JP4958821B2 - Negative resist composition and pattern forming method using the same - Google Patents

Abstract

The present invention provides a negative resist composition and a pattern forming method using the same. The negative resist composition contains (A) an alkaline soluble polymer including specifically defined repeating units; (B) a crosslinking agent which can be crosslinked with an alkaline soluble polymer (A) under the action of an acid; (C) a compound capable of generating an acid by an irradiation of actinic rays or radiation; (D) specifically defined quaternary ammonium salt; and (E) an organic carboxylic acid.

Description

  The present invention relates to a negative resist composition suitably used 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 beams and X-rays, and a pattern forming method using the same, and uses a substrate having a specific base film. The present invention relates to a negative resist composition used in a process for forming a pattern 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 photoresist 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. Along with this, 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, in addition to excimer laser light, lithography using electron beams and X-rays is currently 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 addition, this electron beam lithography is widely used for producing a photomask used for semiconductor exposure because of its high resolution characteristics. The photomask creation process is as follows. Prepare a shielding substrate with a shielding layer composed mainly of a shielding material such as chrome on a transparent substrate such as a glass substrate, form a resist layer on it, and perform selective exposure on the shielding layer. A resist pattern is formed on the substrate. Next, the resist pattern is used as a mask to etch the portion of the shielding layer where the pattern is not formed and transfer the pattern to the shielding layer, thereby providing a transparent substrate and a shielding layer having a predetermined pattern thereon. Photomask can be obtained.
High sensitivity is a very important issue for shortening the processing time, especially in processing that uses a different type of electron beam exposure than batch exposure of light, but high sensitivity is required for negative resists for electron beams. Therefore, in addition to deterioration of resolution and pattern shape, line edge roughness deteriorates, and development of a resist satisfying these characteristics is strongly desired. Here, the line edge roughness means that when the pattern is viewed from directly above because the resist pattern and the edge of the substrate interface vary irregularly in the direction perpendicular to the line direction due to the characteristics of the resist. Say that the edge looks uneven. The unevenness is transferred by an etching process using a resist as a mask, and the dimensional accuracy is lowered. Particularly in the ultrafine region of 0.25 μm or less, the line edge roughness is an extremely important improvement issue.
In addition, it is known that when a resist pattern is formed on a shielding layer used for creating a photomask, the pattern shape deteriorates. In particular, when a negative resist is used, the pattern collapses due to the bite shape of the substrate interface. Occurs, and the problem that the resolving power is greatly deteriorated occurs.
High sensitivity, high resolution, good pattern shape, and good line edge roughness are in a trade-off relationship, and it is very important how to satisfy them simultaneously.

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 made to improve the performance of chemically amplified negative resists. The following studies have been made on additives, particularly ammonium salt type additives. JP-A-4-51243 discloses a combination of a tetraalkylammonium salt and a novolak resin, JP-A-8110638 discloses a trialkylammonium hydroxide salt, JP-A-11-149159 discloses a tetraalkylammonium salt and the side. A combination with a polymer having a carboxylic acid in the chain is disclosed.
However, in any combination of these known compounds, high sensitivity in the ultrafine region, high resolution, good pattern shape, good line edge roughness, and good vacuum PED characteristics are simultaneously achieved. It was not satisfactory.
Japanese Patent Application Laid-Open No. 10-186660 discusses using an organic carboxylic acid, but no example using a specific resin and a specific ammonium salt is given as in the present invention. In JP-A-2003-295439, examples using ammonium salts are given, but examples using organic carboxylic acids are not mentioned. Further, none of these methods improve the line edge roughness while showing a good pattern shape with little biting shape, which is effective in the present invention.

Japanese Unexamined Patent Publication No. 4-51243 Japanese Patent Laid-Open No. 8-110638 Japanese Patent Laid-Open No. 11-149159 Japanese Patent Laid-Open No. 10-186660 JP 2003-295439 A

  Accordingly, an object of the present invention is to solve the problem of performance improvement technology in fine processing of semiconductor elements and photomasks, and in particular, high sensitivity in fine processing of semiconductor elements and photomasks using electron beams or X-rays. An object of the present invention is to provide a negative resist composition that simultaneously satisfies high resolution, good pattern shape, good line edge roughness, and good vacuum PED characteristics, and a pattern forming method using the same.

As a result of intensive studies, the present inventors have achieved the above object with a negative resist composition using an alkali-soluble resin having a specific structure, a crosslinking agent, an acid generator, an ammonium salt having a specific structure, and an organic carboxylic acid. I found.
That is, the present invention is as follows.

(1) (A) an alkali-soluble polymer having a repeating unit represented by the following general formula (1),
(B) a crosslinking agent that crosslinks with the alkali-soluble polymer of (A) by the action of an acid,
(C) a compound that generates an acid upon irradiation with an actinic ray or radiation,
(D) A negative resist composition comprising a quaternary ammonium salt represented by the following general formula (2) and (E) an organic carboxylic acid.

(In the formula, A represents a hydrogen atom, an alkyl group, a halogen atom or a cyano group, and 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, Represents an aralkyl group, an alkoxy group or an alkylcarbonyloxy group, and n represents an integer of 1 to 3.)

(Wherein R _{3 to} R ₆ each independently represents an alkyl group, an alkenyl group, an aryl group or an aralkyl group, and B ⁻ represents an OH ⁻ group, a halogen atom, an R ₇ —CO ₂ ^— group or R ₇ —SO _3. ^- group, R ₇ represents an alkyl group, an alkenyl group, an aryl group or an aralkyl group).

  (2) The negative resist composition as described in (1), wherein the crosslinking agent (B) is a phenol compound having two or more benzene rings in the molecule and containing no nitrogen atom.

  (3) A pattern forming method comprising a step of forming a resist film from the negative resist composition according to (1) or (2), and exposing and developing the resist film.

  The preferred embodiments of the present invention will be further described below.

  (4) The polymer of the component (A) is at least 1 selected from the repeating unit represented by the general formula (1) and the repeating unit represented by the following general formula (3), (4) or (5) The negative resist composition as described in (1) or (2) above, which contains a seed.

(In the formula, 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 represents an alkyl group .R ₁₁ to R ₁₅ each independently formula (1) R ₁ synonymous to .R ₁₀₁ to R ₁₀₆ each independently of, a hydroxy group, a halogen atom, an alkyl group, an alkoxy group, an alkyl A carbonyloxy group, an alkylsulfonyloxy group, an alkenyl group, an aryl group, an aralkyl group or a carboxy group, a to f each independently represents an integer of 0 to 3)

  According to the present invention, it is possible to provide a negative resist composition excellent in sensitivity, resolution, pattern shape, line edge roughness, and vacuum PED characteristics, and a pattern forming method using the same.

Hereinafter, the negative resist composition of 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 polymer The alkali-soluble polymer used in the present invention contains the repeating unit represented by the general formula (1) as an essential component.

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 as 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, alkenyl group, cycloalkyl group, aryl group, aralkyl group, alkoxy group, alkylcarbonyloxy group or alkylsulfonyloxy group as R ₁ and R ₂ 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).

  The polymer of the component (A) used in the present invention preferably has at least one repeating unit represented by the general formulas (3) to (5) together with the repeating unit represented by the general formula (1).

In the general formulas (3) to (5), 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 having 1 to 3 carbon atoms (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 each independently a hydroxy group, a halogen atom (Cl, Br, F, I), a linear or branched alkyl group having 1 to 8 carbon atoms which may have a substituent, A linear or branched alkoxy group having 1 to 8 carbon atoms which may have a group, a linear or branched alkylcarbonyloxy group having 1 to 8 carbon atoms which may have a substituent, and a substituent A linear or branched alkylsulfonyloxy group having 1 to 8 carbon atoms which may have a group, an alkenyl group having 1 to 8 carbon atoms which may have a substituent, and a substituent. Or an aryl group having 7 to 15 carbon atoms, 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).

Preferably, R _{101 to} R ₁₀₆ are each independently a hydrogen atom, a halogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms, or an optionally substituted carbon atom having 1 to 1 carbon atoms. An alkoxy group having 4 alkoxy groups and an alkylcarbonyloxy group having 1 to 4 carbon atoms which may have a substituent, particularly preferably a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, or an alkyl group having 1 to 3 carbon atoms. 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 represents an integer of 0 to 3;

  The polymer of the component (A) used in the present invention is a resin having only one type of repeating unit represented by the general formula (1), a resin having two or more types of repeating units represented by the general formula (1), Any of resins having at least one of the repeating units represented by the general formula (1) and the repeating units represented by the general formulas (3) to (5) may be used. Other polymerizable monomers that can control the property may be polymerized.

  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 polymer of the component (A) used in the present invention is generally 50 to 100 mol%, preferably 70 to 100 mol%.
In the polymer of the component (A), the ratio of the repeating unit represented by the general formula (1) and the repeating unit represented by the general formulas (3) to (5) 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 preferred molecular weight of the polymer of component (A) is 1000 to 200000 on a weight average, and more preferably 2000 to 50000.
(A) The preferable molecular weight distribution (Mw / Mn) of the polymer of a component is 1.0-2.0, More preferably, it is 1.0-1.35.
The amount of the component (A) polymer added is 30 to 95% by mass, preferably 40 to 90% by mass, particularly preferably 50 to 80% by mass, based on the total solid content of the composition.
In addition, the molecular weight and molecular weight distribution of a polymer are defined as a polystyrene conversion value by GPC measurement.

  The polymer 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 an appropriate organic solvent, 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.

  Specific examples of the alkali-soluble polymer of component (A) used in the present invention are shown below, but the present 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 a resin composed of three components, x = 10 to 90, y = 5 to 85
, Z = 5-85, preferably x = 40-80, y = 10-50, z = 10-50.
Moreover, these may be used independently and may mix and use 2 or more types.

[2] Acid crosslinking agent (component (B))
In the present invention, an alkali-soluble polymer and a compound that crosslinks with an acid (hereinafter, appropriately referred to as an acid crosslinking agent or simply a crosslinking agent) are used. Here, a known acid crosslinking agent can be used effectively.
A compound or resin having two or more hydroxymethyl groups, alkoxymethyl groups, acyloxymethyl groups, or alkoxymethyl ether groups, or an epoxy compound is preferable.

  More preferably, alkoxymethylated, acyloxymethylated melamine compound or resin, alkoxymethylated, acyloxymethylated urea compound or resin, hydroxymethylated or alkoxymethylated phenolic compound or resin, and alkoxymethyletherified phenolic compound or resin, etc. Is mentioned.

As the particularly preferred component (B), the molecular weight is 1200 or less, the molecule contains 3 to 5 benzene rings, and further has two or more hydroxymethyl groups or alkoxymethyl groups. Mention may be made of phenol derivatives formed by concentrating the groups on at least one of the benzene rings, or by linking them together. By using such a phenol derivative, the effect of the present invention can be made more remarkable.
As the alkoxymethyl group bonded to the benzene ring, those having 6 or less carbon atoms are preferable. Specifically, a methoxymethyl group, an ethoxymethyl group, an n-propoxymethyl group, an i-propoxymethyl group, an n-butoxymethyl group, an i-butoxymethyl group, a sec-butoxymethyl group, and a t-butoxymethyl group are preferable. Further, alkoxy-substituted alkoxy groups such as 2-methoxyethoxy group and 2-methoxy-1-propyl group are also preferable.

  The crosslinking agent (B) is preferably a phenol compound having two or more benzene rings in the molecule and not containing a nitrogen atom.

  Among these phenol derivatives, particularly preferable ones are listed below.

(In formula, L < ¹ > -L < ⁸ > may be same or different and shows a hydroxymethyl group, a methoxymethyl group, or an ethoxymethyl group.)
A phenol derivative having a hydroxymethyl group can be obtained by reacting a phenol compound not having a corresponding 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. it can. 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.

A phenol derivative 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 EP632003A1 and the like.
A phenol derivative having a hydroxymethyl group or an alkoxymethyl group synthesized in this manner 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.
Such a phenol derivative having two or more hydroxymethyl groups or alkoxymethyl groups in total and concentrated on any benzene ring or distributed and bonded may be used alone or in combination of two kinds. A combination of the above may also be used.

  Preferred examples of the crosslinking agent include the following (i) a compound having an N-hydroxymethyl group, an N-alkoxymethyl group, or an N-acyloxymethyl group, and (ii) an epoxy compound.

(I) As compounds having an N-hydroxymethyl group, an N-alkoxymethyl group, or an N-acyloxymethyl group, EP0,133,216A, West German Patent No. 3,634,671, No. 3,711,264 Monomer and oligomer-melamine-formaldehyde condensates and urea-formaldehyde condensates disclosed in No. 1, benzoguanamine-formaldehyde condensates disclosed in alkoxy-substituted compounds disclosed in EP 0,212,482A, etc. .
More preferable examples include, for example, melamine-formaldehyde derivatives having at least two free N-hydroxymethyl groups, N-alkoxymethyl groups, or N-acyloxymethyl groups, and among them, N-alkoxymethyl derivatives are particularly preferable. .

  (Ii) Examples of the epoxy compound include monomer, dimer, oligomer, and polymer epoxy compounds containing one or more epoxy groups. For example, the reaction product of bisphenol A and epichlorohydrin, the reaction product of low molecular weight phenol-formaldehyde resin and epichlorohydrin, etc. are mentioned. Other examples include epoxy resins described and used in US Pat. No. 4,026,705 and British Patent 1,539,192.

  The cross-linking agent is preferably used in an added amount of 3 to 65% by mass, more preferably 5 to 50% by mass in the total solid content of the resist composition. By making the addition amount of the crosslinking agent 3 to 65% by mass, it is possible to prevent the remaining film ratio and the resolution from being lowered, and to maintain good stability during storage of the resist solution.

In this invention, a crosslinking agent may be used independently and may be used in combination of 2 or more type.
For example, in addition to the above-mentioned phenol derivative, when other cross-linking agents such as the above (i), (ii) and the like are used in combination, the ratio of the above-mentioned phenol derivative and other cross-linking agent is 100/0 in molar ratio. 20/80, preferably 90/10 to 40/60, more preferably 80/20 to 50/50.

[3] Compound that generates acid upon irradiation with actinic rays or radiation (component (C))
The negative resist composition of the present invention contains a compound that generates an acid upon irradiation with actinic rays or radiation (hereinafter also referred to as “acid generator”).
Examples of such an acid generator include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or an actinic ray or radiation used for a microresist. A known compound that generates an acid by irradiation and a mixture thereof can be appropriately selected and used.

  Examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o-nitrobenzyl sulfonates.

  Further, a group that generates an acid upon irradiation with these actinic rays or radiation, or a compound in which a compound is introduced into the main chain or side chain of the polymer, for example, US Pat. No. 3,849,137, German Patent No. 3914407. JP, 63-26653, JP, 55-164824, JP, 62-69263, JP, 63-146038, JP, 63-163452, JP, 62-153853, The compounds described in JP-A 63-146029 can be used.

  Furthermore, compounds capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, compounds represented by the following general formulas (ZI), (ZII), and (ZIII) can be exemplified.

In general formula (ZI):
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents a non-nucleophilic anion, preferably sulfonate anion, carboxylate anion, bis (alkylsulfonyl) amide anion, tris (alkylsulfonyl) methide anion, BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ^{− and the} like. Preferably, it is an organic anion containing a carbon atom.

  Preferred organic anions include organic anions represented by the following general formulas (AN1) to (AN4).

In general formulas (AN1) and (AN2):
Rc ₁ represents an organic group.

Examples of the organic group in Rc ₁ include those having 1 to 30 carbon atoms, and preferably an alkyl group, an aryl group, or a plurality thereof, which may be substituted, is a single bond, —O—, —CO ₂ —, — _{S -, - SO 3 -,} - SO 2 N (Rd 1) - can be exemplified linked group a linking group such as.
Rd ₁ represents a hydrogen atom or an alkyl group, and may form a ring structure with the bonded alkyl group or aryl group.
The organic group of Rc ₁ is more preferably an alkyl group substituted at the 1-position with a fluorine atom or a fluoroalkyl group, or a phenyl group substituted with a fluorine atom or a fluoroalkyl group. By having a fluorine atom or a fluoroalkyl group, the acidity of the acid generated by light irradiation is increased and the sensitivity is improved. When Rc ₁ has 5 or more carbon atoms, it is preferable that at least one carbon atom does not have all the hydrogen atoms replaced by fluorine atoms, but a part of the hydrogen atoms remains. It is more preferable that the number of is greater than that of fluorine atoms. By not having a perfluoroalkyl group having 5 or more carbon atoms, ecotoxicity is reduced.
The most preferred embodiment of Rc ₁ is a group represented by the following general formula.

In the above general formula, Rc ₆ has 4 or less carbon atoms, more preferably 2 to 4, more preferably 2 to 3 perfluoroalkylene groups, or 1 to 4 fluorine atoms and / or 1 to 3 carbon atoms. Represents a phenylene group substituted with a fluoroalkyl group.
Ax represents a single bond or a divalent linking group (preferably —O—, —CO ₂ —, —S—, —SO ₃ —, —SO ₂ N (Rd ₁ ) —). Rd ₁ represents a hydrogen atom or an alkyl group, and may combine with Rc ₇ to form a ring structure.
Rc ₇ represents a hydrogen atom, a fluorine atom, an optionally substituted linear or branched alkyl group, a monocyclic or polycyclic cycloalkyl group, or an aryl group. The optionally substituted alkyl group, cycloalkyl group and aryl group preferably do not contain a fluorine atom as a substituent.

In the general formulas (AN3) and (AN4),
Rc ₃ , Rc ₄ and Rc ₅ each independently represents an organic group.

In the general formulas (AN3) and (AN4), the organic groups represented by Rc ₃ , Rc ₄ , and Rc ₅ are preferably the same as the preferred organic groups in Rc ₁ .
Rc ₃ and Rc ₄ may be bonded to form a ring.
Examples of the group formed by combining Rc ₃ and Rc ₄ include an alkylene group and an arylene group. Preferably, it is a C2-C4 perfluoroalkylene group. Rc ₃ and Rc ₄ are preferably bonded to form a ring, so that the acidity of the acid generated by light irradiation is increased and the sensitivity is improved, which is preferable.

In formula (ZI), the carbon number of the organic group as R _201, R ₂₀₂ and R ₂₀₃ is generally from 1 to 30, preferably 1 to 20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group.
The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

In addition, the compound which has two or more structures represented by general formula (Z1) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (ZI) is, at least one bond with structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (ZI) It may be a compound.

  Further preferred examples of the component (Z1) include compounds (ZI-1), (ZI-2) and (ZI-3) described below.

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or a part of R _{201 to} R ₂₀₃ may be an aryl group, and the rest may be an alkyl group or a cycloalkyl group.
Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.
The aryl group of the arylsulfonium compound is preferably an aryl group such as a phenyl group or a naphthyl group, or a heteroaryl group such as an indole residue or a pyrrole residue, more preferably a phenyl group or an indole residue. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.
The alkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.
Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are straight chain having 1 to 12 carbon atoms,
A branched alkyl group, a cycloalkyl group having 3 to 12 carbon atoms, a linear, branched or cyclic alkoxy group having 1 to 12 carbon atoms, and particularly preferably an alkyl group having 1 to 4 carbon atoms and 1 to 4 carbon atoms. Of the alkoxy group. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is a compound in the case where R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group not containing an aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.
The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.
R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear, branched, cyclic 2-oxoalkyl group, or an alkoxycarbonylmethyl group, particularly preferably Is a linear, branched 2-oxoalkyl group.

The alkyl group as R ₂₀₁ to R ₂₀₃ may be either straight-chain, branched, preferably a straight-chain or branched alkyl group (e.g., methyl group, an ethyl group having 1 to 10 carbon atoms, a propyl group Butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ is a straight-chain or branched 2-oxoalkyl group, more preferably an alkoxycarbonylmethyl group.
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is more preferably a cyclic 2-oxoalkyl group.
The 2-oxoalkyl group as R _{201 to} R ₂₀₃ may be linear, branched or cyclic, and preferably a group having> C═O at the 2-position of the above alkyl group or cycloalkyl group Can be mentioned.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group).
R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

  The compound (ZI-3) is a compound represented by the following general formula (ZI-3), and is a compound having a phenacylsulfonium salt structure.

In general formula (ZI-3),
R _{1c to} R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Rx and Ry each independently represents an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group.
Any two or more of R _1c to R _7c, and R _x and R _y may be bonded to each other to form a ring structure, the ring structure may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond May be included. Examples of the group formed by combining any two or more of R _{1c to} R _7c and R _x and R _y include a butylene group and a pentylene group.
X ^- represents a non-nucleophilic anion, in formula (ZI) in, X ^- are those same as the.

The alkyl group as R _{1c to} R _7c may be either linear or branched, for example, an alkyl group having 1 to 20 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms. Examples thereof include a group (for example, methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group).
Preferable examples of the cycloalkyl group as R _{1c to} R _7c include a cycloalkyl group having 3 to 8 carbon atoms (for example, a cyclopentyl group and a cyclohexyl group).
The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).
Preferably, any one of R _{1c to} R _5c is a straight chain, branched alkyl group, cycloalkyl group, or a straight chain, branched, or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c is 2 ~ 15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

_Examples of the alkyl group as R _x and R _y include the same alkyl groups as R _{1c to} R _7c . The alkyl group as R _x and R _y is more preferably a linear or branched 2-oxoalkyl group or an alkoxycarbonylmethyl group.
Examples of the linear, branched, or cyclic 2-oxoalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .
Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as R _{1c to} R _5c .
R _x and R _y are preferably an alkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more.

In the general formulas (ZII) and (ZIII), R _{204 to} R ₂₀₇ each independently have an aryl group which may have a substituent, an alkyl group which may have a substituent, or a substituent. Represents an optionally substituted cycloalkyl group.
The aryl group of R ₂₀₄ to R _207, a phenyl group, a naphthyl group, more preferably a phenyl group.
The alkyl group as R ₂₀₄ to R ₂₀₇ may be either straight-chain, branched, preferably a straight-chain or branched alkyl group (e.g., methyl group, an ethyl group having 1 to 10 carbon atoms, a propyl group Butyl group, pentyl group).
The cycloalkyl group as R ₂₀₄ to R ₂₀₇ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl).
The R ₂₀₄ to R ₂₀₇ are substituents which may have, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (e.g., 6 carbon atoms 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.
X ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as X ^{− in} formula (ZI).

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by the following general formulas (ZIV), (ZV), and (ZVI) can be further exemplified.

In general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represent a substituted or unsubstituted aryl group.
R ₂₀₈ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted aryl group.
R ₂₀₉ and R _{210 each} represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or an electron withdrawing group. R ₂₀₉ is preferably a substituted or unsubstituted aryl group. R ₂₁₀ is preferably an electron-withdrawing group, more preferably a cyano group or a fluoroalkyl group.
A represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted alkenylene group, or a substituted or unsubstituted arylene group.

Of the compounds that generate an acid upon irradiation with actinic rays or radiation, more preferred are compounds represented by the general formulas (ZI) to (ZIII), and still more preferred are general formulas (ZI) and (ZII). Particularly preferred are compounds (ZI-1) to (ZI-3).
Furthermore, the compound which generate | occur | produces the acid represented by the following general formula (AC1)-(AC3) by irradiation of actinic light or a radiation is preferable.

That is, a more preferable acid generator is a compound in which, in the structure of the general formula (ZI), X ⁻ is an anion selected from the general formulas (AN1), (AN3), and (AN4). A compound in which X ⁻ is an anion selected from the general formulas (AN3) and (AN4).

  Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, examples of particularly preferable compounds are listed below.

An acid generator can be used individually by 1 type or in combination of 2 or more types. When two or more types are used in combination, it is preferable to combine two types of compounds that generate two types of organic acids that differ in the total number of atoms excluding hydrogen atoms by two or more.
The content of the acid generator in the composition is preferably from 0.1 to 20% by mass, more preferably from 0.5 to 10% by mass, and still more preferably from 1 to 20% by mass, based on the total solid content of the negative resist composition. 7% by mass.

[4] Quaternary ammonium salt represented by general formula (2) (component (D))
The alkyl group, alkenyl group, aryl group and aralkyl group as R _{3 to} R _{6 in} the general formula (2) may have a substituent. Two or more groups out of R _{3 to} R ₆ may be bonded to form an alicyclic ring or an aromatic ring.

The alkyl group of R _{3 to} R ₆ is preferably a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 1 to 30 carbon atoms, or an aryl having 6 to 18 carbon atoms. Group, an aralkyl group having 7 to 18 carbon atoms, or a combination of these groups.
These groups may have a substituent, and examples of the substituent include the same as those exemplified as the substituent of R _{1 in} the general formula (1) and a hydroxyl group. Furthermore, these groups may have a linking group such as an ether group, an ester group or an amide group in the group.

R _{3 to} R ₆ are more preferably a linear or branched alkyl group having 1 to 25 carbon atoms or a linear or branched alkenyl group having 1 to 25 carbon atoms, particularly preferably 1 carbon atom. -20 linear or branched alkyl groups.

B ^- R ₇ as -CO ₂ ^- group, and R ₇ -SO ₃ ^- R ₇ in the group is preferably a linear or branched alkyl group having 1 to 8 carbon atoms, straight-chain having 1 to 8 carbon atoms Alternatively, it represents a branched alkenyl group, an aryl group having 6 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms.
B ⁻ is preferably an OH ⁻ group, a halogen atom (a chlorine atom, a bromine atom, an iodine atom, a fluorine atom), an R ₇ —CO ₂ ^— group (R ₇ preferably has 1 to 12 carbon atoms, particularly preferably a carbon atom. Number 1
Particularly preferably an OH group, a halogen atom (chlorine atom, bromine atom, iodine atom, fluorine atom), R ₇ —CO ₂ ^— group (R ₇ is an alkyl group having 1 to 4 carbon atoms). ).

  Although the preferable specific example of (D) component is shown below, it is not limited to these.

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 quaternary ammonium salt of component (D) may be used alone or in combination of two or more.

[5] Organic carboxylic acid (component (E))
As the organic carboxylic acid compound of component (E), any of saturated or unsaturated aliphatic carboxylic acid, alicyclic carboxylic acid, oxycarboxylic acid, alkoxycarboxylic acid, ketocarboxylic acid, aromatic carboxylic acid and the like can be used, and particularly limited. For example, monovalent or polyvalent aliphatic carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, 1,1- Cycloaliphatic carboxylic acids such as cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,1-cyclohexyldiacetic acid, acrylic acid, crotonic acid, isocrotone Acid, 3-butenoic acid, methacrylic acid, 4-pentenoic acid, propiolic acid, 2-butenoic acid, male Insaturated aliphatic carboxylic acids such as fumaric acid and acetylene carboxylic acid, oxycarboxylic acids such as oxyacetic acid, alkoxycarboxylic acids such as methoxyacetic acid and ethoxyacetic acid, ketocarboxylic acids such as pyruvic acid, benzoic acid, P-hydroxy Benzoic acid, O-hydroxybenzoic acid, 2-hydroxy-3-nitrobenzoic acid, 3,5-dinitrobenzoic acid, 2-nitrobenzoic acid, 2,4-dinitrobenzoic acid, 2,5-dinitrobenzoic acid, 2, 6-dinitrobenzoic acid, 3,5-dinitrobenzoic acid, 2-vinylbenzoic acid, 4-vinylbenzoic acid, phthalic acid, terephthalic acid, isophthalic acid, 2-naphthoic acid, 1-hydroxy-2-naphthoic acid, 2 -Hydroxy-3-naphthoic acid and the like can be mentioned. In the present invention, when patterning is performed using an electron beam in a vacuum, the surface of the resist film may volatilize and contaminate the drawing chamber. Among them, benzoic acid, 1-hydroxy-2-naphthoic acid, and 2-hydroxy-3-naphthoic acid are preferable among them.

  These organic carboxylic acids may be used alone or in combination of two or more.

As a compounding quantity of organic carboxylic acid (E), the inside of the range of 0.01-10 mass parts is preferable with respect to 100 mass parts of alkali-soluble polymer (A), More preferably, 0.01-5 mass parts, More more Preferably it is 0.01-3 mass parts.
The blending ratio of the quaternary ammonium salt of the component (D) and the organic carboxylic acid of the component (E) is preferably (D) :( E) = 5 to 95:95 to 5 (mass ratio). More preferably, (D) :( E) = 10 to 90:90 to 10 (mass ratio).

  If necessary, the negative resist composition of the present invention further contains a known nitrogen-containing organic basic compound, dye, surfactant, plasticizer, photodegradable base compound, photobase generator, and the like. be able to. As for these compounds, the respective compounds described in JP-A No. 2002-6500 can be mentioned.

In addition, examples of the solvent used in the negative resist composition of the present invention include the solvents described in JP-A No. 2002-6500.
For example, ethylene glycol monoethyl ether acetate, cyclohexanone, 2-heptanone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether acetate, methyl 3-methoxypropionate, 3- Ethyl ethoxypropionate, methyl β-methoxyisobutyrate, ethyl butyrate, propyl butyrate, methyl isobutyl ketone, ethyl acetate, isoamyl acetate, ethyl lactate, toluene, xylene, cyclohexyl acetate, diacetone alcohol, N-methylpyrrolidone, N, N- Dimethylformamide, γ-butyrolactone, N, N-dimethylacetamide, propylene carbonate, ethylene carbonate Nate is preferred. These solvents are used alone or in combination.
It is preferable that 1-40 mass% of solid content of a resist composition melt | dissolves in the said solvent and is made into solid content concentration. More preferably, it is 1-30 mass%, More preferably, it is 3-20 mass%.

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. Further, an antireflection film can be applied to the upper layer of the resist. As these antireflection films, the antireflection films described in JP-A-2002-6500 can be used.

Next, the usage pattern of the negative resist composition of the present invention will be described.
In the manufacture of precision integrated circuit elements, the pattern formation process on the resist film is performed on a substrate (for example, a silicon / silicon dioxide cover, a glass substrate, a metal substrate, a silicon nitride substrate, a titanium nitride substrate, a chromium oxide substrate, etc.) Apply the negative resist composition of the present invention directly or on the antireflection film previously coated on these substrates, and then irradiate directly or through a mask with radiation or actinic light as a light source and heat A good resist pattern can be formed by developing, rinsing and drying. In the present invention, a preferred substrate is a substrate other than silicon (bare silicon), more preferably a substrate provided with a metal vapor deposition film or a film containing metal on the surface, and even more preferably, Cr on the surface. Mo, MoSi, TaSi or their oxides, nitride deposited films or Cr, Mo, MoSi, TaSi or their oxides, nitride-containing substrates, particularly preferably Cr on the surface , MoSi, TaSi or their oxides and nitrides are provided on the substrate.
Here, the light source is preferably light having a wavelength of 150 to 250 nm (specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157 nm)), electron beam, and X-ray. In the present invention, an apparatus using an electron beam or X-ray as an exposure light source is most preferably used.

  As a developing solution of the negative resist composition of the present invention, a known developing solution can be used, and examples thereof include a developing solution described in JP-A-2002-6500.

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

1. Examples of composition materials (1) Alkali-soluble polymer (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 2.0 in terms of dispersity (Mw / Mn).
Hereinafter, the polymer of the component (A) of the present invention was synthesized in the same manner.

(2) Synthesis of crosslinking agent (component B)
Synthesis of (HM-1) 20 g of 1- [α-methyl-α- (4-hydroxyphenyl) ethyl] -4- [α, α-bis (4-hydroxyphenyl) ethyl] benzene (Honshu Chemical Industry Co., Ltd.) Trisp-PA) 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 (MM-1) 20 g of the phenol derivative [HM-1] having a hydroxymethyl group obtained in the above synthesis example was added to 1 liter of methanol and dissolved by heating under stirring. Next, 1 ml of concentrated sulfuric acid was added to this solution and heated under reflux for 12 hours. After completion of the reaction, the reaction solution was cooled, and 2 g of potassium carbonate was added. After sufficiently concentrating the mixture, 300 ml of ethyl acetate was added. The solution was washed with water and then concentrated to dryness to obtain 22 g of a phenol derivative [MM-1] having a methoxymethyl group having the following structure as a white solid. The purity was 90% (liquid chromatography method).

  Further, the following phenol derivatives were synthesized in the same manner.

2. Example [Example 1]
(1) Preparation and application of negative resist coating solution

(Negative resist coating composition)
(A) component: Resin (29) 0.40 g
(B) component: 0.12 g of crosslinking agent MM-1
Component (C): Acid generator C-1 0.05 g
(D) component: ammonium salt D-1 0.002g
(E) component: Organic carboxylic acid E-1 0.012 g

The above coating composition was dissolved in 9.0 g of propylene glycol monomethyl ether acetate, and 0.001 g of PF6320 (manufactured by OMNOVA, hereinafter abbreviated as W-1) was added and dissolved therein as a surfactant. The obtained solution was microfiltered with a 0.1 μm aperture membrane filter to obtain a resist solution.
This resist solution was coated on a 6-inch wafer deposited with Cr oxide by the same process as the shielding film used for the photomask using a spin coater Mark8 manufactured by Tokyo Electron, and dried on a hot plate at 110 ° C. for 90 seconds, A resist film having a thickness of 0.3 μm was obtained.

(2) Production of Negative Resist Pattern Pattern irradiation was performed on this resist film using an electron beam drawing apparatus (HL750 manufactured by Hitachi, Ltd., acceleration voltage 50 KeV). After irradiation, it was heated on a hot plate at 120 ° 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, pattern shape, and line edge roughness 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) Pattern Shape The cross-sectional shape of the 0.15 μm line pattern at the exposure amount showing the above sensitivity was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.). A rectangular, slightly eaten, and eaten three-level evaluation.

(2-4) Line Edge Roughness The line width was measured at arbitrary 30 points in the length direction of 50 μm of the 0.15 μm line pattern at the irradiation dose showing the above sensitivity, and the variation was evaluated by 3σ.

(2-5) PED characteristics in vacuum A wafer is set in a vacuum chamber, irradiated with an electron beam at the irradiation amount showing the above sensitivity, and baked at 120 ° C. for 90 seconds as described above (heat treatment) immediately after irradiation or after 3 hours. Thereafter, development processing was performed to obtain a line pattern.
Then, a 0.15 μm line pattern obtained by baking and developing immediately after electron beam irradiation and a 0.15 μm line pattern obtained by baking and developing 3 hours after electron beam irradiation were scanned with a scanning electron microscope ( Line width was measured by Hitachi, Ltd. S-9220), and the difference between the two was used as the PED characteristics in vacuum.

The results of Example 1 were good: sensitivity: 6.0 μC / cm ² , resolution: 0.11 μm, pattern shape: rectangular, line edge roughness: 6.0 nm, PED characteristics in vacuum: 2.0 nm.

[Examples 2 to 16]
A resist solution was prepared and a negative pattern was formed in the same manner as in Example 1 except that each component shown in Table 1 below was used. In Table 1, the ratio when two or more components are used is a mass ratio. The evaluation results are shown in Table 2 below.

[Comparative Example 1]
As shown in Table 1, a resist solution was prepared and a negative pattern was formed in the same manner as in Example 1 except that the organic carboxylic acid (E) was not used. The evaluation results are shown in Table 2.

[Comparative Example 2]
As shown in Table 1, the resist solution was prepared and the negative pattern was formed in the same manner as in Example 1 except that the novolak resin having no repeating unit of the general formula (1) was used as the component (A) resin. went. The evaluation results are shown in Table 2.

[Comparative Examples 3 and 4]
As shown in Table 1, a resist solution was prepared in the same manner as in Example 1 except that only a known nitrogen-containing organic basic compound was used without using the quaternary ammonium salt of component (D). Pattern formation was performed. The evaluation results are shown in Table 2.

  Hereinafter, abbreviations in the table will be described.

The acid generator used in Table 1 was as follows.
C-1: Triphenylsulfonium nonafluorobutanesulfonate C-2: Triphenylsulfonium pentafluorobenzenesulfonate C-3: Triphenylsulfonium-2,4-dimethylbenzenesulfonate C-4: Bisphenyl-4-cyclohexylphenylsulfonium pentafluorobenzene Sulfonate

The following organic carboxylic acids were used in Table 1.
E-1: Benzoic acid E-2: 2-naphthoic acid E-3: 2-hydroxy-3-naphthoic acid E-4: o-hydroxybenzoic acid

The other components used in Table 1 represent the following (all are manufactured by Tokyo Chemical Industry Co., Ltd.).
F-1: 2,4,5-triphenylimidazole F-2: 4-dimethylaminopyridine F-3: triethylamine G-1: trimethylammonium hydrochloride

The solvent used in Table 1 represents the following.
S-1: Propylene glycol monomethyl ether acetate S-2: Propylene glycol monomethyl ether

The surfactant used in Table 1 represents the following.
W-1: PF6320 (manufactured by OMNOVA)
W-2: Megafire F176 (Dainippon Ink Co., Ltd.)

  From Table 2, it can be seen that the negative resist composition of the present invention is excellent in sensitivity, resolution, pattern shape, line edge roughness, and vacuum PED characteristics, and has good performance.

Claims (3)

(A) an alkali-soluble polymer having a repeating unit represented by the following general formula (1):
(B) a crosslinking agent that crosslinks with the alkali-soluble polymer of (A) by the action of an acid,
(C) a compound that generates an acid upon irradiation with an actinic ray or radiation,
(D) A negative resist composition comprising a quaternary ammonium salt represented by the following general formula (2) and (E) an organic carboxylic acid.

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

(Wherein R _{3 to} R ₆ each independently represents an alkyl group, an alkenyl group, an aryl group, or an aralkyl group, and B ⁻ represents an OH ⁻ group, a halogen atom, an R ₇ —CO ₂ ^— group, or R ₇ represents a —SO ₃ ^— group, and R ₇ represents an alkyl group, an alkenyl group, an aryl group, or an aralkyl group.   The negative resist composition according to claim 1, wherein the crosslinking agent (B) is a phenol compound having two or more benzene rings in the molecule and containing no nitrogen atom.   A pattern forming method comprising: forming a resist film from the negative resist composition according to claim 1; and exposing and developing the resist film.