JP2007279493A - Negative resist composition and resist pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a negative resist composition giving a resist pattern with high rectangularity and a resist pattern forming method. <P>SOLUTION: The negative resist composition contains an alkali-soluble resin component (A), an acid generator component (B) which generates an acid upon exposure to light and a crosslinker component (C), wherein the negative resist composition further contains a photobase generator component (F) which generates a base upon exposure to light. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film. A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. In addition, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.

  Conventionally, as a negative resist material used in a process using i-line or KrF excimer laser light (248 nm) as a light source, an acid generator, an alkali-soluble resin such as a novolac resin or polyhydroxystyrene, a melamine resin, a urea resin, etc. A chemically amplified negative resist composition containing a combination with an amino resin is used (for example, Patent Document 1).

Further, as a negative resist material applied to a process using an ArF excimer laser having a shorter wavelength, a resin component having a carboxy group, a crosslinking agent having an alcoholic hydroxyl group, for example, having improved transparency to an ArF excimer laser , And a negative resist composition containing an acid generator has been proposed. This is a type in which the resin component is changed from alkali-soluble to insoluble by the reaction of the carboxy group of the resin component and the alcoholic hydroxyl group of the crosslinking agent by the action of the acid generated from the acid generator.
A negative resist composition comprising a resin component having both a carboxy group or carboxylic acid ester group and an alcoholic hydroxyl group, and an acid generator, wherein the carboxy group or carboxylic acid ester group and the alcoholic hydroxyl group in the resin component Have been proposed in which the resin component is changed from alkali-soluble to insoluble by reacting between the molecules by the action of an acid generated from an acid generator (for example, non-patent documents 1 to 3, patents). Literature 2 etc.).
As the acid generator, conventionally, onium salt acid generators such as triphenylsulfonium trifluoromethanesulfonate are generally used.
Japanese Patent Publication No. 8-3635 JP 2000-206694 A Journal of Photopolymer Science and Technology (J. Photopolym. Sci. Tech.), Vol. 10, No. 4, 579-584 (1997) Journal of Photopolymer Science and Technology (J. Photopolym. Sci. Tech.), Vol. 11, No. 3, pp. 507-512 (1998) SPIE Advances in Resist Technology and Processing XIV, Vol. 3333, p417-424 (1998) SPIE Advances in Resist technology and Processing XIX, Vol. 4690 p94-100 (2002)

  However, the conventional negative resist composition as described above has a problem that it is difficult to obtain a resist pattern with high rectangularity.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the negative resist composition and resist pattern formation method from which a resist pattern with high rectangularity is obtained.

The present inventors propose the following means in order to solve the above problems.
That is, the first aspect of the present invention is a negative resist composition comprising an alkali-soluble resin component (A), an acid generator component (B) that generates an acid upon exposure, and a crosslinking agent component (C). The negative resist composition further comprises a photobase generator component (F) that generates a base upon exposure.

  The second aspect of the present invention includes a step of forming a resist film on a substrate using the negative resist composition of the first aspect, a step of exposing the resist film, and developing the resist film. It is a resist pattern formation method characterized by including the process of forming a resist pattern.

In the present specification, the “structural unit” means a monomer unit (monomer unit) constituting the resin component (polymer).
The term “exposure” includes not only light irradiation but also general radiation irradiation such as electron beam irradiation.
The “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
In the “alkoxy group”, the alkyl group in the alkoxy group is the same as the “alkyl group”, and includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups.
The “lower alkyl group” refers to an alkyl group having 1 to 5 carbon atoms.

  ADVANTAGE OF THE INVENTION According to this invention, the negative resist composition and resist pattern formation method from which a resist pattern with high rectangularity is obtained are provided.

≪Negative resist composition≫
The negative resist composition of the present invention has an alkali-soluble resin component (A) (hereinafter referred to as “component (A)”), an acid generator component (B) that generates acid upon exposure (hereinafter referred to as “component (B)”). ) And a crosslinking agent component (C) (hereinafter referred to as component (C)).
Such a negative resist composition is alkali-soluble before exposure. When an acid is generated from the component (B) by exposure, the acid acts to cause crosslinking between the component (A) and the component (C). It becomes insoluble in alkali. Therefore, in the formation of the resist pattern, when the resist film formed by applying the negative resist composition on the substrate is selectively exposed, the exposed portion becomes alkali-insoluble while the unexposed portion remains alkali-soluble. A negative resist pattern can be formed by alkali development.
In addition to these components (A) to (C), the negative resist composition of the present invention further contains a photobase generator component (F) that generates a base by exposure.
Hereinafter, each component will be described.

<(A) component>
In the present invention, the component (A) is not particularly limited, and those previously proposed as resins for negative resist compositions for electron beams (EB), KrF excimer lasers, ArF excimer lasers, etc. are used. can do. Among these, a resin for a negative resist composition that is suitably used for an ArF excimer laser is preferable.
Hereinafter, examples of the resin component that is suitably used in lithography using an ArF excimer laser will be described.

The component (A) used for the ArF excimer laser is preferably an alkali-soluble resin having a fluorinated hydroxyalkyl group represented by the general formula (a1-1-1) described later.
Specific examples of suitable component (A) include a structural unit (a1) having an aliphatic cyclic group having a fluorinated hydroxyalkyl group in the main chain, and a structural unit (a2 having a hydroxyalkyl group). And a copolymer containing a copolymer (A1).
Moreover, as a suitable thing of (A) component, the acrylate ester containing the structural unit (a21) containing the aliphatic cyclic group which has a fluorinated hydroxyalkyl group, and a hydroxyl-containing aliphatic cyclic group, for example A copolymer comprising a structural unit derived from (a22) and, preferably, a structural unit (a23) derived from acrylic acid having no cyclic structure and having an alcoholic hydroxyl group in the side chain ( Those containing A2) are also preferably used.

(Copolymer (A1))
In the present invention, the copolymer (A1) includes a structural unit (a1) having an aliphatic cyclic group having a fluorinated hydroxyalkyl group in the main chain (hereinafter abbreviated as a structural unit (a1)). And a structural unit (a2) having a hydroxyalkyl group (hereinafter abbreviated as structural unit (a2)).

・ Structural unit (a1)
The copolymer (A1) includes a structural unit (a1) having an aliphatic cyclic group having a fluorinated hydroxyalkyl group in the main chain.
In the structural unit (a1), the “aliphatic cyclic group having a fluorinated hydroxyalkyl group” means that the fluorinated hydroxyalkyl group is bonded to the carbon atom constituting the ring of the aliphatic cyclic group. Means the group.
Further, “having an aliphatic cyclic group in the main chain” means that at least one, preferably two or more carbon atoms on the ring of the aliphatic cyclic group are in the main chain of the copolymer (A1). Means to configure.
In the present invention, the component (A) contains the copolymer (A1) containing the structural unit (a1), so that the solubility in an alkali developer is increased, and the resist pattern shape and line width roughness (LWR) are increased. Lithographic properties such as are improved. Further, by having an aliphatic cyclic group (for example, a structure of norbornane or tetracyclododecane) in the main chain, the carbon density is increased and the etching resistance is also improved.

Here, the “fluorinated hydroxyalkyl group” is a hydroxyalkyl group in which part of the hydrogen atoms of the alkyl group is substituted with a hydroxy group, and part or all of the remaining hydrogen atoms in the hydroxyalkyl group are It is substituted by a fluorine atom.
In the fluorinated hydroxyalkyl group, the hydrogen atom of the hydroxy group is easily released by fluorination.
In the fluorinated hydroxyalkyl group, the alkyl group is preferably a linear or branched alkyl group.
Although carbon number of this alkyl group is not specifically limited, 1-20 are preferable, 4-16 are more preferable, and it is most preferable that it is 4-12.
The number of hydroxy groups is not particularly limited, but is preferably one.
As the fluorinated hydroxyalkyl group, in particular, a fluorinated alkyl group and / or a fluorine atom is bonded to a carbon atom to which the hydroxy group is bonded (here, the α-position carbon atom of the hydroxyalkyl group). Is preferred.
Here, in the fluorinated alkyl group bonded to the α-position, it is preferable that all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. Further, the alkyl group of the fluorinated alkyl group is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and more preferably 1 carbon atom.

“Aliphatic” in “aliphatic cyclic group having a fluorinated hydroxyalkyl group” is a relative concept with respect to aromaticity, and means a group or compound having no aromaticity. It is defined as The aliphatic cyclic group may be monocyclic or polycyclic.
“Monocyclic aliphatic cyclic group” means a monocyclic group having no aromaticity, and “polycyclic aliphatic cyclic group” means a polycyclic group having no aromaticity. Means a group.
In the structural unit (a1), the aliphatic cyclic group is preferably polycyclic because it is excellent in etching resistance and the like.
An aliphatic cyclic group is a hydrocarbon group composed of carbon and hydrogen (alicyclic group), and a part of the carbon atoms constituting the ring of the alicyclic group is a heterogeneous group such as an oxygen atom, a nitrogen atom, or a sulfur atom. Heterocyclic groups and the like substituted with atoms are included. These aliphatic cyclic groups may have a substituent, and examples of the substituent include an alkyl group having 1 to 5 carbon atoms.
Here, “having a substituent” means that part or all of the hydrogen atoms bonded to the carbon atoms constituting the ring of the aliphatic cyclic group are substituted with a substituent (atom or group other than a hydrogen atom). Means that In the present invention, the alicyclic group is preferable as the aliphatic cyclic group.
The aliphatic cyclic group may be either saturated or unsaturated, but is preferably saturated because it is highly transparent to ArF excimer laser and the like, and has excellent resolution and depth of focus (DOF). .
It is preferable that carbon number of an aliphatic cyclic group is 5-15.

Specific examples of the aliphatic cyclic group include the following.
Examples of the monocyclic group include groups in which two or more hydrogen atoms have been removed from a cycloalkane. More specifically, a group in which two or more hydrogen atoms have been removed from cyclopentane or cyclohexane can be mentioned, and a group in which two or more hydrogen atoms have been removed from cyclohexane is preferred.
Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. More specifically, a group in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane can be used.
Such an aliphatic cyclic group can be appropriately selected and used from among many proposed resins for photoresist compositions for ArF excimer laser processes, for example.
Among these, a group obtained by removing two or more hydrogen atoms from cyclohexane, adamantane, norbornane, or tetracyclododecane is preferable because it is easily available from an industrial viewpoint.
Among these exemplified alicyclic groups, a group obtained by removing three hydrogen atoms from norbornane or tetracyclododecane is preferable, as in the structural unit (a1-1) described later, and in particular, three hydrogen atoms are removed from norbornane. Excluded groups are preferred.

  Preferred examples of the structural unit (a1) include the structural unit (a1-1) represented by the following general formula (a1-1). By having the said structural unit (a1-1), the solubility with respect to an alkali developing solution improves especially. Also, lithography properties such as resolution are improved.

［式中、Ｘはフッ素化されたヒドロキシアルキル基であり、ｒは０または１である。］

[Wherein, X is a fluorinated hydroxyalkyl group, and r is 0 or 1. ]

  In formula (a1-1), r is 0 or 1, and is preferably 0 because it is easily available industrially.

Further, in formula (a1-1), the “fluorinated hydroxyalkyl group” represented by X is the same as described above, and among them, X particularly improves the effect of the present invention. It is preferable that it is group represented by the following general formula (a1-1-1). Further, the resist pattern shape is excellent, and line edge roughness (LER) and the like are reduced, which is preferable.
“Line edge roughness (LER)” refers to uneven unevenness on the side wall of a line.

［式中、Ｒ^１１，Ｒ^１２はそれぞれ独立して水素原子または低級アルキル基であり、ｍ，ｎはそれぞれ独立して１〜５の整数であり、ｑは１〜５の整数である。］

[Wherein, R ¹¹ and R ¹² are each independently a hydrogen atom or a lower alkyl group, m and n are each independently an integer of 1 to 5, and q is an integer of 1 to 5. ]

In formula (a1-1-1), R ¹¹ and R ¹² are each independently a hydrogen atom or a lower alkyl group.
As the lower alkyl group, a linear or branched lower alkyl group having 5 or less carbon atoms is preferable. For example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, A pentyl group, an isopentyl group, a neopentyl group, etc. are mentioned, and a methyl group is preferable.
Especially, it is preferable that both R < ¹¹ >, R < ¹² > is a hydrogen atom.
q is an integer of 1 to 5, more preferably an integer of 1 to 3, and most preferably 1.
m and n are each independently an integer of 1 to 5, more preferably an integer of 1 to 3. In particular, those in which m and n are 1 are preferable because they are excellent in terms of synthesis and the effects of the present invention.

As the structural unit (a1), one type or a mixture of two or more types can be used.
In the copolymer (A1), the proportion of the structural unit (a1) is preferably from 50 to 90 mol%, more preferably from 60 to 90 mol%, based on the total of all structural units constituting the copolymer (A1). Preferably, 60-80 mol% is more preferable. The effect by containing a structural unit (a1) improves by being more than the lower limit of the said range, and a balance with another structural unit becomes favorable by being below an upper limit.

・ Structural unit (a2)
The copolymer (A1) includes a structural unit (a2) having a hydroxyalkyl group.
In the present invention, when the component (A) contains the copolymer (A1) containing the structural unit (a2), the solubility in an alkali developer is improved. In addition, the crosslinkability with the component (C) is increased, and the difference (contrast) in solubility between the exposed portion and the unexposed portion in the alkaline developer is increased, so that it can sufficiently function as a negative resist.
Examples of the structural unit (a2) include a structural unit (a210) having an aliphatic cyclic group having a hydroxyalkyl group in the main chain (hereinafter abbreviated as a structural unit (a210)), and a hydroxyl group-containing alkyl group. A structural unit (a220) derived from an acrylic ester having (hereinafter abbreviated as a structural unit (a220)) or the like is preferably used.
These structural units (a2) can be used alone or in combination of two or more.

Structural unit (a210)
In the present invention, the structural unit (a210) is a structural unit having an aliphatic cyclic group having a hydroxyalkyl group in the main chain.
As the structural unit (a210), in the “fluorinated hydroxyalkyl group” of the structural unit (a1), a non-fluorinated hydroxyalkyl group, that is, a part of hydrogen atoms of the alkyl group is substituted with a hydroxy group. The structural unit similar to the structural unit (a1) is preferable except that the remaining hydrogen atoms in the hydroxyalkyl group are not substituted with fluorine atoms.
Preferred examples of the structural unit (a210) include the structural unit (a2-1) represented by the following general formula (a2-1). By including the structural unit (a2-1), lithography characteristics such as a resist pattern shape and line width roughness (LWR) are improved. In addition, good contrast is easily obtained and etching resistance is improved.

［式中、Ｒ^１，Ｒ^２はそれぞれ独立して水素原子または低級アルキル基であり、Ｒ’は水素原子またはヒドロキシアルキル基であり、ｒは０または１であり、ｐは１〜３の整数である。］

[Wherein, R ¹ and R ² are each independently a hydrogen atom or a lower alkyl group, R ′ is a hydrogen atom or a hydroxyalkyl group, r is 0 or 1, and p is an integer of 1 to 3. It is. ]

The structural unit (a2-1) represented by the general formula (a2-1) is a structural unit having a norbornane or tetracyclododecane structure having a hydroxyalkyl group in the main chain.
In formula (a2-1), R ¹ and R ² are each independently a hydrogen atom or a lower alkyl group. As the lower alkyl group, the same as the lower alkyl groups represented by R ¹¹ and R ¹² in formula (a1-1-1) can be exemplified. Especially, it is preferable that both R < ¹ > and R < ² > are hydrogen atoms.
R ′ is a hydrogen atom or a hydroxyalkyl group.
The hydroxyalkyl group is preferably a linear or branched hydroxyalkyl group having 10 or less carbon atoms, more preferably a linear or branched hydroxyalkyl group having 8 or less carbon atoms, and further preferably Is a linear lower hydroxyalkyl group having 1 to 3 carbon atoms.
The number of hydroxyl groups and the bonding position in the hydroxyalkyl group are not particularly limited, but are usually one and preferably bonded to the terminal of the alkyl group.
R ′ is particularly preferably a hydrogen atom.
r is 0 or 1, and 0 is preferable.
p is an integer of 1 to 3, preferably 1 or 2, and most preferably 1.

  Specific examples of the structural unit (a2-1) include the following chemical formulas (a2-1-1) to (a2-1-7).

Among these, the chemical formulas (a2-1-1), (a2-1-2), and (a2-1-3) are preferable because the effects of the present invention are particularly high.
The structural unit (a210) can be used alone or in combination of two or more.
In the copolymer (A1), the proportion of the structural unit (a210) is preferably from 11 to 40 mol%, more preferably from 15 to 35 mol%, based on the total of all the structural units constituting the copolymer (A1). Preferably, 15 to 30 mol% is more preferable. By being more than the lower limit of the above range, the effect of containing the structural unit (a2) such as improved alkali solubility and easy to obtain good contrast is improved. On the other hand, the balance with other structural units becomes favorable by being below an upper limit.

Structural unit (a220)
The structural unit (a220) is a structural unit derived from an acrylate ester having a hydroxyl group-containing alkyl group.

When the structural unit (a220) is a structural unit having a hydroxyl group-containing cyclic alkyl group (hereinafter abbreviated as the structural unit (a221)), the effect of the present invention is improved and the effect of suppressing pattern swelling is enhanced. Also, the resolution is improved. Furthermore, good contrast and etching resistance are easily obtained.
As the structural unit (a221), for example, in the description of the “structural unit (a22) derived from an acrylate ester containing a hydroxyl group-containing aliphatic cyclic group” constituting the copolymer (A2) described later, Among the structural units, an aliphatic cyclic group is a saturated hydrocarbon group. Among them, the substituent bonded to the α-position of the acrylate ester is more preferably a fluorine atom or a fluorinated alkyl group, particularly preferably a fluorinated alkyl group, and a trifluoromethyl group (—CF ₃ ) is most preferred.

Further, in the case where the structural unit (a220) is a structural unit having a hydroxyl group-containing chain alkyl group (hereinafter abbreviated as the structural unit (a222)), the hydrophilicity of the entire component (A) becomes high and the alkaline developer is used. Solubility increases and resolution improves. Further, the controllability of the cross-linking reaction at the time of forming the resist pattern becomes good, and the pattern shape and resolution are improved. Furthermore, the film density tends to be improved, whereby the film loss during etching can be suppressed and the heat resistance tends to be improved.
Examples of the structural unit (a222) include a structural unit (a23 derived from acrylic acid having no cyclic structure and having an alcoholic hydroxyl group in the side chain, which constitutes the copolymer (A2) described later. Among the structural units exemplified in the description of “)”, those having a hydroxyalkyl group are exemplified. Among them, those having a hydroxyalkyl group in the ester portion of the acrylate ester are preferable, and among them, the substituent bonded to the α-position of the acrylate ester is more preferably a fluorine atom or a fluorinated alkyl group, Those that are fluorinated alkyl groups are particularly preferred, and those that are trifluoromethyl groups (—CF ₃ ) are most preferred.

The structural unit (a220) can be used alone or in combination of two or more.
In the copolymer (A1), the proportion of the structural unit (a220) is preferably 10 to 80 mol%, more preferably 15 to 60 mol%, based on the total of all the structural units constituting the copolymer (A1). Preferably, 20 to 55 mol% is more preferable. The effect by containing a structural unit (a220) is acquired by being more than the lower limit of the said range, and a balance with another structural unit becomes favorable by being below an upper limit.

In the case where the structural unit (a220) includes both the structural unit (a221) and the structural unit (a222), the mixing ratio of both is a molar ratio, that is, the structural unit (a221): the structural unit (a222) = It is preferably 9: 1 to 1: 9, more preferably 8: 2 to 2: 8, and even more preferably 6: 4 to 7: 3.
A good exposure margin can be obtained by blending the structural unit (a221) and the structural unit (a222) in a balanced manner at the mixing ratio. Moreover, a moderate contrast is obtained and the resolution is improved. Furthermore, etching resistance is also improved.

Other structural units In the negative resist composition of the present invention, the component (A) is conventionally known as a structural unit other than the structural units (a1) and (a2) described above for a chemically amplified resist composition. The structural unit used for the component (A) can be appropriately used.
However, from the viewpoint of the effect of the present invention, the copolymer (A1) is preferably a resin mainly composed of the structural units (a1) and (a2).

Here, the “main component” means that the total of the structural unit (a1) and the structural unit (a2) occupies 70 mol% or more, and preferably 80 mol% or more. Among these, a copolymer composed of the structural units (a1) and (a2) is preferable.
In the present invention, the combination of the structural unit (a1) and the structural unit (a2) in the copolymer (A1) is preferably a combination of the structural unit (a1) and the structural unit (a210). Examples of the combination include the following chemical formulas (A1-1) to (A1-4).

In the copolymer (A1) containing the structural unit (a1) and the structural unit (a210), the proportion of the structural unit (a1) in the copolymer (A1) is the same as the structural unit (a1) and the structural unit (a210). 60 to 89 mol% is preferable, 65 to 85 mol% is more preferable, and 65 to 80 mol% is more preferable.
The proportion of the structural unit (a210) is preferably 11 to 40 mol%, more preferably 15 to 35 mol%, and more preferably 15 to 30 mol, based on the total of the structural unit (a1) and the structural unit (a210). % Is more preferable.

In the present invention, the copolymer (A1) has a mass average molecular weight (Mw; polystyrene conversion value by gel permeation chromatography) of preferably 2000 to 10,000, more preferably 3000 to 6000, and more preferably 3000 to 5000. It is particularly preferred. A favorable contrast can be obtained by being more than the lower limit of the said range, and swelling of a resist pattern can be suppressed by being below an upper limit. As a result, the resolution is improved. Further, since the swelling of the pattern can be suppressed, the effect of improving the depth of focus (DOF) characteristic and the effect of suppressing the line edge roughness (LER) can be obtained.
Moreover, it is preferable to make the said mass mean molecular weight into this range from the point that the swelling inhibitory effect of a resist pattern is also high. When the weight average molecular weight is lower within this range, good characteristics tend to be obtained.
The dispersity (Mw / Mn) is preferably 1.0 to 5.0, and more preferably 1.0 to 2.5. “Mn” represents a number average molecular weight.

In (A) component, when using a copolymer (A1), 1 type (s) or 2 or more types of the said copolymer (A1) can be mixed and used.
However, when the copolymer (A1) is used, the proportion of the copolymer (A1) contained in the component (A) is preferably 70% by mass or more, and more preferably 80% by mass or more. 100% by mass is most preferable.

(Copolymer (A2))
In the present invention, the copolymer (A2) includes a structural unit (a21) containing an aliphatic cyclic group having a fluorinated hydroxyalkyl group (hereinafter abbreviated as the structural unit (a21)), a hydroxyl group. And a structural unit (a22) derived from an acrylate ester containing an aliphatic cyclic group (hereinafter abbreviated as a structural unit (a22)).
In addition, the copolymer (A2) is preferably a structural unit (a23) (hereinafter referred to as a structural unit (a23) derived from acrylic acid having no cyclic structure and having an alcoholic hydroxyl group in the side chain. Abbreviated as))).

In this specification, “acrylic acid” is not only acrylic acid (CH ₂ ═CH—COOH) in which a hydrogen atom is bonded to the α-position carbon atom, but also a hydrogen atom bonded to the α-position carbon atom. The α-substituted acrylic acid substituted with the above-mentioned substituents, and acrylic acid derivatives such as the acrylic acid ester are also included in the concept. Examples of the substituent include a halogen atom, an alkyl group, and a halogenated alkyl group.
“Acrylic acid ester” is not only an acrylic acid ester in which a hydrogen atom is bonded to a carbon atom at the α-position, but also an α-substituted acrylic acid in which the hydrogen atom bonded to the carbon atom in the α-position is substituted with another substituent. The concept includes esters. Examples of the substituent include a halogen atom, an alkyl group, and a halogenated alkyl group.
In “acrylic acid” and “acrylic acid ester”, “α-position (α-position carbon atom)” means a carbon atom to which a carbonyl group is bonded, unless otherwise specified. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
“Structural unit derived from acrylic acid” means a structural unit formed by cleavage of an ethylenic double bond of acrylic acid.
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
In the acrylic ester, as an alkyl group as a substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl And a lower linear or branched alkyl group such as a neopentyl group.
The α-position of the acrylate ester is preferably a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and preferably a hydrogen atom, a fluorine atom, a lower alkyl group or a fluorinated lower alkyl group. It is more preferable that

・ Structural unit (a21)
The structural unit (a21) is a structural unit containing an aliphatic cyclic group having a fluorinated hydroxyalkyl group. By including the structural unit (a21), the solubility in the antkari developer is improved. Moreover, swelling of the resist is suppressed, and lithography properties such as pattern shape and LWR are improved.

The aliphatic cyclic group having a fluorinated hydroxyalkyl group is the same as that of the structural unit (a1), and is an aliphatic cyclic group (a state before the fluorinated hydroxyalkyl group is bonded). Among them, a group in which two hydrogen atoms are removed from cyclohexane, adamantane, norbornane, and tetracyclododecane is preferable because it is easily available on the industry.
Of these exemplified monocyclic groups and polycyclic groups, groups in which two hydrogen atoms have been removed from norbornane are particularly preferred.

  The structural unit (a21) is preferably a structural unit derived from acrylic acid, and in particular, the above fatty acid is bonded to the oxygen atom (—O—) of the carbonyloxy group [—C (O) O—] of the acrylate ester. A structure in which an aromatic cyclic group is bonded (a structure in which a hydrogen atom of a carboxy group of acrylic acid is substituted with the aliphatic cyclic group) is preferable.

  More specifically, the structural unit (a21) is preferably a structural unit represented by the following general formula (I).

［式中、Ｒは水素原子、ハロゲン原子、アルキル基又はハロゲン化アルキル基であり；ｓ、ｔ、ｔ’はそれぞれ独立して１〜５の整数である。］

[Wherein, R represents a hydrogen atom, a halogen atom, an alkyl group or a halogenated alkyl group; and s, t and t ′ each independently represents an integer of 1 to 5. ]

In the formula (I), R represents a hydrogen atom, a halogen atom, an alkyl group or a halogenated alkyl group. The halogen atom, alkyl group or halogenated alkyl group of R is the same as the halogen atom, alkyl group or halogenated alkyl group which may be bonded to the α-position of the acrylate ester.
Examples of the halogen atom for R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
The alkyl group for R is preferably a lower alkyl group having 5 or less carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, A neopentyl group etc. are mentioned, A methyl group is preferable.
The halogenated alkyl group for R is preferably a group in which one or more hydrogen atoms of a lower alkyl group having 5 or less carbon atoms are substituted with a halogen atom. Specific examples of the alkyl group are the same as described above. The hydrogen atom substituted with a halogen atom may be a part or all of the hydrogen atoms constituting the alkyl group.
In the present invention, R is preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom or a methyl group in terms of industrial availability.
s is an integer of 1-5 independently, Preferably it is an integer of 1-3, and 1 is the most preferable.
t is an integer of 1 to 5, preferably an integer of 1 to 3, and 1 is most preferable.
t ′ is an integer of 1 to 3, preferably an integer of 1 to 2, and 1 is most preferable.
In the structural unit (a21) represented by the general formula (I), a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of (α-lower alkyl) acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a21), one type or a mixture of two or more types can be used.
In the copolymer (A2), the proportion of the structural unit (a21) is preferably from 10 to 90 mol%, more preferably from 20 to 90 mol%, based on the total of all the structural units constituting the copolymer (A2). 40 to 90 mol% is particularly preferable, and 45 to 85 mol% is most preferable. The effect by containing a structural unit (a21) is acquired by being more than the lower limit of the said range, and a balance with another structural unit is favorable by being below an upper limit.

・ Structural unit (a22)
The structural unit (a22) is a structural unit derived from an acrylate ester containing a hydroxyl group-containing aliphatic cyclic group. When the copolymer (A2) containing the structural unit (a22) is blended with the negative resist composition, the hydroxyl group (alcoholic hydroxyl group) of the structural unit (a22) is caused by the action of an acid generated from the component (B). , (C) and thereby the copolymer (A2) changes from a property soluble in an alkali developer to an insoluble property.

A “hydroxyl group-containing aliphatic cyclic group” is a group in which a hydroxyl group is bonded to an aliphatic cyclic group.
The number of hydroxyl groups bonded to the aliphatic cyclic group is preferably 1 to 3, more preferably 1.
The aliphatic cyclic group may be monocyclic or polycyclic, but is preferably a polycyclic group. Moreover, it is preferable that it is an alicyclic hydrocarbon group. Moreover, it is preferable that it is saturated. Moreover, it is preferable that carbon number of an aliphatic cyclic group is 5-15.
Specific examples of the aliphatic cyclic group (the state before the hydroxyl group is bonded) include those similar to the aliphatic cyclic group of the structural unit (a21).
As the aliphatic cyclic group of the structural unit (a22), among them, a cyclohexyl group, an adamantyl group, a norbornyl group, and a tetracyclododecanyl group are preferable because they are industrially available. Among these, a cyclohexyl group and an adamantyl group are preferable, and an adamantyl group is particularly preferable.
In addition to the hydroxyl group, a linear or branched alkyl group having 1 to 4 carbon atoms may be bonded to the aliphatic cyclic group.

In the structural unit (a22), the hydroxyl group-containing aliphatic cyclic group is preferably bonded to the ester group (—C (O) O—) of the acrylate ester.
In this case, in the structural unit (a22), another substituent may be bonded to the α-position (α-position carbon atom) of the acrylate ester instead of the hydrogen atom. As the substituent, an alkyl group, a halogenated alkyl group, or a halogen atom is preferable.
These explanations are the same as those of R in the general formula (I) of the structural unit (a21), and among those capable of bonding to the α-position, preferred are a hydrogen atom or an alkyl group, A hydrogen atom or a methyl group is preferred, and a hydrogen atom is most preferred.

  As a specific example of the structural unit (a22), for example, a structural unit represented by the following general formula (2) is preferable.

［式中、Ｒは前記と同じであり；Ｒ”は水素原子、アルキル基、または炭素数１〜５のアルコキシ基であり；ｒ’は１〜３の整数である。］

[Wherein, R is as defined above; R ″ is a hydrogen atom, an alkyl group, or an alkoxy group having 1 to 5 carbon atoms; and r ′ is an integer of 1 to 3].

R is the same as described in the general formula (I).
The alkyl group of R ″ is the same as the alkyl group of R.
In the general formula (2), R and R ″ are most preferably hydrogen atoms.
r ′ is an integer of 1 to 3, and is preferably 1.
The bonding position of the hydroxyl group is not particularly limited, but is preferably bonded to the 3rd position of the adamantyl group.

As the structural unit (a22), one type or a mixture of two or more types can be used.
In the copolymer (A2), the proportion of the structural unit (a22) is preferably from 10 to 70 mol%, more preferably from 10 to 50 mol%, based on the total of all the structural units constituting the copolymer (A2). Preferably, 20-40 mol% is more preferable. The effect by containing a structural unit (a22) is acquired by being more than the lower limit of the said range, and a balance with another structural unit is favorable by being below an upper limit.

・ Structural unit (a23)
In addition to the structural unit (a21) and the structural unit (a22), the copolymer (A2) further has a cyclic structure and is derived from acrylic acid having an alcoholic hydroxyl group in the side chain. It is preferable that (a23) is included.
When the copolymer (A2) containing the structural unit (a23) is blended with the negative resist composition, the alcoholic hydroxyl group of the structural unit (a23) is generated from the component (B) together with the hydroxyl group of the structural unit (a22). It reacts with the component (C) by the action of acid.
Therefore, the copolymer (A2) easily changes from a soluble property to an insoluble property with respect to an alkaline developer, and an effect of improving lithography properties such as resolution can be obtained. Moreover, film loss can be suppressed. Moreover, the controllability of the crosslinking reaction during pattern formation is improved. Furthermore, the film density tends to improve. Thereby, there exists a tendency for heat resistance to improve. Furthermore, etching resistance is also improved.

In the structural unit (a23), “having no cyclic structure” means having no aliphatic cyclic group or aromatic group.
The structural unit (a23) is clearly distinguished from the structural unit (a22) by not having a cyclic structure.
Examples of the structural unit having an alcoholic hydroxyl group in the side chain include a structural unit having a hydroxyalkyl group.
Examples of the hydroxyalkyl group include those similar to the hydroxyalkyl group in the “fluorinated hydroxyalkyl group” of the structural unit (a21).
For example, the hydroxyalkyl group may be directly bonded to the α-position carbon atom of the main chain (the portion where the ethylenic double bond of acrylic acid is cleaved), or may be substituted with the hydrogen atom of the carboxy group of acrylic acid. You may comprise ester.
In the structural unit (a23), it is preferable that at least one or both of these be present.
When a hydroxyalkyl group is not bonded to the α-position, an alkyl group, a halogenated alkyl group, or a halogen atom may be bonded to the α-position carbon atom instead of a hydrogen atom. These are the same as the description of R in the general formula (I).

  As the structural unit (23), the structural unit (a23) represented by the following general formula (3) is preferable because of excellent effects of the present invention.

［式中、Ｒ^４は水素原子、アルキル基、ハロゲン化アルキル基、ハロゲン原子またはヒドロキシアルキル基であり、Ｒ^３は、水素原子、アルキル基、またはヒドロキシアルキル基であり、かつＲ^４、Ｒ^３の少なくとも一方はヒドロキシアルキル基である。］

[Wherein, R ⁴ represents a hydrogen atom, an alkyl group, a halogenated alkyl group, a halogen atom or a hydroxyalkyl group, R ³ represents a hydrogen atom, an alkyl group or a hydroxyalkyl group, and R ⁴ , R ³ At least one of these is a hydroxyalkyl group. ]

The hydroxyalkyl group in R ⁴ is preferably a hydroxyalkyl group having 10 or less carbon atoms, desirably a linear or branched chain, more preferably a hydroxyalkyl group having 2 to 8 carbon atoms, Most preferred is a hydroxymethyl group or a hydroxyethyl group.
The number of hydroxyl groups and the bonding position are not particularly limited, but are usually one and preferably bonded to the terminal of the alkyl group.
The alkyl group in R ⁴ is preferably an alkyl group having 10 or less carbon atoms, more preferably an alkyl group having 2 to 8 carbon atoms, and most preferably an ethyl group or a methyl group.
The halogenated alkyl group for R ⁴ is preferably a lower alkyl group having 5 or less carbon atoms (preferably an ethyl group or a methyl group), and part or all of the hydrogen atoms are halogen atoms (preferably fluorine atoms). A substituted group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Examples of the alkyl group and hydroxyalkyl group for R ³ include the same groups as the alkyl group and hydroxyalkyl group for R ⁴ .

As the structural unit represented by the general formula (3), specifically, a structural unit derived from α- (hydroxyalkyl) acrylic acid (however, a structural unit derived from an acrylate ester is not included here). ), Structural units derived from α- (hydroxyalkyl) acrylic acid alkyl esters, and structural units derived from (α-alkyl) acrylic acid hydroxyalkyl esters.
Among these, when the structural unit (a23) includes a structural unit derived from an α- (hydroxyalkyl) acrylic acid alkyl ester, it is preferable from the viewpoint of improving the effect of the present invention and improving the film density. Structural units derived from α- (hydroxymethyl) -acrylic acid ethyl ester or α- (hydroxymethyl) -acrylic acid methyl ester are preferred.
Moreover, when the structural unit (a23) includes a structural unit derived from (α-alkyl) acrylic acid hydroxyalkyl ester, it is preferable in terms of crosslinking efficiency. Among them, a structural unit derived from α-methyl-acrylic acid hydroxyethyl ester or α-methyl-acrylic acid hydroxymethyl ester is preferable.

The structural unit (a23) can be used alone or in combination of two or more.
In the copolymer (A2), the proportion of the structural unit (a23) is preferably from 5 to 50 mol%, more preferably from 5 to 40 mol%, based on the total of all the structural units constituting the copolymer (A2). Preferably, 5 to 30 mol% is particularly preferable, and 10 to 25 mol% is most preferable. The effect by containing a structural unit (a23) is acquired by being more than the lower limit of the said range, and a balance with another structural unit becomes favorable by being below an upper limit.

-Other structural unit The copolymer (A2) may have another structural unit which can be copolymerized as structural units other than said each structural unit (a21)-(a23).
As such a constitutional unit, a constitutional unit conventionally used for a known resin component for a chemically amplified resist composition can be used. For example, it is derived from an acrylate ester containing a lactone-containing monocyclic or polycyclic group. And a structural unit (a24).
When the lactone-containing monocyclic or polycyclic group of the structural unit (a24) is used for forming a resist film, it increases the adhesion of the resist film to the substrate or increases the hydrophilicity with the developer. It is effective. In addition, the effect of suppressing swelling is improved.
The lactone here refers to one ring containing the —O—C (O) — structure, and this is counted as the first ring. Therefore, when it has only a lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
The structural unit (a24) does not include a lactone-containing monocyclic or polycyclic group in which one or more hydrogen atoms are substituted with a fluorinated hydroxyalkyl group.

As the structural unit (a24), any structural unit can be used without any particular limitation as long as it has a lactone ring having both the ester structure (—O—C (O) —) and a ring structure. is there.
Specifically, examples of the lactone-containing monocyclic group include groups in which one hydrogen atom has been removed from γ-butyrolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.

In the structural unit (a24), another substituent may be bonded to the α-position (the α-position carbon atom) instead of the hydrogen atom. As the substituent, an alkyl group, a halogenated alkyl group, or a halogen atom is preferable.
The explanation of these substituents is the same as the explanation of R in the general formula (I) of the structural unit (a21), and among those capable of bonding to the α-position, a hydrogen atom or an alkyl group is preferred. In particular, a hydrogen atom or a methyl group is preferable, and a hydrogen atom is most preferable.

  More specifically, examples of the structural unit (a24) include structural units represented by general formulas (a4-1) to (a4-5) shown below.

［式中、Ｒは前記と同じである。Ｒ”はそれぞれ独立して水素原子、アルキル基、または炭素数１〜５のアルコキシ基であり、ｒは０または１である。］

[Wherein, R is the same as defined above. R ″ each independently represents a hydrogen atom, an alkyl group, or an alkoxy group having 1 to 5 carbon atoms, and r is 0 or 1.]

In general formulas (a4-1) to (a4-5), the alkyl group represented by R ″ is the same as the alkyl group represented by R. In general formulas (a4-1) to (a4-5), R ″ represents In view of industrial availability and the like, a hydrogen atom is preferable.
As the structural unit (a24), units represented by general formulas (a4-2) to (a4-3) are most preferable.

As the structural unit (a24), one type or a mixture of two or more types can be used.
When the structural unit (a24) is contained in the copolymer (A2), the proportion of the structural unit (a24) in the copolymer (A2) is based on the total of all the structural units constituting the copolymer (A2). 10 to 70 mol% is preferable, 10 to 40 mol% is more preferable, and 10 to 25 mol% is most preferable. The effect by containing a structural unit (a24) is acquired by being more than the lower limit of the said range, and a balance with another structural unit becomes favorable by being below an upper limit.

However, from the viewpoint of the effect of the present invention, the copolymer (A2) is particularly preferably a resin mainly composed of the structural units (a21) to (a23).
Here, the “main component” means that the total of the structural units (a21) to (a23) occupies 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more. is there. Most preferably 100 mol%, that is, the copolymer (A2) is preferably a copolymer comprising the structural unit (a21), the structural unit (a22) and the structural unit (a23).

  As the copolymer (A2), one containing a combination of structural units such as the following formula (A2-1) is particularly preferable.

［式中、Ｒは前記と同じである。］

[Wherein, R is the same as defined above. ]

In the present invention, the copolymer (A2) has a mass average molecular weight (Mw; polystyrene-converted value by gel permeation chromatography) of preferably 2000 to 30000, more preferably 2000 to 10000, still more preferably 3000 to 3000. 8000. By setting it within this range, a good dissolution rate in an alkali developer can be obtained, which is preferable from the viewpoint of high resolution. When the mass average molecular weight is lower within this range, good characteristics tend to be obtained.
Further, the dispersity (Mw / Mn) is preferably 1.0 to 5.0, and more preferably 1.0 to 2.5.

In (A) component, when using a copolymer (A2), the 1 type (s) or 2 or more types of the said copolymer (A2) can be mixed and used.
However, when the copolymer (A2) is used, the proportion of the copolymer (A2) contained in the component (A) is preferably 50% by mass or more, and more preferably 70% by mass or more. 80% by mass or more is particularly preferable, and 100% by mass is most preferable.

  The component (A) used in the present invention can be synthesized by, for example, a method of radical polymerization of a monomer for deriving each structural unit by a conventional method, a method described in WO 2004/076495, or the like.

The component (A) is an alkali-soluble resin component other than the copolymer (A1) and the copolymer (A2), such as other polymer compounds (hydroxystyrene resin) used in conventional negative resist compositions. , Novolac resin, acrylic resin, etc.) can also be used.
The content of the component (A) in the negative resist composition may be adjusted according to the resist film thickness to be formed.

<(B) component>
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.

  As the onium salt acid generator, for example, an acid generator represented by the following general formula (b-0) can be preferably used.

[Wherein, R ⁵¹ represents a linear, branched or cyclic alkyl group, or a linear, branched or cyclic fluorinated alkyl group; R ⁵² represents a hydrogen atom, a hydroxyl group, a halogen atom, linear or A branched alkyl group, a linear or branched halogenated alkyl group, or a linear or branched alkoxy group; R ⁵³ is an aryl group which may have a substituent; u '' Is an integer of 1 to 3. ]

In the general formula (b-0), R ⁵¹ represents a linear, branched or cyclic alkyl group, or a linear, branched or cyclic fluorinated alkyl group.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. Further, the fluorination rate of the fluorinated alkyl group (ratio of the number of substituted fluorine atoms to the total number of hydrogen atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. Those in which all hydrogen atoms are substituted with fluorine atoms are preferred because the strength of the acid is increased.
R ⁵¹ is most preferably a linear alkyl group or a fluorinated alkyl group.

R ⁵² is a hydrogen atom, a hydroxyl group, a halogen atom, a linear or branched alkyl group, a linear or branched alkyl halide group, or a linear or branched alkoxy group.
In R ⁵² , examples of the halogen atom include a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom, and a fluorine atom is preferable.
In R ⁵² , the alkyl group is linear or branched, and the carbon number thereof is preferably 1 to 5, particularly 1 to 4, and more preferably 1 to 3.
In R ⁵² , the halogenated alkyl group is a group in which part or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms. Examples of the alkyl group herein are the same as the “alkyl group” in R ⁵² . Examples of the halogen atom to be substituted include the same as those described above for the “halogen atom”. In the halogenated alkyl group, it is desirable that 50 to 100% of the total number of hydrogen atoms are substituted with halogen atoms, and it is more preferable that all are substituted.
In R ⁵² , the alkoxy group is linear or branched, and the carbon number thereof is preferably 1 to 5, particularly 1 to 4, and more preferably 1 to 3.
Among these, R ⁵² is preferably a hydrogen atom.

R ⁵³ is an aryl group which may have a substituent, and examples of the structure of the basic ring (matrix ring) excluding the substituent include a naphthyl group, a phenyl group, an anthracenyl group, and the like. From the viewpoint of absorption of exposure light such as ArF excimer laser, a phenyl group is desirable.
Examples of the substituent include a hydroxyl group and a lower alkyl group (straight or branched chain, particularly preferably a methyl group).
As the aryl group for R ^53, an aryl group having no substituent is more preferable.
u ″ is an integer of 1 to 3, preferably 2 or 3, and particularly preferably 3.

  Preferable examples of the acid generator represented by the general formula (b-0) include the following.

  The acid generator represented by general formula (b-0) can be used alone or in combination of two or more.

  As other onium salt-based acid generators represented by the general formula (b-0), for example, compounds represented by the following general formula (b-1) or (b-2) are also preferably used. It is done.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；Ｒ^４”は、直鎖、分岐または環状のアルキル基またはフッ素化アルキル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[Wherein R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; R ⁴ ″ represents a linear, branched or cyclic alkyl group or fluorinated group. Represents an alkyl group; at least one of R ¹ ″ to R ³ ″ represents an aryl group, and at least one of R ⁵ ″ to R ⁶ ″ represents an aryl group.]

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. At least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.
The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups It may or may not be substituted with a group, a halogen atom or the like. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is most preferred.
The alkoxy group that may be substituted for the hydrogen atom of the aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and most preferably a methoxy group or an ethoxy group.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.
The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, a straight, include alkyl groups such as branched or cyclic. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
Among these, R ¹ ″ to R ³ ″ are most preferably a phenyl group or a naphthyl group, respectively.

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group is a cyclic group as indicated by R ¹ ″ and preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and more preferably 6 carbon atoms. Most preferably, it is -10.
The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms. The fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. Particularly, all the hydrogen atoms are substituted with fluorine atoms. It is preferable because the strength of the acid is increased.
R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
"As ^{R 4} in the formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

  Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate. In addition, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

  In addition, in the general formula (b-1) or (b-2), an onium salt-based acid generator in which the anion moiety is replaced with an anion moiety represented by the following general formula (b-3) or (b-4). Can also be used (the cation moiety is the same as (b-1) or (b-2)).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, Preferably it is C3.
Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably It is C1-C7, More preferably, it is C1-C3.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, as the number of hydrogen atoms substituted with fluorine atoms increases, the strength of the acid increases, and high-energy light or electron beam of 200 nm or less The ratio of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all. Are a perfluoroalkylene group or a perfluoroalkyl group in which a hydrogen atom is substituted with a fluorine atom.

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

(In formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ³¹ , a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.

As the organic group for R ³² , a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ’’は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3. ]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more, and still more preferably 90% or more.

As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthracyl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.

The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group, and most preferably a partially fluorinated alkyl group.
The fluorinated alkyl group in R ³⁵ preferably has 50% or more of the hydrogen atom of the alkyl group fluorinated, more preferably 70% or more, and even more preferably 90% or more. This is preferable because the strength of the acid is increased. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Also, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), WO 2004 / 074242A2 (pages 65 to 85). The oxime sulfonate acid generators disclosed in Examples 1 to 40) of No. 1 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

  Of the above exemplified compounds, the following four compounds are preferred.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
In the present invention, it is particularly preferable to use an onium salt having a fluorinated alkyl sulfonate ion as an anion as the component (B).
Content of (B) component in the negative resist composition of this invention is 0.5-30 mass parts with respect to 100 mass parts of (A) component, Preferably it is 1-10 mass parts. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(C) component>
The component (C) is not particularly limited, and can be arbitrarily selected from cross-linking agents used in chemically amplified negative resist compositions known so far.
Specifically, for example, 2,3-dihydroxy-5-hydroxymethylnorbornane, 2-hydroxy-5,6-bis (hydroxymethyl) norbornane, cyclohexanedimethanol, 3,4,8 (or 9) -trihydroxytri Aliphatic cyclic carbonization having a hydroxyl group or a hydroxyalkyl group or both such as cyclodecane, 2-methyl-2-adamantanol, 1,4-dioxane-2,3-diol, 1,3,5-trihydroxycyclohexane Examples thereof include hydrogen or an oxygen-containing derivative thereof.

In addition, amino group-containing compounds such as melamine, acetoguanamine, benzoguanamine, urea, ethylene urea, propylene urea, glycoluril are reacted with formaldehyde or formaldehyde and lower alcohol, and the hydrogen atom of the amino group is hydroxymethyl group or lower alkoxymethyl. And a compound substituted with a group.
Of these, those using melamine are melamine-based crosslinking agents, those using urea are urea-based crosslinking agents, those using alkylene ureas such as ethylene urea and propylene urea are alkylene urea-based crosslinking agents, and glycoluril is used. This was called a glycoluril-based crosslinking agent.
The component (C) is preferably at least one selected from the group consisting of melamine-based crosslinking agents, urea-based crosslinking agents, alkylene urea-based crosslinking agents, and glycoluril-based crosslinking agents, and glycoluril-based crosslinking agents are particularly preferred. preferable.

  Melamine-based crosslinking agents include compounds in which melamine and formaldehyde are reacted to replace the amino group hydrogen atom with a hydroxymethyl group, and melamine, formaldehyde and lower alcohol are reacted to convert the amino group hydrogen atom into a lower alkoxy group. Examples include compounds substituted with a methyl group. Specific examples include hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, hexabutoxybutyl melamine, and the like, among which hexamethoxymethyl melamine is preferable.

  Urea-based crosslinking agents include compounds in which urea and formaldehyde are reacted to replace amino group hydrogen atoms with hydroxymethyl groups, and urea, formaldehyde and lower alcohols are reacted to convert amino group hydrogen atoms into lower alkoxy groups. Examples include compounds substituted with a methyl group. Specific examples include bismethoxymethylurea, bisethoxymethylurea, bispropoxymethylurea, bisbutoxymethylurea and the like, with bismethoxymethylurea being preferred.

  As an alkylene urea type crosslinking agent, the compound represented by the following general formula (C-1) is mentioned.

［式中のＲ^５’とＲ^６’はそれぞれ独立に水酸基又は低級アルコキシ基であり、Ｒ^３’とＲ^４’はそれぞれ独立に水素原子、水酸基又は低級アルコキシ基であり、ｖは０又は１〜２の整数である。］

[In the formula, R ⁵ ′ and R ⁶ ′ are each independently a hydroxyl group or a lower alkoxy group, R ³ ′ and R ⁴ ′ are each independently a hydrogen atom, a hydroxyl group or a lower alkoxy group, and v is 0 or 1 It is an integer of ~ 2. ]

When R ⁵ ′ and R ⁶ ′ are lower alkoxy groups, they are preferably alkoxy groups having 1 to 4 carbon atoms, and may be linear or branched. R ⁵ ′ and R ⁶ ′ may be the same or different from each other. More preferably, they are the same.
When R ³ ′ and R ⁴ ′ are lower alkoxy groups, they are preferably alkoxy groups having 1 to 4 carbon atoms, and may be linear or branched. R ³ ′ and R ⁴ ′ may be the same or different from each other. More preferably, they are the same.
v is 0 or an integer of 1 to 2, preferably 0 or 1.
As the alkylene urea crosslinking agent, a compound in which v is 0 (ethylene urea crosslinking agent) and / or a compound in which v is 1 (propylene urea crosslinking agent) are particularly preferable.

  The compound represented by the general formula (C-1) can be obtained by a condensation reaction of alkylene urea and formalin and by reacting this product with a lower alcohol.

  Specific examples of the alkylene urea crosslinking agent include, for example, mono and / or dihydroxymethylated ethylene urea, mono and / or dimethoxymethylated ethylene urea, mono and / or diethoxymethylated ethylene urea, mono and / or dipropoxy Ethylene urea-based crosslinking agents such as methylated ethylene urea, mono and / or dibutoxymethylated ethylene urea; mono and / or dihydroxymethylated propylene urea, mono and / or dimethoxymethylated propylene urea, mono and / or diethoxymethyl Propylene urea-based cross-linking agents such as propylene urea, mono and / or dipropoxymethylated propylene urea, mono and / or dibutoxymethylated propylene urea; 1,3-di (methoxymethyl) 4,5-dihydroxy-2- Imidazolidinone, 1,3-di (Metoki Like, etc.) -4,5-dimethoxy-2-imidazolidinone.

Examples of the glycoluril-based crosslinking agent include glycoluril derivatives in which the N position is substituted with one or both of a hydroxyalkyl group and an alkoxyalkyl group having 1 to 4 carbon atoms. Such glycoluril derivatives can be obtained by condensation reaction of glycoluril and formalin, and by reacting this product with a lower alcohol.
Specific examples of the glycoluril-based crosslinking agent include, for example, mono, di, tri and / or tetrahydroxymethylated glycoluril, mono, di, tri and / or tetramethoxymethylated glycoluril, mono, di, tri and / or Examples include tetraethoxymethylated glycoluril, mono, di, tri and / or tetrapropoxymethylated glycoluril, mono, di, tri and / or tetrabutoxymethylated glycoluril.

As the component (C), one type may be used alone, or two or more types may be used in combination.
(C) As for content of a component, 3-30 mass parts is preferable with respect to 100 mass parts of (A) component, 3-15 mass parts is more preferable, and 5-10 mass parts is the most preferable. When the content of the component (C) is at least the lower limit value, the crosslinking formation proceeds sufficiently and a good resist pattern can be obtained.
Moreover, when it is below this upper limit, the storage stability of the resist coating solution is good, and the deterioration of sensitivity with time is suppressed.

<(F) component>
The negative resist composition of the present invention contains a photobase generator component (F) (hereinafter referred to as (F) component) that generates a base upon exposure. By containing the component (F), a resist pattern with high rectangularity can be formed. In addition, it is possible to form a resist pattern in which the change amount of the pattern size with a change in the exposure amount is small (EL margin is large).

The component (F) is not particularly limited, and examples thereof include triphenylsulfonium compounds, triphenylmethanol; photoactive carbamates such as benzylcarbamate and benzoincarbamate; o-carbamoylhydroxylamide, o-carbamoyloxime. Amides such as aromatic sulfonamides, alpha-lactams and N- (2-allylethynyl) amides; oxime esters, α-aminoacetophenones, cobalt complexes and the like.
Among these, a photobase generator (F1) represented by the following general formula (f1): 2-nitrobenzylcyclohexylcarbamate, [[(2,6-dinitrobenzyl) oxy] carbonyl] cyclohexylamine, N- (2- Carbamate photobase generator (F2) selected from nitrobenzyloxycarbonyl) pyrrolidine, bis [[(2-nitrobenzyl) oxy] carbonyl] hexane 1,6-diamine; triphenylmethanol, o-carbamoylhydroxylamide, o-carbamoyloxime, 4- (methylthiobenzoyl) -1-methyl-1-morpholinoethane, (4-morpholinobenzoyl) -1-benzyl-1-dimethylaminopropane, 2-benzyl-2-dimethylamino-1- ( 4-morpholinophenyl) -butanone, hexaan Nkobaruto (III) tris (triphenylmethyl borate) is preferably used, photobase generator (F1), a photobase generator (F2) is used more preferably, photobase generator (F1) is particularly preferably used.

［式中、Ｒ^４１〜Ｒ^４３はそれぞれ独立してアルキル基、アルコキシ基またはハロゲン原子を示し；ｎ^１〜ｎ^３はそれぞれ独立して０〜３の整数である。］

[Wherein, R ^{41 to} R ⁴³ each independently represents an alkyl group, an alkoxy group, or a halogen atom; n ^{1 to} n ³ are each independently an integer of 0 to 3. ]

In the general formula (f1), R ^{41 to} R ⁴³ each independently represents an alkyl group, an alkoxy group, or a halogen atom.
As the alkyl group, an alkyl group having 1 to 5 carbon atoms is preferable, and a linear or branched alkyl group is more preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable. Particularly preferred.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and among them, a fluorine atom is most preferable.
n ^{1 to} n ³ are each independently an integer of 0 to 3, preferably 0 to 1 each independently. Of these, n ^{1 to} n ³ are all preferably 0.

  Specific examples of suitable photobase generator (F1) are shown below.

  Among the photobase generators (F2), 2-nitrobenzylcyclohexyl carbamate is most preferable from the viewpoint of the effect of the present invention.

As the component (F), one type may be used alone, or two or more types may be used in combination.
(F) As for content of a component, 0.05-2 mass parts is preferable with respect to 100 mass parts of (A) component, 0.05-1.5 mass parts is more preferable, 0.1-1.0 mass Part is most preferred. The effect of this invention improves that content of (F) component is more than a lower limit. In addition, the exposure margin (EL margin) increases. On the other hand, when the amount is not more than the upper limit value, the acid generation efficiency by exposure increases and the sensitivity is improved.

  In the negative resist composition of the present invention, the amount of the photobase generator component (F) used is preferably 5 to 80% by mass based on the amount of the acid generator component (B) used. More preferably, it is -75 mass%, and it is especially preferable that it is 5-70 mass%. By being at least the lower limit of the range, the effect of the present invention is improved. In addition, the exposure margin (EL margin) increases. On the other hand, by being below the upper limit value, the acid generation efficiency by exposure is increased and the sensitivity is improved.

<(D) component>
In the negative resist composition of the present invention, a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) is further added as an optional component in order to improve the resist pattern shape, the stability over time. It is preferable to contain.
Since a wide variety of components (D) have already been proposed, any known one may be used. Cyclic amines, aliphatic amines, particularly secondary aliphatic amines and tertiary fats may be used. Group amines are preferred. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include amines (alkyl amines or alkyl alcohol amines) in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms. Specific examples thereof include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di-n-heptylamine, Dialkylamines such as di-n-octylamine and dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine, tri-n-heptyl Trialkylamines such as amine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n -Ok Noruamin, alkyl alcohol amines such as tri -n- octanol amine.
Among these, alkyl alcohol amines and trialkyl amines are preferable, and alkyl alcohol amines are most preferable. Of the alkyl alcohol amines, triethanolamine and triisopropanolamine are most preferred.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
In the present invention, it is particularly preferable to use an alkyl alcohol amine as the component (D).
(D) A component may be used individually by 1 type and may be used in combination of 2 or more type.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

<Optional component>
The negative resist composition of the present invention includes, as optional components, organic carboxylic acids, phosphorus oxoacids and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, etc. At least one compound (E) selected from the group consisting of (hereinafter referred to as component (E)) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids and derivatives thereof include phosphoric acid, phosphonic acid, phosphinic acid and the like, and among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.
As the component (E), an organic carboxylic acid is preferable, and salicylic acid is particularly preferable.
(E) A component may be used individually by 1 type and may use 2 or more types together.
The component (E) is preferably used at a ratio of 0.01 to 5.0 parts by mass per 100 parts by mass of the component (A).

  In the negative resist composition of the present invention, if desired, there are further miscible additives such as an additional resin for improving the performance of the resist film, a surfactant for improving the coating property, a dissolution inhibitor, Plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be added and contained as appropriate.

The negative resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-amyl ketone, methyl isoamyl ketone, 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol A compound having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, or propylene glycol monoacetate, monomethyl ether, monoethyl ether of the polyhydric alcohol or the compound having an ester bond, A monoalkyl ether such as monopropyl ether or monobutyl ether or an ether bond such as monophenyl ether Derivatives of polyhydric alcohols such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred among these; cyclic ethers such as dioxane, methyl lactate, lactic acid Esters such as ethyl (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, di Aromatic organic solvents such as benzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, amylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. Can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
The amount of the component (S) used is not particularly limited, but is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 2 -20% by mass, preferably 5-15% by mass.

The negative resist composition of the present invention has an effect that a resist pattern having high rectangularity can be obtained. The reason is not clear, but is presumed as follows.
In the negative resist composition of the present invention, by including the photobase generator (F) that generates a base upon exposure, for example, the exposure amount varies somewhat, and the amount of acid generated from the acid generator changes. In this case, it is considered that the acid diffused in the resist film is controlled to an appropriate amount by the base generated from the component (F). For example, in a negative resist composition containing a large amount of an acid generator, when the exposure amount is increased, an excess acid than the set amount generated from the acid generator is neutralized by the base generated from the component (F). It is considered that the acid diffusing into the resist film is moderately controlled. From the above, the negative resist composition of the present invention is presumed to have an effect that a resist pattern with high rectangularity can be obtained.

  In addition, according to the negative resist composition of the present invention, an effect of improving lithography properties such as exposure margin (EL margin) and line width roughness (LWR) can be obtained.

≪Resist pattern formation method≫
Next, the resist pattern forming method of the second aspect of the present invention will be described.
The resist pattern forming method of the present invention includes a step of forming a resist film on a substrate using the negative resist composition of the first aspect of the present invention, a step of exposing the resist film, and developing the resist film. And a step of forming a resist pattern.

The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the negative resist composition is applied onto a substrate such as a silicon wafer with a spinner or the like, and pre-baking (post-apply baking (PAB)) is preferably performed for 40 to 120 seconds under a temperature condition of 80 to 150 ° C. Is applied for 60 to 90 seconds, and ArF excimer laser light is selectively exposed through a desired mask pattern using, for example, an ArF exposure apparatus, followed by heating after exposure (PEB) at a temperature of 80 to 150 ° C. For 40 to 120 seconds, preferably 60 to 90 seconds.
Subsequently, this is developed using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide. In this way, a resist pattern faithful to the mask pattern can be obtained.
An organic or inorganic antireflection film can be provided between the substrate and the coating layer of the resist composition.
The wavelength used for exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray Or the like. The negative resist composition according to the present invention is particularly effective for an ArF excimer laser.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.

<Resin component (A)>
The copolymers (A1) -1 and (A2) -1 of the resin component (A) used in Examples and Comparative Examples are shown below.
In addition, the weight average molecular weight (Mw) and dispersity (Mw / Mn) of the copolymers (A1) -1 and (A2) -1 are also shown. The mass average molecular weight (Mw) and dispersity (Mw / Mn) were determined on a polystyrene conversion basis by gel permeation chromatography (GPC).
The composition ratio (molar ratio) of the structural units was calculated by carbon NMR.

[Copolymer (A1) -1]

（ａ１：ａ２＝７２：２８（モル比）、Ｍｗ：４４００、Ｍｗ／Ｍｎ：１．６２、プロメラス社製）

(A1: a2 = 72: 28 (molar ratio), Mw: 4400, Mw / Mn: 1.62, manufactured by Promelas)

[Copolymer (A2) -1]
(Synthesis method)
13.58 g of norbornene hexafluoroalcohol acrylate (NBHFAA), 1.76 g of hydroxyethyl methacrylate (HEMA) and 6.0 g of 3-hydroxy-1-adamantyl acrylate (HAdA) and dimethyl azobisisobutyrate (trade name) : V-601, manufactured by Wako Pure Chemical Industries, Ltd.) 0.6 g was dissolved in tetrahydrofuran (THF) 200 mL. Next, nitrogen bubbling was performed for about 10 minutes, and the mixture was stirred for 4 hours while heating using an oil bath at 70 ° C., and then cooled to room temperature. Next, after concentrating this reaction liquid with an evaporator, the concentrate was dissolved in 120 mL of THF, and poured into 1000 mL of heptane to precipitate a resin, followed by filtration. The obtained resin was dried in a dryer at 40 ° C. for 24 hours to obtain 18.8 g of a white solid. The white solid was designated as copolymer (A2) -1.

（ａ２１：ａ２３：ａ２２＝５０：１７：３３（モル比）、Ｍｗ：６０００、Ｍｗ／Ｍｎ：１．６７）

(A21: a23: a22 = 50: 17: 33 (molar ratio), Mw: 6000, Mw / Mn: 1.67)

<Preparation of negative resist composition solution>
(Examples 1-5, Comparative Example 1)
Each component shown in Table 1 was mixed and dissolved to prepare a negative resist composition solution.

Each abbreviation in Table 1 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(B) -1: Triphenylsulfonium trifluoromethanesulfonate.
(C) -1: Tetramethoxymethylated glycoluril MX270 (product name, manufactured by Sanwa Chemical Co., Ltd.).
(D) -1: Triisopropanolamine.
(F) -1: A photobase generator represented by the following chemical formula.

(S) -1: PGMEA / PGME = 6/4 (mass ratio) mixed solvent.
(S) -2: PGME.

  The lithography characteristics shown below were evaluated using the obtained negative resist composition solution.

<Evaluation of lithography characteristics (1)>
First, an organic antireflection film composition “AR46” (trade name, manufactured by Rohm and Haas) was applied onto a silicon wafer using a spinner, and baked on a hot plate at 215 ° C. for 60 seconds to dry. As a result, an organic antireflection film having a thickness of 30 nm was formed.
On the organic antireflection film, the negative resist composition solutions of Example 1 and Comparative Example 1 were applied using a spinner, and prebaked (PAB) treatment at 80 ° C. for 60 seconds on a hot plate. As a result, a resist film having a thickness of 160 nm was formed.
Next, an ArF excimer laser (193 nm) was applied to the resist film with a mask pattern (halftone) using an ArF exposure apparatus NSR-S302 (product name, manufactured by Nikon; NA (numerical aperture) = 0.78, DipoleY). ) Selectively.
Then, a post-exposure heating (PEB) treatment is performed at 100 ° C. for 60 seconds, followed by development with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution at 23 ° C. for 60 seconds, followed by washing with water for 20 seconds and drying. Thus, a line-and-space (1: 1) resist pattern (L / S pattern) is formed, and an optimum exposure amount (sensitivity: Eop, mJ / cm ² ) for forming an L / S pattern having a line width of 80 nm and a pitch of 160 nm. )

(EL margin)
An L / S pattern having a line width of 80 nm and a pitch of 160 nm as target dimensions was formed by changing the exposure amount.
At this time, an exposure amount when an L / S (1: 1) pattern having a target size (80 nm) ± 10% in range (ie, 72 to 88 nm) is formed is obtained, and an EL margin ( Unit:%). The results are shown in Table 2.
EL margin (%) = (| E1-E2 | / Eop) × 100.
E1: Exposure amount (mJ / cm ² ) when forming an L / S pattern having a line width of 88 nm.
E2: exposure amount (mJ / cm ² ) when forming an L / S pattern with a line width of 72 nm.
The EL margin indicates that the larger the value is, the smaller the change amount of the pattern size with the variation of the exposure amount.

(LWR)
In the line width of the L / S pattern with a line width of 80 nm and a pitch of 160 nm formed by the Eop, a side length SEM (manufactured by Hitachi, Ltd., trade name: S-9220) was used to measure five locations in the longitudinal direction of the line, From the result, a triple value (3 s) of the standard deviation (s) was calculated as a scale indicating LWR. The results are shown in Table 2.
Note that the smaller the value of 3s, the smaller the roughness of the line width, which means that a resist pattern with a more uniform width was obtained.

From the results shown in Table 2, it was confirmed that the EL margin of Example 1 according to the present invention was larger than that of Comparative Example 1, and the change amount of the pattern size accompanying the change in exposure amount was small.
Regarding LWR, it was confirmed that Example 1 according to the present invention had a smaller LWR value than Comparative Example 1, a smaller line width roughness of the L / S pattern, and a resist pattern having a more uniform width.

<Evaluation of lithography characteristics (2)>
First, an organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science) is uniformly applied on a silicon wafer using a spinner, and baked on a hot plate at 225 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a thickness of 77 nm was formed.
On the organic antireflection film, the negative resist composition solutions of Examples 2 to 5 were uniformly applied using a spinner, and prebaked (PAB) treatment at 80 ° C. for 60 seconds on a hot plate. As a result, a resist film having a thickness of 200 nm was formed.
Next, an ArF excimer laser (193 nm) was applied to the resist film by an ArF exposure apparatus NSR-S302 (product name, manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination). It selectively exposed through the mask pattern (halftone).
Then, a post-exposure heating (PEB) treatment is performed at 100 ° C. for 60 seconds, followed by development with an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution at 23 ° C. for 60 seconds, followed by washing with water for 30 seconds and drying. Thus, a line-and-space (1: 1) resist pattern (L / S pattern) is formed, and an optimal exposure amount (sensitivity: Eop, mJ / cm ² ) for forming an L / S pattern having a line width of 120 nm and a pitch of 240 nm. )

(Resist pattern shape)
In the above Eop, the size of the mask pattern was changed, and the shapes of the formed L / S patterns with line widths of 140 nm, 130 nm, and 120 nm were observed and evaluated with a scanning electron microscope (SEM). The results are shown in Table 3.

From the results in Table 3, it was confirmed that Examples 2 to 5 according to the present invention can obtain a resist pattern having a high rectangularity.

Claims (12)

A negative resist composition comprising an alkali-soluble resin component (A), an acid generator component (B) that generates acid upon exposure, and a crosslinking agent component (C),
Furthermore, the negative resist composition characterized by containing the photobase generator component (F) which generate | occur | produces a base by exposure. The photobase generator component (F) is represented by the following general formula (f1)

[Wherein, R ^{41 to} R ⁴³ each independently represents an alkyl group, an alkoxy group, or a halogen atom; n ^{1 to} n ³ are each independently an integer of 0 to 3. ]
The negative resist composition of Claim 1 containing the photobase generator (F1) represented by these.   The negative resist composition according to claim 1 or 2, wherein the amount of the photobase generator component (F) used is 5 to 80% by mass with respect to the amount of the acid generator component (B) used.   The alkali-soluble resin component (A) is derived from a structural unit (a21) containing an aliphatic cyclic group having a fluorinated hydroxyalkyl group and an acrylate ester containing a hydroxyl group-containing aliphatic cyclic group. The negative resist composition as described in any one of Claims 1-3 containing the copolymer (A2) containing a structural unit (a22).   The negative resist composition according to claim 4, wherein the copolymer (A2) further comprises a structural unit (a23) that has no cyclic structure and is derived from acrylic acid having an alcoholic hydroxyl group in the side chain. object.   The alkali-soluble resin component (A) includes a structural unit (a1) having an aliphatic cyclic group having a fluorinated hydroxyalkyl group in the main chain and a structural unit (a2) having a hydroxyalkyl group. The negative resist composition as described in any one of Claims 1-3 containing a polymer (A1). The structural unit (a1) is represented by the following general formula (a1-1).

[Wherein, X is a fluorinated hydroxyalkyl group, and r is 0 or 1. ]
The negative resist composition of Claim 6 containing the structural unit (a1-1) represented by these. X is the following general formula (a1-1-1)

[Wherein, R ¹¹ and R ¹² are each independently a hydrogen atom or a lower alkyl group, m and n are each independently an integer of 1 to 5, and q is an integer of 1 to 5. ]
The negative resist composition according to claim 7, which is a group represented by the formula: The structural unit (a2) is represented by the following general formula (a2-1)

[Wherein, R ¹ and R ² are each independently a hydrogen atom or a lower alkyl group, R ′ is a hydrogen atom or a hydroxyalkyl group, r is 0 or 1, and p is an integer of 1 to 3. It is. ]
The negative resist composition as described in any one of Claims 6-8 containing the structural unit (a2-1) represented by these.   The said crosslinking agent component (C) is at least 1 sort (s) chosen from the group which consists of a melamine type crosslinking agent, a urea type crosslinking agent, an alkylene urea type crosslinking agent, and a glycoluril type crosslinking agent. Negative resist composition as described in the item.   Furthermore, the negative resist composition as described in any one of Claims 1-10 containing a nitrogen-containing organic compound (D). A step of forming a resist film on a substrate using the negative resist composition according to claim 1, a step of exposing the resist film, and developing the resist film to form a resist pattern The resist pattern formation method characterized by including the process to do.