JP7210364B2 - PATTERN FORMATION METHOD, ION IMPLANTATION METHOD, AND ELECTRONIC DEVICE MANUFACTURING METHOD - Google Patents

Description

The present invention relates to a pattern forming method, an ion implantation method, and an electronic device manufacturing method. More specifically, the present invention relates to the production of semiconductors such as ICs, the production of circuit boards such as liquid crystals and thermal heads, other photofabrication processes, lithographic printing plates, and actinic ray-sensitive compositions used in acid-curable compositions. The present invention relates to a pattern forming method, an ion implantation method, and an electronic device manufacturing method using a photosensitive or radiation-sensitive resin composition.

After resists for KrF excimer lasers (248 nm), an image forming method called chemical amplification has been used as an image forming method for resists in order to compensate for sensitivity reduction due to light absorption. Taking the positive type chemically amplified image forming method as an example, exposure to an excimer laser, an electron beam, extreme ultraviolet light, or the like decomposes an acid generator in the exposed area to generate acid, followed by post-exposure baking (PEB). : Post Exposure Bake), the generated acid is used as a reaction catalyst to convert alkali-insoluble groups into alkali-soluble groups, and the exposed areas are removed with an alkaline developer.
In the above method, various alkaline developers have been proposed, but an aqueous alkaline developer containing 2.38 mass % TMAH (tetramethylammonium hydroxide aqueous solution) is commonly used.

In addition to the positive type, development of a negative type fine pattern formation using an organic developer is also underway. This is because there is a demand for forming patterns having various shapes such as lines, trenches, holes, etc. in the manufacture of semiconductor devices, etc., and in forming such patterns, it is sometimes advantageous to use a negative pattern forming method. Because there is

Also, various film thicknesses of the resist film have been proposed depending on the application. Using an actinic ray-sensitive or radiation-sensitive resin composition with a 5% or more, actinic ray-sensitive or radiation-sensitive film having a thickness of 1 μm or more is formed, and actinic ray or radiation with a wavelength of 200 to 300 nm A pattern forming method has been proposed in which development is performed using a developing solution after exposure, and according to this pattern forming method, it is believed that a pattern having an excellent cross-sectional shape can be formed with high sensitivity.

Furthermore, as an application of the resist technology as described above, microfabrication applications such as ion implantation using a resist composition in ion implantation (ion implantation), which is one step in the production of image sensors and the like, are progressing.

WO2017/078031

However, in the case of forming a thick film (for example, 1 μm or more) resist pattern and using the resist pattern (especially an isolated space pattern) as a mask to perform ion implantation, the rectangularity of the cross-sectional shape and the ion implantation resistance are excellent. It has been difficult to form a resist pattern with

The present invention solves the above-mentioned problems, and when an actinic ray-sensitive or radiation-sensitive film having a thickness of 1 μm or more is exposed to KrF light, it is excellent in cross-sectional rectangularity and ion implantation resistance. An object of the present invention is to provide a pattern forming method, an ion implantation method, and an electronic device manufacturing method using an actinic ray-sensitive or radiation-sensitive resin composition, which can form a pattern (particularly an isolated space pattern).

一般式（ＺＩ－３）中、
Ｍは、アルキル基、シクロアルキル基、又はアリール基を表し、環構造を有するとき、上記環構造は、酸素原子、硫黄原子、エステル結合、アミド結合、及び炭素－炭素二重結合の少なくとも１種を含んでいてもよい。
Ｒ _１ｃ 及びＲ _２ｃ は、各々独立に、水素原子、アルキル基、シクロアルキル基、ハロゲン原子、シアノ基又はアリール基を表す。Ｒ _１ｃ とＲ _２ｃ とが結合して環を形成してもよい。
Ｒ _ｘ 及びＲ _ｙ は、各々独立に、アルキル基、シクロアルキル基、又はアルケニル基を表す。Ｒ _ｘ 及びＲ _ｙ が結合して環を形成してもよい。また、Ｍ、Ｒ _１ｃ 及びＲ _２ｃ から選ばれる少なくとも２つが結合して環構造を形成してもよく、上記環構造に炭素－炭素二重結合を含んでいてもよい。
Ｚ ^－ は、アニオンを表す。

一般式（ＺＩ－４）中、
ｌは０～２の整数を表す。
ｒは０～８の整数を表す。
Ｒ _１３ は、水素原子、フッ素原子、水酸基、アルキル基、シクロアルキル基、アルコキシ基、アルコキシカルボニル基、又は単環若しくは多環のシクロアルキル骨格を有する基を表す。
Ｒ _１４ は、複数存在する場合は各々独立して、アルキル基、シクロアルキル基、アルコキシ基、アルキルスルホニル基、シクロアルキルスルホニル基、アルキルカルボニル基、アルコキシカルボニル基、又は単環若しくは多環のシクロアルキル骨格を有するアルコキシ基を表す。
Ｒ _１５ は、各々独立して、アルキル基、シクロアルキル基、又はナフチル基を表す。２つのＲ _１５ が互いに結合して環を形成してもよい。２つのＲ _１５ が互いに結合して環を形成するとき、環骨格内に、酸素原子、又は窒素原子等のヘテロ原子を含んでもよい。
Ｚ ^－ は、アニオンを表す。
＜９＞
上記化合物（Ｂ）におけるフッ素原子の数が６以下である、＜１＞～＜８＞のいずれか１項に記載のパターン形成方法。
＜１０＞
上記感活性光線性又は感放射線性樹脂組成物が酸拡散制御剤を含む、＜１＞～＜９＞のいずれか１項に記載のパターン形成方法。
＜１１＞
上記感活性光線性又は感放射線性樹脂組成物が架橋剤を含まない、＜１＞～＜１０＞のいずれか１項に記載のパターン形成方法。
＜１２＞
上記感活性光線性又は感放射線性樹脂組成物の固形分濃度が１５質量％以上である、＜１＞～＜１１＞のいずれか１項に記載のパターン形成方法。
＜１３＞
＜１＞～＜１２＞のいずれか１項に記載のパターン形成方法により得られたパターンをマスクとして、イオンを注入する工程を含む、イオン注入方法。
＜１４＞
＜１＞～＜１２＞のいずれか１項に記載のパターン形成方法又は＜１３＞に記載のイオン注入方法を含む、電子デバイスの製造方法。
本発明は、上記＜１＞～＜１４＞に係る発明であるが、以下、それ以外の事項（例えば、下記［１］～［１３］）についても記載している。 That is, the inventors have found that the above problems can be solved by the following configuration.
<1>
(i) forming an actinic ray-sensitive or radiation-sensitive film having a thickness of 1 μm or more using an actinic ray-sensitive or radiation-sensitive resin composition;
(ii) irradiating the actinic ray-sensitive or radiation-sensitive film with KrF light, and
(iii) A pattern forming method comprising the step of developing the actinic ray-sensitive or radiation-sensitive film irradiated with KrF light with a developer containing an organic solvent to form a negative pattern,
The actinic ray-sensitive or radiation-sensitive resin composition comprises (A) a resin having a repeating unit having an aromatic group and a repeating unit having a group that decomposes under the action of an acid to form a polar group, and (B) containing a compound that generates an acid upon exposure to actinic rays or radiation, and (C) a solvent,
The pattern forming method, wherein the content of the repeating unit having the aromatic group is 15 to 60 mol % with respect to the total repeating units of the resin (A).
<2>
The pattern forming method according to <1>, wherein the repeating unit having a group that decomposes to form a polar group by the action of an acid has an alicyclic hydrocarbon group having 5 to 20 carbon atoms.
<3>
(i) forming an actinic ray-sensitive or radiation-sensitive film having a thickness of 1 μm or more using an actinic ray-sensitive or radiation-sensitive resin composition;
(ii) irradiating the actinic ray-sensitive or radiation-sensitive film with KrF light, and
(iii) A pattern forming method comprising the step of developing the actinic ray-sensitive or radiation-sensitive film irradiated with KrF light with a developer containing an organic solvent to form a negative pattern,
The actinic ray-sensitive or radiation-sensitive resin composition comprises (A) a resin having a repeating unit having an aromatic group and a repeating unit having a group that decomposes under the action of an acid to form a polar group, and (B) containing a compound that generates an acid upon exposure to actinic rays or radiation, and (C) a solvent,
The content of the repeating unit having the aromatic group is 15 mol% or more with respect to the total repeating units of the resin (A),
The pattern forming method, wherein the repeating unit having a group that decomposes to form a polar group by the action of an acid has an alicyclic hydrocarbon group having 5 to 20 carbon atoms.
<4>
The pattern forming method according to <3>, wherein the content of the repeating unit having the aromatic group is 15 to 60 mol % with respect to the total repeating units of the resin (A).
<5>
The pattern forming method according to any one of <1> to <4>, wherein the step (ii) is performed multiple times.
<6>
<1> to <5>, wherein the content of the repeating unit having a group that decomposes to form a polar group by the action of an acid is 25 to 50 mol% with respect to the total repeating units of the resin (A). The pattern forming method according to any one of the items.
<7>
<1> to <, wherein the repeating unit having a polar group that is decomposed by the action of an acid to generate a polar group is a repeating unit corresponding to (meth)acrylic acid. 6> The pattern forming method according to any one of items 6>.
<8>
The pattern forming method according to any one of <1> to <7>, wherein the compound (B) is a compound represented by the following general formula (ZI-3) or general formula (ZI-4).

In general formula (ZI-3),
M represents an alkyl group, a cycloalkyl group, or an aryl group, and when it has a ring structure, the ring structure is at least one of an oxygen atom, a sulfur atom, an ester bond, an amide bond, and a carbon-carbon double bond. may contain
R1c and _R2c each independently _represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an aryl group. R _1c and R _2c may combine to form a ring.
R _x and R _y each independently represent an alkyl group, a cycloalkyl group, or an alkenyl group. R _x and R _y may combine to form a ring. Also, at least two selected from M, R _1c and R _2c may combine to form a ring structure, and the ring structure may contain a carbon-carbon double bond.
Z ⁻ represents an anion.

In general formula (ZI-4),
l represents an integer of 0 to 2;
r represents an integer of 0 to 8;
R ₁₃ represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a group having a monocyclic or polycyclic cycloalkyl skeleton.
When multiple R ₁₄ are present, they are each independently an alkyl group, cycloalkyl group, alkoxy group, alkylsulfonyl group, cycloalkylsulfonyl group, alkylcarbonyl group, alkoxycarbonyl group, or monocyclic or polycyclic cycloalkyl represents an alkoxy group having a skeleton.
Each R ₁₅ independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. Two R ₁₅ may be joined together to form a ring. When two R ₁₅ are combined to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom.
Z ⁻ represents an anion.
<9>
The pattern forming method according to any one of <1> to <8>, wherein the number of fluorine atoms in the compound (B) is 6 or less.
<10>
The pattern forming method according to any one of <1> to <9>, wherein the actinic ray-sensitive or radiation-sensitive resin composition contains an acid diffusion controller.
<11>
The pattern forming method according to any one of <1> to <10>, wherein the actinic ray-sensitive or radiation-sensitive resin composition does not contain a cross-linking agent.
<12>
The pattern forming method according to any one of <1> to <11>, wherein the actinic ray-sensitive or radiation-sensitive resin composition has a solid content concentration of 15% by mass or more.
<13>
An ion implantation method, comprising a step of implanting ions using the pattern obtained by the pattern formation method according to any one of <1> to <12> as a mask.
<14>
A method for manufacturing an electronic device, comprising the pattern forming method according to any one of <1> to <12> or the ion implantation method according to <13>.
The present invention relates to the above <1> to <14>, but other matters (for example, the following [1] to [13]) are also described below.

[1]
(i) forming an actinic ray-sensitive or radiation-sensitive film having a thickness of 1 μm or more using an actinic ray-sensitive or radiation-sensitive resin composition;
(ii) irradiating the actinic ray-sensitive or radiation-sensitive film with KrF light; A pattern forming method comprising the step of forming a negative pattern by developing using
The actinic ray-sensitive or radiation-sensitive resin composition comprises (A) a resin having a repeating unit having an aromatic group and a repeating unit having a group that decomposes under the action of an acid to form a polar group, and (B) containing a compound that generates an acid upon exposure to actinic rays or radiation, and (C) a solvent,
The pattern forming method, wherein the content of the repeating unit having the aromatic group is 15 mol % or more relative to the total repeating units of the resin (A).

[2]
The pattern forming method according to [1], wherein the step (ii) is performed multiple times.
[3]
The pattern forming method according to [1] or [2], wherein the content of the repeating unit having the aromatic group is 15 to 60 mol % with respect to the total repeating units of the resin (A).
[4]
[1] to [3], wherein the content of the repeating unit having a group that is decomposed by the action of an acid to generate a polar group is 25 to 50 mol% with respect to the total repeating units of the resin (A). The pattern forming method according to any one of the items.

[5]
The pattern according to any one of [1] to [4], wherein the repeating unit having a group that decomposes under the action of an acid to generate a polar group has an alicyclic hydrocarbon group with 5 to 20 carbon atoms. Forming method.
[6]
[1]-[ 5], the pattern forming method according to any one of items.
[7]
The pattern forming method according to any one of [1] to [6], wherein the compound (B) is a compound represented by the following general formula (ZI-3) or general formula (ZI-4).

In general formula (ZI-3),
M represents an alkyl group, a cycloalkyl group, or an aryl group, and when it has a ring structure, the ring structure is at least one of an oxygen atom, a sulfur atom, an ester bond, an amide bond, and a carbon-carbon double bond. may contain
_R1c and _R2c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an aryl group. R _1c and R _2c may combine to form a ring.
R _x and R _y each independently represent an alkyl group, a cycloalkyl group, or an alkenyl group. R _x and R _y may combine to form a ring. Also, at least two selected from M, R _1c and R _2c may combine to form a ring structure, and the ring structure may contain a carbon-carbon double bond.
Z ⁻ represents an anion.

In general formula (ZI-4),
l represents an integer of 0 to 2;
r represents an integer of 0 to 8;
R ₁₃ represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a group having a monocyclic or polycyclic cycloalkyl skeleton.
When multiple R ₁₄ are present, they are each independently an alkyl group, cycloalkyl group, alkoxy group, alkylsulfonyl group, cycloalkylsulfonyl group, alkylcarbonyl group, alkoxycarbonyl group, or monocyclic or polycyclic cycloalkyl represents an alkoxy group having a skeleton.
Each R ₁₅ independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. Two R ₁₅ may be joined together to form a ring. When two R ₁₅ are combined to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom.
Z ⁻ represents an anion.

[8]
The pattern forming method according to any one of [1] to [7], wherein the number of fluorine atoms in the compound (B) is 6 or less.
[9]
The pattern forming method according to any one of [1] to [8], wherein the actinic ray-sensitive or radiation-sensitive resin composition contains an acid diffusion controller.
[10]
The pattern forming method according to any one of [1] to [9], wherein the actinic ray-sensitive or radiation-sensitive resin composition does not contain a cross-linking agent.

[11]
The pattern forming method according to any one of [1] to [10], wherein the actinic ray-sensitive or radiation-sensitive resin composition has a solid content concentration of 15% by mass or more.
[12]
An ion implantation method, comprising a step of implanting ions using the pattern obtained by the pattern formation method according to any one of [1] to [11] as a mask.
[13]
A method for manufacturing an electronic device, comprising the pattern forming method according to any one of [1] to [11] or the ion implantation method according to [12].

According to the present invention, when an actinic ray-sensitive or radiation-sensitive film having a thickness of 1 μm or more is exposed to KrF light, a pattern excellent in cross-sectional rectangularity and ion implantation resistance (especially It is possible to provide a pattern forming method, an ion implantation method, and an electronic device manufacturing method using an actinic ray-sensitive or radiation-sensitive resin composition capable of forming an isolated space pattern.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail.
In the description of a group (atomic group) in the present specification, a description that does not describe substitution or unsubstituted includes not only those having no substituents but also those having substituents. For example, an "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). Also, the term "organic group" as used herein refers to a group containing at least one carbon atom.
The term "actinic ray" or "radiation" as used herein means, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV light), X-rays, electron beams (EB), and the like. . Moreover, in the present invention, light means actinic rays or radiation.
In addition, unless otherwise specified, the term "exposure" as used herein means not only exposure by far ultraviolet rays, extreme ultraviolet rays, X-rays, and EUV light represented by mercury lamps and excimer lasers, but also electron beams, ion beams, and the like. Drawing with a particle beam is also included in exposure.
In the specification of the present application, the term "~" is used to mean that the numerical values before and after it are included as the lower limit and the upper limit.

Moreover, in this specification, (meth)acrylate represents acrylate and methacrylate, and (meth)acryl represents acrylic and methacryl.
In this specification, the weight-average molecular weight (Mw), number-average molecular weight (Mn), and degree of dispersion (Mw/Mn) of the resin are determined by GPC measurement (solvent : Tetrahydrofuran, flow rate (sample injection volume): 10 μl, column: TSK gel Multipore HXL-M (× 4) manufactured by Tosoh Corporation, column temperature: 40 ° C., flow rate: 1.0 mL / min, detector: differential refractive index ( RI) is defined as a polystyrene conversion value by a detector).

Moreover, in the present specification, the type of substituent, the position of the substituent, and the number of substituents are not particularly limited when it is said that it may have a substituent. The number of substituents can be, for example, one, two, three, or more. Examples of substituents include monovalent nonmetallic atomic groups excluding hydrogen atoms, and can be selected from the following substituent group T, for example.

(Substituent Group T)
The substituent group T includes halogen atoms such as fluorine, chlorine, bromine and iodine atoms; alkoxy groups such as methoxy, ethoxy and tert-butoxy groups; aryloxy groups such as phenoxy and p-tolyloxy groups. alkoxycarbonyl groups such as methoxycarbonyl group, butoxycarbonyl group and phenoxycarbonyl group; acyloxy groups such as acetoxy group, propionyloxy group and benzoyloxy group; acetyl group, benzoyl group, isobutyryl group, acryloyl group, methacryloyl group and methoxalyl group Alkylsulfanyl groups such as methylsulfanyl group and tert-butylsulfanyl group; Arylsulfanyl groups such as phenylsulfanyl group and p-tolylsulfanyl group; Alkyl group; Cycloalkyl group; Aryl group; carboxy group; formyl group; sulfo group; cyano group; alkylaminocarbonyl group; arylaminocarbonyl group; sulfonamide group; silyl group; is mentioned.

[Pattern formation method]
The pattern forming method of the present invention comprises
(i) a step of forming (forming) an actinic ray-sensitive or radiation-sensitive film (hereinafter simply referred to as film) having a thickness of 1 μm or more using an actinic ray-sensitive or radiation-sensitive resin composition;
(ii) a step of irradiating the actinic ray-sensitive or radiation-sensitive film with KrF light (KrF excimer laser); A pattern forming method comprising the step of forming a negative pattern by developing using a developer containing
The actinic ray-sensitive or radiation-sensitive resin composition comprises (A) a resin having a repeating unit having an aromatic group and a repeating unit having a group that decomposes under the action of an acid to form a polar group, and (B) containing a compound that generates an acid upon exposure to actinic rays or radiation, and (C) a solvent,
In the pattern forming method, the content of the repeating unit having the aromatic group is 15 mol % or more relative to the total repeating units in the resin (A).

Although the mechanism by which the present invention can solve the above problems has not been completely clarified, the present inventors presume as follows.
First, it is required to form resist patterns of various shapes with high precision even in the case of resist patterns for ion implantation applications. When forming an isolated space pattern as a resist pattern, a positive pattern forming method in which a region of the resist film corresponding to the isolated space formed after development is used as an exposure region, and a resist not corresponding to the isolated space region. A method of forming a negative pattern in which a region of the film is used as an exposure region can be considered. In the negative pattern formation method, the exposure region is the broad region surrounding the narrow region corresponding to the isolated space region. is likely to be formed on the resist film. As a result, for example, in the case of using the technique described in Patent Document 1, even if it is a positive pattern forming method using an alkaline developer or a negative pattern forming method using an organic developer, , the cross-sectional shape of the pattern is excellent, but in the case of forming a pattern of a specific shape, the use of a negative pattern forming method using an organic developer results in a rectangular cross-sectional shape of the pattern. characteristics tend to be more accurate.
In the present invention, first, as described in the above step (iii), the actinic ray-sensitive or radiation-sensitive film irradiated with KrF light is developed with a developer containing an organic solvent to obtain a negative type film. In order to form a pattern, it is considered that a resist pattern excellent in cross-sectional rectangularity can be obtained even when an isolated space pattern is formed.
Further, as a result of extensive studies by the present inventors, it was found that the resin as a constituent component of the actinic ray-sensitive or radiation-sensitive composition used in the pattern forming method of the present invention has a repeating unit having an aromatic ring group, By setting the content of the repeating unit having the aromatic group to 15 mol% or more based on the total repeating units in the resin (A), the rectangularity of the cross-sectional shape of the resist pattern is excellent. As a matter of fact, the present inventors have found that the ion implantation resistance performance is greatly improved, and thus ion implantation can be carried out in a desired region of the substrate with high accuracy.
The reason for this is not clear in detail, but the aromatic ring group in the repeating unit having an aromatic ring group has some effect on the resistance to ions, and such repeating units are present in the resin in a certain amount or more. As a result, it is presumed that in the ion implantation process, ions are prevented from entering an unintended region such as by passing through the resist film portion of the resist pattern.
Note that Patent Document 1 does not clearly describe the implementation of ion implantation, ion implantation resistance performance, and the like.

First, the actinic ray-sensitive or radiation-sensitive resin composition used in the pattern forming method of the present invention will be described.

[Actinic ray- or radiation-sensitive resin composition]
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention (hereinafter also simply referred to as the composition of the present invention) comprises (A) a repeating unit having an aromatic group and a polar group that is decomposed by the action of an acid. (B) a compound that generates an acid upon exposure to actinic rays or radiation, and (C) a solvent,
The content of the repeating unit having the aromatic group is 15 mol % or more based on the total repeating units in the resin (A).

The actinic ray-sensitive or radiation-sensitive resin composition of the present invention is preferably for KrF exposure.
The actinic ray-sensitive or radiation-sensitive resin composition of the present invention is a negative resist composition for organic solvent development. Also, the composition according to the present invention is typically a chemically amplified resist composition.

<(A) Resin Having a Repeating Unit Having an Aromatic Group and a Repeating Unit Having a Group That Decomposes Under the Action of an Acid to Generate a Polar Group>
The composition of the present invention contains a resin (hereinafter also referred to as resin (A)) having a repeating unit having an aromatic group and a repeating unit having a group that is decomposed by the action of an acid to generate a polar group.
Since the resin (A) has a repeating unit having a group that is decomposed by the action of an acid to generate a polar group (hereinafter also referred to as an "acid-decomposable group"), the resin (A) is typically It is preferably a resin whose solubility in a developer containing an organic solvent as a main component is reduced by the action of an acid.

(Repeating unit having an aromatic group)
The aromatic ring in the aromatic group constituting the repeating unit having an aromatic group is a monocyclic or polycyclic aromatic ring, such as a benzene ring, naphthalene ring, anthracene ring, fluorene ring, phenanthrene ring, etc. An aromatic hydrocarbon ring optionally having 6 to 18 substituents, or, for example, a thiophene ring, a furan ring, a pyrrole ring, a benzothiophene ring, a benzofuran ring, a benzopyrrole ring, a triazine ring, an imidazole ring, a benzo Aromatic heterocycles including heterocycles such as imidazole ring, triazole ring, thiadiazole ring and thiazole ring can be mentioned. Among them, a benzene ring and a naphthalene ring are preferable from the viewpoint of resolution, and a benzene ring is most preferable.
The aromatic group may further have a substituent. Preferred substituents include, but are not limited to, alkyl groups, cycloalkyl groups, aryl groups, amino groups, amido groups, ureido groups, urethane groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups, thioether groups, acyl group, acyloxy group, alkoxycarbonyl group, cyano group, nitro group and the like.

The resin (A) contains a repeating unit having an aromatic group, and the content of the repeating unit having the aromatic group is 15 mol % or more based on the total repeating units of the resin (A). As a result, when exposed to KrF light, a pattern having a rectangular cross-sectional shape and excellent ion implantation resistance can be formed.
The content of the repeating unit having the aromatic group is 15 mol % or more based on the total repeating units of the resin (A).
Although the upper limit of the content of the repeating unit having the aromatic group is not particularly limited, it is usually 85 mol % or less based on the total repeating units of the resin (A).
The content of the repeating unit having an aromatic group is preferably 15 mol% to 70 mol%, more preferably 15 mol% to 60 mol%, based on the total repeating units of the resin (A). , more preferably 15 mol % to 55 mol %.

Repeating units having an aromatic group include, for example, repeating units represented by the following general formula (A).

In the formula, R ₀₁ , R ₀₂ and R ₀₃ each independently represent, for example, a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. Ar ₁ represents an aromatic ring group. R ₀₃ represents an alkylene group and may combine with Ar ₁ to form a 5- or 6-membered ring together with the —C—C— chain.
Each of n Y's independently represents a hydrogen atom or a group that leaves under the action of an acid. However, at least one of Y represents a group that leaves under the action of an acid.
n represents an integer of 1 to 4, preferably 1 to 2, more preferably 1;

Alkyl groups as R ₀₁ to R ₀₃ are, for example, alkyl groups having 20 or less carbon atoms, preferably methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group and hexyl group. , 2-ethylhexyl group, octyl group or dodecyl group. More preferably, these alkyl groups are those having 8 or less carbon atoms. In addition, these alkyl groups may have a substituent.
The alkyl group contained in the alkoxycarbonyl group is preferably the same as the alkyl group for R ₀₁ to R ₀₃ above.
The cycloalkyl group may be a monocyclic cycloalkyl group or a polycyclic cycloalkyl group. Preferred are monocyclic cycloalkyl groups having 3 to 8 carbon atoms such as cyclopropyl group, cyclopentyl group and cyclohexyl group. In addition, these cycloalkyl groups may have a substituent.
A halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is more preferable.

When R ₀₃ represents an alkylene group, the alkylene group preferably has 1 to 8 carbon atoms such as a methylene group, ethylene group, propylene group, butylene group, hexylene group or octylene group.
The aromatic ring group for Ar ₁ preferably has 6 to 14 carbon atoms, such as benzene ring, toluene ring and naphthalene ring. In addition, these aromatic ring groups may have a substituent.
As at least one of Y, the group capable of being eliminated by the action of an acid is preferably the repeating unit having a group that is decomposed by the action of an acid to form a polar group, as described later.

It is more preferable that the group which is eliminated by the action of an acid as at least one of Y has a structure represented by the following general formula (B).

In the formula, L ₁ and L ₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group.
M represents a single bond or a divalent linking group.
Q represents an alkyl group, a cycloalkyl group, a cycloaliphatic group, an aromatic ring group, an amino group, an ammonium group, a mercapto group, a cyano group or an aldehyde group. Cycloaliphatic groups and aromatic ring groups may contain heteroatoms.
At _least two of Q, M, and L1 may combine with each other to form a 5- or 6-membered ring.

The alkyl groups for L ₁ and L ₂ are, for example, alkyl groups having 1 to 8 carbon atoms, and specific examples include methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, hexyl group and An octyl group is mentioned.
Cycloalkyl groups for L ₁ and L ₂ are, for example, cycloalkyl groups having 3 to 15 carbon atoms, and specific examples include cyclopentyl, cyclohexyl, norbornyl and adamantyl groups.
The aryl group for L ₁ and L ₂ is, for example, an aryl group having 6 to 15 carbon atoms, and specific examples include phenyl group, tolyl group, naphthyl group and anthryl group.
The aralkyl group for L ₁ and L ₂ is, for example, an aralkyl group having 6 to 20 carbon atoms, and specific examples include a benzyl group and a phenethyl group.

The divalent linking group as M is, for example, an alkylene group (e.g., methylene group, ethylene group, propylene group, butylene group, hexylene group or octylene group), a cycloalkylene group (e.g., cyclopentylene group or cyclohexylene group ), alkenylene group (e.g. ethylene group, propenylene group or butenylene group), arylene group (e.g. phenylene group, tolylene group or naphthylene group), -S-, -O-, -CO-, -SO ₂ -, - N(R ₀ )—, or a combination of two or more thereof. Here, R ₀ is a hydrogen atom or an alkyl group. The alkyl group as R ₀ is, for example, an alkyl group having 1 to 8 carbon atoms, and specific examples include methyl group, ethyl group, propyl group, n-butyl group, sec-butyl group, hexyl group and octyl group. mentioned.

The alkyl group and cycloalkyl group for Q are the same as the groups for L ₁ and L ₂ described above.
Examples of the cycloaliphatic group or aromatic ring group for Q include the cycloalkyl groups and aryl groups for L ₁ and L ₂ described above. These cycloalkyl groups and aryl groups are preferably groups having 3 to 15 carbon atoms.
Examples of heteroatom-containing cyclic aliphatic groups or aromatic ring groups for Q include thiirane, cyclothiolane, thiophene, furan, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, Examples thereof include groups having a heterocyclic structure such as thiazole and pyrrolidone. However, it is not limited to these as long as it is a ring formed by carbon atoms and heteroatoms or a ring formed only by heteroatoms.
The ring structure that can be formed by combining at _least two of Q, M and L1 includes, for example, a 5- or 6-membered ring structure in which these form a propylene group or a butylene group. In addition, this 5- or 6-membered ring structure contains an oxygen atom.

Each group represented by L ₁ , L ₂ , M and Q in general formula (B) may have a substituent. Examples of such substituents include alkyl groups, cycloalkyl groups, aryl groups, amino groups, amide groups, ureido groups, urethane groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups, thioether groups, acyl groups, and acyloxy groups. , alkoxycarbonyl groups, cyano groups and nitro groups. These substituents preferably have 8 or less carbon atoms.
The group represented by -(MQ) is preferably a group having 1 to 20 carbon atoms, more preferably a group having 1 to 10 carbon atoms, and still more preferably 1 to 8 carbon atoms.

The content of the repeating unit represented by the general formula (A) is preferably 5 to 60 mol%, more preferably 20 to 60 mol%, based on the total repeating units of the resin (A). More preferably 30 to 60 mol %.

Moreover, as a repeating unit having an aromatic group, it is also preferable to have, for example, a repeating unit having a phenolic hydroxyl group.
A phenolic hydroxyl group is a group obtained by substituting a hydrogen atom of an aromatic group with a hydroxyl group. The aromatic ring that constitutes the aromatic group is as described above.
Repeating units having a phenolic hydroxyl group include, for example, repeating units represented by the following general formula (B-1).

In general formula (BH-1),
R _B1 , R _B2 and R _B3 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group. R 3 _B3 may combine with Ar 2 _B1 to form a ring, in which case R 3 _B3 represents an alkylene group.
X _B3 represents a single bond or a divalent linking group.
Ar _B1 represents a (n _B +1)-valent aromatic ring group, and represents a (n _B +2)-valent aromatic ring group when combined with R _B3 to form a ring.
n _B represents an integer of 1-4.

The alkyl groups represented by R _B1 , R _B2 and R _B3 in general formula (BH-1) include optionally substituted methyl, ethyl, propyl, isopropyl and n-butyl groups. , sec-butyl group, hexyl group, 2-ethylhexyl group, octyl group, and dodecyl group. is more preferred.

Cycloalkyl groups represented by R _B1 , R _B2 and R _B3 in general formula (BH-1) may be monocyclic or polycyclic. A monocyclic cycloalkyl group having 3 to 8 carbon atoms, such as a cyclopropyl group, a cyclopentyl group and a cyclohexyl group, which may have a substituent, is preferred.
The halogen atoms represented by R _B1 , R _B2 and R _B3 in general formula (BH-1) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, with a fluorine atom being preferred.
As the alkyl group contained in the alkoxycarbonyl groups represented by R _B1 , R _B2 and R _B3 in general formula (BH-1), the same alkyl groups as those for R _B1 , R _B2 and R _B3 are preferred.

Preferred substituents for the above groups include, for example, an alkyl group, a cycloalkyl group, an aryl group, an amino group, an amido group, a ureido group, a urethane group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group, a thioether group, and an acyl group. group, acyloxy group, alkoxycarbonyl group, cyano group, nitro group, etc., and the number of carbon atoms in the substituent is preferably 8 or less.

Ar _B1 represents a (n _B +1)-valent aromatic ring group. The divalent aromatic ring group when n _B is 1 is, for example, a phenylene group, a tolylene group, a naphthylene group, an arylene group having 6 to 18 carbon atoms such as an anthracenylene group, or, for example, thiophene, furan, pyrrole, Preferred examples include heterocyclic aromatic ring groups such as benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, and thiazole.

Specific examples of the (n _B +1)-valent aromatic ring group when n _B is an integer of 2 or more include any (n _B −1) of the above specific examples of the divalent aromatic ring group A group obtained by removing a hydrogen atom can be preferably mentioned.

The divalent linking group for X _B3 includes -COO- or -CONR ₆₄ -.
The alkyl group for R ₆₄ in —CONR ₆₄ — (R ₆₄ represents a hydrogen atom or an alkyl group) as X _B3 is a methyl group, an ethyl group, a propyl group, or an isopropyl group, which may have a substituent. , n-butyl, sec-butyl, hexyl, 2-ethylhexyl, octyl, and dodecyl.
X _B3 preferably represents a single bond, -COO- or -CONH-, more preferably a single bond or -COO-, still more preferably a single bond.

Ar _B1 is more preferably an aromatic ring group having 6 to 18 carbon atoms, and particularly preferably a benzene ring group, a naphthalene ring group, or a biphenylene ring group.
Ar _B1 is preferably a benzene ring group.

n _B represents an integer of 1 to 4, preferably 1 or 2, more preferably 1;

The repeating unit represented by the above general formula (BH-1) is preferably a repeating unit represented by the following general formula (BH-2).

In general formula (BH-2), R _B1 , R _B2 and R _B3 each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an alkoxycarbonyl group.
Ar _B1 represents a (n _B +1)-valent aromatic ring group.
n _B represents an integer of 1-4.

Specific and preferred examples of R _B1 , R _B2 , R _B3 , Ar _B1 and n _B in general formula (BH-2) are R _B1 , R _B2 , R _B3 , Ar _B1 and n _B are synonymous with specific examples and preferred examples. However, R _B3 does not form a ring by combining with Ar _B1 .

Specific examples of the repeating unit represented by formula (BH-1) are shown below, but are not limited thereto. In the formula, a represents 1 or 2.

The content of the repeating unit having a phenolic hydroxyl group is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, more preferably 30 to 60 mol, based on the total repeating units of the resin (A). % is more preferred.

(Repeating unit having a group (acid-decomposable group) that decomposes under the action of an acid to form a polar group)
The acid-decomposable group preferably has a structure in which the polar group is protected with a group that decomposes and leaves under the action of an acid.
Polar groups include phenolic hydroxyl group, carboxyl group, fluorinated alcohol group, sulfonic acid group, sulfonamide group, sulfonylimide group, (alkylsulfonyl)(alkylcarbonyl)methylene group, (alkylsulfonyl)(alkylcarbonyl)imide group. , bis(alkylcarbonyl)methylene group, bis(alkylcarbonyl)imide group, bis(alkylsulfonyl)methylene group, bis(alkylsulfonyl)imide group, tris(alkylcarbonyl)methylene group, tris(alkylsulfonyl)methylene group, etc. Examples thereof include acidic groups (groups dissociated in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide, which is conventionally used as a developer for resists), alcoholic hydroxyl groups, and the like.
Preferred polar groups include carboxyl groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), and sulfonic acid groups.

Groups preferred as acid-decomposable groups are groups obtained by substituting hydrogen atoms of these polar groups with groups that leave under the action of acid.
Examples of groups that leave by the action of an acid include -C(R ₃₆ )(R ₃₇ )(R ₃₈ ), -C(R ₃₆ )(R ₃₇ )(OR ₃₉ ), -C(R ₀₁ )( R ₀₂ )(OR ₃₉ ), —C(R ₀₁ )(R ₀₂ ) —C(═O) —OC(R ₃₆ )(R ₃₇ )(R ₃₈ ) or —CH(R ₃₆ )(Ar) etc. can be mentioned.
In the formula, R ₃₆ to R ₃₉ each independently represent an alkyl group, cycloalkyl group, aryl group, aralkyl group or alkenyl group. R ₃₆ and R ₃₇ may combine with each other to form a ring.
R ₀₁ and R ₀₂ each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group or an alkenyl group.
Ar represents an aryl group.

The alkyl group for R ₃₆ to R ₃₉ , R ₀₁ or R ₀₂ is preferably an alkyl group having 1 to 8 carbon atoms, such as methyl group, ethyl group, propyl group, n-butyl group, sec- Butyl, hexyl and octyl groups may be mentioned.
The cycloalkyl group for R ₃₆ to R ₃₉ , R ₀₁ or R ₀₂ may be a monocyclic cycloalkyl group or a polycyclic cycloalkyl group. The monocyclic cycloalkyl group is preferably a cycloalkyl group having 3 to 8 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cyclooctyl. The polycyclic cycloalkyl group is preferably a cycloalkyl group having 6 to 20 carbon atoms, such as adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinanyl group, tricyclodecanyl group, A tetracyclododecyl group and an androstanyl group are included. Some of the carbon atoms in the cycloalkyl group may be substituted with heteroatoms such as oxygen atoms.
The aryl group as R ₃₆ to R ₃₉ , R ₀₁ , R ₀₂ or Ar is preferably an aryl group having 6 to 10 carbon atoms, such as phenyl group, naphthyl group and anthryl group.
The aralkyl group for R ₃₆ to R ₃₉ , R ₀₁ or R ₀₂ is preferably an aralkyl group having 7 to 12 carbon atoms, such as benzyl, phenethyl and naphthylmethyl.
The alkenyl group for R ₃₆ to R ₃₉ , R ₀₁ or R ₀₂ is preferably an alkenyl group having 2 to 8 carbon atoms, such as vinyl, allyl, butenyl and cyclohexenyl. .

The ring that can be formed by combining R ₃₆ and R ₃₇ may be monocyclic or polycyclic. As the monocyclic type, a cycloalkane structure having 3 to 8 carbon atoms is preferable, and examples thereof include a cyclopropane structure, a cyclobutane structure, a cyclopentane structure, a cyclohexane structure, a cycloheptane structure and a cyclooctane structure. As the polycyclic type, a cycloalkane structure having 6 to 20 carbon atoms is preferable, and examples thereof include an adamantane structure, a norbornane structure, a dicyclopentane structure, a tricyclodecane structure and a tetracyclododecane structure. Some of the carbon atoms in the ring structure may be substituted with heteroatoms such as oxygen atoms.
Each of the above groups may have a substituent. Examples of such substituents include alkyl groups, cycloalkyl groups, aryl groups, amino groups, amide groups, ureido groups, urethane groups, hydroxyl groups, carboxyl groups, halogen atoms, alkoxy groups, thioether groups, acyl groups, and acyloxy groups. , alkoxycarbonyl groups, cyano groups and nitro groups. These substituents preferably have 8 or less carbon atoms.

The acid-decomposable group is preferably a cumyl ester group, an enol ester group, an acetal ester group, a tertiary alkyl ester group, or the like. More preferably, it is a tertiary alkyl ester group.

As the repeating unit having an acid-decomposable group that can be contained in the resin (A), a repeating unit represented by the following general formula (AI) is preferable.

In general formula (AI),
Xa ₁ represents a hydrogen atom or an alkyl group.
T represents a single bond or a divalent linking group.
Rx ₁ to Rx ₃ each independently represent an alkyl group (linear or branched) or a cycloalkyl group (monocyclic or polycyclic).
Two of Rx ₁ to Rx ₃ may combine to form a cycloalkyl group (monocyclic or polycyclic).

The alkyl group represented by Xa ₁ may or may not have a substituent, and examples thereof include a methyl group and a group represented by —CH ₂ —R ₁₁ . R ₁₁ represents a halogen atom (such as a fluorine atom), a hydroxyl group, or a monovalent organic group, such as an alkyl group having 5 or less carbon atoms and an acyl group having 5 or less carbon atoms, preferably 3 or less carbon atoms. is an alkyl group, more preferably a methyl group. In one aspect, Xa ₁ is preferably a hydrogen atom, a methyl group, a trifluoromethyl group, a hydroxymethyl group, or the like.
The divalent linking group of T includes an alkylene group, -COO-Rt- group, -O-Rt- group and the like. In the formula, Rt represents an alkylene group or a cycloalkylene group.
T is preferably a single bond or a -COO-Rt- group. Rt is preferably an alkylene group having 1 to 5 carbon atoms, more preferably -CH ₂ -, -(CH ₂ ) ₂ -, or -(CH ₂ ) ₃ -.

Preferred alkyl groups for Rx ₁ to Rx ₃ are those having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and t-butyl group.
Cycloalkyl groups represented by Rx ₁ to Rx ₃ include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group; polycyclic cycloalkyl groups such as norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group and adamantyl group; groups are preferred.
Cycloalkyl groups formed by combining two of Rx ₁ to Rx ₃ include monocyclic cycloalkyl groups such as cyclopentyl group and cyclohexyl group, norbornyl group, tetracyclodecanyl group, tetracyclododecanyl group and adamantyl group. Polycyclic cycloalkyl groups such as groups are preferred. A monocyclic cycloalkyl group having 5 to 6 carbon atoms is particularly preferred.
A cycloalkyl group formed by combining two of Rx ₁ to Rx ₃ is, for example, a group in which one of the methylene groups constituting the ring has a heteroatom such as an oxygen atom or a heteroatom such as a carbonyl group. may be replaced.
In the repeating unit represented by formula (AI), for example, Rx ₁ is a methyl group or an ethyl group, and Rx ₂ and Rx ₃ are preferably combined to form the above-mentioned cycloalkyl group.

Each of the above groups may have a substituent, and examples of the substituent include an alkyl group (having 1 to 4 carbon atoms), a halogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbon atoms), a carboxyl group, and an alkoxy group. A carbonyl group (having 2 to 6 carbon atoms) and the like can be mentioned, and those having 8 or less carbon atoms are preferred.

Preferred specific examples of the repeating unit having an acid-decomposable group are shown below, but the invention is not limited thereto.
In specific examples, Rx and Xa ₁ represent a hydrogen atom, CH ₃ , CF ₃ , or CH ₂ OH. Rxa and Rxb each represent an alkyl group having 1 to 4 carbon atoms. Z represents a substituent containing a polar group, and when there are a plurality of Z, each is independent. p represents 0 or a positive integer. Examples of substituents containing a polar group represented by Z include linear or branched alkyl groups and cycloalkyl groups having a hydroxyl group, a cyano group, an amino group, an alkylamide group, or a sulfonamide group, preferably is an alkyl group having a hydroxyl group. An isopropyl group is particularly preferred as the branched alkyl group.

The repeating unit having a group that is decomposed by the action of an acid to form a polar group preferably has an alicyclic hydrocarbon group having 5 to 20 carbon atoms. Examples of the alicyclic hydrocarbon group include, but are not particularly limited to, a cycloalkyl group.
The cycloalkyl group may be a monocyclic cycloalkyl group or a polycyclic cycloalkyl group. The monocyclic cycloalkyl group is preferably a cycloalkyl group having 5 to 8 carbon atoms, such as cyclopentyl, cyclohexyl and cyclooctyl. The polycyclic cycloalkyl group is preferably a cycloalkyl group having 6 to 20 carbon atoms, such as adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinanyl group, tricyclodecanyl group, A tetracyclododecyl group and an androstanyl group are included. Some of the carbon atoms in the cycloalkyl group may be substituted with heteroatoms such as oxygen atoms.
The number of carbon atoms in the alicyclic hydrocarbon group having 5 to 20 carbon atoms represents the number of carbon atoms constituting the skeleton of the alicyclic hydrocarbon ring.
The above alicyclic hydrocarbon group may further have a substituent.

Resin (A) preferably contains, for example, a repeating unit represented by general formula (3) as a repeating unit represented by general formula (AI).

In the general formula (3),
_R31 represents a hydrogen atom or an alkyl group.
R ₃₂ represents an alkyl group or a cycloalkyl group, specific examples of which include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl groups. , a cyclohexyl group, and the like.
_R33 represents an atomic group necessary to form a monocyclic alicyclic hydrocarbon structure together with the carbon atom to which _R32 is bonded. In the alicyclic hydrocarbon structure, some of the carbon atoms constituting the ring may be substituted with a heteroatom or a heteroatom-containing group.

The alkyl group of R ₃₁ may have a substituent, and examples of the substituent include a fluorine atom and a hydroxyl group. R ₃₁ preferably represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₃₂ is preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a tert-butyl group or a cyclohexyl group, more preferably a methyl group, an ethyl group, an isopropyl group or a tert-butyl group. .
The monocyclic alicyclic hydrocarbon structure formed by R ₃₃ together with carbon atoms is preferably a 3- to 8-membered ring, more preferably a 5- or 6-membered ring.
In the monocyclic alicyclic hydrocarbon structure formed by R ₃₃ together with a carbon atom, the heteroatom that can constitute the ring includes an oxygen atom, a sulfur atom and the like, and the group having a heteroatom includes a carbonyl group and the like. mentioned. However, the heteroatom-containing group is preferably not an ester group (ester bond).
The monocyclic alicyclic hydrocarbon structure formed by R ₃₃ together with carbon atoms is preferably formed only from carbon atoms and hydrogen atoms.

The repeating unit represented by the general formula (3) is preferably a repeating unit represented by the following general formula (3').

In general formula (3′), R ₃₁ and R ₃₂ have the same definitions as in general formula (3) above.
Specific examples of the repeating unit having the structure represented by formula (3) are shown below, but are not limited thereto.

The content of the repeating unit having the structure represented by the general formula (3) is preferably 10 to 70 mol%, more preferably 20 to 60 mol%, based on the total repeating units in the resin (A). is more preferred, and 30 to 50 mol % is even more preferred.

The repeating unit having an acid-decomposable group is also preferably a repeating unit represented by the general formula (A).
In view of the fact that polarity is likely to be generated by the action of an acid, the repeating unit having a group that decomposes by the action of an acid to generate a polar group is a repeating unit that has a polar group that is generated by the action of an acid. A repeating unit corresponding to an acid is preferred.

The total content of repeating units having an acid-decomposable group is preferably 20 to 90 mol%, more preferably 25 to 85 mol%, more preferably 25 to 90 mol%, based on the total repeating units of the resin (A). More preferably 50 mol %.

Resin (A) has a repeating unit having an aromatic group and a repeating unit having a group that is decomposed by the action of an acid to generate a polar group. In addition to the repeating unit having a group that forms a polar group when combined, other repeating units may be included.

(Other repeating units)
In one aspect, the resin (A) preferably contains a repeating unit having a cyclic carbonate structure. This cyclic carbonate structure is a structure having a ring containing a bond represented by -OC(=O)-O- as a group of atoms constituting the ring. A ring containing a bond represented by -OC(=O)-O- as a ring-constituting atom group is preferably a 5- to 7-membered ring, most preferably a 5-membered ring. Such a ring may be fused with another ring to form a fused ring.

Moreover, the resin (A) may contain a repeating unit having a lactone structure or a sultone (cyclic sulfonate) structure.
As the lactone group or sultone group, any one having a lactone structure or sultone structure can be used, but a 5- to 7-membered ring lactone structure or sultone structure is preferable, Structures or sultone structures are preferably condensed with other ring structures to form bicyclo structures or spiro structures. It is more preferable to have a repeating unit having a lactone structure or sultone structure represented by any one of the following general formulas (LC1-1) to (LC1-17), (SL1-1) and (SL1-2). Also, the lactone structure or sultone structure may be directly bonded to the main chain. Preferred lactone structures or sultone structures are (LC1-1), (LC1-4), (LC1-5) and (LC1-8), with (LC1-4) being more preferred. Use of a specific lactone structure or sultone structure improves line width roughness (LWR) and development defects.

The lactone structure portion or sultone structure portion may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 2 to 8 carbon atoms, and a carboxyl group. , a halogen atom, a hydroxyl group, a cyano group, an acid-decomposable group, and the like. More preferred are alkyl groups having 1 to 4 carbon atoms, cyano groups, and acid-decomposable groups. _n2 represents an integer of 0-4. When n ₂ is 2 or more, the multiple substituents (Rb ₂ ) may be the same or different, and the multiple substituents (Rb ₂ ) may combine to form a ring. .

A repeating unit having a lactone group or a sultone group usually has an optical isomer, and any optical isomer may be used. Moreover, one kind of optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, its optical purity (ee) is preferably 90% or more, more preferably 95% or more.

Resin (A) may have a repeating unit having a hydroxyl group or a cyano group other than those represented by general formula (AI). This improves the adhesion to the substrate and the compatibility with the developer. A repeating unit having a hydroxyl group or a cyano group is preferably a repeating unit having an alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, and preferably does not have an acid-decomposable group. Among the alicyclic hydrocarbon structures substituted with a hydroxyl group or a cyano group, the alicyclic hydrocarbon structure is preferably an adamantyl group, a diamantyl group, or a norbornane group. As the alicyclic hydrocarbon structure substituted with a hydroxyl group or a cyano group, partial structures represented by the following general formulas (VIIa) to (VIId) are preferred.

In general formulas (VIIa) to (VIIc),
R ₂ c to R ₄ c each independently represent a hydrogen atom, a hydroxyl group or a cyano group. However, at least one of R ₂ c to R ₄ c represents a hydroxyl group or a cyano group. Preferably, one or two of R ₂ c to R ₄ c are hydroxyl groups and the rest are hydrogen atoms. In general formula (VIIa), more preferably two of R ₂ c to R ₄ c are hydroxyl groups and the rest are hydrogen atoms.
Examples of repeating units having partial structures represented by general formulas (VIIa) to (VIId) include repeating units represented by the following general formulas (AIIa) to (AIId).

In general formulas (AIIa) to (AIId),
R ₁ c represents a hydrogen atom, a methyl group, a trifluoromethyl group or a hydroxymethyl group.
R ₂ c to R ₄ c have the same definitions as R ₂ c to R ₄ c in general formulas (VIIa) to (VIIc).
The content of repeating units having a hydroxyl group or a cyano group is preferably 5 to 40 mol%, more preferably 5 to 30 mol%, still more preferably 10 to 25 mol%, based on all repeating units in the resin (A).
Specific examples of repeating units having a hydroxyl group or a cyano group are shown below, but the present invention is not limited thereto.

The resin (A) used in the composition of the present invention may have a repeating unit having an acid group. The acid group includes a carboxyl group, a sulfonamide group, a sulfonylimide group, a bissulfonylimide group, and an aliphatic alcohol substituted with an electron-withdrawing group at the α-position (e.g., a hexafluoroisopropanol group) having a carboxyl group. It is more preferable to have repeating units. Containing a repeating unit having an acid group increases the resolution in contact hole applications. Examples of the repeating unit having an acid group include repeating units in which an acid group is directly bonded to the main chain of the resin, such as repeating units of acrylic acid and methacrylic acid, or those in which the acid group is attached to the main chain of the resin via a linking group. It is preferable to introduce the terminal of the polymer chain using a repeating unit that is bonded, or a polymerization initiator or a chain transfer agent having an acid group during polymerization, and the linking group is a monocyclic or polycyclic cyclic hydrocarbon structure. may have Particularly preferred are repeating units of acrylic acid and methacrylic acid.

In the resin (A), as the repeating unit having an acid group, the above repeating unit having a phenolic hydroxyl group can also be used.

The content of repeating units having an acid group is preferably 30 to 90 mol%, more preferably 35 to 85 mol%, still more preferably 40 to 80 mol%, based on the total repeating units of the resin (A).

Specific examples of repeating units having an acid group are shown below, but the present invention is not limited thereto.
In specific examples, Rx represents H, _CH3 , _CH2OH , or _CF3 .

The resin (A) may further have a repeating unit that has a cyclic hydrocarbon structure that does not have a polar group (eg, an acid group, a hydroxyl group, a cyano group, etc.) and does not exhibit acid decomposition. Examples of such repeating units include repeating units represented by general formula (IV).

In general formula (IV) above, R ₅ represents a hydrocarbon group having at least one cyclic structure and no polar group.
Ra represents a hydrogen atom, an alkyl group or a --CH ₂ --O--Ra ₂ group. _In the formula, Ra2 represents a hydrogen atom, an alkyl group or an acyl group. Ra ₂ is preferably a hydrogen atom, a methyl group, a hydroxymethyl group or a trifluoromethyl group, particularly preferably a hydrogen atom or a methyl group.

The cyclic structure of R ₅ includes monocyclic hydrocarbon groups and polycyclic hydrocarbon groups. Examples of monocyclic hydrocarbon groups include cycloalkyl groups having 3 to 12 carbon atoms such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group, and cycloalkenyl groups having 3 to 12 carbon atoms such as cyclohexenyl group. groups, phenyl groups, and the like. Preferred monocyclic hydrocarbon groups are monocyclic hydrocarbon groups having 3 to 7 carbon atoms, and more preferred are cyclopentyl and cyclohexyl groups.
Polycyclic hydrocarbon groups include ring-assembled hydrocarbon groups and bridged cyclic hydrocarbon groups. Examples of ring-assembled hydrocarbon groups include a bicyclohexyl group, a perhydronaphthalenyl group, a biphenyl group, a 4- A cyclohexylphenyl group and the like are included. Examples of bridged cyclic hydrocarbon rings include bicyclic rings such as pinane, bornane, norpinane, norbornane, and bicyclooctane rings (bicyclo[2.2.2]octane ring, bicyclo[3.2.1]octane ring, etc.) Hydrocarbon rings, tricyclic hydrocarbon rings such as homobredan, adamantane, tricyclo[5.2.1.0 ^2,6 ]decane, tricyclo[4.3.1.1 ^2,5 ]undecane rings, tetracyclo[4 .4.0.1 ^2,5 . 1 ^7,10 ]dodecane, perhydro-1,4-methano-5,8-methanonaphthalene ring and other tetracyclic hydrocarbon rings. Bridged cyclic hydrocarbon rings also include condensed cyclic hydrocarbon rings such as perhydronaphthalene (decalin), perhydroanthracene, perhydrophenanthrene, perhydroacenaphthene, perhydrofluorene, perhydroindene, perhydro Condensed rings in which a plurality of 5- to 8-membered cycloalkane rings such as phenalene rings are condensed are also included.

Preferred bridged cyclic hydrocarbon rings include norbornyl, adamantyl, bicyclooctanyl, tricyclo[5,2,1,0 ^2,6 ]decanyl groups and the like. A norbornyl group and an adamantyl group are mentioned as a more preferable bridged cyclic hydrocarbon ring.
These cyclic hydrocarbon structures may have a substituent, and preferred substituents include halogen atoms, alkyl groups, hydroxyl groups substituted with hydrogen atoms, and amino groups substituted with hydrogen atoms. Preferred halogen atoms include bromine, chlorine and fluorine atoms, and preferred alkyl groups include methyl, ethyl, butyl and t-butyl groups. The above alkyl group may further have a substituent, and examples of the substituent which may further have include a halogen atom, an alkyl group, a hydroxyl group substituted with a hydrogen atom, and an amino group substituted with a hydrogen atom. groups can be mentioned.
Examples of groups in which hydrogen atoms are substituted include alkyl groups, cycloalkyl groups, aralkyl groups, substituted methyl groups, substituted ethyl groups, alkoxycarbonyl groups, and aralkyloxycarbonyl groups. Preferred alkyl groups include alkyl groups having 1 to 4 carbon atoms, preferred substituted methyl groups include methoxymethyl, methoxythiomethyl, benzyloxymethyl, t-butoxymethyl and 2-methoxyethoxymethyl groups, and preferred substituted ethyl groups include , 1-ethoxyethyl, 1-methyl-1-methoxyethyl, preferred acyl groups include aliphatic acyl groups having 1 to 6 carbon atoms such as formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl and pivaloyl groups, alkoxycarbonyl Examples of groups include alkoxycarbonyl groups having 1 to 4 carbon atoms.

The resin (A) may or may not contain a repeating unit having a cyclic hydrocarbon structure having no polar group and exhibiting no acid decomposability. The amount is preferably 1 to 40 mol %, more preferably 2 to 20 mol %, based on all repeating units in the resin (A).
Specific examples of repeating units having a polar group-free cyclic hydrocarbon structure and not exhibiting acid decomposability are shown below, but the present invention is not limited thereto. In the formula, Ra represents H, _CH3 , _CH2OH , or _CF3 .

In addition to the repeating structural unit described above, the resin (A) used in the composition of the present invention has dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution, which is a generally required property of a resist. It can have various repeating structural units for the purpose of adjusting , heat resistance, sensitivity and the like. Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.
Thereby, the performance required for the resin used in the composition of the present invention, particularly (1) solubility in a coating solvent, (2) film forming property (glass transition point), (3) alkali developability, (4) ) film thickness (selection of hydrophilicity/hydrophobicity and acid group), (5) adhesion of the unexposed portion to the substrate, and (6) dry etching resistance can be finely adjusted.

Examples of such monomers include compounds having one addition-polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, and the like. etc. can be mentioned.
In addition, any addition-polymerizable unsaturated compound that is copolymerizable with the monomers corresponding to the above-described various repeating structural units may be copolymerized.
In the resin (A) used in the composition of the present invention, the molar ratio of each repeating structural unit is determined by the resist dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and general required performance of the resist. are appropriately set in order to adjust the resolving power, heat resistance, sensitivity, and the like.

Resin (A) in the present invention can be synthesized according to a conventional method (for example, radical polymerization). For example, general synthesis methods include a batch polymerization method in which a monomer species and an initiator are dissolved in a solvent and then polymerized by heating; and the like, and the dropping polymerization method is particularly preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane and diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Further examples include solvents capable of dissolving the composition of the present invention, such as propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone, which will be described later. More preferably, the same solvent as that used in the composition of the present invention is used for polymerization. This can suppress the generation of particles during storage.
The polymerization reaction is preferably carried out under an inert gas atmosphere such as nitrogen or argon. Polymerization is initiated using a commercially available radical initiator (azo initiator, peroxide, etc.) as the polymerization initiator. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group or a carboxyl group is preferable. Preferred initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2'-azobis(2-methylpropionate), and the like. If desired, an initiator is added additionally or dividedly, and after the reaction is completed, the desired polymer is recovered by a method such as powder or solid recovery by pouring it into a solvent. The concentration of the reaction is 5-50% by weight, preferably 10-30% by weight. The reaction temperature is generally 10 to 150°C, preferably 30 to 120°C, more preferably 60 to 100°C.

The weight average molecular weight of the resin (A) of the present invention is preferably 1,000 to 200,000, more preferably 2,000 to 20,000, even more preferably 3,000 to 15,000, and particularly preferably is between 3,000 and 11,000. By setting the weight average molecular weight to 1,000 to 200,000, deterioration of heat resistance and dry etching resistance can be prevented, and developability is deteriorated, and viscosity increases to deteriorate film formability. You can prevent it from falling.
The dispersity (molecular weight distribution) is usually 1.0 to 3.0, preferably 1.0 to 2.6, more preferably 1.0 to 2.0, particularly preferably 1.1 to 2.0. range is used. The smaller the molecular weight distribution, the better the resolution and resist shape, the smoother the side walls of the resist pattern, and the better the roughness.

The content of resin (A) in the entire composition is preferably 30 to 99% by mass, more preferably 50 to 97% by mass, based on the total solid content.
Also, the resin (A) may be used alone or in combination.

<(B) A compound that generates an acid upon exposure to actinic rays or radiation>
The composition of the present invention contains (B) a compound that generates an acid upon exposure to actinic rays or radiation (also referred to as “compound (B)” or “photoacid generator”).
A photoacid generator is a compound that generates an acid upon exposure to actinic rays or radiation.
As the photoacid generator, a compound that generates an organic acid upon exposure to actinic rays or radiation is preferred. Examples include sulfonium salt compounds, iodonium salt compounds, diazonium salt compounds, phosphonium salt compounds, imidosulfonate compounds, oximesulfonate compounds, diazodisulfone compounds, disulfone compounds, and o-nitrobenzylsulfonate compounds.

As the photoacid generator, a known compound that generates an acid upon exposure to actinic rays or radiation can be appropriately selected and used either singly or as a mixture thereof. For example, paragraphs [0125]-[0319] of US Patent Application Publication No. 2016/0070167A1, paragraphs [0086]-[0094] of US Patent Application Publication No. 2015/0004544A1, and US Patent Application Publication No. 2016/ Known compounds disclosed in paragraphs [0323] to [0402] of 0237190A1 can be preferably used.

As the photoacid generator, for example, compounds represented by the following general formula (ZI), general formula (ZII), or general formula (ZIII) are preferred.

In the above general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represent an organic group.
The number of carbon atoms in the organic groups as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1-30, preferably 1-20.
Also, two of R ₂₀₁ to R ₂₀₃ may combine to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. Groups formed by combining two of R ₂₀₁ to R ₂₀₃ include alkylene groups (eg, butylene group and pentylene group) and —CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —.
Z ⁻ represents an anion (preferably a non-nucleophilic anion).

Preferred embodiments of the cation in the general formula (ZI) include the compound (ZI-1), the compound (ZI-2), and the compound represented by the general formula (ZI-3) (compound (ZI-3)), which will be described later. and corresponding groups in the compound represented by general formula (ZI-4) (compound (ZI-4)).
The photoacid generator may be a compound having a plurality of structures represented by general formula (ZI). For example, at least one of R ₂₀₁ to R ₂₀₃ of the compound represented by general formula (ZI) and at least one of R ₂₀₁ to R ₂₀₃ of another compound represented by general formula (ZI) are single bonds. Alternatively, it may be a compound having a structure bonded via a linking group.

First, compound (ZI-1) will be described.
Compound (ZI-1) is an arylsulfonium compound in which at least one of R ₂₀₁ to R ₂₀₃ in general formula (ZI) is an aryl group, that is, a compound having an arylsulfonium cation.
In the arylsulfonium compound, all of R ₂₀₁ to R ₂₀₃ may be aryl groups, or part of R ₂₀₁ to R ₂₀₃ may be aryl groups and the rest may be alkyl groups or cycloalkyl groups.
Arylsulfonium compounds include, for example, triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.

The aryl group contained in the arylsulfonium compound is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Heterocyclic structures include pyrrole residues, furan residues, thiophene residues, indole residues, benzofuran residues, benzothiophene residues, and the like. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group or cycloalkyl group optionally possessed by the arylsulfonium compound is a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or 3 to 15 carbon atoms. is preferred, and examples thereof include methyl, ethyl, propyl, n-butyl, sec-butyl, t-butyl, cyclopropyl, cyclobutyl and cyclohexyl groups.

The aryl group, alkyl group and cycloalkyl group of R ₂₀₁ to R ₂₀₃ are each independently an alkyl group (eg, 1 to 15 carbon atoms), a cycloalkyl group (eg, 3 to 15 carbon atoms), an aryl group (eg, carbon 6 to 14), an alkoxy group (eg, 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group as a substituent.

Next, compound (ZI-2) will be described.
Compound (ZI-2) is a compound in which R ₂₀₁ to R ₂₀₃ in formula (ZI) each independently represent an aromatic ring-free organic group. Here, the aromatic ring also includes an aromatic ring containing a heteroatom.
The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R ₂₀₁ to R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group or a vinyl group, and more preferably a linear or branched 2-oxoalkyl group, 2-oxocyclo It is an alkyl group or an alkoxycarbonylmethyl group, more preferably a linear or branched 2-oxoalkyl group.

The alkyl group and cycloalkyl group represented by R ₂₀₁ to R ₂₀₃ are preferably linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (eg, methyl group, ethyl group, propyl group, butyl group, and pentyl group), and cycloalkyl groups having 3 to 10 carbon atoms (eg, cyclopentyl group, cyclohexyl group, and norbornyl group).
R ₂₀₁ to R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, 1-5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

Next, compound (ZI-3) will be described.

In general formula (ZI-3), M represents an alkyl group, a cycloalkyl group, or an aryl group, and when it has a ring structure, the ring structure is an oxygen atom, a sulfur atom, an ester bond, an amide bond, and a carbon - may contain at least one carbon double bond. _R1c and _R2c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an aryl group. R _1c and R _2c may combine to form a ring. R _x and R _y each independently represent an alkyl group, a cycloalkyl group, or an alkenyl group. R _x and R _y may combine to form a ring. In addition, at least two selected from M, R _1c and R _2c may combine to form a ring structure, and the ring structure may contain a carbon-carbon double bond. Z ⁻ represents an anion.

In general formula (ZI-3), the alkyl group and cycloalkyl group represented by M include a linear alkyl group having 1 to 15 carbon atoms (preferably 1 to 10 carbon atoms), 3 to 15 carbon atoms ( Branched alkyl groups preferably having 3 to 10 carbon atoms) or cycloalkyl groups having 3 to 15 carbon atoms (preferably 1 to 10 carbon atoms) are preferred, and specifically, methyl, ethyl and propyl groups. , n-butyl group, sec-butyl group, t-butyl group, cyclopropyl group, cyclobutyl group, cyclohexyl group, norbornyl group and the like.
The aryl group represented by M is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a sulfur atom, or the like. Heterocyclic structures include a furan ring, a thiophene ring, a benzofuran ring, a benzothiophene ring, and the like.

M above may further have a substituent (for example, substituent group T). As this embodiment, for example, M may be a benzyl group.
When M has a ring structure, the ring structure may contain at least one of an oxygen atom, a sulfur atom, an ester bond, an amide bond, and a carbon-carbon double bond.

Examples of the alkyl group, cycloalkyl group, and aryl group represented by R _1c and R _2c are the same as those for M described above, and preferred embodiments thereof are also the same. Also, R _1c and R _2c may combine to form a ring.
Halogen atoms represented by R _1c and R _2c include, for example, fluorine, chlorine, bromine and iodine atoms.

Examples of the alkyl group and cycloalkyl group represented by R _x and R _y include the same groups as those for M described above, and preferred embodiments thereof are also the same.
The alkenyl group represented by R _x and R _y is preferably an allyl group or a vinyl group.
The above R _x and R _y may further have a substituent (for example, substituent group T). Examples of this embodiment include a 2-oxoalkyl group or an alkoxycarbonylalkyl group as R _x and R _y .
Examples of the 2-oxoalkyl group represented by R _x and R _y include those having 1 to 15 carbon atoms (preferably 1 to 10 carbon atoms), specifically 2-oxopropyl group, and 2-oxobutyl group.
Alkoxycarbonylalkyl groups represented by R _x and R _y include, for example, those having 1 to 15 carbon atoms (preferably 1 to 10 carbon atoms). Also, R _x and R _y may combine to form a ring.
The ring structure formed by combining R _x and R _y may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbon-carbon double bond.

In general formula (ZI-3), M and R _1c may combine to form a ring structure, and the formed ring structure may contain a carbon-carbon double bond.

Compound (ZI-3) above is preferably compound (ZI-3A).
Compound (ZI-3A) is a compound represented by the following general formula (ZI-3A) and having a phenacylsulfonium salt structure.

In general formula (ZI-3A),
R _1c to R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, or a hydroxyl group , represents a nitro group, an alkylthio group or an arylthio group.
R _6c and R _7c have the same definitions as R ₂ and R ₃ in general formula (ZI-3) described above, and preferred embodiments thereof are also the same.
R _x and R _y have the same meanings as R _x and R _y in general formula (ZI-3) described above, and preferred embodiments thereof are also the same.

Any two or more of R _1c to R _5c and R _x and R _y may each combine to form a ring structure, which ring structure is each independently an oxygen atom, a sulfur atom, an ester bond, It may contain an amide bond or a carbon-carbon double bond. In addition, R _5c and R _6c , R _5c and R _x may each combine to form a ring structure, and this ring structure may each independently contain a carbon-carbon double bond. Also, R _6c and R _7c may be combined to form a ring structure.
Examples of the ring structure include aromatic or non-aromatic hydrocarbon rings, aromatic or non-aromatic heterocyclic rings, and polycyclic condensed rings in which two or more of these rings are combined. The ring structure includes a 3- to 10-membered ring, preferably a 4- to 8-membered ring, and more preferably a 5- or 6-membered ring.

Examples of groups formed by bonding two or more of R _1c to R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.
The group formed by combining R _5c and R _6c and R _5c and R _x is preferably a single bond or an alkylene group. The alkylene group includes a methylene group, an ethylene group, and the like.
^Zc- represents an anion.

Next, compound (ZI-4) will be described.
Compound (ZI-4) is represented by the following general formula (ZI-4).

In general formula (ZI-4),
l represents an integer of 0 to 2;
r represents an integer of 0 to 8;
R ₁₃ represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a group having a monocyclic or polycyclic cycloalkyl skeleton. These groups may have a substituent.
When multiple R ₁₄ are present, they are each independently an alkyl group, cycloalkyl group, alkoxy group, alkylsulfonyl group, cycloalkylsulfonyl group, alkylcarbonyl group, alkoxycarbonyl group, or monocyclic or polycyclic cycloalkyl represents an alkoxy group having a skeleton. These groups may have a substituent.
Each _R15 independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. These groups may have a substituent. Two R ₁₅ may be joined together to form a ring. When two R ₁₅ are combined to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom. In one aspect, two R ₁₅ are alkylene groups, preferably joined together to form a ring structure.
Z ⁻ represents an anion.

In general formula (ZI-4), the alkyl groups of R ₁₃ , R ₁₄ and R ₁₅ are linear or branched. The number of carbon atoms in the alkyl group is preferably 1-10. As the alkyl group, a methyl group, an ethyl group, an n-butyl group, a t-butyl group, or the like is more preferable.

The compound (B) is preferably a compound represented by the general formula (ZI-3) or general formula (ZI-4).

Next, general formulas (ZII) and (ZIII) will be described.
In general formulas (ZII) and (ZIII), R ₂₀₄ to R ₂₀₇ each independently represent an aryl group, an alkyl group or a cycloalkyl group.
The aryl group represented by R ₂₀₄ to R ₂₀₇ is preferably a phenyl group or a naphthyl group, more preferably a phenyl group. The aryl group of R ₂₀₄ to R ₂₀₇ may be an aryl group having a heterocyclic structure containing an oxygen atom, a nitrogen atom, a sulfur atom, or the like. Skeletons of aryl groups having a heterocyclic structure include, for example, pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.
The alkyl group and cycloalkyl group represented by R ₂₀₄ to R ₂₀₇ include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl group and pentyl group), or a cycloalkyl group having 3 to 10 carbon atoms (eg, cyclopentyl group, cyclohexyl group and norbornyl group) are preferred.

Each of the aryl groups, alkyl groups and cycloalkyl groups of R ₂₀₄ to R ₂₀₇ may independently have a substituent. Examples of substituents that the aryl group, alkyl group and cycloalkyl group of R ₂₀₄ to R ₂₀₇ may have include an alkyl group (eg, 1 to 15 carbon atoms) and a cycloalkyl group (eg, 3 to 3 carbon atoms). 15), aryl groups (eg, 6 to 15 carbon atoms), alkoxy groups (eg, 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, and phenylthio groups.
Z ⁻ represents an anion.

Z - in general formula (ZI), Z ^- in general formula (ZII), Z ^- in general formula (ZI-3), Zc ^- in general formula (ZI ^- 3A), and Z in general formula (ZI-4) ^- is preferably an anion represented by the following general formula (3).

In the general formula (3),
o represents an integer of 1 to 3; p represents an integer from 0 to 10; q represents an integer from 0 to 10;

Xf represents a fluorine atom or an alkyl group substituted with at least one fluorine atom. The number of carbon atoms in this alkyl group is preferably 1-10, more preferably 1-4. A perfluoroalkyl group is preferable as the alkyl group substituted with at least one fluorine atom.
Xf is preferably a fluorine atom or a C 1-4 perfluoroalkyl group, more preferably a fluorine atom or CF ₃ . In particular, it is more preferable that both Xf are fluorine atoms.

_R4 and R5 each independently represent a hydrogen atom, a fluorine atom, an alkyl group, or an alkyl group substituted with at _least one fluorine atom. When multiple R ₄ and R ₅ are present, each of R ₄ and R ₅ may be the same or different.
The alkyl groups represented by R ₄ and R ₅ may have substituents and preferably have 1 to 4 carbon atoms. R ₄ and R ₅ are preferably hydrogen atoms.
Specific examples and preferred aspects of the alkyl group substituted with at least one fluorine atom are the same as the specific examples and preferred aspects of Xf in general formula (3).

L represents a divalent linking group. When there are multiple L's, each L may be the same or different.
Examples of divalent linking groups include -COO-(-C(=O)-O-), -OCO-, -CONH-, -NHCO-, -CO-, -O-, -S-, - SO—, —SO ₂ —, an alkylene group (preferably having 1 to 6 carbon atoms), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms), and a combination of a plurality of these and a divalent linking group. Among these, -COO-, -OCO-, -CONH-, -NHCO-, -CO-, -O-, -SO ₂ -, -COO-alkylene group-, -OCO-alkylene group-, -CONH- Alkylene group- or -NHCO-alkylene group- is preferred, and -COO-, -OCO-, -CONH-, -SO ₂ -, -COO-alkylene group- or -OCO-alkylene group- is more preferred.

W represents an organic group containing a cyclic structure. Among these, a cyclic organic group is preferable.
Cyclic organic groups include, for example, alicyclic groups, aryl groups, and heterocyclic groups.
Alicyclic groups may be monocyclic or polycyclic. Monocyclic alicyclic groups include, for example, monocyclic cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. Examples of polycyclic alicyclic groups include polycyclic cycloalkyl groups such as norbornyl, tricyclodecanyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups. Among them, alicyclic groups having a bulky structure with 7 or more carbon atoms, such as norbornyl, tricyclodecanyl, tetracyclodecanyl, tetracyclododecanyl, and adamantyl groups, are preferred.

Aryl groups may be monocyclic or polycyclic. The aryl group includes, for example, phenyl group, naphthyl group, phenanthryl group and anthryl group.
A heterocyclic group may be monocyclic or polycyclic. The polycyclic type can further suppress acid diffusion. Moreover, the heterocyclic group may or may not have aromaticity. Heterocyclic rings having aromaticity include, for example, furan ring, thiophene ring, benzofuran ring, benzothiophene ring, dibenzofuran ring, dibenzothiophene ring, and pyridine ring. Non-aromatic heterocycles include, for example, tetrahydropyran, lactone, sultone and decahydroisoquinoline rings. Examples of the lactone ring and sultone ring include the lactone structure and sultone structure exemplified in the resins described above. The heterocyclic ring in the heterocyclic group is particularly preferably a furan ring, a thiophene ring, a pyridine ring, or a decahydroisoquinoline ring.

The cyclic organic group may have a substituent. Examples of this substituent include alkyl groups (either linear or branched, preferably having 1 to 12 carbon atoms), cycloalkyl groups (monocyclic, polycyclic, and spirocyclic). any group, preferably having 3 to 20 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), hydroxyl group, alkoxy group, ester group, amide group, urethane group, ureido group, thioether group, sulfonamide groups, and sulfonate ester groups. In addition, carbonyl carbon may be sufficient as carbon (carbon which contributes to ring formation) which comprises a cyclic|annular organic group.

The anions represented by the general formula (3) include SO ₃ ⁻ —CF ₂ —CH ₂ —OCO-(L)q′-W, SO ₃ ^— —CF ₂ —CHF—CH ₂ —OCO-(L) q′-W, SO ₃ ⁻ —CF ₂ —COO-(L)q′-W, SO ₃ ^— —CF ₂ —CF ₂ —CH ₂ —CH ₂ —(L)qW, SO ₃ ^— —CF ₂ -CH(CF ₃ )-OCO-(L)q'-W is preferred. Here, L, q and W are the same as in general formula (3). q' represents an integer from 0 to 10;

In one embodiment, Z - in general formula (ZI), Z ^- in general formula (ZII), Zc ^- in general formula (ZI-3), ^{and Z - in} general formula (ZI-4) are the following general Anions of formula (4) are also preferred.

In general formula (4),
X ^B1 and X ^B2 each independently represent a hydrogen atom or a monovalent organic group having no fluorine atom. X ^B1 and X ^B2 are preferably hydrogen atoms.
X ^B3 and X ^B4 each independently represent a hydrogen atom or a monovalent organic group. At least one of X ^B3 and X ^B4 is preferably a fluorine atom or a monovalent organic group having a fluorine atom, and both of X ^B3 and X ^B4 are a fluorine atom or a monovalent organic group having a fluorine atom is more preferred. More preferably, both X ^B3 and X ^B4 are fluorine-substituted alkyl groups.
L, q and W are the same as in general formula (3).

Z - in general formula (ZI), Z ^- in general formula (ZII), Zc ^- in general formula (ZI-3), ^{and Z - in} general formula (ZI-4) may be benzenesulfonate anions. Often preferred is a benzenesulfonate anion substituted by a branched alkyl group or a cycloalkyl group.

Z - in general formula (ZI), Z ^- in general formula (ZII), Zc ^- in general formula (ZI-3), ^{and Z - in} general formula (ZI-4) are represented by the following general formula (SA1) An aromatic sulfonate anion represented by is also preferred.

In formula (SA1),
Ar represents an aryl group and may further have a substituent other than the sulfonate anion and -(D-B) group. Substituents which may be further included include a fluorine atom and a hydroxyl group.

n represents an integer of 0 or more. n is preferably 1 to 4, more preferably 2 to 3, and still more preferably 3.

D represents a single bond or a divalent linking group. Examples of divalent linking groups include ether groups, thioether groups, carbonyl groups, sulfoxide groups, sulfone groups, sulfonate ester groups, ester groups, and groups consisting of combinations of two or more thereof.

B represents a hydrocarbon group.

Preferably D is a single bond and B is an aliphatic hydrocarbon structure. B is more preferably an isopropyl group or a cyclohexyl group.

Preferred examples of the sulfonium cation in general formula (ZI) and the iodonium cation in general formula (ZII) are shown below.

Preferable examples of the anion Z ⁻ in general formula (ZI) and general formula (ZII), Zc ⁻ in general formula (ZI-3), and Z ⁻ in general formula (ZI-4) are shown below.

Any combination of the above cations and anions can be used as a photoacid generator.

The photoacid generator is preferably a sulfonium salt having no or only one aromatic ring group, from the viewpoint of the rectangular cross-sectional shape of the pattern.

It is preferable that the number of fluorine atoms in the photo-acid generator is 6 or less from the viewpoint of the cross-sectional shape of the pattern and the ion implantation resistance.

The photoacid generator may be in the form of a low-molecular-weight compound, or may be in the form of being incorporated into a part of the polymer. Moreover, the form of a low-molecular-weight compound and the form incorporated into a part of a polymer may be used in combination.
The photoacid generator is preferably in the form of a low molecular weight compound.
When the photoacid generator is in the form of a low-molecular-weight compound, the molecular weight is preferably 3,000 or less, more preferably 2,000 or less, even more preferably 1,000 or less.
When the photoacid generator is in the form of being incorporated in part of the polymer, it may be incorporated in part of the resin (A) described above, or may be incorporated in a resin different from the resin (A). .
A photo-acid generator may be used individually by 1 type, and may use 2 or more types together.
In the composition of the present invention, the content of the photoacid generator (the total when multiple types are present) is preferably 0.1 to 35% by mass, preferably 0.5 to 35% by mass, based on the total solid content of the composition. 25% by mass is more preferable, 0.5 to 20% by mass is even more preferable, and 0.5 to 10% by mass is particularly preferable.
When the compound represented by the above general formula (ZI-3) or (ZI-4) is contained as a photoacid generator, the content of the photoacid generator contained in the composition (if multiple types are present, The total) is preferably 1 to 35% by mass, more preferably 1 to 30% by mass, based on the total solid content of the composition.

<(C) Solvent>
The composition of the invention contains a solvent.
Solvents that can be used in preparing the composition include, for example, alkylene glycol monoalkyl ether carboxylates, alkylene glycol monoalkyl ethers, alkyl lactate esters, alkyl alkoxypropionates, and cyclic lactones (preferably having 4 to 4 carbon atoms). 10), organic solvents such as monoketone compounds (preferably having 4 to 10 carbon atoms) which may have a ring, alkylene carbonates, alkyl alkoxyacetates and alkyl pyruvates.
Specific examples of these solvents include those described in US Patent Application Publication No. 2008/0187860 [0441] to <0455>, isoamyl acetate, butyl butanoate, methyl 2-hydroxyisobutyrate, isobutyl isobutyrate, Butyl propionate and the like can be mentioned.

In the present invention, a mixed solvent in which a solvent containing a hydroxyl group in its structure and a solvent containing no hydroxyl group are mixed may be used as the organic solvent.
As the solvent containing a hydroxyl group and the solvent not containing a hydroxyl group, the aforementioned exemplary compounds can be appropriately selected. As the solvent containing a hydroxyl group, alkylene glycol monoalkyl ether, alkyl lactate, etc. are preferable, and propylene glycol monomethyl ether ( PGME, also known as 1-methoxy-2-propanol), ethyl lactate are more preferred. Moreover, as the solvent containing no hydroxyl group, alkylene glycol monoalkyl ether acetate, alkylalkoxypropionate, monoketone compound which may contain a ring, cyclic lactone, alkyl acetate and the like are preferable, and among these, propylene glycol monomethyl ether is preferable. Acetate (PGMEA, also known as 1-methoxy-2-acetoxypropane), ethyl ethoxy propionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate are particularly preferred, propylene glycol monomethyl ether acetate, ethyl ethoxy propionate, 2 - heptanone is most preferred.
The mixing ratio (mass) of the hydroxyl-containing solvent and the hydroxyl-free solvent is 1/99 to 99/1, preferably 10/90 to 90/10, more preferably 20/80 to 60/40. . A mixed solvent containing 50% by mass or more of a solvent containing no hydroxyl group is particularly preferable in terms of coating uniformity.
The solvent preferably contains propylene glycol monomethyl ether acetate, and is preferably a single solvent of propylene glycol monomethyl ether acetate or a mixed solvent of two or more kinds containing propylene glycol monomethyl ether acetate.

<Acid diffusion control agent (D)>
The composition of the present invention preferably contains an acid diffusion control agent. The acid diffusion control agent traps the acid generated from the photoacid generator or the like during exposure, and acts as a quencher that suppresses the reaction of the acid-decomposable resin in the unexposed area due to excess generated acid. For example, a basic compound (DA), a basic compound (DB) whose basicity is reduced or lost by irradiation with actinic rays or radiation, an onium salt (DC) that becomes a relatively weak acid to an acid generator, and a nitrogen atom. and a low-molecular-weight compound (DD) having a group that is eliminated by the action of an acid, or an onium salt compound (DE) having a nitrogen atom in the cation portion, or the like can be used as an acid diffusion controller. Known acid diffusion control agents can be used as appropriate in the composition of the present invention. For example, paragraphs [0627] to [0664] of US Patent Application Publication No. 2016/0070167A1, paragraphs [0095] to [0187] of US Patent Application Publication No. 2015/0004544A1, US Patent Application Publication No. 2016/0237190A1. Known compounds disclosed in paragraphs [0403] to [0423] of the specification and paragraphs [0259] to [0328] of US Patent Application Publication No. 2016/0274458A1 are suitable as the acid diffusion control agent (D) can be used for

As the basic compound (DA), compounds having structures represented by the following formulas (A) to (E) are preferred.

In general formulas (A) and (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different and each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl represents a group (6 to 20 carbon atoms). R ²⁰¹ and R ²⁰² may combine with each other to form a ring.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each independently represent an alkyl group having 1 to 20 carbon atoms.

The alkyl groups in general formulas (A) and (E) may be substituted or unsubstituted.
Regarding the above alkyl group, the substituted alkyl group is preferably an aminoalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl group having 1 to 20 carbon atoms.
The alkyl groups in general formulas (A) and (E) are more preferably unsubstituted.

As the basic compound (DA), guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, or piperidine are preferable, and imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, A compound having a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and/or an ether bond, or an aniline derivative having a hydroxyl group and/or an ether bond is more preferred.

A basic compound (DB) whose basicity is reduced or lost by irradiation with actinic rays or radiation (hereinafter also referred to as "compound (DB)") has a proton acceptor functional group, and actinic rays or It is a compound whose proton acceptor property is reduced or lost, or whose proton acceptor property is changed to acidic by being decomposed by irradiation with radiation.

The proton-accepting functional group is a functional group having electrons or a group capable of electrostatically interacting with protons, for example, a functional group having a macrocyclic structure such as cyclic polyether, or a π-conjugated means a functional group having a nitrogen atom with a lone pair of electrons that does not contribute to A nitrogen atom having a lone pair of electrons that does not contribute to π-conjugation is, for example, a nitrogen atom having a partial structure represented by the following formula.

Preferred partial structures of proton acceptor functional groups include, for example, crown ether structures, azacrown ether structures, primary to tertiary amine structures, pyridine structures, imidazole structures, and pyrazine structures.

The compound (DB) is decomposed by exposure to actinic rays or radiation to reduce or eliminate its proton acceptor property, or to generate a compound whose proton acceptor property is changed to an acidic one. Here, the reduction or disappearance of proton acceptor property, or the change from proton acceptor property to acidity is a change in proton acceptor property due to the addition of protons to the proton acceptor functional group. means that when a proton adduct is produced from a compound (DB) having a proton-accepting functional group and a proton, the equilibrium constant in the chemical equilibrium decreases.
Proton acceptor properties can be confirmed by measuring pH.

The acid dissociation constant pKa of the compound generated by decomposition of the compound (DB) by irradiation with actinic rays or radiation preferably satisfies pKa<−1, more preferably satisfies −13<pKa<−1, and − More preferably, 13<pKa<-3 is satisfied.

The acid dissociation constant pKa means the acid dissociation constant pKa in an aqueous solution, and is defined, for example, in Kagaku Binran (II) (revised 4th edition, 1993, edited by The Chemical Society of Japan, Maruzen Co., Ltd.). A lower acid dissociation constant pKa indicates a higher acid strength. Specifically, the acid dissociation constant pKa in an aqueous solution can be measured by measuring the acid dissociation constant at 25° C. using an infinitely diluted aqueous solution. Alternatively, a value based on a database of Hammett's substituent constants and known literature values can be obtained by calculation using Software Package 1 described below. All pKa values described herein are calculated using this software package.

Software Package 1: Advanced Chemistry Development (ACD/Labs) Software V8.14 for Solaris (1994-2007 ACD/Labs).

An onium salt (DC), which is a relatively weak acid relative to the photoacid generator, can be used as an acid diffusion control agent in the compositions of the present invention.
When a photo-acid generator and an onium salt that generates an acid that is relatively weak to the acid generated from the photo-acid generator are mixed and used, the photo-acid generator is exposed to actinic rays or radiation. When the acid generated from collides with an onium salt with an unreacted weak acid anion, salt exchange releases the weak acid to yield an onium salt with a strong acid anion. In this process, the strong acid is exchanged for a weak acid with a lower catalytic activity, so that the acid is apparently deactivated and acid diffusion can be controlled.

Compounds represented by the following general formulas (d1-1) to (d1-3) are preferred as the onium salt that is relatively weakly acidic with respect to the photoacid generator.

In the formula, R ⁵¹ is an optionally substituted hydrocarbon group, and Z ^2c is an optionally substituted hydrocarbon group having 1 to 30 carbon atoms (provided that the carbon adjacent to S is not substituted with a fluorine atom), R ⁵² is an organic group, Y ³ is a linear, branched or cyclic alkylene group or arylene group, and Rf is a fluorine atom and each M ⁺ is independently an ammonium cation, a sulfonium cation, or an iodonium cation.

Preferred examples of the sulfonium cation or iodonium cation represented by M ⁺ include the sulfonium cations exemplified by general formula (ZI) and the iodonium cations exemplified by general formula (ZII).

An onium salt (DC), which is a relatively weak acid with respect to a photoacid generator, is a compound ( Hereinafter, it may also be referred to as a “compound (DCA)”).
As the compound (DCA), compounds represented by any one of the following general formulas (C-1) to (C-3) are preferable.

In general formulas (C-1) to (C-3),
R ₁ , R ₂ and R ₃ each independently represent a substituent having 1 or more carbon atoms.
L ₁ represents a divalent linking group or a single bond that links the cation site and the anion site.
—X ^— represents an anionic moiety selected from —COO ⁻ , —SO ₃ ⁻ , —SO ₂ ⁻ , and —N ⁻ —R ₄ . R ₄ has a carbonyl group (-C(=O)-), a sulfonyl group (-S(=O) ₂ -), and a sulfinyl group (-S(=O)- ) represents a monovalent substituent having at least one of
R ₁ , R ₂ , R ₃ , R ₄ and L ₁ may combine with each other to form a ring structure. In general formula (C-3), two of R ₁ to R ₃ together represent one divalent substituent, which may be bonded to the N atom via a double bond.

Examples of substituents having 1 or more carbon atoms for R ₁ to R ₃ include an alkyl group, a cycloalkyl group, an aryl group, an alkyloxycarbonyl group, a cycloalkyloxycarbonyl group, an aryloxycarbonyl group, an alkylaminocarbonyl group, and a cycloalkylamino A carbonyl group, an arylaminocarbonyl group, and the like can be mentioned. An alkyl group, a cycloalkyl group, or an aryl group is preferred.

L ₁ as a divalent linking group is a linear or branched alkylene group, a cycloalkylene group, an arylene group, a carbonyl group, an ether bond, an ester bond, an amide bond, a urethane bond, a urea bond, and two of these A group formed by combining more than one species and the like can be mentioned. L ₁ is preferably an alkylene group, an arylene group, an ether bond, an ester bond, or a group formed by combining two or more of these.

A low-molecular-weight compound (DD) having a nitrogen atom and a group that leaves under the action of an acid (hereinafter also referred to as "compound (DD)") has a group that leaves under the action of an acid on the nitrogen atom. It is preferably an amine derivative having
The group that leaves by the action of an acid is preferably an acetal group, a carbonate group, a carbamate group, a tertiary ester group, a tertiary hydroxyl group, or a hemiaminal ether group, more preferably a carbamate group or a hemiaminal ether group. .
The molecular weight of the compound (DD) is preferably 100-1000, more preferably 100-700, even more preferably 100-500.
Compound (DD) may have a carbamate group with a protecting group on the nitrogen atom. A protecting group constituting a carbamate group is represented by the following general formula (d-1).

In general formula (d-1),
Rb each independently represents a hydrogen atom, an alkyl group (preferably having 1 to 10 carbon atoms), a cycloalkyl group (preferably having 3 to 30 carbon atoms), an aryl group (preferably having 3 to 30 carbon atoms), an aralkyl group ( preferably 1 to 10 carbon atoms) or an alkoxyalkyl group (preferably 1 to 10 carbon atoms). Rb's may combine with each other to form a ring.
The alkyl group, cycloalkyl group, aryl group, and aralkyl group represented by Rb are each independently a hydroxyl group, a cyano group, an amino group, a pyrrolidino group, a piperidino group, a morpholino group, a functional group such as an oxo group, an alkoxy group, or It may be substituted with a halogen atom. The same applies to the alkoxyalkyl group represented by Rb.

Rb is preferably a linear or branched alkyl group, cycloalkyl group or aryl group, more preferably a linear or branched alkyl group or cycloalkyl group.
Examples of the ring formed by connecting two Rb's to each other include alicyclic hydrocarbons, aromatic hydrocarbons, heterocyclic hydrocarbons and derivatives thereof.
Specific structures of the group represented by formula (d-1) include, but are not limited to, structures disclosed in paragraph [0466] of US Patent Publication No. US2012/0135348A1.

Compound (DD) preferably has a structure represented by the following general formula (6).

In general formula (6),
l represents an integer of 0 to 2, m represents an integer of 1 to 3, and satisfies l+m=3.
Ra represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group. When l is 2, the two Ra's may be the same or different, and the two Ra's may be linked together to form a heterocyclic ring together with the nitrogen atom in the formula. This heterocyclic ring may contain a heteroatom other than the nitrogen atom in the formula.
Rb has the same definition as Rb in formula (d-1) above, and preferred examples are also the same.
In the general formula (6), the alkyl group, cycloalkyl group, aryl group, and aralkyl group as Ra are each independently substituted with an alkyl group, cycloalkyl group, aryl group, and aralkyl group as Rb. It may be substituted with the same groups as the groups described above as good groups.

Specific examples of the alkyl group, cycloalkyl group, aryl group, and aralkyl group (these groups may be substituted with the above groups) for Ra include the same groups as the specific examples described above for Rb. be done.
As a preferred embodiment, in general formula (6), l is 2 and m is 1, and two Ra's are linked together to form a heterocyclic ring together with the nitrogen atom in the formula.
Specific examples of particularly preferred compounds (DD) in the present invention include, but are not limited to, compounds disclosed in paragraph [0475] of US Patent Application Publication No. 2012/0135348A1.

The onium salt compound (DE) having a nitrogen atom in the cation moiety (hereinafter also referred to as "compound (DE)") is preferably a compound having a basic site containing a nitrogen atom in the cation moiety. The basic moiety is preferably an amino group, more preferably an aliphatic amino group. More preferably all of the atoms adjacent to the nitrogen atom in the basic moiety are hydrogen atoms or carbon atoms. Moreover, from the viewpoint of improving basicity, it is preferable that an electron-withdrawing functional group (a carbonyl group, a sulfonyl group, a cyano group, a halogen atom, etc.) is not directly connected to the nitrogen atom.
Preferred specific examples of the compound (DE) include, but are not limited to, compounds disclosed in paragraph [0203] of US Patent Application Publication No. 2015/0309408A1.

Preferred examples of acid diffusion control agents are shown below.

In the composition of the present invention, the acid diffusion controller (D) may be used singly or in combination of two or more.
The content of the acid diffusion control agent in the composition of the present invention (the total when multiple types are present) is preferably 0.05 to 10% by mass, preferably 0.05 to 10% by mass, based on the total solid content of the composition. 5% by mass is more preferred.

<Hydrophobic resin (E)>
The composition of the invention may contain a hydrophobic resin. It should be noted that the hydrophobic resin is preferably a resin different from the resin (A).
Hydrophobic resins are preferably designed so that they are unevenly distributed on the surface of the resist film. does not have to contribute to

Hydrophobic resin, from the viewpoint of uneven distribution to the film surface layer, at least one selected from the group consisting of "fluorine atom", "silicon atom", and " _CH3 partial structure contained in the side chain portion of the resin" A resin having a repeating unit having a seed is preferred.
When the hydrophobic resin contains fluorine atoms and/or silicon atoms, the fluorine atoms and/or silicon atoms in the hydrophobic resin may be contained in the main chain of the resin, or may be contained in side chains. may

When the hydrophobic resin contains a fluorine atom, the partial structure containing a fluorine atom is preferably a resin containing an alkyl group containing a fluorine atom, a cycloalkyl group containing a fluorine atom, or an aryl group containing a fluorine atom.

The hydrophobic resin preferably has at least one group selected from the group (x) to (z) below.
(x) an acid group (y) a group that decomposes under the action of an alkaline developer to increase its solubility in the alkaline developer (hereinafter also referred to as a polarity conversion group)
(z) a group that decomposes under the action of an acid

The acid group (x) includes phenolic hydroxyl group, carboxylic acid group, fluorinated alcohol group, sulfonic acid group, sulfonamide group, sulfonylimide group, (alkylsulfonyl)(alkylcarbonyl)methylene group, (alkylsulfonyl)(alkyl carbonyl)imide group, bis(alkylcarbonyl)methylene group, bis(alkylcarbonyl)imide group, bis(alkylsulfonyl)methylene group, bis(alkylsulfonyl)imide group, tris(alkylcarbonyl)methylene group, and tris(alkylsulfonyl) ) methylene group and the like.
Preferred acid groups are fluorinated alcohol groups (preferably hexafluoroisopropanol), sulfonimide groups, or bis(alkylcarbonyl)methylene groups.

Examples of the group (y) that decomposes under the action of an alkaline developer to increase the solubility in the alkaline developer include a lactone group, a carboxylic acid ester group (—COO—), an acid anhydride group (—C(O)OC (O)-), an acid imide group (-NHCONH-), a carboxylic acid thioester group (-COS-), a carbonate group (-OC(O)O-), a sulfate group (-OSO ₂ O-), and A sulfonic acid ester group (--SO ₂ O--) and the like can be mentioned, and a lactone group or a carboxylic acid ester group (--COO--) is preferred.
Repeating units containing these groups are, for example, repeating units in which these groups are directly bonded to the main chain of the resin, and examples thereof include repeating units of acrylic acid esters and methacrylic acid esters. These repeating units may be bonded to the main chain of the resin via a linking group. Alternatively, this repeating unit may be introduced at the end of the resin using a polymerization initiator or chain transfer agent having these groups during polymerization.
Examples of the repeating unit having a lactone group include those similar to the repeating unit having a lactone structure described above in the section of resin (A).

The content of the repeating unit having a group (y) that is decomposed by the action of an alkaline developer to increase the solubility in the alkaline developer is 1 to 100 mol% with respect to the total repeating units in the hydrophobic resin (E). is preferred, 3 to 98 mol% is more preferred, and 5 to 95 mol% is even more preferred.

Examples of the repeating unit having a group (z) decomposable by the action of an acid in the hydrophobic resin (E) are the same as the repeating units having an acid-decomposable group exemplified for the resin (A). A repeating unit having a group (z) decomposable under the action of an acid may have at least one of a fluorine atom and a silicon atom. The content of repeating units having a group (z) decomposable by the action of an acid is preferably 1 to 80 mol%, more preferably 10 to 80 mol%, based on all repeating units in the hydrophobic resin (E). , 20 to 60 mol % is more preferred.
The hydrophobic resin (E) may further have repeating units other than the repeating units described above.

The repeating unit containing a fluorine atom is preferably 10 to 100 mol %, more preferably 30 to 100 mol %, relative to all repeating units in the hydrophobic resin (E). Also, the repeating unit containing a silicon atom is preferably 10 to 100 mol %, more preferably 20 to 100 mol %, relative to all repeating units in the hydrophobic resin (E).

On the other hand, especially when the hydrophobic resin (E) contains a CH ₃ partial structure in the side chain portion, it is also preferable that the hydrophobic resin (E) does not substantially contain fluorine atoms and silicon atoms. Moreover, it is preferable that the hydrophobic resin (E) is substantially composed only of repeating units composed only of atoms selected from carbon atoms, oxygen atoms, hydrogen atoms, nitrogen atoms and sulfur atoms.

The weight average molecular weight of the hydrophobic resin (E) in terms of standard polystyrene is preferably 1,000 to 100,000, more preferably 1,000 to 50,000.

The total content of residual monomers and/or oligomer components contained in the hydrophobic resin (E) is preferably 0.01 to 5% by mass, more preferably 0.01 to 3% by mass. Further, the dispersity (Mw/Mn) is preferably in the range of 1-5, more preferably in the range of 1-3.

As the hydrophobic resin (E), known resins can be appropriately selected and used either singly or as a mixture thereof. For example, known resins disclosed in paragraphs [0451] to [0704] of US Patent Application Publication No. 2015/0168830A1 and paragraphs [0340] to [0356] of US Patent Application Publication No. 2016/0274458A1 can be suitably used as the hydrophobic resin (E). Further, repeating units disclosed in paragraphs [0177] to [0258] of US Patent Application Publication No. 2016/0237190A1 are also preferable as repeating units constituting the hydrophobic resin (E).

Preferred examples of monomers corresponding to repeating units constituting the hydrophobic resin (E) are shown below.

The hydrophobic resin (E) may be used singly or in combination of two or more.
It is preferable to use a mixture of two or more types of hydrophobic resins (E) having different surface energies from the viewpoint of compatibility between immersion liquid followability and development characteristics in immersion exposure.
The content of the hydrophobic resin (E) in the composition is preferably 0.01-10% by mass, more preferably 0.05-8% by mass, based on the total solid content in the composition of the present invention.

<Crosslinking agent (G)>
The composition of the present invention may contain a compound that cross-links the resin by the action of acid (hereinafter also referred to as a cross-linking agent (G)). As the cross-linking agent (G), known compounds can be appropriately used. For example, known compounds disclosed in paragraphs [0379] to [0431] of US Patent Application Publication No. 2016/0147154A1 and paragraphs [0064] to [0141] of US Patent Application Publication No. 2016/0282720A1 can be suitably used as the cross-linking agent (G).
The cross-linking agent (G) is a compound having a cross-linkable group capable of cross-linking the resin. and an oxetane ring.
The crosslinkable group is preferably a hydroxymethyl group, an alkoxymethyl group, an oxirane ring or an oxetane ring.
The cross-linking agent (G) is preferably a compound (including resin) having two or more cross-linkable groups.
The cross-linking agent (G) is more preferably a phenol derivative, a urea compound (compound having a urea structure) or a melamine compound (compound having a melamine structure) having a hydroxymethyl group or an alkoxymethyl group.
The cross-linking agents may be used singly or in combination of two or more.
The content of the cross-linking agent (G) is preferably 1 to 50% by mass, preferably 3 to 40% by mass, more preferably 5 to 30% by mass, based on the total solid content of the composition of the present invention.

The composition of the present invention may or may not contain a cross-linking agent (G). As one aspect, it is preferable not to contain the cross-linking agent (G).

<Surfactant (H)>
The composition of the invention preferably contains a surfactant. When a surfactant is contained, a fluorine-based and/or silicon-based surfactant (specifically, a fluorine-based surfactant, a silicon-based surfactant, or a surfactant having both fluorine atoms and silicon atoms ) is preferred.

By containing a surfactant in the composition of the present invention, when an exposure light source of 250 nm or less, particularly 220 nm or less is used, a pattern with good adhesion and little development defects can be obtained with good sensitivity and resolution. .
Fluorinated and/or silicon-based surfactants include surfactants described in paragraph [0276] of US Patent Application Publication No. 2008/0248425.
Also, other surfactants than the fluorine-based and/or silicon-based surfactants described in paragraph [0280] of US Patent Application Publication No. 2008/0248425 can be used.

These surfactants may be used singly or in combination of two or more.
When the composition of the present invention contains a surfactant, the content of the surfactant is preferably 0.0001 to 2% by mass, and 0.0005 to 1% by mass, based on the total solid content of the composition. more preferred.
On the other hand, when the content of the surfactant is 10 ppm (parts per million) or more relative to the total solid content of the composition, the uneven surface distribution of the hydrophobic resin (E) is increased. As a result, the surface of the actinic ray-sensitive or radiation-sensitive film can be made more hydrophobic, and the water followability during immersion exposure is improved.

<Other additives>
The compositions of the present invention may or may not contain an onium carboxylate. Examples of such onium carboxylic acid salts include those described in US Patent Application Publication No. 2008/0187860 <0605> to <0606>.
These onium carboxylic acid salts can be synthesized by reacting sulfonium hydroxide, iodonium hydroxide, ammonium hydroxide and carboxylic acid with silver oxide in a suitable solvent.

When the composition of the present invention contains an onium carboxylate, its content is generally 0.1 to 20% by mass, preferably 0.5 to 10% by mass, based on the total solid content of the composition. , more preferably 1 to 7% by mass.
The composition of the present invention may optionally further contain an acid multiplier, a dye, a plasticizer, a photosensitizer, a light absorber, an alkali-soluble resin, a dissolution inhibitor, and a compound that promotes solubility in a developer ( For example, a phenolic compound having a molecular weight of 1,000 or less, an alicyclic or aliphatic compound having a carboxyl group, or the like can be contained.

Such a phenol compound having a molecular weight of 1,000 or less can be obtained, for example, by referring to the methods described in JP-A-4-122938, JP-A-2-28531, US Pat. It can be easily synthesized by those skilled in the art.
Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, and lithocholic acid, adamantanecarboxylic acid derivatives, adamantanedicarboxylic acid, cyclohexanecarboxylic acid, and cyclohexane. Examples include, but are not limited to, dicarboxylic acids.

<Application>
The composition of the present invention used in the pattern forming method of the present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition that reacts with exposure to actinic rays or radiation to change its properties. More specifically, the composition of the present invention can be used in semiconductor manufacturing processes such as IC (Integrated Circuit), circuit board manufacturing such as liquid crystals or thermal heads, manufacturing of imprint mold structures, other photofabrication processes, or The present invention relates to an actinic ray- or radiation-sensitive resin composition used for producing a lithographic printing plate or an acid-curable composition. A pattern formed by the pattern forming method of the present invention can be used in an etching process, an ion implantation process, a bump electrode forming process, a rewiring forming process, MEMS (Micro Electro Mechanical Systems), and the like.

The actinic ray-sensitive or radiation-sensitive resin composition of the present invention is a composition for forming an actinic ray-sensitive or radiation-sensitive film having a film thickness of 1 μm or more. The film thickness is more preferably 2 μm or more, and even more preferably 3 μm or more.
Moreover, the film thickness of the actinic ray-sensitive or radiation-sensitive film is usually 15 μm or less.

The solid content concentration of the composition of the present invention is usually 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more.
The solid content concentration of the composition of the present invention is usually 50% by mass or less, preferably 45% by mass or less, from the viewpoint of ensuring the coating properties of the composition.
The solid content concentration of the composition of the present invention is preferably 10 to 50% by mass, more preferably 15 to 45% by mass, still more preferably 15 to 40% by mass.
The solid content concentration is the mass percentage of the mass of other resist components excluding the solvent relative to the total mass of the composition.

The composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably in the above mixed solvent, filtering the solution, and coating it on a predetermined substrate. The pore size of the filter used for filtration is generally 1.0 μm or less, preferably 100 nm or less, more preferably 10 nm or less, and is preferably made of polytetrafluoroethylene, polyethylene or nylon. In filter filtration, for example, as disclosed in Japanese Patent Laid-Open No. 2002-62667, cyclic filtration may be performed, or multiple types of filters may be connected in series or in parallel to perform filtration. Also, the composition may be filtered multiple times. Furthermore, before and after filtration, the composition may be subjected to degassing treatment or the like.

As described above, the pattern formation method of the present invention includes:
(i) a step of forming (forming) an actinic ray-sensitive or radiation-sensitive film (hereinafter simply referred to as film) having a thickness of 1 μm or more using an actinic ray-sensitive or radiation-sensitive resin composition;
(ii) a step of irradiating the actinic ray-sensitive or radiation-sensitive film with KrF light (exposure step); A pattern forming method comprising a step (developing step) of forming a negative pattern by developing using a developer containing
The actinic ray-sensitive or radiation-sensitive resin composition comprises (A) a resin having a repeating unit having an aromatic group and a repeating unit having a group that decomposes under the action of an acid to form a polar group, and (B) containing a compound that generates an acid upon exposure to actinic rays or radiation, and (C) a solvent,
In the pattern forming method, the content of the repeating unit having the aromatic group is 15 mol % or more relative to the total repeating units in the resin (A).

The pattern forming method of the present invention preferably includes (iv) a heating step after the (ii) exposure step.
The pattern forming method of the present invention may include (ii) the exposure step multiple times.
(ii) Multiple exposure is mentioned as what includes an exposure process several times.
Multiple exposure is exposing a plurality of focal depths of the actinic ray-sensitive or radiation-sensitive film using KrF light, and these focal depths are different in the actinic ray-sensitive or radiation-sensitive film. It refers to crossing the territory.
In the multiple exposure, it is preferable to expose a plurality of focal depths in the film thickness direction.
The pattern formation method of the present invention may include (iv) the heating step multiple times.

In the pattern forming method of the present invention, the step of forming a film on a substrate using the composition of the present invention, the step of exposing the film, and the developing step can be performed by generally known methods.
The substrate on which the film is formed in the present invention is not particularly limited, and includes inorganic substrates such as silicon, SiN, SiO ₂ and SiN, coating inorganic substrates such as SOG, semiconductor manufacturing processes such as ICs, liquid crystals, and thermal heads. Substrates that are generally used in the manufacturing process of circuit boards such as substrates and other lithography processes in photofabrication can be used. Furthermore, if necessary, an antireflection film may be formed between the resist film and the substrate. As the antireflection film, a known organic or inorganic antireflection film can be appropriately used.

As described above, the thickness of the film obtained from the actinic ray-sensitive or radiation-sensitive resin composition of the present invention is 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more.
Also, the thickness of the film is usually 15 μm or less.

It is also preferable to include a pre-heating step (PB; Prebake) after film formation and before the exposure step.
Moreover, it is also preferable to include a post-exposure baking process (PEB; Post Exposure Bake) after the exposure process and before the development process.
The heating temperature for both PB and PEB is preferably 70 to 160°C, more preferably 80 to 150°C.
The heating time is preferably 30 to 300 seconds, more preferably 30 to 180 seconds, even more preferably 30 to 90 seconds.
Heating can be performed by a means provided in a normal exposure/developing machine, and may be performed using a hot plate or the like.
Baking accelerates the reaction of the exposed area, improving the sensitivity and pattern profile.

The light source wavelength used in the exposure apparatus of the present invention is 200-300 nm. Therefore, the light source is a KrF excimer laser (248 nm).

A developer containing an organic solvent (hereinafter also referred to as an organic developer) is used as the developer used in the step of developing the film formed using the composition of the present invention.

As the organic developer, polar solvents and hydrocarbon solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents can be used. -218223, paragraph <0507>, isoamyl acetate, butyl butanoate, methyl 2-hydroxyisobutyrate, and the like.
A plurality of the above solvents may be mixed, or a solvent other than the above or water may be mixed and used. However, in order to fully exhibit the effects of the present invention, the water content of the developer as a whole is preferably less than 10% by mass, and more preferably substantially free of water.
That is, the amount of the organic solvent used in the organic developer is preferably 90% by mass or more and 100% by mass or less, and preferably 95% by mass or more and 100% by mass or less, relative to the total amount of the developer.

In particular, the organic developer is preferably a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents. .

The vapor pressure of the organic developer at 20° C. is preferably 5 kPa or less, more preferably 3 kPa or less, and particularly preferably 2 kPa or less. By setting the vapor pressure of the organic developer to 5 kPa or less, evaporation of the developer on the substrate or in the developing cup is suppressed, temperature uniformity within the wafer surface is improved, and as a result, dimensional uniformity within the wafer surface is achieved. sex improves.

An appropriate amount of surfactant can be added to the organic developer as needed.
Although the surfactant is not particularly limited, for example, ionic or nonionic fluorine-based and/or silicon-based surfactants can be used. Examples of these fluorine and/or silicon surfactants include JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, US Pat. No. 5,405,720, the same 5360692, 5529881, 5296330, 5436098, 5576143, 5294511 and 5824451. , preferably non-ionic surfactants. Although the nonionic surfactant is not particularly limited, it is more preferable to use a fluorine-based surfactant or a silicon-based surfactant.

The amount of surfactant used is generally 0.001 to 5% by mass, preferably 0.005 to 2% by mass, more preferably 0.01 to 0.5% by mass, relative to the total amount of the developer.

The organic developer may contain a basic compound. Specific examples and preferred examples of the basic compound that the organic developer used in the present invention may contain are the same as those in the basic compound that the composition may contain as the acid diffusion control agent (D).

Examples of the development method include a method of immersing the substrate in a bath filled with a developer for a certain period of time (dip method), and a method of developing by standing still for a certain period of time while the developer is heaped up on the surface of the substrate by surface tension (puddle method). method), a method of spraying the developer onto the substrate surface (spray method), and a method of continuously discharging the developer while scanning the developer discharge nozzle at a constant speed onto the substrate rotating at a constant speed (dynamic dispensing method). etc. can be applied.

When the above-described various developing methods include a step of discharging the developer from the developing nozzle of the developing device toward the resist film, the discharge pressure of the discharged developer (flow velocity per unit area of the discharged developer) is It is preferably 2 mL/sec/mm ² or less, more preferably 1.5 mL/sec/mm ² or less, and even more preferably 1 mL/sec/mm ² or less. Although there is no particular lower limit for the flow rate, it is preferably 0.2 mL/sec/mm ² or more in consideration of throughput.
By setting the ejection pressure of the ejected developer within the above range, pattern defects caused by resist residues after development can be significantly reduced.
Although the details of this mechanism are not clear, it is probable that by setting the ejection pressure within the above range, the pressure exerted by the developing solution on the resist film is reduced, and the resist film and resist pattern are inadvertently scraped or collapsed. This is thought to be due to the suppression of
The developer discharge pressure (mL/sec/mm ² ) is the value at the outlet of the developing nozzle in the developing device.

Examples of methods for adjusting the discharge pressure of the developer include a method of adjusting the discharge pressure with a pump or the like, and a method of changing the pressure by adjusting the pressure supplied from a pressure tank.
Further, after the step of developing with a developer containing an organic solvent, a step of stopping the development while replacing with another solvent may be performed.

It is preferable to include a step of washing with a rinse after the step of developing with a developer containing an organic solvent.
The rinse solution used in the rinse step after the step of developing with a developer containing an organic solvent is not particularly limited as long as it does not dissolve the resist pattern, and a common solution containing an organic solvent can be used. . The rinse liquid should contain at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents. is preferred.
Specific examples of the hydrocarbon-based solvent, ketone-based solvent, ester-based solvent, alcohol-based solvent, amide-based solvent, and ether-based solvent are the same as those described for the developer containing an organic solvent.

After the step of developing with a developer containing an organic solvent, more preferably at least one solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, and hydrocarbon solvents. , more preferably a rinse solution containing an alcohol solvent or an ester solvent, particularly preferably a monohydric alcohol The step of washing is performed using the containing rinse solution, and most preferably, the step of washing using the rinse solution containing a monohydric alcohol having 5 or more carbon atoms is performed.

Here, the monohydric alcohol used in the rinsing step includes linear, branched, and cyclic monohydric alcohols, specifically 1-butanol, 2-butanol, and 3-methyl-1-butanol. , tert-butyl alcohol, 1-pentanol, 2-pentanol, 1-hexanol, 4-methyl-2-pentanol, 1-heptanol, 1-octanol, 2-hexanol, cyclopentanol, 2-heptanol, 2 - Octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, etc. can be used, and particularly preferred monohydric alcohols having 5 or more carbon atoms include 1-hexanol, 2-hexanol, 4-methyl- 2-pentanol, 1-pentanol, 3-methyl-1-butanol and the like can be used.
The hydrocarbon solvent used in the rinsing step is preferably a hydrocarbon compound having 6 to 30 carbon atoms, more preferably a hydrocarbon compound having 8 to 30 carbon atoms, and still more preferably a hydrocarbon compound having 7 to 30 carbon atoms. Hydrocarbon compounds having 10 to 30 carbon atoms are particularly preferred. In particular, pattern collapse is suppressed by using a rinse containing decane and/or undecane.

A plurality of each component may be mixed, or a mixture with an organic solvent other than the above may be used.
The water content in the rinse liquid is preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 3% by mass or less. Good developing properties can be obtained by setting the water content to 10% by mass or less.

The vapor pressure of the rinsing solution used after the step of developing with the developer containing an organic solvent is preferably 0.05 kPa or more and 5 kPa or less, more preferably 0.1 kPa or more and 5 kPa or less, at 20°C. 12 kPa or more and 3 kPa or less are most preferable. By setting the vapor pressure of the rinsing liquid to 0.05 kPa or more and 5 kPa or less, the temperature uniformity in the wafer surface is improved, swelling caused by the permeation of the rinsing liquid is suppressed, and the dimensional uniformity in the wafer surface is improved. improves.

An appropriate amount of surfactant may be added to the rinse solution before use.
In the rinsing step, the wafer that has been developed with the developer containing the organic solvent is washed with the rinse liquid containing the organic solvent. The method of cleaning treatment is not particularly limited, but for example, a method of continuously discharging the rinse solution onto the substrate rotating at a constant speed (rotation coating method), or a method of immersing the substrate in a tank filled with the rinse solution for a certain period of time. A method (dip method), a method of spraying a rinse solution onto the substrate surface (spray method), etc. can be applied. It is preferable to rotate to remove the rinse liquid from the substrate. It is also preferable to include a heating step (Post Bake) after the rinsing step. The developer and rinse liquid remaining between the patterns and inside the patterns are removed by baking. The heating step after the rinsing step is usually carried out at 40 to 160° C., preferably 70 to 95° C., for usually 10 seconds to 3 minutes, preferably 30 seconds to 90 seconds.

In the pattern forming method of the present invention, in addition to the step of developing using a developer containing an organic solvent (organic solvent developing step), the step of developing using an alkaline aqueous solution (alkali developing step) is used in combination. may Thereby, a finer pattern can be formed.
In the present invention, portions of weakly exposed light intensity are removed by the organic solvent developing step, and portions of strong exposed light intensity are also removed by further performing the alkali developing step. By the multiple development process in which development is performed multiple times in this way, pattern formation can be performed without dissolving only the intermediate exposure intensity region, so that a finer pattern than usual can be formed (Japanese Patent Laid-Open No. 2008-292975 <0077 >).
In the pattern forming method of the present invention, the order of the alkali development step and the organic solvent development step is not particularly limited, but it is more preferable to carry out the alkali development before the organic solvent development step.

Examples of the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, Secondary amines such as di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium Hydroxide, tetrabutylammonium hydroxide, tetrapentylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, ethyltrimethylammonium hydroxide, butyltrimethylammonium hydroxide, methyltriamylammonium hydroxide, dibutyldipentylammonium hydroxide Alkaline aqueous solutions of tetraalkylammonium hydroxide such as hydroxide, quaternary ammonium salts such as trimethylphenylammonium hydroxide, trimethylbenzylammonium hydroxide and triethylbenzylammonium hydroxide, and cyclic amines such as pyrrole and pyrridine are used. be able to. Furthermore, appropriate amounts of alcohols and surfactants may be added to the alkaline aqueous solution. The alkali concentration of the alkali developer is usually 0.1 to 20 mass %. The pH of the alkaline developer is usually 10.0-15.0. The alkali concentration and pH of the alkali developer can be appropriately adjusted and used. The alkaline developer may be used by adding a surfactant or an organic solvent.
Pure water may be used as the rinse solution in the rinse treatment performed after alkali development, and an appropriate amount of surfactant may be added.

Further, after the development processing or the rinsing processing, a processing for removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.

Various materials used in the actinic ray-sensitive or radiation-sensitive resin composition of the present invention and the pattern forming method of the present invention (e.g., resist solvent, developer, rinse, composition for forming an antireflection film, top The composition for forming a coat, etc.) preferably does not contain impurities such as metals. The content of impurities contained in these materials is preferably 1 ppm or less, more preferably 10 ppb or less, still more preferably 100 ppt or less, particularly preferably 10 ppt or less, and substantially free (below the detection limit of the measuring device). ) is most preferred.
As a method for removing impurities such as metals from the above various materials, for example, filtration using a filter can be mentioned. The pore size of the filter is preferably 10 nm or less, more preferably 5 nm or less, and even more preferably 3 nm or less. Filters made of polytetrafluoroethylene, polyethylene, or nylon are preferable as the material of the filter. The filter may be a composite material combining these materials and ion exchange media. A filter that has been pre-washed with an organic solvent may be used. In the filter filtration step, multiple types of filters may be connected in series or in parallel for use. When multiple types of filters are used, filters with different pore sizes and/or materials may be used in combination. Further, various materials may be filtered multiple times, and the process of filtering multiple times may be a circulation filtration process.
In addition, as a method for reducing impurities such as metals contained in the various materials, selecting raw materials with a low metal content as raw materials constituting various materials, performing filter filtration on raw materials constituting various materials, For example, distillation may be performed under conditions in which contamination is suppressed as much as possible by lining the inside of the apparatus with Teflon (registered trademark). Preferred conditions for filtering the raw materials constituting various materials are the same as those described above.
In addition to filter filtration, an adsorbent may be used to remove impurities, or a combination of filter filtration and an adsorbent may be used. As the adsorbent, known adsorbents can be used. For example, inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon can be used.

A method for improving surface roughness of the pattern may be applied to the pattern formed by the method of the present invention. As a method of improving the surface roughness of the pattern, for example, there is a method of treating the resist pattern with hydrogen-containing gas plasma disclosed in WO 2014/002808. In addition, Japanese Unexamined Patent Application Publication No. 2004-235468, US Published Patent Application No. 2010/0020297, Japanese Unexamined Patent Application Publication No. 2009-19969, Proc. of SPIE Vol. 8328 83280N-1 "EUV Resist Curing Technique for LWR Reduction and Etch Selectivity Enhancement" may be applied.
The pattern forming method of the present invention can also be used for guide pattern formation in DSA (Directed Self-Assembly) (see, for example, ACS Nano Vol.4 No.8 Pages 4815-4823).
In addition, the resist pattern formed by the above method can be used as a core for spacer processes disclosed in, for example, JP-A-3-270227 and JP-A-2013-164509.

The present invention also relates to an ion implantation method (also referred to as the ion implantation method of the present invention) including a step of implanting ions using the pattern obtained by the pattern forming method of the present invention as a mask.
After a pattern is formed by the pattern forming method of the present invention, ion implantation is performed using the pattern as a mask.
The ion implantation method itself is well known, and involves ionizing a target substance, electrostatically accelerating it, and implanting it into a solid (a thin film on a substrate). As conditions such as ion acceleration energy at the time of ion implantation, known conditions can be adopted as they are. Ion sources include ions of boron, phosphorous, arsenic, argon, and the like. Thin films on substrates include silicon, silicon dioxide, Tikka silicon, aluminum, and the like.

The present invention also relates to an electronic device manufacturing method including the pattern forming method of the present invention or the ion implantation method of the present invention, and an electronic device manufactured by this manufacturing method.
The electronic device of the present invention is preferably mounted in electrical and electronic equipment (household appliances, OA/media-related equipment, optical equipment, communication equipment, etc.).

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

<Preparation of actinic ray-sensitive or radiation-sensitive resin composition>
The components shown in Table 1 below were dissolved in a solvent to prepare a resist solution for each, which was filtered through a UPE (ultra high molecular weight polyethylene) filter having a pore size of 1.0 μm. Thus, an actinic ray-sensitive or radiation-sensitive resin composition (resist composition) having a solid concentration shown in Table 1 was prepared.

The components and abbreviations in Table 1 above are as follows.

The structure, composition ratio (molar ratio), weight average molecular weight (Mw), and degree of dispersion (Mw/Mn) of the resin are shown below.

The structure of the photoacid generator is as follows. Bu represents an n-butyl group.

The structure of the acid diffusion control agent is as follows.

C-1: Trioctylamine

The structure of the surfactant is shown below.

G-2: Troisol S366 (silicon-based surfactant, manufactured by Troy Chemical Co., Ltd.)
G-3: Megafac-R4 (fluorosurfactant, manufactured by DIC Corporation)

Solvents are as follows.
PGMEA: propylene glycol monomethyl ether acetate PGME: propylene glycol monomethyl ether EL: ethyl lactate

Examples 1-36, and Comparative Examples 1-2
(pattern formation)
Using Tokyo Electron's spin coater "ACT-8", hexamethyldisilazane-treated 8-inch Si substrate (manufactured by Advanced Materials Technology (hereinafter also referred to as "Si substrate" or "substrate")) on Then, without providing an antireflection layer, the resist composition prepared above was dropped while the substrate was stationary. After the dropping, the substrate was rotated, and the rotation speed was maintained at 500 rpm for 3 seconds, then at 100 rpm for 2 seconds, at 500 rpm for further 3 seconds, and again at 100 rpm for 2 seconds, after which the film thickness setting rotation was performed. (the number of revolutions to achieve the film thickness listed in Table 2) and maintained for 60 seconds. After that, it was baked on a hot plate at 150° C. for 60 seconds (PreBake; PB) to form an actinic ray-sensitive or radiation-sensitive film (resist film) having the film thickness (μm) shown in Table 2.

The wafer on which the resist film was formed was subjected to pattern exposure through an exposure mask using a KrF excimer laser scanner (PAS5500/850C, manufactured by ASML, wavelength 248 nm, NA 0.55). After that, it was baked at 115° C. for 60 seconds (Post Exposure Bake; PEB), developed with an organic developer shown in Table 2 below for 60 seconds, rinsed with 4-methyl-2-pentanol, and spin-dried. . As a result, an isolated space pattern with a space of 400 nm and a pitch of 3000 nm was obtained.
In Table 2 below, nBA represents n-butyl acetate and MAK represents 2-heptanone (methyl amyl ketone).
One inch is 25.4 millimeters.

<Evaluation>
(Cross-sectional shape of isolated space pattern)
The space pattern is exposed through a mask having a line and space pattern such that the space pattern after reduction projection exposure is 400 nm and the pitch is 3000 nm. ) was defined as 100%, the optimum exposure amount was defined as the amount of space width of 400 nm at the 10% position, and this optimum exposure amount was defined as the sensitivity (mJ/cm ² ). A scanning electron microscope (SEM) (9380II manufactured by Hitachi) was used to measure the space pattern width.
A wafer having an isolated space pattern formed at the above sensitivity was cut, and the cut surface was observed using a scanning electron microscope (SEM). The space widths at the 90% and 10% positions when the height of the pattern in the film thickness direction (film thickness shown in Table 2) in the isolated space pattern in the cross section is taken as 100% are CD(Top) and CD, respectively. CD-Bias (nm) was defined as the absolute value of the difference between CD(Top) and CD(bottom) ((CD(Top))-(CD(bottom))). The smaller the value of CD-Bias, the more rectangular the isolated space pattern. Also, the value of CD-Bias satisfying the following formula is within the practically acceptable range.

(Ion implantation resistance performance evaluation)
Using Tokyo Electron's spin coater "ACT-8", hexamethyldisilazane-treated 8-inch Si substrate (manufactured by Advanced Materials Technology (hereinafter also referred to as "substrate")), an antireflection layer , the resist composition prepared above was dropped while the substrate was stationary. After the dropping, the substrate was rotated, and the rotation speed was maintained at 500 rpm for 3 seconds, then at 100 rpm for 2 seconds, at 500 rpm for further 3 seconds, and again at 100 rpm for 2 seconds, after which the film thickness setting rotation was performed. (the number of revolutions to achieve the film thickness listed in Table 2) and maintained for 60 seconds. Then, it was dried by heating on a hot plate at 150° C. for 90 seconds to form a resist film having a film thickness (μm) shown in Table 2.
Through the above procedure, a wafer with a resist film having a substrate and a solid film of the resist film formed on the substrate was obtained. This resist film-coated wafer was used as an evaluation wafer without exposure and development.

Next, ion implantation was performed on the wafer for evaluation, and ion leakage to the substrate was evaluated.
Specifically, phosphorus was implanted by ion implantation under conditions of a dose of 2×10 ¹³ cm ⁻² and an energy of 80 KeV, and then the mask was removed. After that, the amount of phosphorus implanted into the substrate was quantified by dynamic SIMS (Secondary Ion Mass Spectrometry) analysis. Each value of Examples and Comparative Examples is shown by standardizing the value of Comparative Example 1 as 1 (reference).
The smaller this value, the less ion leakage to the Si substrate, and when ion implantation is performed using a resist pattern as a mask, the ion leakage to the substrate located in the region below the mask is suppressed, and the ion implantation resistance performance is improved. means superior.

(Pattern formation by multiple exposure)
A pattern was formed in the same manner as in Examples 33 and 34, except that the focus position in the exposure was changed to two optimal focus positions during the exposure, and the exposure was performed twice at these optimal focus positions. Examples 35 and 36 were used.
In Examples 1 to 32, a good cross-sectional shape was obtained in the same manner as above in which the same two exposures were performed.

From the above results, in Examples 1 to 36 using the pattern forming method of the present invention, the content of the repeating unit having the aromatic group is less than 15 mol% with respect to the total repeating units of the resin (A). As compared with Comparative Example 1, it was found that the rectangularity of the cross-sectional shape of the resist pattern was excellent, and the ion implantation resistance was also excellent.

Claims (14)

(i) forming an actinic ray-sensitive or radiation-sensitive film having a thickness of 1 μm or more using an actinic ray-sensitive or radiation-sensitive resin composition;
(ii) irradiating the actinic ray-sensitive or radiation-sensitive film with KrF light; A pattern forming method comprising the step of forming a negative pattern by developing using
The actinic ray-sensitive or radiation-sensitive resin composition comprises (A) a resin having a repeating unit having an aromatic group and a repeating unit having a group that decomposes under the action of an acid to form a polar group, and (B) containing a compound that generates an acid upon exposure to actinic rays or radiation, and (C) a solvent,
A pattern forming method, wherein the content of the repeating unit having the aromatic group is 15 to 60 mol % with respect to the total repeating units of the resin (A). 2. The pattern forming method according to claim 1, wherein the repeating unit having a group that is decomposed by the action of an acid to generate a polar group has an alicyclic hydrocarbon group having 5 to 20 carbon atoms. (i) forming an actinic ray-sensitive or radiation-sensitive film having a thickness of 1 μm or more using an actinic ray-sensitive or radiation-sensitive resin composition;
(ii) irradiating the actinic ray-sensitive or radiation-sensitive film with KrF light; A pattern forming method comprising the step of forming a negative pattern by developing using
The actinic ray-sensitive or radiation-sensitive resin composition comprises (A) a resin having a repeating unit having an aromatic group and a repeating unit having a group that decomposes under the action of an acid to form a polar group, and (B) containing a compound that generates an acid upon exposure to actinic rays or radiation, and (C) a solvent,
The content of the repeating unit having the aromatic group is 15 mol% or more with respect to the total repeating units of the resin (A) ,
The pattern forming method, wherein the repeating unit having a group that decomposes to form a polar group by the action of an acid has an alicyclic hydrocarbon group having 5 to 20 carbon atoms . 4. The pattern forming method according to claim 3, wherein the content of the repeating unit having an aromatic group is 15 to 60 mol % with respect to the total repeating units of the resin (A). 5. The pattern forming method according to any one of claims 1 to 4 , wherein the step (ii) is performed multiple times. 6. The content of the repeating unit having a group that decomposes to form a polar group by the action of an acid is 25 to 50 mol % of the total repeating units of the resin (A). 2. The pattern forming method according to item 1. Claims 1 to 6 , wherein the repeating unit having a group that is decomposed by the action of an acid to generate a polar group is a repeating unit corresponding to (meth)acrylic acid. The pattern formation method according to any one of the above. The pattern forming method according to any one of claims 1 to 7 , wherein the compound (B) is a compound represented by the following general formula (ZI-3) or general formula (ZI-4).

In general formula (ZI-3),
M represents an alkyl group, a cycloalkyl group, or an aryl group, and when it has a ring structure, the ring structure is at least one of an oxygen atom, a sulfur atom, an ester bond, an amide bond, and a carbon-carbon double bond. may contain
_R1c and _R2c each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group or an aryl group. R _1c and R _2c may combine to form a ring.
R _x and R _y each independently represent an alkyl group, a cycloalkyl group, or an alkenyl group. R _x and R _y may combine to form a ring. Also, at least two selected from M, R _1c and R _2c may combine to form a ring structure, and the ring structure may contain a carbon-carbon double bond.
Z ⁻ represents an anion.

In general formula (ZI-4),
l represents an integer of 0 to 2;
r represents an integer of 0 to 8;
R ₁₃ represents a hydrogen atom, a fluorine atom, a hydroxyl group, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, or a group having a monocyclic or polycyclic cycloalkyl skeleton.
When multiple R ₁₄ are present, they are each independently an alkyl group, cycloalkyl group, alkoxy group, alkylsulfonyl group, cycloalkylsulfonyl group, alkylcarbonyl group, alkoxycarbonyl group, or monocyclic or polycyclic cycloalkyl represents an alkoxy group having a skeleton.
Each R ₁₅ independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. Two R ₁₅ may be joined together to form a ring. When two R ₁₅ are combined to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom.
Z ⁻ represents an anion. 9. The pattern forming method according to any one of claims 1 to 8 , wherein the compound (B) has 6 or less fluorine atoms. The pattern forming method according to any one of claims 1 to 9 , wherein the actinic ray-sensitive or radiation-sensitive resin composition contains an acid diffusion controller. The pattern forming method according to any one of claims 1 to 10 , wherein the actinic ray-sensitive or radiation-sensitive resin composition does not contain a cross-linking agent. The pattern forming method according to any one of claims 1 to 11 , wherein the actinic ray-sensitive or radiation-sensitive resin composition has a solid content concentration of 15% by mass or more. An ion implantation method, comprising a step of implanting ions using the pattern obtained by the pattern formation method according to any one of claims 1 to 12 as a mask. A method for manufacturing an electronic device, comprising the pattern forming method according to any one of claims 1 to 12 or the ion implantation method according to claim 13 .