JP2006215180A - Negative resist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a negative resist composition which satisfies high sensitivity, high resolution, good heat resistance of a pattern, suppression of outgassing and reduction of surface roughness in microfabrication of a semiconductor device, and also to provide a pattern forming method using the composition. <P>SOLUTION: The negative resist composition contains (A) an alkali-soluble resin, (B) a compound which generates an acid upon irradiation with an actinic ray or a radiation, and (C) a crosslinker which reacts under the action of an acid to form crosslink in the alkali-soluble resin with release of a ≥3C alcohol or a ≥7C carboxylic acid. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a negative resist composition suitable for use in an ultramicrolithography process such as the manufacture of VLSI and high-capacity microchips and other fabrication processes, and a pattern forming method using the same. More specifically, the present invention relates to a negative resist composition capable of forming a highly refined pattern using electron beam, X-ray, EUV light, and a pattern forming method using the same.

  Conventionally, in the manufacturing process of semiconductor devices such as IC and LSI, fine processing by lithography using a resist composition has been performed. In recent years, with the high integration of integrated circuits, the formation of ultrafine patterns in the submicron region and the quarter micron region has been required. Accordingly, there is a tendency for the exposure wavelength to be shortened from g-line to i-line, and further to KrF excimer laser light. Furthermore, at present, in addition to excimer laser light, lithography using electron beams, X-rays, and EUV light is being developed.

  In particular, electron beam lithography is positioned as a next-generation or next-generation pattern forming technology, and a negative resist with high sensitivity and high resolution is desired. In order to shorten the wafer processing time, increasing the resist sensitivity is a very important issue. However, in the negative resist for electron beams, the resolution decreases when attempting to increase the sensitivity. Development of a resist that satisfies these characteristics simultaneously is strongly desired.

As a resist suitable for such an electron beam or X-ray lithography process, a chemically amplified resist using an acid-catalyzed reaction is mainly used from the viewpoint of high sensitivity. A chemically amplified composition comprising a soluble resin, a crosslinking agent, an acid generator and an additive is effectively used.
Various studies have been conducted with a focus on crosslinking agents to improve the performance of chemically amplified negative resists. For example, Patent Document 1 (JP-A-2-15270) discloses a glycoluril-based crosslinking agent, Patent Document 2 (Japanese Patent No. 2985968) discloses a hexamethoxymelamine-based crosslinking agent, and Patent Document 3 (Japanese Patent). No. 2861309) discloses a crosslinking agent having a urea skeleton, and Patent Document 4 (Japanese Patent Application Laid-Open No. 2001-51417) discloses a phenolic crosslinking agent having a polynuclear phenol skeleton.
However, in any of these conventionally known crosslinking agents, high sensitivity in the ultrafine region, high resolution, reduction of outgas (reduction of the amount of vaporized product from the resist film during exposure), Reduction in surface roughness (reduction in surface roughness of the pattern top after development) and good pattern heat resistance were not satisfactory at the same time.

Japanese Patent Laid-Open No. 2-15270 Japanese Patent No. 2985968 Japanese Patent No. 2861309 JP 2001-51417 A

  Accordingly, an object of the present invention is to solve the problem of performance improvement technology in microfabrication of semiconductor elements, and in particular, high sensitivity and high resolution in microfabrication of semiconductor elements using electron beams, X-rays, and EUV light. An object of the present invention is to provide a negative resist composition that simultaneously satisfies image quality, reduction of outgas, reduction of surface roughness, and good pattern heat resistance, and a pattern forming method using the same.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by a chemically amplified negative resist composition containing an alkali-soluble resin, a specific crosslinking agent, and an acid generator, and have reached the present invention. .

  The present invention is as follows.

(1) A negative resist composition comprising at least the following (A), (B) and (C).
(A) an alkali-soluble resin,
(B) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (C) an alkali-soluble resin that reacts with the action of the acid to release an alcohol having 3 or more carbon atoms or a carboxylic acid having 7 or more carbon atoms. A cross-linking agent that forms a cross-link.

  (2) The crosslinking agent of component (C) has (C1) 3 to 10 benzene rings, and an alkoxymethyl group having 7 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms bonded to any benzene ring. The negative resist composition as described in (1), which is a phenol-based crosslinking agent having two or more substituents selected from the group consisting of:

  (3) The crosslinking agent of component (C) is a melamine-based crosslinking agent having (C2) two or more substituents selected from an alkoxymethyl group having 4 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms. The negative resist composition as described in (1), which is characterized in that

  (4) The crosslinking agent of component (C) is a uril-based crosslinking agent having two or more substituents selected from (C3) an alkoxymethyl group having 4 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms. The negative resist composition as described in (1), which is characterized in that

  (5) The cross-linking agent of component (C) is a cross-linking agent that reacts by the action of an acid to form a cross-link in an alkali-soluble resin with the elimination of an alcohol having 7 or more carbon atoms ( The negative resist composition according to any one of 1) to (4).

  (6) The negative resist according to any one of (1) to (5), wherein the alcohol or carboxylic acid released from the crosslinking agent of component (C) by the action of an acid has a cyclic structure. Composition.

  (7) The negative resist composition as described in any one of (1) to (6), which is for electron beam, X-ray or EUV light.

  (8) A pattern forming method comprising the steps of: forming a resist film from the negative resist composition according to any one of (1) to (7); and exposing and developing the resist film.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a negative resist composition that simultaneously satisfies high sensitivity, high resolution, reduced outgas, reduced surface roughness, and good pattern heat resistance, and a pattern forming method using the same.

Hereinafter, the present invention will be described in detail.
In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what does not have a substituent and what has a substituent. . For example, the “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

[1] (A) Alkali-soluble resin The alkali-soluble resin used in the present invention is not particularly limited, and phenol novolac resins, polyvinyl phenol resins, vinyls that have been used in negative chemically amplified resists so far. A polymer having a phenol skeleton, such as a copolymer having a phenol-derived structural unit and a resin obtained by partially protecting or modifying a polyvinylphenol resin, can be widely used.

  The alkali dissolution rate of the alkali-soluble resin used in the present invention is preferably 20 Å / sec or more as measured with 0.261N tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferred is 200 liters / second or more.

The molecular weight of the alkali-soluble resin is preferably 1000 to 200000 on a weight average, and more preferably 2000 to 50000.
The molecular weight distribution (Mw / Mn) of the alkali-soluble resin is preferably 1.0 to 2.5, more preferably 1.0 to 2.0, and particularly preferably 1.0 to 1.5.
Here, the weight average molecular weight is defined as a polystyrene equivalent value of gel permeation chromatography.
The addition amount of the alkali-soluble resin is usually 30 to 95% by mass, preferably 40 to 90% by mass, and more preferably 50 to 80% by mass with respect to the total solid content of the composition.

  In the present invention, preferred alkali-soluble resins include resins having a repeating unit represented by the following general formula (1).

In general formula (1),
A represents a hydrogen atom, an alkyl group, a halogen atom, or a cyano group.
R ₁ and R ₂ each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkoxy group or an alkylcarbonyloxy group.
n represents an integer of 1 to 3.

In general formula (1), the alkyl group as A is preferably an alkyl group having 1 to 3 carbon atoms. Examples of the halogen atom for A include Cl, Br, and F.
A is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms (such as a methyl group or an ethyl group), and particularly preferably a hydrogen atom or a methyl group.

Examples of the halogen atom as R ₁ and R ₂ include Cl, Br, F, and I.
The alkyl group as R ₁ and R _2, alkenyl group, cycloalkyl group, aryl group, aralkyl group, alkoxy group or alkylcarbonyloxy group may have a substituent. R ₁ and R ₂ may be combined with each other to form a ring.

R ₁ and R ₂ are preferably each independently, a linear or branched alkyl group having 1 to 8 carbon atoms which may have a substituent, or a carbon number which may have a substituent. An alkenyl group having 1 to 8 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms which may have a substituent, and a substituent. An optionally substituted aralkyl group having 7 to 16 carbon atoms, an optionally substituted alkoxy group having 1 to 8 carbon atoms, or an optionally substituted alkylcarbonyloxy group having 1 to 8 carbon atoms It is.

  Examples of the substituent include an alkyl group (methyl group, ethyl group, propyl group, isopropyl group, butyl group, t-butyl group, hexyl group, etc.), aryl group (phenyl group, naphthyl group, etc.), aralkyl group, hydroxyl group. Groups, alkoxy groups (methoxy group, ethoxy group, butoxy group, octyloxy group, dodecyloxy group, etc.), acyl groups (acetyl group, propanoyl group, benzoyl group, etc.) and oxo groups.

More preferably, each of R ₁ and R ₂ is independently a hydrogen atom, a halogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted carbon number. An alkoxycarbonyl group having 1 to 4 carbon atoms and an optionally substituted alkylcarbonyloxy group having 1 to 4 carbon atoms, particularly preferably a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, or 1 to 3 carbon atoms. Alkyl groups (methyl group, ethyl group, propyl group, isopropyl group) and alkoxy groups having 1 to 3 carbon atoms (methoxy group, ethoxy group, propyloxy group, isopropyloxy group).
n represents an integer of 1 to 3, and is preferably 1 or 2. In the general formula (1), the OH group may be bonded to any position of the ring, but is preferably bonded to the 3-position or 4-position of the ring.

  In addition, the resin (A) preferably has at least one repeating unit represented by the following general formulas (2) to (4) from the viewpoint of improving the alkali dissolution rate of the resist film and improving the film quality. In addition, the resin which has at least 1 type of the repeating unit represented by General formula (2)-(4) with the repeating unit represented by General formula (1) is also preferable.

In general formulas (2) to (4),
A has the same meaning as A in formula (1).
X represents a single bond, —COO— group, —O— group or —CON (R ₁₆ ) — group, and R ₁₆ represents a hydrogen atom or an alkyl group.
R _{11 to} R ₁₅ are each independently synonymous with R ₁ in the general formula (1).
R _{101 to} R ₁₀₆ each independently represents a hydroxy group, a halogen atom, an alkyl group, an alkoxy group, an alkylcarbonyloxy group, an alkylsulfonyloxy group, an alkenyl group, an aryl group, an aralkyl group or a carboxy group.
a to f each independently represent an integer of 0 to 3;

In the general formulas (2) to (4), A has the same meaning as A in the general formula (1). X represents a single bond, —COO— group, —O— group, —CON (R ₁₆ ) — group, and R ₁₆ represents a hydrogen atom or an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms, for example, Methyl group, ethyl group, propyl group, etc.). X is preferably a single bond, —COO— or —CON (R ₁₆ ) —, and particularly preferably a single bond or a —COO— group.

R _{11 to} R ₁₅ are each independently synonymous with R ₁ in the general formula (1).
R _{101 to} R ₁₀₆ are preferably each independently a hydroxy group, a halogen atom (Cl, Br, F, I), or a linear or branched chain having 1 to 8 carbon atoms which may have a substituent. An alkyl group, a linear or branched alkoxy group having 1 to 8 carbon atoms which may have a substituent, and a linear or branched alkylcarbonyl group having 1 to 8 carbon atoms which may have a substituent. An oxy group, an optionally substituted linear or branched alkylsulfonyloxy group having 1 to 8 carbon atoms, an optionally substituted alkenyl group having 1 to 8 carbon atoms, and a substituent. It represents an aryl group having 7 to 15 carbon atoms which may have, an aralkyl group having 7 to 16 carbon atoms which may have a substituent, or a carboxy group.
Examples of these substituents include the same ones as those exemplified as the substituent for R _{1 in} the general formula (1).

More preferably, each of R _{101 to} R ₁₀₆ is independently a hydrogen atom, a halogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted carbon number 1. Is an alkoxy group having 1 to 4 carbon atoms and an alkylcarbonyloxy group having 1 to 4 carbon atoms which may have a substituent, and particularly preferably a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, or 1 to 3 carbon atoms. Alkyl group (methyl group, ethyl group, propyl group, isopropyl group), C1-C3 alkoxy group (methoxy group, ethoxy group, propyloxy group, isopropyloxy group), C1-C3 alkylcarbonyloxy group (Acetyl group, propionyl group, etc.).
a to f each independently represent an integer of 0 to 3;

  (A) Resin having a repeating unit represented by the general formula (1), resin having a repeating unit represented by the general formulas (2) to (4), represented by the general formula (1) as the resin of the component (A) The resin having at least one of the repeating units represented by the general formulas (2) to (4) together with the repeating unit may be polymerized with other polymerizable monomers capable of controlling the film formability and alkali solubility. Good.

  Examples of these polymerizable monomers include styrene, alkyl-substituted styrene, alkoxy-substituted styrene, O-alkylated styrene, O-acylated styrene, hydrogenated hydroxystyrene, maleic anhydride, acrylic acid derivatives (acrylic acid, acrylic acid Esters), methacrylic acid derivatives (methacrylic acid, methacrylic esters, etc.), N-substituted maleimides, acrylonitrile, methacrylonitrile, and the like, but are not limited thereto.

The range of the content of the repeating unit represented by the general formula (1) in the component (A) resin is generally 50 to 100 mol%, preferably 70 to 100 mol%.
The range of the content of the repeating units represented by the general formulas (2) to (4) in the component (A) resin is generally 3 to 50 mol%, preferably 5 to 30 mol%.
In the resin of component (A), the ratio of the repeating unit represented by the general formula (1) and the repeating unit represented by the general formulas (2) to (4) is 100/0 to 50/50 in molar ratio. Is more preferable, 100/0 to 60/40 is more preferable, and 100/0 to 70/30 is particularly preferable.

  The resin of component (A) can be synthesized by a known radical polymerization method or anionic polymerization method. For example, in the radical polymerization method, a vinyl monomer is dissolved in a suitable organic solvent, and a peroxide (benzoyl peroxide, etc.), a nitrile compound (azobisisobutyronitrile, etc.), or a redox compound (cumene hydroperoxide-first An iron salt or the like) can be used as an initiator to react at room temperature or under heating conditions to obtain a polymer. In the anionic polymerization method, a vinyl monomer can be dissolved in a suitable organic solvent, and a polymer can be obtained usually by reacting under a cooling condition using a metal compound (such as butyl lithium) as an initiator.

  Although the specific example of the alkali-soluble resin which has a repeating unit represented by General formula (1) preferably used for this invention below is shown, this invention is not limited to these.

  N in the above specific examples represents a positive integer. x, y, z represents the molar ratio of the resin composition, and in the case of a resin composed of two components, x = 10 to 95, y = 5 to 90, preferably x = 40 to 90, y = 10 to 60 Is done. In the resin composed of three components, x = 10 to 90, y = 5 to 85, z = 5 to 85, preferably x = 40 to 80, y = 10 to 50, z = 10 to 50 are used. .

  Although the example of alkali-soluble resin which has a repeating unit represented by General formula (2)-(4) preferably used by this invention below is shown, this invention is not limited to these.

  As the alkali-soluble resin of the component (A) in the present invention, a copolymer having a repeating unit having a monocyclic aromatic structure and a repeating unit having a polycyclic aromatic structure is more preferable.

Other alkali-soluble resins can be used in combination with the alkali-soluble resin having any of the repeating units represented by the general formulas (1) to (4) preferably used in the present invention. Regarding the use ratio, other alkali-soluble resins can be used in combination up to 100 parts by mass with respect to 100 parts by mass of the preferable alkali-soluble resin described above.
Examples of other alkali-soluble resins used in combination include novolak resins, hydrogenated novolac resins, acetone-pyrogallol resins, styrene-maleic anhydride copolymers, carboxyl group-containing methacrylic resins and derivatives thereof. It is not limited to.

[2] Compounds that generate acid upon irradiation with actinic rays or radiation (component (B))
As the acid generator of component (B) used in the present invention, a wide variety of known acid generators can be used. Examples of these acid generators include compounds described in JP-A No. 2002-6500, JP-A No. 2002-14470, European Patent No. 1117004, and European Patent No. 1109066.
Preferably, onium salts such as diazonium salts, sulfonium salts, iodonium salts, organic halogen compounds, photoacid generators having an o-nitrobenzyl type protecting group, iminosulfonate compounds, disulfone compounds, diazoketosulfonic acids, diazodisulfone compounds, An oxime sulfonate compound etc. can be mentioned.

  Although the preferable example of the acid generator of the (B) component used by this invention below is given, of course, it is not limited to these.

The content of the acid generator as the component (B) used in the present invention is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, based on the solid content of the entire negative resist composition. ˜18% by weight is particularly preferred.
In this invention, the acid generator of (B) component may be used independently, and 2 or more types may be mixed and used for it.

[3] (C) A cross-linking agent that reacts by the action of an acid to form a cross-link in an alkali-soluble resin with the elimination of an alcohol having 3 or more carbon atoms or a carboxylic acid having 7 or more carbon atoms. The composition reacts by the action of an acid to form a crosslinker (hereinafter referred to as “(C) component”) that forms a crosslink in the alkali-soluble resin with the elimination of an alcohol having 3 or more carbon atoms or a carboxylic acid having 7 or more carbon atoms Also referred to as “crosslinking agent”.
The crosslinking agent of component (C) is preferably the following crosslinking agent (C1), (C2) or (C3).

(C1) A phenolic group having 3 to 10 benzene rings and having two or more substituents selected from an alkoxymethyl group having 7 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms bonded to any benzene ring Crosslinker.
(C2) A melamine-based crosslinking agent having two or more substituents selected from an alkoxymethyl group having 4 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms.
(C3) A uril-based crosslinking agent having two or more substituents selected from an alkoxymethyl group having 4 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms.

(C1) A phenolic group having 3 to 10 benzene rings and having two or more substituents selected from an alkoxymethyl group having 7 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms bonded to any benzene ring Cross-linking agent (hereinafter also referred to as “(C1) component cross-linking agent”)
As a particularly preferred component (C1), the cross-linking agent has a molecular weight of 2000 or less, more preferably 1200 or less, 3 to 5 benzene rings, concentrated on any benzene ring, or distributed and bonded. A phenol derivative having two or more substituents selected from an alkoxymethyl group having 7 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms can be given. By using such a phenol derivative, the effect of the present invention can be made more remarkable.

  The alkoxymethyl group having 7 or more carbon atoms in the crosslinking agent of component (C1) is preferably an alkoxymethyl group having 7 to 20 carbon atoms, such as a hexyloxymethyl group, a heptyloxymethyl group, and an octyloxymethyl group. , Nonyloxymethyl group, decyloxymethyl group, undecyloxymethyl group, dodecyloxymethyl group, tridecyloxymethyl group, tetradecyloxymethyl group, octadecyloxymethyl group, cyclohexyloxymethyl group, norbornyloxymethyl group, Adamantyloxymethyl group, cyclohexylmethyloxymethyl group, bidecylmethyloxymethyl group, norbornylmethyloxymethyl group, phenylmethyloxymethyl group, 4-methyl-phenylmethyloxymethyl group, 2,4,6-trimethyl- Phenylmethyl Oxymethyl group and the like. The alkoxymethyl group preferably has a cyclic structure. The alkoxymethyl group may further have a substituent. Preferred examples of the substituent for the alkoxymethyl group include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, and an alkoxy group.

  The acyloxymethyl group having 8 or more carbon atoms in the (C1) crosslinking agent is preferably an acyloxymethyl group having 8 to 20 carbon atoms, such as hexylcarbonyloxymethyl group, heptylcarbonyloxymethyl group, octylcarbonyl. Oxymethyl group, nonylcarbonyloxymethyl group, decylcarbonyloxymethyl group, undecylcarbonyloxymethyl group, dodecylcarbonyloxymethyl group, tridecylcarbonyloxymethyl group, tetradecylcarbonyloxymethyl group, octadecylcarbonyloxymethyl group, cyclohexyl Carbonyloxymethyl group, norbornylcarbonyloxymethyl group, adamantylcarbonyloxymethyl group, bidecylcarbonyloxymethyl group, phenylcarbonyloxymethyl group, 4-methyl Le - phenyl carbonyloxy methyl group, 2,4,6-trimethyl - phenyl carbonyloxy methyl group, and the like. The acyloxymethyl group preferably has a cyclic structure. The acyloxymethyl group may further have a substituent. Preferred examples of the substituent for the acyloxymethyl group include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, and an alkoxy group.

The lower limit of the molecular weight of the component (C1) crosslinking agent is usually 150 or more, preferably 200 or more, more preferably 300 or more.
The number of alkoxymethyl groups or acyloxymethyl groups is preferably 1 to 2 on average per benzene ring, and more preferably 1.2 to 2 on average.

  Among the crosslinking agents as component (C1), particularly preferred are listed below.

In the formula, L ^{1 to} L ⁸ may be the same or different and each represents an alkoxymethyl group having 7 or more carbon atoms or an acyloxymethyl group having 8 or more carbon atoms. It is more preferable in terms of pattern heat resistance that L ^{1 to} L ⁸ have a cyclic structure.

Preferred specific examples of L ¹ ~L ⁸ is, the present invention is not limited thereto.

The crosslinking agent of the component (C1) having an alkoxymethyl group can be obtained by reacting a corresponding phenol derivative having a hydroxymethyl group with an alcohol in the presence of an acid catalyst. At this time, in order to prevent resinification and gelation, the reaction temperature is preferably 100 ° C. or lower. Specifically, it can be synthesized by the method described in European Patent EP632003A1 and the like.
The phenol derivative having the hydroxymethyl group is obtained by reacting a corresponding phenol compound not having a hydroxymethyl group (a compound in which L ^{1 to} L ⁸ are hydrogen atoms in the above formula) with formaldehyde in the presence of a base catalyst. Can do. At this time, in order to prevent resinification or gelation, the reaction temperature is preferably 60 ° C. or lower. Specifically, it can be synthesized by the methods described in JP-A-6-282067, JP-A-7-64285 and the like.

  The crosslinking agent of the component (C1) having an acyloxymethyl group can be synthesized by reacting a corresponding phenol derivative having a hydroxymethyl group with a carboxylic acid anhydride under neutral conditions.

  The crosslinking agent of component (C1) is preferable from the viewpoint of stability during storage, but a phenol derivative having an alkoxymethyl group is particularly preferable from the viewpoint of stability during storage.

  (C1) The crosslinking agent of a component may be used independently and may be used in combination of 2 or more type.

  (C2) Melamine-based crosslinking agent having two or more substituents selected from an alkoxymethyl group having 4 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms (hereinafter also referred to as “crosslinking agent of component (C2)”)

  The alkoxymethyl group having 4 or more carbon atoms in the crosslinking agent of component (C2) is preferably an alkoxymethyl group having 4 to 20 carbon atoms, such as a propyloxymethyl group, a butyloxymethyl group, or a pentyloxymethyl group. Hexyloxymethyl group, heptyloxymethyl group, octyloxymethyl group, nonyloxymethyl group, decyloxymethyl group, undecyloxymethyl group, dodecyloxymethyl group, tridecyloxymethyl group, tetradecyloxymethyl group, octadecyl Oxymethyl group, cyclohexyloxymethyl group, norbornyloxymethyl group, adamantyloxymethyl group, cyclohexylmethyloxymethyl group, bidecylmethyloxymethyl group, norbornylmethyloxymethyl group, phenylmethyloxymethyl group, 4-methyl - phenylmethyl oxymethyl group, 2,4,6-trimethyl - such phenylmethyl oxymethyl group and the like, more preferably an alkoxymethyl group having 7 to 20 carbon atoms. The alkoxymethyl group preferably has a cyclic structure. The alkoxymethyl group may further have a substituent. Preferred examples of the substituent for the alkoxymethyl group include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, and an alkoxy group.

  Examples of the acyloxymethyl group having 8 or more carbon atoms in the crosslinking agent of component (C2) include those similar to the acyloxymethyl group having 8 or more carbon atoms in the crosslinking agent of component (C1). .

  The molecular weight of the (C2) component crosslinking agent is preferably 150 to 600, more preferably 200 to 450, in weight average.

  Specific examples of the preferred component (C2) are shown below, but the present invention is not limited thereto.

In the formula, L ^{1a to} L ^6a may be the same or different and each represents an alkyl group having 3 or more carbon atoms or an acyl group having 7 or more carbon atoms. L ^{1a to} L ^6a are more preferable in terms of pattern heat resistance when they have a cyclic structure.
Preferable specific examples of L ^{1a to} L ^6a include the above L ^{1 to} L ^{8 in} the crosslinking agent of component (C1).
The structure which remove | excluded the oxymethylene group from the preferable specific example of can be mentioned.

  (C2) The crosslinking agent of a component may be used independently and may be used in mixture of 2 or more types.

  (C3) Uril-based crosslinking agent having two or more substituents selected from an alkoxymethyl group having 4 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms (hereinafter also referred to as “(C2) component crosslinking agent”)

  Examples of the alkoxymethyl group having 4 or more carbon atoms in the crosslinking agent of component (C3) include the same as the alkoxymethyl group having 4 or more carbon atoms in the crosslinking agent of component (C2).

  Examples of the acyloxymethyl group having 8 or more carbon atoms in the crosslinking agent of component (C3) include those similar to the acyloxymethyl group having 8 or more carbon atoms in the crosslinking agent of component (C1). .

  The molecular weight of the (C3) component crosslinking agent is preferably 150 to 600, more preferably 200 to 450, in terms of weight average.

  Specific preferred examples of the component (C3) are shown below, but the present invention is not limited thereto.

In the formula, L ^{1a to} L ^4a may be the same or different and each represents an alkyl group having 3 or more carbon atoms or an acyl group having 7 or more carbon atoms. It is more preferable in terms of pattern heat resistance that L ^{1a to} L ^4a have a cyclic structure.
Preferable specific examples of L ^{1a to} L ^4a include structures obtained by removing the oxymethylene group from the preferable specific examples of L ^{1 to} L ^{8 in} the crosslinking agent of component (C1).

  (C3) The crosslinking agent of a component may be used independently and may be used in mixture of 2 or more types.

  (C) 0.5-50 mass% is preferable with respect to solid content of all negative resist compositions, content of the crosslinking agent of a component is more preferable 1-40 mass%, and 2-35 mass% is preferable. Particularly preferred.

[4] Nitrogen-containing basic compound (component D)
The composition of the present invention preferably further contains a nitrogen-containing basic compound. The nitrogen-containing basic compound preferably used is a compound having a stronger basicity than phenol.
As a preferable chemical environment, structures of the following formulas (A) to (E) can be exemplified. Formulas (B) to (E) may be part of a ring structure.

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² may be the same or different, and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 1 to 20 carbon atoms, or 6 to 20 carbon atoms. Wherein R ²⁵¹ and R ²⁵² may combine with each other to form a ring. The alkyl group, cycloalkyl group, and aryl group may have a substituent. Examples of the substituent for the alkyl group, cycloalkyl group, and aryl group include a hydroxyl group and an amino group.
R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 1 to 20 carbon atoms.
Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms of different chemical environments in one molecule, and particularly preferably both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom. Or a compound having an alkylamino group.

  Preferred examples include substituted or unsubstituted guanidine, substituted or unsubstituted aminopyridine, substituted or unsubstituted aminoalkylpyridine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted indazole, imidazole, substituted or unsubstituted Substituted pyrazole, substituted or unsubstituted pyrazine, substituted or unsubstituted pyrimidine, substituted or unsubstituted purine, substituted or unsubstituted imidazoline, substituted or unsubstituted pyrazoline, substituted or unsubstituted piperazine, substituted or unsubstituted Aminomorpholine, substituted or unsubstituted aminoalkylmorpholine, and the like. Preferred substituents are amino group, aminoalkyl group, alkylamino group, aminoaryl group, arylamino group, alkyl group, alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, nitro group, hydroxyl group, cyano group It is.

  Particularly preferred compounds include guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, imidazole, 2-methylimidazole, 4-methylimidazole, N-methylimidazole, 2-phenylimidazole, 4 , 5-diphenylimidazole, 2,4,5-triphenylimidazole, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (Aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, 4- Aminoethylpyridine,

3-aminopyrrolidine, piperazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine, 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl)- Examples include 5-methylpyrazine, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine. It is not limited to this.
These nitrogen-containing basic compounds are used alone or in combination of two or more.

  The use ratio of the acid generator and the nitrogen-containing basic compound in the composition is preferably (acid generator) / (nitrogen-containing basic compound) (molar ratio) = 2.5 to 300. (Acid generator) / (nitrogen-containing basic compound) (molar ratio) is preferably 5.0 to 200, more preferably 7.0 to 150.

The content of the component (D) used in the present invention is preferably 0.01 to 10% by mass, more preferably 0.03 to 5% by mass, based on the solid content of the entire negative resist composition. 0.05 to 3% by mass is particularly preferable.
In the present invention, the nitrogen-containing basic compound of component (D) may be used alone or in combination of two or more.

[5] Other components The negative resist composition of the present invention may further contain a solvent, a surfactant, a photodegradable base compound, a photobase generator, and the like, if necessary.

(5) -1 Solvents The composition of the present invention is dissolved in a solvent that dissolves each of the above components and coated on a support. Solvents used here include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate , Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-dimethyl Formamide, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable. Or mixed to use.

(5) -2 Surfactants A surfactant may be added to the solvent. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, etc. Sorbitans such as polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopal Te - door,

Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, F-top EF301, EF303, EF352 (Shin-Akita Kasei) (Made by Co., Ltd.), MegaFuck F171, F173 (Dainippon Ink Co., Ltd.), Florad FC430, FC431 (Sumitomo 3M Co., Ltd.), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103 , SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), Troysol S-366 (manufactured by Troy Chemical Co., Ltd.), silicon surfactants, organosiloxane polymer KP341 (Shin-Etsu Chemical) Manufactured by Gaku Kogyo Co., Ltd.) and acrylic acid or methacrylic acid (co) polymerized polyflow No. 75, no. 95 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.).
These surfactants may be added alone or in some combination.

The surfactant is any one of fluorine and / or silicon surfactants (fluorine surfactants and silicon surfactants, surfactants containing both fluorine atoms and silicon atoms), or It is preferable to contain 2 or more types.
As these surfactants, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540 No. 7, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A 2002-277862, US Pat. No. 5,405,720. , No. 5,360,692, No. 5,529,881, No. 5,296,330, No. 5,543,098, No. 5,576,143, No. 5,294,511, No. 5,824,451. The following commercially available surfactants can also be used as they are.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.)
Fluorosurfactants such as Surflon S-382, SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (manufactured by Troy Chemical Co., Ltd.), or silicon surfactants Can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).
Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) Copolymer) of (ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate), acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

  The amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total amount of the negative resist composition (excluding the solvent).

(5) -3 Photodegradable base compound Further, the composition of the present invention includes JP-A-7-28247, European Patent 616258, US Pat. No. 5,525,443, JP-A-9-127700, European Patent 762207, US Ammonium salts described in Japanese Patent No. 578354, specifically, tetramethylammonium hydroxide, tetra-n-butylammonium hydroxide, betaine and the like can be added, and JP-A-5-232706, 6-11835 and 6 -242606, 6-266100, 7-333851, 7-333844, U.S. Pat. No. 5,663,035, European Patent 677788 You can also

(5) -4 Photobase generator As the photobase generator that can be added to the composition of the present invention, JP-A-4-151156, 4-162040, 5-197148, 5-5995, 6-194434,
Examples thereof include compounds described in JP-A-8-146608, JP-A-10-83079 and European Patent No. 622682, specifically, 2-nitrobenzylcarbamate, 2,5-dinitrobenzylcyclohexylcarbamate, N-cyclohexyl-4- Methylphenylsulfonamide, 1,1-dimethyl-2-phenylethyl-N-isopropylcarbamate and the like can be suitably used. These photobase generators are added for the purpose of improving the resist shape and the like.

  The negative resist composition of the present invention is applied onto a substrate to form a thin film. The thickness of this coating film is preferably 0.05 to 4.0 μm.

  In the present invention, a commercially available inorganic or organic antireflection film can be used if necessary. Furthermore, an antireflection film can be applied to the resist lower layer and used.

  As the antireflection film used as the lower layer of the resist, either an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, amorphous silicon, or an organic film type made of a light absorber and a polymer material may be used. it can. The former requires equipment such as a vacuum deposition apparatus, a CVD apparatus, and a sputtering apparatus for film formation. Examples of the organic antireflection film include a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin described in JP-B-7-69611, an alkali-soluble resin, a light absorber, and maleic anhydride copolymer described in US Pat. No. 5,294,680. A reaction product of a coalescence and a diamine type light absorbing agent, a resin binder described in JP-A-6-186863 and a methylolmelamine thermal crosslinking agent, a carboxylic acid group, an epoxy group and a light-absorbing group described in JP-A-6-118656. An acrylic resin-type antireflection film in the same molecule, a composition comprising methylol melamine and a benzophenone-based light absorber described in JP-A-8-87115, and a low-molecular light absorber added to a polyvinyl alcohol resin described in JP-A-8-179509 And the like.

  In addition, as the organic antireflection film, commercially available organic antireflection films such as DUV30 series, DUV-40 series manufactured by Brewer Science, AR-2, AR-3, AR-5 manufactured by Shipley, etc. may be used. it can.

  In the manufacture of precision integrated circuit elements, the pattern forming process on the resist film is performed on a substrate (eg, a silicon / silicon dioxide film substrate, a glass substrate, an ITO substrate, a quartz / chromium oxide coated substrate, etc.). A good resist pattern can be formed by applying a type resist composition, then irradiating with X-ray, electron beam, ion beam or the like, heating, developing, rinsing and drying.

The developer of the negative resist composition of the present invention includes inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine and the like. Primary amines, secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethyl Aqueous solutions of alkalis such as quaternary ammonium salts such as ammonium hydroxide and choline, cyclic amines such as pyrrole and piperidine, and the like can be used. Furthermore, an appropriate amount of an alcohol such as isopropyl alcohol or a nonionic surfactant may be added to the alkaline aqueous solution.
Among these developers, quaternary ammonium salts are preferable, and tetramethylammonium hydroxide and choline are more preferable.
The alkali concentration of the alkali developer is usually from 0.1 to 20% by mass.
The pH of the alkali developer is usually from 10.0 to 15.0.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, the content of this invention is not limited by this.

1. Composition example of constituent materials (1) Alkali-soluble resin of component (A) Synthesis example 1 (synthesis of resin example (29))
3.9 g (0.024 mol) of 4-acetoxystyrene and 0.8 g (0.006 mol) of 4-methoxystyrene were dissolved in 30 ml of 1-methoxy-2-propanol at 70 ° C. under a nitrogen stream and stirring. Polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) (manufactured by Wako Pure Chemical Industries, Ltd .; trade name V-65) 50 mg, 4-acetoxystyrene 9.1 g (0.056 mol), A solution of 1.9 g (0.014 mol) of 4-methoxystyrene in 70 ml of 1-methoxy-2-propanol was added dropwise over 2 hours. Two hours later, 50 mg of initiator was added, and the reaction was further performed for 2 hours. Thereafter, the temperature was raised to 90 ° C. and stirring was continued for 1 hour. The reaction solution was allowed to cool and then poured into 1 L of ion exchange water with vigorous stirring to precipitate a white resin. The obtained resin was dried, dissolved in 100 mL of methanol, 25% tetramethylammonium hydroxide was added, the acetoxy group in the resin was hydrolyzed, and then neutralized with an aqueous hydrochloric acid solution to precipitate a white resin. After washing with ion-exchanged water and drying under reduced pressure, 11.6 g of the resin (29) of the present invention was obtained. When the molecular weight was measured by GPC, it was 9,200 in terms of weight average (Mw: polystyrene conversion) and 2.2 in terms of dispersity (Mw / Mn).
Hereinafter, the resin of the present invention (A) was synthesized in the same manner.

(2) Synthesis of Component (C) Crosslinking Agent [HM-1] 1- [α-Methyl-α- (4-hydroxyphenyl) ethyl] -4- [α, α-bis (4-hydroxyphenyl) ethyl ] 20 g of benzene (Trisp-PA manufactured by Honshu Chemical Industry Co., Ltd.) was added to a 10% aqueous potassium hydroxide solution and stirred and dissolved. Next, 60 ml of 37% formalin aqueous solution was gradually added over 1 hour at room temperature while stirring this solution. The mixture was further stirred at room temperature for 6 hours, and then poured into a dilute sulfuric acid aqueous solution. The precipitate was filtered, sufficiently washed with water, and then recrystallized from 30 ml of methanol to obtain 20 g of a white powder of a phenol derivative [HM-1] having a hydroxymethyl group having the following structure. The purity was 92% (liquid chromatography method).

Synthesis of [BM-1] 20 g of the phenol derivative [HM-1] having a hydroxymethyl group obtained in the above synthesis example was dissolved in 500 ml of DMF. When this solution was cooled to 0 ° C., 8 g of benzoic anhydride was added, and then the reaction solution was reacted at room temperature for 10 hours. The reaction solution was poured into distilled water to precipitate the product, water was removed by decantation, and 1000 ml of ethyl acetate was added and dissolved. After separating and washing with 500 ml of an aqueous sodium hydrogen carbonate solution, it was washed with 1 L of distilled water three times. This solution was concentrated to dryness to obtain a phenol derivative [BM-1] having a benzoyloxymethyl group having the following structure. The purity was 75% (liquid chromatography).

  Furthermore, a crosslinking agent of component (C) shown below was synthesized in the same manner.

(3) Acid generator of component (B) Synthesis example 1 (Synthesis of acid generator (I-1))
16.4 g of AgBF ₄ was mixed with 150 ml of acetonitrile, and 16.0 g of phenacyl bromide and 12.4 g of di-n-butyl sulfide dissolved in 50 ml of acetonitrile were added thereto over 30 minutes. The mixture was stirred overnight at room temperature, and the reaction solution was concentrated to precipitate a powder. When this was washed with diisopropyl ether, 27 g of phenacyl di-n-butylsulfonium tetrafluoroborate was obtained.
10 g of phenacyldi n-butylsulfonium tetrafluoroborate was dissolved in 200 ml of methanol, and 10.1 g of potassium nonafluorobutanesulfonate was added thereto, followed by stirring at room temperature for 1 hour. After adding 500 ml of chloroform to the reaction solution, it was washed twice with 300 ml of distilled water. When the organic layer was concentrated, 9.8 g of acid generator (I-1) was obtained.
Other compounds were synthesized using the same method.

Example 1
(1) Preparation and coating of negative resist
(A) component: Resin (29) 0.727g
Component (B): Acid generator (I-1) 0.07 g
Component (C): Cross-linking agent (BM-1) 0.20 g
Component (D): Basic compound (D-1) 0.003 g
Is dissolved in a mixed solvent of 7.5 g of propylene glycol monomethyl ether acetate and 1.5 g of propylene glycol monomethyl ether, and Megafac F176 (manufactured by Dainippon Ink & Chemicals, Inc., hereinafter abbreviated as W-1) is used as a surfactant. ) 0.001 g was added and dissolved, and the resulting solution was microfiltered with a 0.1 μm aperture membrane filter to obtain a resist solution.
This resist solution was applied onto a silicon wafer using a spin coater Mark8 manufactured by Tokyo Electron, and dried on a hot plate at 110 ° C. for 90 seconds to obtain a resist film having a thickness of 0.3 μm.

(2) Production of negative resist pattern This resist film was irradiated using an electron beam drawing apparatus (HL750, acceleration voltage 50 KeV manufactured by Hitachi, Ltd.). After irradiation, it was heated on a hot plate at 110 ° C. for 90 seconds, immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds and dried. The obtained pattern was evaluated for sensitivity, resolution, and heat resistance by the following methods.
(2-1) Sensitivity The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.). The exposure amount (electron beam irradiation amount) when resolving 0.15 μm (line: space = 1: 1) was defined as sensitivity.
(2-2) Resolving power The resolving power was defined as the limiting resolving power (line and space were separated and resolved) at the exposure amount showing the above sensitivity.
(2-3) Heat resistance A silicon wafer on which a resist pattern having a line width of 0.15 μm was formed was heated on an oven set at 150 ° C. for 3 minutes. Thereafter, a pattern shape having a line width of 0.15 μm was observed by SEM, and a case where no change in the pattern shape was observed was evaluated as ◯, and a case where thermal deformation of the pattern was observed was evaluated as Δ.
(2-4) Surface roughness A wafer sample irradiated with EUV light having an exposure amount corresponding to the sensitivity obtained in the above experiment was developed in 1 second to 60 seconds in increments of 5 seconds (2.48% by mass, TMAH Aqueous solution). The surface roughness (Ra (nm)) was determined for each using AFM, and the maximum value was defined as the surface roughness.
The evaluation results are shown in Table 1.

Examples 2-16 and Comparative Examples 1-2
The other components shown in Table 1 were used, and the others were prepared in the same manner as in Example 1 to prepare a resist solution, form a negative pattern, and evaluated. The evaluation results are shown in Table 1.

  The symbols in Table 1 represent the following.

[Basic compounds]
D-1: 1,5-diazabicyclo [4.3.0] non-5-ene D-2: 2,4,5-triphenylimidazole D-3: 4-dimethylaminopyridine

  [Crosslinking agent]

  From Table 1, it can be seen that the negative resist composition of the present invention is excellent in sensitivity and resolution, and has good pattern heat resistance.

<Outgassing by EUV light exposure>
Examples 17-21 and Comparative Examples 3 and 4
Using the resist compositions of Examples 1, 5, 8, 11, 15 and Comparative Examples 1 and 2, resist films were obtained in the same manner as in Example 1. Subsequently, the film thickness after exposure with respect to the film thickness before 5 mJ / cm < ² > exposure was measured using the EUVES exposure apparatus by Risotech Japan, and the quantity of outgas (vaporization thing generate | occur | produced during exposure) was evaluated.
The evaluation results are shown in Table 2.

  From the results shown in Table 2, it can be seen that the composition of the present invention has less outgas generation in EUV light exposure and has better performance than the composition of the comparative example.

Claims (8)

A negative resist composition comprising at least the following (A), (B) and (C).
(A) an alkali-soluble resin,
(B) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (C) an alkali-soluble resin that reacts with the action of the acid to release an alcohol having 3 or more carbon atoms or a carboxylic acid having 7 or more carbon atoms. A cross-linking agent that forms a cross-link.   The crosslinking agent of component (C) is selected from (C1) 3 to 10 benzene rings and an alkoxymethyl group having 7 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms bonded to any benzene ring. The negative resist composition according to claim 1, wherein the negative resist composition is a phenol-based crosslinking agent having two or more substituents.   The cross-linking agent of component (C) is a melamine-based cross-linking agent having two or more substituents selected from (C2) an alkoxymethyl group having 4 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms. The negative resist composition according to claim 1.   The cross-linking agent of component (C) is a uril-based cross-linking agent having two or more substituents selected from (C3) an alkoxymethyl group having 4 or more carbon atoms and an acyloxymethyl group having 8 or more carbon atoms. The negative resist composition according to claim 1.   The cross-linking agent of component (C) is a cross-linking agent that reacts by the action of an acid to form a cross-link in an alkali-soluble resin with the elimination of an alcohol having 7 or more carbon atoms. The negative resist composition as described in any one of 4 above.   The negative resist composition according to claim 1, wherein the alcohol or carboxylic acid released from the crosslinking agent of component (C) by the action of an acid has a cyclic structure.   The negative resist composition according to claim 1, wherein the negative resist composition is for electron beam, X-ray or EUV light.   A pattern forming method comprising the steps of: forming a resist film from the negative resist composition according to claim 1; and exposing and developing the resist film.