 mol% to 90 mol%, and 40 mol% to 85 mol% with respect to all the structural units constituting the [A2] polymer. More preferably, 50 mol%-80 mol% are further more preferable. By making the said content rate into the said range, the sensitivity and resolution of the said resin composition improve more, and, as a result, lithography performance improves. When the said content rate is less than the said minimum, the pattern formation property of the said resin composition may fall. When the said content rate exceeds the said upper limit, the adhesiveness to the board | substrate of a resist pattern may fall.

[Structural unit (III)]
The structural unit (III) is a structural unit other than the structural unit (I) and includes at least one selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure. [A] The polymer further includes the structural unit (III) in addition to the structural unit (I), whereby the solubility in the developer can be further adjusted. As a result, the lithography of the resin composition can be performed. Performance and the like can be improved. Moreover, the adhesiveness of the resist pattern formed from the said resin composition and a board | substrate can be improved.

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

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

  Among these, the structural unit (III) is preferably a structural unit containing a norbornane lactone structure, a structural unit containing a γ-butyrolactone structure, a structural unit containing an ethylene carbonate structure, or a structural unit containing a norbornane sultone structure. -Structural unit derived from yl (meth) acrylate, structural unit derived from cyano-substituted norbornanelactone-yl (meth) acrylate, structural unit derived from norbornanelactone-yloxycarbonylmethyl (meth) acrylate, γ-butyrolactone-yl Structural unit derived from (meth) acrylate, structural unit derived from ethylene carbonate-ylmethyl (meth) acrylate, structural unit derived from norbornane sultone-yl (meth) acrylate, norbornane sultone-yl A structural unit derived from oxycarbonylmethyl (meth) acrylate is more preferred.

  [A1] The content ratio of the structural unit (III) of the polymer is preferably 0 mol% to 70 mol%, and preferably 10 mol% to 65 mol%, based on all structural units constituting the [A1] polymer. More preferably, it is more preferably 25 mol% to 55 mol%. By making the said content rate into the said range, the adhesiveness to the board | substrate of the resist pattern formed from the said resin composition can be improved more. When the said content rate is less than the said minimum, the adhesiveness to the board | substrate of the resist pattern formed from the said resin composition may fall. When the said content rate exceeds the said upper limit, the pattern formation property of the said resin composition may fall.

[Structural unit (IV)]
The structural unit (IV) is a structural unit containing a group (z) having a hydroxy group at the terminal and a carbon atom adjacent to the hydroxy group having at least one fluorine atom or fluorinated alkyl group. [A] By having the structural unit (IV), the polymer can adjust the solubility in the developer more appropriately, and as a result, the lithography performance of the resin composition can be further improved. . Moreover, the sensitivity of the resin composition in the case of EUV exposure can be increased.

  Examples of the group (z) include a group represented by the following formula (z-1).

In said formula (z-1), ^Rf4 and ^Rf5 are respectively independently a C1-C10 alkyl group or a C1-C10 fluorinated alkyl group. However, at least one of R ^f4 and R ^f5 is a fluorinated alkyl group.

Examples of the fluorinated alkyl group having 1 to 10 carbon atoms represented by R ^f4 and R ^f5 include, for example, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a fluoroethyl group, a difluoroethyl group, and a trifluoroethyl group. , Pentafluoroethyl group, hexafluoropropyl group, heptafluoropropyl group, nonafluorobutyl group and the like.
Among these, a trifluoromethyl group and a pentafluoroethyl group are preferable, and a trifluoromethyl group is more preferable.

  The group (z) is preferably a hydroxy-di (trifluoromethyl) methyl group, a hydroxy-di (pentafluoroethyl) methyl group, or a hydroxy-methyl-trifluoromethylmethyl group, and hydroxy-di (trifluoromethyl). A methyl group is more preferred.

  As the structural unit (IV), for example, structural units represented by the following formulas (4-1) to (4-9) (hereinafter also referred to as “structural units (IV-1) to (IV-9)”) Etc.

In the above formulas (4-1) to (4-9), R ^L3 is independently a hydrogen atom or a methyl group.

  Among these, the structural unit (IV-4) and the structural unit (IV-6) are preferable.

[A3] The content ratio of the structural unit (IV) in the polymer is preferably 0 mol% to 80 mol%, and 20 mol% to 70 mol% with respect to all structural units constituting the [A3] polymer. More preferably, it is more preferably 30 mol% to 60 mol%.
[A3] By adjusting the content ratio of the structural unit (IV) in the above range, the polymer can further adjust the solubility in the developer more appropriately. As a result, the lithography performance of the resin composition can be further improved. Can be improved. Moreover, the sensitivity of the resin composition in the case of EUV exposure can be further increased.

[Structural unit (V)]
The structural unit (V) is a structural unit containing a sulfo group. [A] By having the structural unit (V), the polymer [A] can improve adhesion to the substrate, and can be suitably used, for example, as a protective film-forming resin composition for immersion exposure.

  Examples of the structural unit (V) include a structural unit represented by the following formula (5).

In said formula (5), ^RG is a hydrogen atom, a methyl group, a fluorine atom, or a trifluoromethyl group. L ² is a single bond, an oxygen atom, a sulfur atom, a divalent linear or branched hydrocarbon group having 1 to 6 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, carbon It is a bivalent aromatic hydrocarbon group or a —C (═O) —X ⁴ —R ^g — group having a formula 6 to 12. X ⁴ is an oxygen atom, a sulfur atom or an NH group. R ^g is a single bond, a divalent linear or branched hydrocarbon group having 1 to 6 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, or 2 having 6 to 12 carbon atoms. Valent aromatic hydrocarbon group.

Examples of the divalent linear or branched hydrocarbon group having 1 to 6 carbon atoms represented by L ² and R ^g, preferably a saturated hydrocarbon group such as methylene group, ethylene group, 1,3 -Propylene group, 1,2-propylene group, 1,1-propylene group, 2,2-propylene group, tetramethylene group, pentamethylene group, hexamethylene group, 1-methyl-1,3-propylene group, 2- Examples include methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group and the like.

The divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms represented by L ² and R ^g may be monocyclic or polycyclic, and has a crosslinked structure in polycyclic. Also good. Examples of the monocyclic hydrocarbon group include cyclobutylene groups such as 1,3-cyclobutylene groups, cyclopentylene groups such as 1,3-cyclopentylene groups, and cyclohexylene groups such as 1,4-cyclohexylene groups. Group, a cyclooctylene group such as a 1,5-cyclooctylene group, and the like. Examples of the polycyclic hydrocarbon group include a hydrocarbon group having a 2- to 4-membered ring, a norbornylene group such as a 1,4-norbornylene group and a 2,5-norbornylene group, and a 1,5-adamantylene group. And adamantylene groups such as 2,6-adamantylene group.

Examples of the divalent aromatic hydrocarbon group having 6 to 12 carbon atoms represented by L ² and R ^g, for example, a phenylene group, such as an arylene group such as a tolylene group.

As L ² , a single bond, a divalent linear or branched hydrocarbon group having 1 to 6 carbon atoms, a divalent aromatic hydrocarbon having 6 to 12 carbon atoms, or R ^g having 1 carbon atom. -C (= O) -NH- ^RC, which is a divalent linear or branched hydrocarbon group of -6, is preferably a single bond, methylene group, phenylene group, -C (= O) -NH-. C (CH ₃ ) ₂ —CH ₂ — is more preferred.

  Examples of the structural unit (V) include structural units represented by the following formulas (5-1) to (5-4) (hereinafter also referred to as “structural units (V-1) to (V-4)”). Etc.

In the above formulas (5-1) to (5-4), R ^G has the same ^{meaning as} in the above formula (5).

  Of these, the structural unit (V-1) is preferable.

The content ratio of the structural unit (V) in the [A3] polymer is preferably 0 mol% to 20 mol%, and 0 mol% to 10 mol% with respect to all the structural units constituting the [A3] polymer. More preferably, 0.1 mol%-5 mol% are further more preferable, and 0.5 mol%-3 mol% are especially preferable.
[A] By making the content rate of the structural unit (V) of a polymer into the said range, the adhesiveness of the film | membrane formed from the said resin composition and a board | substrate can further be improved.

[Structural unit (VI)]
The structural unit (VI) is a structural unit containing a hydroxy group. [A] A polymer can have more moderate solubility by having a structural unit (VI). Moreover, the adhesiveness to the board | substrate of the resist pattern formed from the said resin composition can be improved.

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

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

  As a content rate of the structural unit containing the said hydroxyl group, 30 mol% or less is preferable with respect to all the structural units which comprise a [A] polymer, 20 mol% or less is preferable and 3 mol%-15 mol% are preferable. Further preferred. When the said content rate exceeds the said upper limit, the pattern formation property of the said resin composition may fall.

[Other structural units]
[A] The polymer may have other structural units other than the structural units (I) to (VI). As a content rate of the said other structural unit, it is structural units other than structural unit (I), Comprising: The structural unit containing a fluorine atom etc. are mentioned, for example. Examples of the structural unit containing a fluorine atom include structural units (Ea) and (Eb) in the [E] polymer described later. [A] 20 mol% or less is preferable with respect to all the structural units constituting the polymer, and 10 mol% or less is more preferable.

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

  Examples of the radical polymerization initiator include azobisisobutyronitrile (AIBN), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobis (2-cyclopropylpropylene). Pionitrile), azo radical initiators such as 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2′-azobisisobutyrate; benzoyl peroxide, t-butyl hydroperoxide, And peroxide radical initiators such as cumene hydroperoxide. Of these, AIBN and dimethyl 2,2'-azobisisobutyrate are preferred, and AIBN is more preferred. These radical initiators can be used alone or in combination of two or more.

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

  As reaction temperature in the said superposition | polymerization, 40 to 150 degreeC and 50 to 120 degreeC are preferable normally. The reaction time is usually preferably 1 hour to 48 hours and 1 hour to 24 hours.

  [A] The weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer is not particularly limited, but is preferably 1,000 or more and 50,000 or less, more preferably 2,000 or more and 30,000 or less. Preferably, 3,000 or more and 20,000 or less are more preferable, and 5,000 or more and 15,000 are particularly preferable. [A] By making Mw of a polymer into the said range, the applicability | paintability and development defect inhibitory property of the said resin composition improve. [A] If the Mw of the polymer is less than the lower limit, a resist film having sufficient heat resistance may not be obtained. [A] If the Mw of the polymer exceeds the above upper limit, the developability of the resist film may deteriorate.

  [A] The ratio (Mw / Mn) of Mw to the number average molecular weight (Mn) in terms of polystyrene by GPC of the polymer is usually from 1 to 5, preferably from 1 to 3, more preferably from 1 to 2. .

Mw and Mn of the polymer in this specification are values measured using gel permeation chromatography (GPC) under the following conditions.
GPC column: 2 G2000HXL, 1 G3000HXL, 1 G4000HXL (above, manufactured by Tosoh)
Column temperature: 40 ° C
Elution solvent: Tetrahydrofuran (Wako Pure Chemical Industries)
Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass
Sample injection volume: 100 μL
Detector: Differential refractometer Standard material: Monodisperse polystyrene

<[B] Solvent>
The resin composition usually contains a [B] solvent. [B] The solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least the [A] polymer and the optionally contained [C] acid generator and [D] acid diffusion controller.

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

As an alcohol solvent, for example,
Methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert- Pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n- Nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, furf Alcohol, phenol, cyclohexanol, methyl cyclohexanol, 3,3,5-trimethyl cyclohexanol, benzyl alcohol, mono-alcohol solvents such as diacetone alcohol;
Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2 -Polyhydric alcohol solvents such as ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl Ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol Monomethyl ether, dipropylene glycol monoethyl ether, polyhydric alcohol partial ether solvents such as dipropylene glycol monopropyl ether.

As an ether solvent, for example,
Dialkyl ether solvents such as diethyl ether, dipropyl ether, dibutyl ether;
Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran;
Aromatic ring-containing ether solvents such as diphenyl ether and anisole (methylphenyl ether) are exemplified.

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

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

Examples of ester solvents include:
Methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, i-pentyl acetate, sec-pentyl acetate, 3-methoxy acetate Acetate solvents such as butyl, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, and n-nonyl acetate;
Ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether Polyhydric alcohol partial ether acetate solvents such as acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate;
Carbonate solvents such as diethyl carbonate;
Glycol acetate, methoxytriglycol acetate, ethyl propionate, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl acetoacetate, ethyl acetoacetate, methyl lactate, ethyl lactate N-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, diethyl phthalate and the like.

Examples of the hydrocarbon solvent include
Aliphatic carbonization such as n-pentane, iso-pentane, n-hexane, iso-hexane, n-heptane, iso-heptane, 2,2,4-trimethylpentane, n-octane, iso-octane, cyclohexane, methylcyclohexane A hydrogen-based solvent;
Fragrances such as benzene, toluene, xylene, mesitylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, iso-propylbenzene, diethylbenzene, iso-butylbenzene, triethylbenzene, di-iso-propylbenzene and n-amylnaphthalene Group hydrocarbon solvents and the like.

  Among these, ester solvents and ketone solvents are preferable, polyhydric alcohol partial ether acetate solvents and cyclic ketone solvents are more preferable, and propylene glycol monomethyl ether acetate and cyclohexanone are further preferable. The resin composition may contain one or more [B] solvents.

<[C] acid generator>
[C] The acid generator is a substance that generates an acid upon exposure. Since the acid-dissociable group of the [A] polymer or the like is dissociated by the generated acid to generate a carboxy group or the like, and the solubility of the [A] polymer in the developer containing the organic solvent is reduced, As the inclusion form of the [C] acid generator in the resin composition that can form a negative resist pattern from the resin composition, the low molecular compound form (hereinafter referred to as “[C ] Acid generators), in the form of acid generating groups incorporated as part of the polymer, or in both forms.

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

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

As the sulfonium salt, for example,
Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1, 1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1-difluoroethanesulfonate, triphenylsulfonium camphorsulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoro Lomethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium Perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium camphor Sulfonate, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methyl Emissions aminosulfonylphenyl camphorsulfonate, triphenylsulfonium 1,1,2,2-tetrafluoro-6- (1-adamantanecarbonyloxy) - hexane-1-sulfonate, and the like.

Examples of tetrahydrothiophenium salts include:
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] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium camphorsulfonate, 1- (6-n-butoxy) Naphthalen-2-yl) tetrahydrothiophenium trifluoromethane Sulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n -Octanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium camphorsulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5 -Dimethyl-4-hydroxyphenyl) tetrahydrothiopheny Munonafluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophene Ni-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium camphorsulfonate Etc.

As an iodonium salt, for example,
Diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2, 2-tetrafluoroethanesulfonate, 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-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1 2,2-tetrafluoroethane sulfonate, bis (4-t- butylphenyl) iodonium camphorsulfonate, and the like.

As the N-sulfonyloxyimide compound, for example,
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 Examples include -5-ene-2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide.

  [C] The acid generator is preferably a compound represented by the following formula (6). [C] It is considered that the acid generator has the following structure, so that the diffusion length of the acid generated by exposure in the resist film is appropriately shortened by the interaction with each structural unit of the [A] polymer. As a result, the lithography performance of the resin composition can be further improved.

In the above formula (6), R ⁹ is a monovalent group containing an alicyclic structure having 6 or more ring members or a monovalent group containing an aliphatic heterocyclic structure having 6 or more ring members. R ¹⁰ is a fluorinated alkanediyl group having 1 to 10 carbon atoms. X ⁺ is a monovalent radiolytic onium cation.

The “number of ring members” in R ⁹ refers to the number of atoms constituting the ring of the alicyclic structure and the aliphatic heterocyclic structure, and in the case of the polycyclic alicyclic structure and the polycyclic aliphatic heterocyclic structure, The number of atoms that make up the ring.

Examples of the monovalent group containing an alicyclic structure having 6 or more ring members represented by R ⁹ include:
A monocyclic cycloalkyl group such as a cyclooctyl group, a cyclononyl group, a cyclodecyl group, a cyclododecyl group;
A monocyclic cycloalkenyl group such as a cyclooctenyl group and a cyclodecenyl group;
A polycyclic cycloalkyl group such as a norbornyl group, an adamantyl group, a tricyclodecyl group, a tetracyclododecyl group;
And polycyclic cycloalkenyl groups such as a norbornenyl group and a tricyclodecenyl group.

Examples of the monovalent group containing an aliphatic heterocyclic structure having 6 or more ring members represented by R ⁹ include:
A group containing a lactone structure such as a norbornanelactone-yl group;
A group containing a sultone structure such as a norbornane sultone-yl group;
An oxygen atom-containing heterocyclic group such as an oxacycloheptyl group and an oxanorbornyl group;
A nitrogen atom-containing heterocyclic group such as an azacyclohexyl group, an azacycloheptyl group, a diazabicyclooctane-yl group;
And sulfur atom-containing heterocyclic groups such as a thiacycloheptyl group and a thianorbornyl group.

The number of ring members of the group represented by R ⁹ is preferably 8 or more, more preferably 9 to 15 and even more preferably 10 to 13 from the viewpoint that the acid diffusion length described above becomes more appropriate.

R ⁹ is preferably a monovalent group containing an alicyclic structure having 9 or more ring members, or a monovalent group containing an aliphatic heterocyclic structure having 9 or more ring members, among which an adamantyl group or a hydroxyadamantyl group , A norbornanelactone-yl group, and a 5-oxo-4-oxatricyclo [4.3.1.1 ^3,8 ] undecan-yl group are more preferable, and an adamantyl group is more preferable.

Examples of the fluorinated alkanediyl group having 1 to 10 carbon atoms represented by R ⁹ include one hydrogen atom of an alkanediyl group having 1 to 10 carbon atoms such as a methanediyl group, an ethanediyl group, and a propanediyl group. Examples include groups in which the above is substituted with a fluorine atom.
Among these, SO ₃ ^- fluorinated alkane diyl group which has a fluorine atom to carbon atom is bonded to adjacent groups are preferred, SO ₃ ^- 2 fluorine atoms to the carbon atom adjacent to the group is attached More preferred are fluorinated alkanediyl groups, 1,1-difluoromethanediyl group, 1,1-difluoroethanediyl group, 1,1,3,3,3-pentafluoro-1,2-propanediyl group, 1,1 1,2,2-tetrafluoroethanediyl group, 1,1,2,2-tetrafluorobutanediyl group, and 1,1,2,2-tetrafluorohexanediyl group are more preferable.

The monovalent radiolytic onium cation represented by X ⁺ is a cation that decomposes upon irradiation with radiation. In the exposed portion, sulfonic acid is generated from protons generated by the decomposition of the radiolytic onium cation and the sulfonate anion. Examples of the monovalent radiolytic onium cation represented by X ⁺ include elements such as S, I, O, N, P, Cl, Br, F, As, Se, Sn, Sb, Te, and Bi. And radiation-decomposable onium cations. Examples of the cation containing S (sulfur) as an element include a sulfonium cation and a tetrahydrothiophenium cation. Examples of the cation containing I (iodine) as an element include an iodonium cation. Among these, a sulfonium cation represented by the following formula (X-1), a tetrahydrothiophenium cation represented by the following formula (X-2), and an iodonium cation represented by the following formula (X-3) preferable.

In the above formula (X-1), R ^a1 , R ^a2 and R ^a3 are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, substituted or unsubstituted. aromatic hydrocarbon group having 6 to 12 carbon atoms, a or a -OSO ₂ -R ^P or _-SO 2 -R ^Q, or two or more are combined with each other configured ring of these groups . R ^P and R ^Q are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms. Or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. k1, k2 and k3 are each independently an integer of 0 to 5. R ^a1 to R ^a3 and when ^{R P} and ^{R Q} are a plurality each of the plurality of ^R a1 ^{to R a3} and ^{R P} and ^{R Q} may be the same as or different from each other.
In the above formula (X-2), R ^b1 represents a substituted or unsubstituted linear or branched alkyl group having 1 to 8 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon having 6 to 8 carbon atoms. It is a group. k4 is an integer of 0-7. If R ^b1 is plural, the plurality of R ^b1 may be the same or different, and plural R ^b1 may represent a constructed ring aligned with each other. R ^b2 is a substituted or unsubstituted linear or branched alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms. k5 is an integer of 0-6. If R ^b2 is plural, the plurality of R ^b2 may be the same or different, and plural R ^b2 may represent a keyed configured ring structure. q is an integer of 0-3.
In the above formula (X-3), R ^c1 and R ^c2 each independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted carbon number of 6 12 aromatic hydrocarbon group, or an -OSO ₂ -R ^R or _-SO 2 -R ^S, or two or more are combined with each other configured ring of these groups. R ^R and R ^S are each independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms. Or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. k6 and k7 are each independently an integer of 0 to 5. R ^{c1, R} c2, ^R when ^R and ^{R S} is plural respective plurality of ^{R c1,} R c2, ^{R R} and ^{R S} may have respectively the same or different.

Examples of the unsubstituted linear alkyl group represented by R ^{a1 to} R ^a3 , R ^b1 , R ^b2 , R ^c1 and R ^c2 include a methyl group, an ethyl group, an n-propyl group, and n-butyl. Groups and the like.
Examples of the unsubstituted branched alkyl group represented by R ^{a1 to} R ^a3 , R ^b1 , R ^b2 , R ^c1 and R ^c2 include an i-propyl group, an i-butyl group, a sec-butyl group, Examples include t-butyl group.
Examples of the unsubstituted aromatic hydrocarbon group represented by R ^{a1 to} R ^a3 , R ^c1, and R ^c2 include aryl groups such as phenyl group, tolyl group, xylyl group, mesityl group, and naphthyl group; benzyl group And aralkyl groups such as a phenethyl group.
Examples of the unsubstituted aromatic hydrocarbon group represented by R ^b1 and R ^b2 include a phenyl group, a tolyl group, and a benzyl group.

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

R ^{a1 to} R ^a3 , R ^b1 , R ^b2 , R ^c1 and R ^c2 include an unsubstituted linear or branched alkyl group, a fluorinated alkyl group, and an unsubstituted monovalent aromatic hydrocarbon group. , —OSO ₂ —R ″ and —SO ₂ —R ″ are preferred, fluorinated alkyl groups, unsubstituted monovalent aromatic hydrocarbon groups are more preferred, and fluorinated alkyl groups are more preferred. R ″ is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

As k1, k2, and k3 in the formula (X-1), integers of 0 to 2 are preferable, 0 or 1 is more preferable, and 0 is more preferable.
As k4 in the formula (X-2), an integer of 0 to 2 is preferable, 0 or 1 is more preferable, and 1 is more preferable. k5 is preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0.
As k6 and k7 in the formula (X-3), an integer of 0 to 2 is preferable, 0 or 1 is more preferable, and 0 is more preferable.

  Examples of the acid generator represented by the above formula (3) include compounds represented by the following formulas (6-1) to (6-13) (hereinafter, “compounds (6-1) to (6-13)”. ) ")) And the like.

  [C] Among these, the acid generator is preferably an onium salt compound, more preferably a sulfonium salt or a tetrahydrothiophenium salt, and a compound (6-1), a compound (6-2), or a compound (6-12). ) And the compound (6-13) are more preferable.

  The content of the [C] acid generator is as follows. When the [C] acid generator is a [C] acid generator, from the viewpoint of ensuring the sensitivity and developability of the resin composition, [A] 100 mass of the polymer. 0.1 parts by mass or more and 30 parts by mass or less are preferable, 0.5 parts by mass or more and 20 parts by mass or less are more preferable, and 1 part by mass or more and 15 parts by mass or less are more preferable. [B] By making content of an acid generator into the said range, the sensitivity and developability of the said resin composition improve. [B] 1 type (s) or 2 or more types can be used for an acid generator.

<[D] Acid diffusion controller>
The resin composition may contain a [D] acid diffusion controller as necessary.
[D] The acid diffusion controller has the effect of controlling the diffusion phenomenon in the resist film of the acid generated from the [C] acid generator by exposure, and suppressing the undesired chemical reaction in the non-exposed region. The storage stability of the product is further improved, the resolution as a resist is further improved, and the change in the line width of the resist pattern due to fluctuations in the holding time from exposure to development processing can be suppressed, resulting in excellent process stability. A resin composition is obtained. [D] The content of the acid diffusion controller in the resin composition may be a free compound (hereinafter referred to as “[D] acid diffusion controller” as appropriate) or a form incorporated as part of the polymer. However, both forms may be used.

  [D] Examples of the acid diffusion controller include a compound represented by the following formula (7) (hereinafter also referred to as “nitrogen-containing compound (I)”), a compound having two nitrogen atoms in the same molecule (hereinafter referred to as “nitrogen-containing compound (I)”). , “Nitrogen-containing compound (II)”, compounds having three nitrogen atoms (hereinafter also referred to as “nitrogen-containing compound (III)”), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, etc. Can be mentioned.

In the above formula (7), R ¹¹ , R ¹² and R ¹³ are each independently 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 monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine; aromatic amines such as aniline. Can be mentioned.

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

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

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

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

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

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

  Further, as the [D] acid diffusion control agent, a photodisintegratable base that is exposed to light and generates a weak acid by exposure can also be used. Examples of the photodegradable base include an onium salt compound that decomposes upon exposure and loses acid diffusion controllability. Examples of the onium salt compound include a sulfonium salt compound represented by the following formula (8-1), an iodonium salt compound represented by the following formula (8-2), and the like.

In the above formulas (8-1) and (8-2), R ^{14 to} R ¹⁸ are each independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, or a halogen atom. E ⁻ and Q ⁻ are each independently an anion represented by OH ⁻ , R ^β —COO ⁻ , R ^β —SO ₃ ^— or the following formula (5-3). However, R ( ^beta) is an alkyl group, an aryl group, or an aralkyl group.

In the above formula (8-3), R ^19, a part or all of the hydrogen atoms linear or branched alkyl group having 1 to 12 carbon atoms which may be substituted by a fluorine atom, or carbon atoms 1 It is a -12 linear or branched alkoxyl group. u is an integer of 0-2.

  As said photodegradable base, the compound etc. which are represented by a following formula are mentioned, for example.

  Of these, the photodegradable base is preferably a sulfonium salt, more preferably a triarylsulfonium salt, further preferably triphenylsulfonium salicylate, triphenylsulfonium 10-camphor sulfonate, and triphenylsulfonium 10-camphor. Sulfonate is particularly preferred.

  [D] The content of the acid diffusion controller is 0 to 20 parts by mass with respect to 100 parts by mass of the polymer [A] when the [D] acid diffusion controller is a [D] acid diffusion controller. Preferably, 0.1 mass part-15 mass parts are more preferable, and 0.3 mass part-10 mass parts are further more preferable. [D] When the content of the acid diffusion controller exceeds the above upper limit, the sensitivity of the resin composition may decrease.

<[E] polymer>
[E] The polymer is a fluorine atom-containing polymer other than the [A] polymer.

[E] The fluorine atom content of the polymer is preferably 1% by mass or more, more preferably 2% by mass to 60% by mass, further preferably 4% by mass to 40% by mass, and 7% by mass to 30% by mass. Particularly preferred. [E] When the fluorine atom content of the polymer is less than the lower limit, the hydrophobicity of the resist film surface may be lowered. In addition, the fluorine atom content rate (mass%) of a polymer can obtain | require the structure of a polymer by < ¹³ > C-NMR spectrum measurement, and can calculate it from the structure.

  [E] The polymer preferably has at least one selected from the group consisting of the following structural unit (E1) and structural unit (E2). [E] The polymer may have one or more structural units (E1) and structural units (E1).

[Structural unit (E1)]
The structural unit (E1) is a structural unit represented by the following formula (9a). [E] A polymer can adjust a fluorine atom content rate by having a structural unit (E1).

In said formula (9a), ^RD is a hydrogen atom, a methyl group, or a trifluoromethyl group. G is a single bond, an oxygen atom, a sulfur atom, —CO—O—, —SO ₂ —O—NH—, —CO—NH— or —O—CO—NH—. R ^E is a monovalent chain hydrocarbon group having 1 to 6 carbon atoms having at least one fluorine atom or a monovalent aliphatic cyclic hydrocarbon group having 4 to 20 carbon atoms having at least one fluorine atom. It is.

The chain hydrocarbon group having 1 to 6 carbon atoms and having at least one fluorine atom represented by R ^E, for example, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, perfluoroethyl Group, 2,2,3,3,3-pentafluoropropyl group, 1,1,1,3,3,3-hexafluoropropyl group, perfluoro n-propyl group, perfluoro i-propyl group, perfluoro Examples include n-butyl group, perfluoro i-butyl group, perfluoro t-butyl group, 2,2,3,3,4,4,5,5-octafluoropentyl group, perfluorohexyl group and the like.

Examples of the aliphatic cyclic hydrocarbon group having 4 to 20 carbon atoms and having at least one fluorine atom represented by R ^E, for example, monofluoromethyl cyclopentyl group, difluorocyclopentyl groups, perfluorocyclopentyl group, monofluoromethyl cyclohexyl , Difluorocyclopentyl group, perfluorocyclohexylmethyl group, fluoronorbornyl group, fluoroadamantyl group, fluorobornyl group, fluoroisobornyl group, fluorotricyclodecyl group, fluorotetracyclodecyl group and the like.

Examples of the monomer that gives the structural unit (E1) include trifluoromethyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, and 2,2,2-trifluoro. Ethyloxycarbonylmethyl (meth) acrylic acid ester, perfluoroethyl (meth) acrylic acid ester, perfluoro n-propyl (meth) acrylic acid ester, perfluoro i-propyl (meth) acrylic acid ester, perfluoro n-butyl (Meth) acrylic acid ester, perfluoro i-butyl (meth) acrylic acid ester, perfluoro t-butyl (meth) acrylic acid ester, 2- (1,1,1,3,3,3-hexafluoropropyl) (Meth) acrylic acid ester, 1- (2,2,3,3,4,4,5,5-octaful Lopentyl) (meth) acrylic acid ester, perfluorocyclohexylmethyl (meth) acrylic acid ester, 1- (2,2,3,3,3-pentafluoropropyl) (meth) acrylic acid ester, monofluorocyclopentyl (meth) Acrylic acid ester, difluorocyclopentyl (meth) acrylic acid ester, perfluorocyclopentyl (meth) acrylic acid ester, monofluorocyclohexyl (meth) acrylic acid ester, difluorocyclopentyl (meth) acrylic acid ester, perfluorocyclohexylmethyl (meth) acrylic Acid ester, fluoronorbornyl (meth) acrylic acid ester, fluoroadamantyl (meth) acrylic acid ester, fluorobornyl (meth) acrylic acid ester, fluoroisobornyl Meth) acrylic acid esters, fluoro tricyclodecyl (meth) acrylate, fluoro tetracyclododecene decyl (meth) acrylic acid ester.
Among these, 2,2,2-trifluoroethyloxycarbonylmethyl (meth) acrylic acid ester is preferable.

  As a content rate of a structural unit (E1), 5 mol%-95 mol% are preferable with respect to all the structural units which comprise a [E] polymer, 10 mol%-90 mol% are more preferable, 30 mol% More preferred is ~ 85 mol%. By setting such a content ratio, a higher dynamic contact angle on the resist film surface can be expressed at the time of immersion exposure.

[Structural unit (E2)]
The structural unit (E2) is a structural unit represented by the following formula (9b). Since the [E] polymer has the structural unit (E2) and becomes hydrophobic, the dynamic contact angle of the resist film surface formed from the resin composition can be further improved.

In said formula (9b), R < ^F > is a hydrogen atom, a methyl group, or a trifluoromethyl group. R ²⁰ is a (s + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, and an oxygen atom, a sulfur atom, —NR′—, a carbonyl group, —CO—O—, or a terminal at the R ²¹ side of R ²⁰ Also includes a structure in which —CO—NH— is bonded. R ′ is a hydrogen atom or a monovalent organic group. R ²⁰ is a single bond, a divalent chain hydrocarbon group having 1 to 10 carbon atoms, or a divalent aliphatic cyclic hydrocarbon group having 4 to 20 carbon atoms. X ² is a divalent chain hydrocarbon group having 1 to 20 carbon atoms and having at least one fluorine atom. A ¹ is an oxygen atom, —NR ″ —, —CO—O— *, or —SO ₂ —O— *. R ″ is a hydrogen atom or a monovalent organic group. * ^Indicates a binding site that binds to ^{R 20.} R ²² is a hydrogen atom or a monovalent organic group. s is an integer of 1 to 3. However, when s is 2 or 3, a plurality of R ²¹ , X ² , A ¹ and R ²² may be the same or different.

When R ²² is a hydrogen atom, it is preferable in that the solubility of the [E] polymer in an alkaline developer can be improved.

Examples of the monovalent organic group represented by R ²² include an acid-dissociable group, an alkali-dissociable group, or a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent.

  Examples of the structural unit (E2) include structural units represented by the following formulas (9b-1) to (9b-3).

In the above formulas (9b-1) to (9b-3), R ^{20 ′} is a divalent linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms. R ^F , X ² , R ²² and s are as defined in the above formula (9b). When s is 2 or 3, the plurality of X ² and R ²² may be the same or different.

  As a content rate of the said structural unit (9b), 0 mol%-90 mol% are preferable with respect to all the structural units which comprise a [E] polymer, 5 mol%-85 mol% are more preferable, 10 mol % To 80 mol% is more preferable. By setting it as such a content rate, the resist film surface formed from the said resin composition can improve the fall degree of a dynamic contact angle in alkali image development.

[Other structural units]
In addition to the above structural unit, the [E] polymer includes, for example, a structural unit containing at least one structure selected from the group consisting of a structural unit containing an alkali-soluble group, a lactone structure, a cyclic carbonate structure, and a sultone structure. And may have other structural units such as a structural unit containing an alicyclic group. As said alkali-soluble group, a carboxy group, a sulfonamide group, a sulfo group etc. are mentioned, for example. Examples of the structural unit having at least one structure selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure include the structural unit (III) in the above-described [A] polymer.

  As a content rate of said other structural unit, it is 30 mol% or less normally with respect to all the structural units which comprise a [E] polymer, and 20 mol% or less is preferable. If the content ratio of the other structural unit exceeds the upper limit, the pattern forming property of the resin composition may be deteriorated.

  As content of the [E] polymer in the said resin composition, 0-20 mass parts is preferable with respect to 100 mass parts of [A] polymer, 0.5 mass part-15 mass parts are more preferable, 1 mass part-10 mass parts are further more preferable. [E] When the content of the polymer exceeds the above upper limit, the pattern forming property of the resin composition may be lowered.

<[F] polymer>
The [F] polymer is a polymer having a structural unit containing an acid dissociable group having a fluorine atom content smaller than that of the [A] polymer. The resin composition preferably contains a [F] polymer as a base polymer when the [A] polymer is used as a water-repellent polymer additive ([A2] polymer). As [F] polymer, what has structural unit (II) and structural unit (III) in [A] polymer is preferable, and you may have structural unit (IV)-(VI).

As a content rate of the said structural unit (II), 20 mol%-80 mol% are preferable with respect to all the structural units which comprise a [F] polymer, and 30 mol%-70 mol% are more preferable.
As a content rate of the said structural unit (III), 20 mol%-70 mol% are preferable with respect to all the structural units which comprise a [F] polymer, and 30 mol%-60 mol% are more preferable.
The content ratio of the structural units (IV) to (VI) is preferably 0 mol% to 40 mol%, more preferably 10 mol to 30 mol%, based on all the structural units constituting the [F] polymer. preferable.

  [F] The Mw of the polymer is preferably 1,000 or more and 50,000 or less, more preferably 2,000 or more and 30,000 or less, further preferably 3,000 or more and 20,000 or less, and 5,000 or more and 15 or less. Is particularly preferred.

  [F] The Mw / Mn of the polymer is usually 1 or more and 5 or less, preferably 1 or more and 3 or less, and more preferably 1 or more and 2 or less.

<Other optional components>
The resin composition may contain other optional components in addition to the components [A] to [F]. Examples of the other optional components include uneven distribution accelerators, surfactants, alicyclic skeleton-containing compounds, and sensitizers. Each of these other optional components may be used alone or in combination of two or more.

[Uneven distribution promoter]
When the resin composition (A) contains a water-repellent polymer additive as the [A] polymer and / or [E] polymer, the uneven distribution accelerator is more suitable for this water-repellent polymer additive. It has the effect of efficiently segregating on the resist film surface. By adding this uneven distribution promoter to the resin composition, the amount of the water-repellent polymer additive added can be reduced as compared with the conventional case. Therefore, it is possible to further suppress the elution of components from the resist film to the immersion liquid without impairing the resolution, LWR performance, and defect suppression, or to perform immersion exposure at a higher speed by high-speed scanning. As a result, it is possible to improve the hydrophobicity of the resist film surface that suppresses immersion-derived defects such as watermark defects. Examples of such an uneven distribution promoter include low molecular compounds having a relative dielectric constant of 30 or more and 200 or less and a boiling point at 1 atm of 100 ° C. or more. Specific examples of such compounds include lactone compounds, carbonate compounds, nitrile compounds, and polyhydric alcohols.

Examples of the lactone compound include γ-butyrolactone, valerolactone, mevalonic lactone, norbornane lactone, and the like.
Examples of the carbonate compound include propylene carbonate, ethylene carbonate, butylene carbonate, vinylene carbonate, and the like.
Examples of the nitrile compound include succinonitrile.
Examples of the polyhydric alcohol include glycerin.

  The content of the uneven distribution accelerator is preferably 10 parts by weight to 500 parts by weight, more preferably 15 parts by weight to 300 parts by weight, and 20 parts by weight with respect to 100 parts by weight of the total amount of the polymer in the resin composition. -200 mass parts is further more preferable, and 25 mass parts-100 mass parts is especially preferable.

(Surfactant)
Surfactants have the effect of improving coatability, striation, developability, and the like. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol diacrylate. Nonionic surfactants such as stearate; commercially available products include KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (above, manufactured by Kyoeisha Chemical Co., Ltd.), F-top EF301, EF303, EF352 (above, manufactured by Tochem Products), MegaFuck F171, F173 (above, manufactured by DIC), Florard FC430, FC431 (above, Sumitomo 3M) Manufactured by Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (above, manufactured by Asahi Glass Industrial Co., Ltd.) Can be mentioned. As content of surfactant in the said resin composition, it is 2 mass parts or less normally with respect to 100 mass parts of [A] polymers.

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

Examples of the alicyclic skeleton-containing compound include:
Adamantane derivatives such as 1-adamantanecarboxylic acid, 2-adamantanone, 1-adamantanecarboxylate t-butyl;
Deoxycholic acid esters such as t-butyl deoxycholate, t-butoxycarbonylmethyl deoxycholic acid, 2-ethoxyethyl deoxycholic acid;
Lithocholic acid esters such as t-butyl lithocholic acid, t-butoxycarbonylmethyl lithocholic acid, 2-ethoxyethyl lithocholic acid;
3- [2-Hydroxy-2,2-bis (trifluoromethyl) ethyl] tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodecane, 2-hydroxy-9-methoxycarbonyl-5-oxo-4-oxa-tricyclo [4.2.1.0 ^3,7 ] nonane, and the like. As content of the alicyclic frame | skeleton containing compound in the said resin composition, it is 5 mass parts or less normally with respect to 100 mass parts of [A] polymers.

(Sensitizer)
The sensitizer exhibits an action of increasing the amount of acid generated from the [C] acid generator or the like, and has an effect of improving the “apparent sensitivity” of the resin composition.

  Examples of the sensitizer include carbazoles, acetophenones, benzophenones, naphthalenes, phenols, biacetyl, eosin, rose bengal, pyrenes, anthracenes, phenothiazines, and the like. These sensitizers may be used alone or in combination of two or more. As content of the sensitizer in the said resin composition, it is 2 mass parts or less normally with respect to 100 mass parts of [A] polymers.

<Method for preparing resin composition>
The resin composition can be prepared, for example, by mixing a [A] polymer, an optional component contained as necessary, and a [B] solvent at a predetermined ratio. The resin composition is preferably filtered, for example, with a filter having a pore size of about 0.2 μm after mixing. As solid content concentration of the said resin composition, it is 0.1 mass%-50 mass% normally, 0.5 mass%-30 mass% are preferable, and 1 mass%-20 mass% are more preferable.

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

Further, the resist pattern forming method using the resin composition (B) (hereinafter also referred to as “resist pattern forming method (B)”)
A step of forming a resist film (hereinafter also referred to as a “resist film forming step”),
A step of laminating a protective film on the resist film (hereinafter also referred to as “protective film laminating step”),
A step of immersion exposure of the resist film on which the protective film is laminated (hereinafter also referred to as “immersion exposure step”), and a step of developing the resist film subjected to immersion exposure (hereinafter also referred to as “development step”). )
With
The protective film is formed from the resin composition.

  According to the resist pattern forming method, since the resin composition described above is used, LWR and CDU are small, resolution is high, and the cross-sectional shape is excellent while exhibiting excellent depth of focus, exposure margin, and MEEF performance. A resist pattern having excellent rectangularity can be formed. Hereinafter, each process of each resist pattern formation method is demonstrated.

<Resist pattern formation method (A)>
[Resist film forming step]
In this step, a resist film is formed from the resin composition. Examples of the substrate on which the resist film is formed include conventionally known ones such as a silicon wafer, silicon dioxide, and a wafer coated with aluminum. Further, for example, an organic or inorganic antireflection film disclosed in Japanese Patent Publication No. 6-12452, Japanese Patent Application Laid-Open No. 59-93448, or the like may be formed on the substrate. Examples of the application method include spin coating (spin coating), cast coating, roll coating, and the like. After application, pre-baking (PB) may be performed as needed to volatilize the solvent in the coating film. As PB temperature, it is 60 to 140 degreeC normally, and 80 to 120 degreeC is preferable. The PB time is usually 5 seconds to 600 seconds, and preferably 10 seconds to 300 seconds. The thickness of the resist film to be formed is preferably 10 nm to 1,000 nm, and more preferably 10 nm to 500 nm.

[Exposure process]
In this step, exposure is performed by irradiating the resist film formed in the resist film forming step with exposure light through a photomask or the like (in some cases through an immersion medium such as water). As the exposure light, depending on the line width of the target pattern, for example, visible rays, ultraviolet rays, far ultraviolet rays, extreme ultraviolet rays (EUV), electromagnetic waves such as X-rays and γ rays; charged particles such as electron rays and α rays Examples include lines. Among these, far ultraviolet rays, EUV, and electron beams are preferable, ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), EUV, and electron beams are more preferable, and ArF excimer laser light, EUV, and electron beams are preferable. Further preferred.

  When exposure is performed by immersion exposure, examples of the immersion liquid to be used include water and a fluorine-based inert liquid. The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient that is as small as possible so as to minimize distortion of the optical image projected onto the film. In the case of excimer laser light (wavelength 193 nm), it is preferable to use water from the viewpoints of availability and easy handling in addition to the above-described viewpoints. When water is used, an additive that reduces the surface tension of water and increases the surface activity may be added in a small proportion. This additive is preferably one that does not dissolve the resist film on the wafer and can ignore the influence on the optical coating on the lower surface of the lens. The water used is preferably distilled water.

  After the exposure, post-exposure baking (PEB) is performed, and in the exposed portion of the resist film, dissociation of the acid-dissociable group of the [A] polymer or the like by the acid generated from the [C] acid generator by exposure. Is preferably promoted. This PEB causes a difference in solubility in the developer between the exposed area and the unexposed area. As PEB temperature, it is 50 to 180 degreeC normally, and 80 to 130 degreeC is preferable. The PEB time is usually 5 seconds to 600 seconds, and preferably 10 seconds to 300 seconds.

[Development process]
In this step, the resist film exposed in the exposure step is developed. Thereby, a predetermined resist pattern can be formed. After development, it is common to wash with water or a rinse solution such as alcohol and then dry.

As a developer used for the above development,
In the case of alkali development, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine , Ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4 .3.0] -5 aqueous solution in which at least one alkaline compound such as 5-nonene is dissolved. Among these, a TMAH aqueous solution is preferable, and a 2.38 mass% TMAH aqueous solution is more preferable.
In the case of organic solvent development, organic solvents such as hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, alcohol solvents, etc., or solvents containing organic solvents can be mentioned. As said organic solvent, 1 type, 2 or more types, etc. of the solvent enumerated as [B] solvent of the above-mentioned resin composition are mentioned, for example. Among these, ester solvents and ketone solvents are preferable. As the ester solvent, an acetate solvent is preferable, and n-butyl acetate is more preferable. As the ketone solvent, a chain ketone is preferable, and 2-heptanone is more preferable. As content of the organic solvent in a developing solution, 80 mass% or more is preferable, 90 mass% or more is more preferable, 95 mass% or more is further more preferable, 99 mass% or more is especially preferable. Examples of components other than the organic solvent in the developer include water and silicone oil.

  As a development method, for example, a method in which a substrate is immersed in a tank filled with a developer for a certain period of time (dip method), a method in which the developer is raised on the surface of the substrate by surface tension and is left stationary for a certain time (paddle) Method), a method of spraying the developer on the substrate surface (spray method), a method of continuously applying the developer while scanning the developer application nozzle at a constant speed on a substrate rotating at a constant speed (dynamic dispensing method) ) And the like.

<Resist pattern formation method (B)>
[Resist film forming step]
In this step, a resist film is formed. This resist film is formed by, for example, a radiation-sensitive resin composition containing a polymer having a structural unit containing an acid-dissociable group and a radiation-sensitive acid generator. Examples of the method for forming this resist film include the same method as in the resist film forming step in the above “resist pattern forming method (A)”.

[Protective film lamination process]
In this step, a protective film is laminated on the resist film formed in the resist film forming step. Examples of the method for applying the resin composition (B) include the same method as the method for applying the resin composition (A) in the resist film forming step of the resist pattern forming method (A). In this step, it is preferable to perform pre-baking (PB) after applying the resin composition (B). By forming a protective film on the resist film, the immersion liquid and the resist film are not in direct contact with each other, so that the lithography performance of the resist film is reduced due to the immersion liquid penetrating the resist film, Contamination of the lens of the projection exposure apparatus due to components eluted from the resist film into the immersion liquid is effectively suppressed.

  The thickness of the protective film to be formed is preferably as close as possible to an odd multiple of λ / 4m (λ: wavelength of radiation, m: refractive index of the protective film). By doing in this way, the reflection suppression effect in the upper interface of a resist film can be enlarged.

[Immersion exposure process]
In this step, the resist film on which the protective film formed in the protective film laminating step is laminated is subjected to immersion exposure. This immersion exposure is performed by placing an immersion liquid on the laminated protective film and exposing through the immersion liquid.

  Examples of the immersion liquid, the exposure light used, and the immersion exposure method include those similar to the immersion exposure in the exposure step of the resist pattern forming method (A).

  After the immersion exposure, post-exposure baking (PEB) is preferably performed in order to improve the resolution, pattern shape, developability, and the like of the resulting resist pattern. Although it can set suitably as a PEB temperature according to the kind etc. of the radiation sensitive resin composition and resin composition (B) to be used, it is 30 to 200 degreeC normally, and 50 to 150 degreeC is preferable. . The PEB time is usually 5 seconds to 600 seconds, and preferably 10 seconds to 300 seconds.

[Development process]
In this step, the resist film subjected to the immersion exposure in the immersion exposure step is developed. Thereby, a predetermined resist pattern can be formed. Examples of the method for performing this step include the same methods as those in the development step of the above-described resist pattern forming method (A).

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, each measurement in an Example and a comparative example was performed with the following method.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)]
Using GPC columns (two "G2000HXL", one "G3000HXL", one "G4000HXL" from Tosoh Corporation), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, sample concentration: 1.0 mass%, sample Injection amount: 100 μL, column temperature: 40 ° C., detector: measured by GPC (Gel Permeation Chromatography) using monodisperse polystyrene as a standard under the analysis conditions of a differential refractometer. The degree of dispersion (Mw / Mn) was calculated from the measurement results of Mw and Mn.

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

<Synthesis of compounds>
[Synthesis Example 1] (Synthesis of Compound (M-1))
A compound represented by the following formula (Mc) is reacted with a bromo compound represented by the following formula (Mb) in the presence of triethylamine in a solvent to obtain a compound represented by the following formula (Mc). It was. The compound (Mc) and the bromo compound represented by the following formula (Md) were reacted in the presence of zinc to synthesize the compound (M-1). Next, the compound represented by the following formula (M-1) was obtained by purification with a column chromatograph.

[Synthesis Examples 2 to 21] (Synthesis of Compounds (M-2) to (M-21))
By appropriately selecting a precursor and performing the same operation as in Synthesis Example 1, compounds represented by the following formulas (M-2) to (M-21) were synthesized.

<Synthesis of polymer>
[Synthesis of [A] polymer, [E] polymer, [F] polymer and [H] polymer]
[A] As a polymer, [A1] used as a base polymer, [A2] used as a water-repellent polymer additive, and used as a protective film forming composition for immersion exposure [A3] [E] polymer used as a polymer, water-repellent polymer additive, [F] polymer used as a base polymer, and [H] polymer used as a protective film forming composition for immersion exposure Synthesized.
The monomers used in the synthesis of polymers other than the synthesized compounds (M-2) to (M-21) are shown below.

[Synthesis of [A1] polymer and [F] polymer]
[Synthesis Example 1]
The above compound (M-1) 3.05 g (10 mol%), compound (MP-1) 9.21 g (55 mol%) and compound (ML-2) 7.74 g (35 mol%) were converted into 2-butanone 40 g. A monomer solution was prepared by adding 0.82 g of AIBN (5 mol% based on the total amount of compounds) as a radical polymerization initiator. Next, a 100 mL three-necked flask containing 20 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80 ° C. with stirring, and the prepared monomer solution was added dropwise over 3 hours using a dropping funnel. The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water and cooled to 30 ° C. or lower. The polymerization solution cooled in 400 g of methanol was added, and the precipitated white powder was separated by filtration. The filtered white powder was washed twice with 80 g of methanol, filtered, and dried at 50 ° C. for 17 hours to synthesize a white powdery polymer (A1-1) (yield 74%). Mw of the polymer (A1-1) was 7,300, Mw / Mn was 1.53, and the content of the low molecular weight component was 0.04% by mass. Moreover, as a result of ¹³ C-NMR analysis, the content ratio of each structural unit derived from (M-1), (MP-1) and (ML-2) was 9.5 mol% and 55.1 mol%, respectively. And 35.4 mol%.

[Synthesis Examples 2-36]
Polymers (A1-2) to (A1-35) and (F-1) are obtained by performing the same operations as in Synthesis Example 1 except that the types and amounts of monomers shown in Table 1 below are used. Was synthesized. “-” In Table 1 indicates that the corresponding monomer was not used. The total mass of the monomers used was 20 g.

[Synthesis of [A2] polymer and [E] polymer]
[Synthesis Example 37]
41.86 g (30 mol%) of the compound (M-1) and 58.14 g (70 mol%) of the compound (MP-2) are dissolved in 100 g of 2-butanone, and dimethyl 2 as a radical polymerization initiator is further dissolved. A monomer solution was prepared by dissolving 3.05 g of 2,2′-azobisisobutyrate. Next, a 1,000 mL three-necked flask containing 100 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80 ° C. with stirring, and the monomer solution prepared above was added dropwise over 3 hours using a dropping funnel. . The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water and cooled to 30 ° C. or lower. The reaction solution was transferred to a 2 L separatory funnel, and then the polymerization solution was uniformly diluted with 150 g of n-hexane, and 600 g of methanol was added and mixed. Next, 30 g of distilled water was added, and the mixture was further stirred and allowed to stand for 30 minutes. Thereafter, the lower layer was recovered to obtain a propylene glycol monomethyl ether acetate solution containing the polymer (A2-1) as a solid content (yield 64%). Mw of the polymer (A2-1) was 7,000, Mw / Mn was 1.99, and the content of the low molecular weight component was 0.05% by mass. As a result of ¹³ C-NMR analysis, the content ratio of each structural unit derived from (M-1) and (MP-2) was 29.9 mol% and 70.1 mol%, respectively.

[Synthesis Examples 38 to 52]
Polymers (A2-2) to (A2-15) and (E-1) are obtained by performing the same operations as in Synthesis Example 37 except that the types and amounts of monomers shown in Table 2 below are used. Was synthesized. “-” In Table 2 indicates that the corresponding monomer was not used. The total mass of the monomers used was 100 g.

[Synthesis of [A3] polymer and [H] polymer]
[Synthesis Example 53] (Synthesis of Polymer (A3-1))
45.80 g (50 mol%) of the compound (M-1) and 54.20 g (50 mol%) of the compound (MF-3) are dissolved in 100 g of 2-butanone, and dimethyl 2, as a radical polymerization initiator, is dissolved. A monomer solution was prepared by further dissolving 2.46 g of 2′-azobisisobutyrate. Next, a 1,000 mL three-necked flask containing 100 g of 2-butanone was purged with nitrogen for 30 minutes, and then heated to 80 ° C. with stirring, and the monomer solution prepared above was added dropwise over 3 hours using a dropping funnel. . The dripping start was set as the polymerization reaction start time, and the polymerization reaction was carried out for 6 hours. After completion of the polymerization reaction, the polymerization solution was cooled with water and cooled to 30 ° C. or lower. The reaction solution was transferred to a 2 L separatory funnel, and then the polymerization solution was uniformly diluted with 150 g of n-hexane, and 600 g of methanol was added and mixed.
Next, 30 g of distilled water was added, and the mixture was further stirred and allowed to stand for 30 minutes. Thereafter, the lower layer was recovered to obtain a propylene glycol monomethyl ether acetate solution containing a polymer (A3-1) as a solid content (yield 74%). Mw of the polymer (A3-1) was 9,900, Mw / Mn was 1.72, and the content of the low molecular weight component was 0.05% by mass. As a result of ¹³ C-NMR analysis, the content ratio of each structural unit derived from (M-1) and (MF-3) was 50.2 mol% and 49.8 mol%, respectively.

[Synthesis Examples 54 to 75]
Polymers (A3-2) to (A3-21) and (H-1) were prepared by carrying out the same operations as in Synthesis Example 1 except that the types and amounts used of the monomers shown in Table 3 below were used. ) And (H-2) were synthesized. “-” In Table 3 indicates that the corresponding monomer was not used. The total mass of the monomers used was 100 g.

<Preparation of resin composition>
[B] Solvent, [C] acid generator, [D] acid diffusion controller and [G] uneven distribution accelerator used for the preparation of the resin composition are shown below.

[[B] solvent]
B-1: Propylene glycol monomethyl ether acetate B-2: Cyclohexanone B-3: 4-Methyl-2-pentanol B-4: Diisoamyl ether

[[C] acid generator]
Each structural formula is shown below.
C-1: Triphenylsulfonium 2- (adamantan-1-ylcarbonyloxy) -1,1,3,3,3-pentafluoropropane-1-sulfonate C-2: Triphenylsulfonium norbornane sultone-2-yloxy Carbonyl difluoromethanesulfonate C-3: Triphenylsulfonium 3- (piperidin-1-ylsulfonyl) -1,1,2,2,3,3-hexafluoropropane-1-sulfonate C-4: Triphenylsulfonium adamantane- 1-yloxycarbonyldifluoromethanesulfonate

[[D] acid diffusion controller]
Each structural formula is shown below.
D-1: Triphenylsulfonium salicylate D-2: Triphenylsulfonium 10-camphorsulfonate D-3: N- (n-undecan-1-ylcarbonyloxyethyl) morpholine D-4: 2,6-dii -Propylaniline D-5: Tri-n-pentylamine

[[G] uneven distribution promoter]
G-1: γ-butyrolactone

[Preparation of Resin Composition (A)]
(Resin Composition (J1): Preparation of ArF Exposure Resin Composition (A) Containing [A1] Polymer as Base Polymer and [A2] Polymer as Water-Repellent Polymer Additive [Example 1]
[A] (A1-1) 100 parts by mass as a polymer, [B] (B-1) 2,240 parts by mass and (B-2) 960 parts by mass as a solvent, [C] as an acid generator (C-1) 8.5 parts by mass, [D] 2.3 parts by mass (D-1) as an acid diffusion controller, (E-1) 3 parts by mass as a polymer, and [G A resin composition (J1-1) was prepared by mixing 30 parts by mass of (G-1) as an uneven distribution accelerator and filtering with a membrane filter having a pore size of 0.2 μm.

[Examples 2 to 37 and Comparative Example 1]
Resin compositions (J1-2) to (J1-37) and (CJ-1) were prepared in the same manner as in Example 1 except that the components of the types and blending amounts shown in Table 4 below were used. did.

(Resin composition (J2): Preparation of resin composition (A) for EUV and electron beam exposure containing [A1] polymer as a base polymer)
[Example 38]
[A1] 100 parts by mass of (A1-1) as a polymer, (B-1) 4,280 parts by mass and (B-2) 1,830 parts by mass of [B] solvent, [C] acid generator (C-1) 20 parts by mass and [D] acid diffusion controller (D-1) 3.6 parts by mass are mixed and filtered through a membrane filter having a pore size of 0.2 μm to obtain a resin composition (J2 -1) was prepared.

[Examples 39 to 76 and Comparative Example 2]
Resin compositions (J2-2) to (J2-39) and (CJ-2) were prepared in the same manner as in Example 38 except that the components of the types and blending amounts shown in Table 5 below were used. did.

[Preparation of Resin Composition (B) (Protective Film-Forming Resin Composition for Immersion Exposure)]
(Resin Composition (J3): Preparation of Resin Composition (B) Containing [A3] Polymer)
[Example 77]
[A3] 50 parts by mass of (A3-1) as a polymer, 50 parts by mass of (H-2) as a [H] polymer, and (B-3) 1,000 parts by mass of a solvent as a solvent. (B-4) A resin composition (J3-1) was prepared by blending 4,000 parts by mass and filtering through a membrane filter having a pore size of 0.2 μm.

[Examples 78 to 99 and Comparative Example 3]
Resin compositions (J3-2) to (J3-23) and (CJ-3) were prepared in the same manner as in Example 77 except that the components of the types and blending amounts shown in Table 6 below were used. did.

(Preparation of radiation-sensitive resin composition in the case of using resin composition (B) (protective film-forming resin composition for immersion exposure))
[Synthesis Example 76]
[F] 100 parts by mass of (F-1) as a polymer, [B-1] 2,240 parts by mass and (B-2) 960 parts by mass of a solvent, [C] as an acid generator (C-1) 8.5 parts by mass, [D] 2.3 parts by mass of (D-1) acid diffusion controller and [G] 30 parts by mass of (G-1) as an uneven distribution promoter And the radiation sensitive resin composition (a) was prepared by filtering with a membrane filter with the hole diameter of 0.2 micrometer.

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

[Formation of resist pattern (2)]
[Resist pattern formation (1)], except that in [Resist pattern formation (1)], organic solvent development was performed using n-butyl acetate instead of TMAH aqueous solution, and washing with water was not performed. In the same manner as described above, a negative resist pattern was formed.

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

(In the case of ArF exposure using the resin composition (B))
[Formation of resist pattern (4)]
A 12-inch silicon wafer surface was coated with a composition for forming a lower antireflection film (“ARC66” from Brewer Science Co., Ltd.) using a spin coater (“CLEAN TRACK ACT12” from Tokyo Electron), and then 205 ° C. Was heated for 60 seconds to form a lower antireflection film having a thickness of 105 nm. On the lower antireflection film, the prepared radiation sensitive resin composition (a) was applied using the spin coater, and PB was performed at 90 ° C. for 60 seconds. Then, it cooled at 23 degreeC for 30 second, and formed the resist film with a film thickness of 90 nm. Next, the resin composition (B) prepared above was applied onto the resist film, and PB was performed at 90 ° C. for 60 seconds to form a resist upper film having a thickness of 30 nm. Next, this resist film was subjected to an optical condition of NA = 1.3 and dipole (Sigma 0.977 / 0.782) using an ArF excimer laser immersion exposure apparatus (“NSR-S610C” manufactured by NIKON). , Exposed through a 40 nm line and space (1L1S) mask pattern. After the exposure, PEB was performed at 90 ° C. for 60 seconds. Thereafter, alkali development was performed using a 2.38% by mass TMAH aqueous solution as an alkali developer, washed with water, and dried to form a positive resist pattern. When this resist pattern is formed, the line width formed through a one-to-one line and space mask having a target dimension of 40 nm is defined as an optimum exposure amount. did.

<Evaluation>
About the resist pattern formed using the said resin composition, by measuring by the following method, LWR performance about a resin composition, CDU performance, resolution, rectangularity of a cross-sectional shape, depth of focus, exposure margin, and MEEF performance was evaluated. In addition to the above, the resin composition (B) was also evaluated for composition stability, upper layer removability, elution amount, peeling resistance, blob defect, and bridge defect. The evaluation results are shown in Tables 7-9. A scanning electron microscope (Hitachi High-Technologies “S-9380”) was used for measuring the resist pattern. In addition, the comparative example used as the criterion in LWR performance, CDU performance, resolution, depth of focus, exposure margin, and MEEF performance is Comparative Example 1 for Examples 1 to 37, and Comparative Example 2 for Examples 38 to 76. Examples 77 to 99 are Comparative Example 3.

[LWR performance]
The resist pattern formed by irradiating the exposure amount of Eop was observed from above the pattern using the scanning electron microscope. A total of 50 line widths were measured at arbitrary points, and a 3-sigma value was obtained from the distribution of the measured values, and this was defined as LWR performance. The LWR performance indicates that the smaller the value, the smaller the backlash of the line. When the LWR performance is 10% or more (LWR performance is 90% or less) when compared with the comparative example, the LWR performance is “good” and less than 10% (LWR performance is improved). When the value was over 90%), it was evaluated as “bad”.

[CDU performance]
The resist pattern formed by irradiating the exposure amount of Eop was observed from above the pattern using the scanning electron microscope. The line width is measured at 20 points in the range of 400 nm, the average value is obtained, the average value is measured at a total of 500 points, and the 3 sigma value is obtained from the distribution of the measured values, which is taken as the CDU performance. . The CDU performance indicates that the smaller the value, the smaller the line width variation in a long cycle. When the CDU performance is improved by 10% or more (the CDU performance value is 90% or less) when the value is compared with that of the comparative example, the improvement is less than 10% (the CDU performance is improved). When the value was over 90%), it was evaluated as “bad”.

[Resolution]
The dimension of the minimum resist pattern resolved by irradiating the exposure amount of Eop was measured, and this measured value was defined as the resolution. The resolution indicates that the smaller the value, the better the pattern can be formed. When the resolution is 10% or more when the value is compared with that of the comparative example (resolution value is 90% or less), “good” and less than 10% (solution) In the case of an image quality value of more than 90%, it was evaluated as “bad”.

[Rectangularity of the cross-sectional shape]
The cross-sectional shape of the resist pattern resolved by irradiating the exposure amount of Eop was observed, and the line width Lb in the middle in the height direction of the resist pattern and the line width La in the upper part of the resist pattern were measured. The rectangularity of the cross-sectional shape indicates that the closer the value is to 1, the more the resist pattern may be rectangular. The rectangularity of the cross-sectional shape is “good” when 0.9 ≦ (La / Lb) ≦ 1.1, and (La / Lb) <0.9 or 1.1 <(La / Lb). The case was evaluated as “bad”.

[Depth of focus]
In the resist pattern resolved by irradiating the exposure amount of Eop, the dimension when the focus is changed in the depth direction is observed, and the pattern dimension is 90% to 110% of the reference without any bridge or residue. The depth of entry in the depth direction was measured, and this measured value was defined as the depth of focus. The larger the value of the focal depth, the smaller the variation in the dimension of the pattern obtained when the focal position varies, and the higher the yield during device fabrication. Depth of focus is 10% or better when the value is compared with that of the comparative example (depth of focus is 110% or more), and better than 10% (depth of focus is less than 110%). ) Was evaluated as “bad”.

[Exposure margin]
In the range of the exposure amount including the Eop, the exposure amount was changed every 1 mJ / cm ² to form resist patterns, respectively, and the respective line widths were measured using the scanning electron microscope. From the relationship between the obtained line width and exposure amount, an exposure amount E (44) at which the line width becomes 44 nm and an exposure amount E (36) at which the line width becomes 36 nm are obtained, and exposure margin = (E (36) The exposure margin (%) was calculated from the equation: −E (44)) × 100 / (optimum exposure amount). The larger the value of the exposure margin, the smaller the variation in the dimension of the pattern obtained when the exposure amount fluctuates, and the higher the yield during device fabrication. When the exposure margin is 10% or more when the value is compared with that of the comparative example (exposure margin is 110% or more), it is “good” and less than 10% (exposure). When the margin value was less than 110%, it was evaluated as “bad”.

[MEEF performance]
In the resist pattern that is resolved by irradiating with the exposure amount of Eop, the line width of the resist pattern formed by using the mask pattern having the line widths of 51 nm, 53 nm, 55 nm, 57 nm, and 59 nm is plotted on the vertical axis. The slope of the straight line when the pattern size was plotted on the horizontal axis was calculated, and this was taken as the MEEF performance. The MEEF performance indicates that the closer the value is to 1, the better the mask reproducibility. When the MEEF performance is 10% or more when the value is compared with that of the comparative example (MEEF performance value is 90% or less), the MEEF performance is less than 10% (MEEF performance is improved). When the value was over 90%), it was evaluated as “bad”.

[Composition stability]
The presence or absence of white turbidity of the protective film-forming resin composition for immersion exposure over time was evaluated. After stirring the protective film-forming resin composition for immersion exposure for 30 minutes, the presence or absence of cloudiness was visually observed. The composition stability was evaluated as “good” when no white turbidity was observed, and “bad” when white turbidity was observed.

[Protective film removal]
The removability of the protective film for immersion exposure with an alkaline developer was evaluated. A coating film forming composition for immersion exposure is spin-coated on an 8-inch silicon wafer with a coating / developing apparatus (“CLEAN TRACK ACT8” manufactured by Tokyo Electron Ltd.), PB is performed at 90 ° C. for 60 seconds, and the film thickness is 90 nm. A protective film for immersion exposure was formed. The film thickness was measured using a film thickness measuring device ("Lambda Ace VM90" manufactured by Dainippon Screen). This immersion exposure protective film was subjected to paddle development for 60 seconds using a 2.38 mass% TMAH aqueous solution as a developer in the coating / developing apparatus, spin-dried by shaking, and the wafer surface was observed. At this time, the protective film removability was evaluated as “good” when no residue was observed and “bad” when the residue was observed.

[Elution volume]
The elution amount of the resist film component from the resist film on which the protective film for immersion exposure was formed was evaluated. At the center of an 8-inch silicon wafer that has been subjected to hexamethyldisilazane (HMDS) treatment (100 ° C. for 60 seconds) with the above coating / development apparatus, the center is a square with a thickness of 1.0 mm and a side of 30 cm. A silicon rubber sheet (Kureha Elastomer Co., Ltd.) cut into a 11.3 cm circular shape was placed. Next, 10 mL of ultrapure water was filled in the hollowed out portion at the center of the silicon rubber using a 10 mL hole pipette.

  On the other hand, an 8-inch silicon wafer different from the 8-inch silicon wafer, in which a lower antireflection film, a resist film, and a protective film are formed in advance, is prepared, and the upper-layer film is on the silicon rubber sheet side. In other words, the substrate was placed so that the ultrapure water did not leak while contacting the protective film for immersion exposure and the ultrapure water.

  The lower antireflection film, resist film, and protective film were formed on an 8-inch silicon wafer as follows. First, a composition for an underlayer antireflection film (“ARC29A” from Brewer Science Co., Ltd.) was applied using “CLEAN TRACK ACT8” so as to form a coating film having a thickness of 77 nm. Next, the prepared radiation sensitive resin composition (a) is spin-coated on the lower antireflection film using the CLEAN TRACK ACT8 and baked at 115 ° C. for 60 seconds to form a resist film having a thickness of 205 nm. Formed. Then, the prepared protective film forming composition for immersion exposure was applied onto the resist film to form a protective film.

  After placing the protective film for immersion exposure, it was kept in that state for 10 seconds. Thereafter, the other 8-inch silicon wafer was removed, and ultrapure water was collected with a glass syringe, which was used as a sample for analysis. Note that the recovery rate of ultrapure water after the experiment was 95% or more.

Subsequently, the peak intensity of the anion part of the radiation-sensitive acid generator in the recovered ultrapure water was measured using an LC-MS liquid chromatograph mass spectrometer (LC part: SERIES1100 AGILENT, MS part: Mariner Perceptive Biosystems, Inc.). Was measured under the following measurement conditions. At that time, create a calibration curve by measuring the peak intensity of the 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the radiation sensitive acid generator used in the above radiation sensitive resin composition (a) under the following measurement conditions. Using this calibration curve, the elution amount was calculated from the peak intensity. Similarly, each peak intensity of the 1 ppb, 10 ppb, and 100 ppb aqueous solutions of the acid diffusion control agent is measured under the following measurement conditions to create a calibration curve, and the calibration curve is used to calculate the acid diffusion control agent from the peak intensity. The amount of elution was calculated. The elution suppression property is “good” when the elution amount is 5.0 × 10 ⁻¹² mol / cm ² or less, and “elution suppression” when the elution amount is larger than 5.0 × 10 ⁻¹² mol / cm ^2. “Bad”.

(Measurement condition)
Column used: (Shiseido's “CAPCELL PAK MG”)
Flow rate: 0.2 mL / min Elution solvent: Water / methanol (3/7) with 0.1% by weight of formic acid Column temperature: 35 ° C.

[Peeling resistance]
The difficulty of peeling off the protective film for immersion exposure from the substrate was evaluated. As the substrate, an 8-inch silicon wafer not subjected to HMDS treatment was used. A coating film (resist upper layer film) with a film thickness of 30 nm is formed on the substrate by spin-coating the protective film-forming resin composition for immersion exposure using the coating / developing apparatus and performing PB at 90 ° C. for 60 seconds. did. Thereafter, rinsing with pure water was performed for 60 seconds in the coating / developing apparatus, followed by drying by shaking. The peel resistance was evaluated as “bad” by visual observation when peeling of the protective film for immersion exposure was observed on the entire wafer surface after rinsing, and “good” when peeling was observed only at the edge portion.

[Blob defect]
The number of occurrences of blob defects in the resist pattern obtained by developing the resist film on which the protective film for immersion exposure was developed was measured. A 12-inch silicon wafer subjected to hexamethyldisilazane (HMDS) treatment at 100 ° C. for 60 seconds was prepared using a coating / developing apparatus (“Lithius Pro-i” manufactured by Tokyo Electron Ltd.). The 12-inch silicon wafer was spin-coated with the radiation sensitive resin composition (a), and PB was performed on a hot plate at 100 ° C. for 60 seconds to form a resist film having a thickness of 100 nm. The prepared protective film-forming resin composition for immersion exposure is spin-coated on this resist film, and PB is applied at 90 ° C. for 60 seconds or 110 ° C. for 60 seconds to form a coating film (protective film) having a thickness of 30 nm. did. Then, it exposed through the frosted glass in which the pattern is not formed. Using the exposed 8-inch silicon wafer, blob defects were evaluated in the following procedure.

  First, ultra-pure water was discharged from the rinse nozzle of “CLEAN TRACK ACT8” for 60 seconds on the upper layer film of the above-described 8-inch silicon wafer, and spin drying was performed by shaking off at 4,000 rpm for 15 seconds. Next, paddle development was performed for 30 seconds using an LD nozzle of “CLEAN TRACK ACT8” to remove the protective film. In this paddle development, a 2.38% TMAH aqueous solution was used as a developer. After development, the degree of undissolved portion of the protective film was measured for blob defects using a defect inspection device (“KLA2351” from KLA Tencor). The case where the number of detected blob defects was 200 or less was evaluated as “good”, and the case where the number exceeded 200 was evaluated as “bad”.

[Bridge defect]
The number of occurrences of bridge defects in the resist pattern obtained by developing the resist film formed with the protective film for immersion exposure was measured. Apply spin coating on the surface of a 12-inch silicon wafer using an anti-reflection coating ("ARC66" manufactured by Nissan Chemical Co., Ltd.) using a coating / developing device ("Lithius Pro-i" manufactured by Tokyo Electron), followed by PB Thus, a coating film having a film thickness of 105 nm was formed. Next, a radiation sensitive resin composition (a) was spin-coated using “CLEAN TRACK ACT12”, PB was applied at 100 ° C. for 60 seconds, and then cooled at 23 ° C. for 30 seconds to form a resist film having a thickness of 100 nm. Formed. Then, the protective film formation resin composition for immersion exposure was apply | coated on the formed resist film, and the protective film was formed.

  Next, using an ArF immersion exposure apparatus (“S610C” manufactured by NIKON), exposure is performed through a mask for projecting a pattern of 45 nm line / 90 nm pitch under the optical conditions of NA: 1.30 and Crosspore. (Hereinafter, the dimension of the pattern projected by the mask is also referred to as the “pattern dimension” of the mask. For example, a mask having a pattern dimension of 40 nm line / 84 nm pitch is a mask for projecting a pattern of 40 nm line / 84 nm pitch. ). After performing PEB on a hot plate of “Lithius Pro-i” at 100 ° C. for 60 seconds and cooling at 23 ° C. for 30 seconds, a 2.38% TMAH aqueous solution was used as a developer at a GP nozzle of the developing cup. Paddle development was performed for 2 seconds, followed by rinsing with ultrapure water. The substrate on which the resist pattern was formed was obtained by spin-drying by shaking off at 2,000 rpm for 15 seconds. At this time, the exposure amount at which a resist pattern having a 45 nm line / 90 nm pitch was formed in a mask having a pattern dimension of 45 nm line / 90 nm pitch was determined as the optimum exposure amount. When a resist pattern having a pitch of 45 nm / 90 nm was formed, it was evaluated as “good” when no bridge defect was observed, and “bad” when it was recognized.

  As is clear from the results in Table 7, the resin compositions (A) of the examples were used as a radiation-sensitive resin composition, so that the LWR performance was obtained in both ArF exposure and alkali development and organic solvent development. It is excellent in CDU performance, resolution, rectangularity in cross-sectional shape, depth of focus, exposure margin and MEEF performance. As is clear from the results in Table 8, the resin compositions (A) of the examples are used as a radiation-sensitive resin composition, and in the case of electron beam exposure and alkali development, LWR performance, CDU performance, and resolution. , Rectangularity of the cross-sectional shape, depth of focus and exposure margin. Further, as is clear from the results in Table 9, the resin compositions (B) of the examples were used as protective film-forming resin compositions for immersion exposure, so that excellent depth of focus was obtained in the case of ArF exposure and alkali development. In addition, while exhibiting exposure margin and MEEF performance, the resist pattern formed is excellent in LWR performance, CDU performance and resolution, rectangular shape of the cross-sectional shape, composition stability, upper layer film removability, elution Excellent in quantity, peeling resistance, blob defects and bridge defects. In general, it is known that the same tendency as in the case of EUV exposure can be obtained by electron beam exposure. Therefore, according to the resin compositions of the examples, lithography is possible even in the case of EUV exposure. It is estimated that the performance is excellent. In Tables 7 to 9, “-” represents a criterion.

  According to the resin composition and resist pattern forming method of the present invention, a resist pattern that exhibits excellent depth of focus, exposure margin, and MEEF performance, has low LWR and CDU, high resolution, and excellent cross-sectional rectangularity. Can be formed. Therefore, these can be suitably used for pattern formation in semiconductor device manufacturing or the like, where miniaturization is expected to progress further in the future.

Claims (11)

A resin composition used in a resist pattern forming method by photolithography,
A first polymer having a first structural unit containing at least one selected from the group consisting of a group represented by the following formula (1) and a group represented by the following formula (2), and an organic solvent A resin composition characterized by the above.

(In Formulas (1) and (2), R ¹ and R ² are each independently a hydrogen atom, a fluorine atom, or a monovalent organic group having 1 to 20 carbon atoms. These groups are combined with each other. R ³ is each independently a monovalent organic group having 1 to 30 carbon atoms, and R ^f2 and R ^f3 are each independently a hydrogen atom, fluorine atom, two or more of .1 or ^{R f2} and ^{R f3} and ^{R 3} is an alkyl group or a fluorinated alkyl group having 1 to 10 carbon atoms having 1 to 10 carbon atoms is constructed aligned with one another A ring structure having 4 to 30 ring members, provided that at least one of R ^f1 , R ^f2 and R ^f3 is a fluorine atom or a fluorinated alkyl group, and m and n are each independently And R ¹ , R ² , R ^When there are a plurality of ^f2 and ^Rf3 , the plurality of R ¹ , R ² , R ^f2 and R ^f3 may be the same or different from each other, and * represents a site bonded to the other part of the structural unit.
In formula (1), R ^f1 is an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or a fluorinated alkyl having 1 to 10 carbon atoms. It is a group. ^Two or more of one or more of R ¹ and R ² and R ^f1 may form a ring structure having 3 to 30 ring members that are combined with each other. ) The resin composition according to claim 1, wherein the first structural unit is represented by at least one selected from the group consisting of the following formula (1-1), formula (1-2), and formula (1-3). .

(In the formula (1-1), (1-2) and (1-3), Z is, .R ⁴ is a group represented by the formula (1) or (2) are each independently It is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.) At least one of those bonded to the carbon atom adjacent to -COO- among R ^f2 and R ^f3 in the formula (1) or (2) is a fluorine atom or a C 1-10 perfluoroalkyl group. The resin composition according to claim 1 or 2. Of R ^f2 and R ^f3 in the above formula (1) or (2), those bonded to the carbon atom adjacent to —COH, and at least one of R ^f1 is a fluorine atom or a C 1-10 perfluoroalkyl The resin composition according to claim 1, which is a group. In the formula (1) or (2), among R ^f2 and R ^f3 , those bonded to the carbon atom adjacent to —COO— are a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. 2. The resin composition according to 2. Used as a radiation sensitive resin composition,
The resin composition according to any one of claims 1 to 5, further comprising a radiation-sensitive acid generator. The resin composition according to claim 6, wherein the first polymer further has a second structural unit containing an acid dissociable group represented by the following formula (p).

(In formula (p), R ^p1 is a hydrogen atom or a monovalent chain hydrocarbon group having 1 to 10 carbon atoms. R ^p2 and R ^p3 are each independently a monovalent group having 1 to 10 carbon atoms. A chain hydrocarbon group or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group having 3 to 20 ring members composed of these groups together with the carbon atoms to which they are bonded. Represents an alicyclic structure.) The resin composition according to claim 6 or 7, further comprising a second polymer having a structural unit containing an acid dissociable group and having a fluorine atom content smaller than that of the first polymer.   The resin composition according to any one of claims 1 to 5, which is used as a protective film forming composition for immersion exposure. Forming a resist film;
A step of exposing the resist film, and a step of developing the exposed resist film,
The resist pattern formation method which forms the said resist film with the resin composition of any one of Claims 1-8. Forming a resist film;
Laminating a protective film on the resist film,
A step of immersion exposure of the resist film on which the protective film is laminated, and a step of developing the resist film subjected to the immersion exposure,
A method for forming a resist pattern, wherein the protective film is formed from the resin composition according to claim 9.