JP2008233877A - Negative resist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a negative resist composition ensuring good resolution and reduced collapse of a fine line pattern not only in normal exposure (dry exposure) but in immersion exposure, and to provide a pattern forming method using the above composition. <P>SOLUTION: The negative resist composition includes: (A) a compound having at least one episulfide structure (a three-membered ring structure comprising two carbon atoms and one sulfur atom); (B) an alkali-soluble resin; and (C) a compound generating an acid upon irradiation with actinic rays or radiation. The composition is used for the pattern forming method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a negative resist composition used in the manufacture of semiconductor elements such as ICs, liquid crystal display devices, circuit boards such as thermal heads, and other photolithography applications, and a pattern forming method using the same. It is about. In particular, the present invention relates to a negative resist composition suitable for exposure with a projection exposure apparatus using far ultraviolet light having a wavelength of 200 nm or less as a light source, and a pattern forming method using the same.

In recent years, semiconductor devices have been increasingly densely and highly integrated. Therefore, further fine pattern processing has been required. In order to satisfy this need, the operating wavelength of an exposure apparatus used for photolithography has been increasingly shortened, and now it is considered to use excimer laser light (XeCl, KrF, ArF, etc.) having a short wavelength among far ultraviolet rays. It is becoming.
The resist composition, on the other hand, uses a resin that is insoluble or insoluble in the developer and forms a pattern by solubilizing the exposed area in the developer by exposure to radiation, and is soluble in the developer. There is a “negative type” in which a pattern is formed by making an exposed portion hardly soluble or insoluble in a developer by exposure to radiation. Of these, positive resist compositions are currently in practical use.
There is a demand for forming various patterns such as lines, trenches, and holes in semiconductor elements and the like. As the pattern becomes finer, higher resolution is required. To achieve this, it is desirable to use a mask that provides high optical contrast. However, in order to use a mask that provides this high optical contrast, a positive resist composition is advantageous when forming a line pattern, and a negative resist composition is advantageous when forming a trench pattern. Accordingly, development of negative resist compositions as well as positive ones is desired in order to meet various pattern formation requirements.
In the case of using 248 nm light of krF excimer laser as an exposure source, a negative resist composition using a polymer in which an acetal group or a ketal group is introduced as a protecting group to a hydroxystyrene-based polymer with little light absorption has been proposed. Yes. These are suitable for use in KrF excimer lasers, but when used in ArF excimer lasers, there are problems such as reduced sensitivity due to strong absorption at 193 nm, and degradation in resolution. Not suitable.
Therefore, development of a negative resist material with less light absorption at 193 nm, good sensitivity and high dry etching resistance is desired, and it is suitable for an exposure method using ArF and has good sensitivity and solution. There is an urgent need to develop resists that provide image quality.
As resists for ArF, resists using (meth) acrylic acid ester-based resins having an aliphatic group with little absorption at 193 nm and resists introduced with alicyclic aliphatic groups to impart etching resistance have been proposed. However, the introduction of these aliphatic groups makes the system hydrophobic, and when a conventional developer (tetramethylammonium hydroxide, hereinafter also referred to as TMAH) is used, there is a problem that the resist film is peeled off from the substrate. In Patent Documents 1 to 6, negative resists in which various additives are added to a resin obtained by copolymerizing a unit having an aliphatic group and a unit having a carboxylic acid moiety are used. There are problems such as inability to obtain the characteristics and pattern collapse.

Japanese Patent Laid-Open No. 11-15159 JP 11-71363 A Japanese Patent Laid-Open No. 11-237741 Japanese Patent Laid-Open No. 11-305436 JP 2001-343748 A Japanese Patent Laid-Open No. 2002-148805

The object of the present invention is to solve the problem of the technology for improving the performance of microphotofabrication using far-ultraviolet light, particularly ArF excimer laser light. More specifically, the present invention shows a good resolution and a fine resolution. It is an object of the present invention to provide a negative resist composition with reduced line pattern collapse and a pattern forming method using the same.

  As a result of intensive studies on constituent materials in negative resists, the present inventors have found that the above object can be achieved by using a specific additive, and have reached the present invention. That is, the above object is achieved by the following configuration.

  (1) (A) Compound having at least one episulfide structure represented by the following general formula (1) (three-membered ring structure composed of two C atoms and one S atom), (B) alkali-soluble A negative resist composition comprising a resin and (C) a compound that generates an acid upon irradiation with actinic rays or radiation.

  (2) The negative resist composition as described in (1), wherein the compound of component (A) is a compound represented by the following general formula (2).

In general formula (2),
R ^{1a to} R ^1c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group.
L represents a single bond or a divalent organic group.
Q represents an O atom, an S atom, or an n-valent organic group.
R ^1a , R ^1b or R ^1c and L may be bonded to each other to form a ring.
n represents an integer of 1 or more. However, when Q is an O atom or an S atom, n = 2.
When n is an integer of 2 or more, a plurality of R ^{1a to} R ^1c and L may be the same or different.

  (3) The negative resist composition as described in (2), wherein, in the general formula (2), Q has an S atom and / or L has an S atom.

  (4) The negative resist composition as described in (2) or (3), wherein in general formula (2), n is 2 or more.

  (5) A group in which the resin of component (B) is soluble in an alkali developer and reacts with a compound having at least one episulfide structure represented by the general formula (1) by the action of an acid. The negative resist composition as described in any one of (1) to (4), which has a repeating unit.

  (6) The negative resist composition as described in any one of (1) to (4), wherein the resin as the component (B) has a repeating unit having a carboxyl group and / or a hydroxyl group.

  (7) The negative resist composition as described in any one of (1) to (6), further comprising (D) a crosslinking agent.

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

  According to the present invention, it is possible to provide a negative resist composition capable of forming a fine and favorable pattern, exhibiting good resolution, and having an excellent pattern collapse margin, and a pattern forming method using the same. Further, by containing a compound having an episulfide structure, the refractive index of the resist film is increased, and a negative resist composition that can be applied to finer pattern formation and a pattern formation method using the same can be provided. .

Hereinafter, the present invention will be described in detail.
In addition, in the description of groups (atomic groups) in this specification, the description that does not indicate substitution and non-substitution includes both those having no substituent and those having 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).

(A) Compound having at least one episulfide structure represented by the general formula (1) (a three-membered ring structure composed of two C atoms and one S atom) The negative resist composition of the present invention comprises: A compound having at least one episulfide structure represented by the following general formula (1) (a three-membered ring structure composed of two C atoms and one S atom) is contained.

  The compound having an episulfide structure used in the present invention may have a plurality of episulfide structures, and in the case of having a plurality, the episulfide structure may have the same or different substituents. The compound having an episulfide structure preferably has 2 to 6 episulfide structures, and more preferably has 2 to 4 episulfide structures.

  The compound having an episulfide structure used in the present invention is preferably a compound represented by the following general formula (2).

In general formula (2),
R ^{1a to} R ^1c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group.
L represents a single bond or a divalent organic group.
Q represents an O atom, an S atom, or an n-valent organic group.
R ^1a , R ^1b or R ^1c and L may be bonded to each other to form a ring.
n represents an integer of 1 or more. However, when Q is an O atom or an S atom, n = 2.
When n is an integer of 2 or more, a plurality of R ^{1a to} R ^1c and L may be the same or different.

In the general formula (2), the alkyl group represented by R ^{1a to} R ^1c is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, or isopropyl. Group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, isopentyl group, neopentyl group, t-pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, A tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an eicosyl group, and the like can be given.
The cycloalkyl group may be monocyclic or polycyclic. The monocyclic type is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. As the polycyclic type, a cycloalkyl group having 6 to 20 carbon atoms is preferable. For example, an adamantyl group, norbornyl group, isobornyl group, camphanyl group, dicyclopentyl group, α-pinel group, tricyclodecanyl group, tetracyclododecyl group. Group, androstanyl group and the like.
The aryl group is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a biphenylene residue (a group generated by the loss of one hydrogen atom from biphenylene), Examples include fluorene residues (groups generated by losing one hydrogen atom from fluorene), pyrene residues (groups generated by losing one hydrogen atom from pyrene), and the like.

In the general formula (2), when Q is an S atom, the number of S atoms may be one, or two or more bonded S atoms such as a disulfide bond or a trisulfide bond may be used.
The n-valent organic group of Q is a chain or cyclic aliphatic group or an aromatic group, and the organic group may contain an S, O, or N atom, and contain an S atom. Is preferred. The aliphatic group may be a saturated aliphatic group or an unsaturated aliphatic group.
Examples of the chain aliphatic group include groups in which n hydrogen atoms have been removed from a linear or branched aliphatic compound. Specific examples include the following groups, but the present invention is not limited thereto.

It is preferable that an S atom is contained in the chain aliphatic group. Specific examples include the following groups, but the present invention is not limited thereto. 2-thiapropane, 2-thiabutane, 3-thiapentane, 2,5-dithiapentane, 2,5-dithiahexane, 2,5-dithiaheptane, 2,6-dithiaheptane, 2,5-dithiaoctane, 2,6-dithiaoctane, 3, It is a group obtained by removing n hydrogen atoms from 6-dithiaoctane, 2,5,8-trithianonane, etc., and these aliphatic groups may have a substituent.
Cycloaliphatic groups include monocyclic aliphatic groups in which n hydrogen atoms have been removed from cyclobutane, cyclopentane, cyclohexane, cycloheptane, etc., norbornane, isobornane, adamantane, bicyclooctane, tricyclodecane, tetracyclo Examples include polycyclic aliphatic groups in which n hydrogen atoms are removed from dodecane, hexacycloheptadecane, spirononan, spirodecane, spiroundecane, etc., and these cyclic aliphatic groups contain S, O, and N atoms. It is preferable that an S atom is contained, a cyclic aliphatic group is preferable from the viewpoint of etching resistance, and a polycyclic aliphatic group is more preferable. Specific examples include groups having the following monocyclic and polycyclic aliphatic structures, but the present invention is not limited thereto.

Examples of the aromatic group include groups in which n hydrogen atoms have been removed from benzene, furan, pyrrole, thiophene, or the like.

  For example, Q may have a structure in which a plurality of groups arbitrarily selected from an S atom, a chain aliphatic group, a cyclic aliphatic group, and an aromatic group are connected as shown below. Although the structure is illustrated below, this invention is not limited to this. In the formula, Ra represents a hydrogen atom or an alkyl group.

Examples of the divalent organic group for L include a chain or cyclic aliphatic group.
Examples of the chain aliphatic group include optionally substituted alkylene, such as methylene, ethylene, propylene, and the like, and it is preferable that the chain aliphatic group contains an S atom. Specific examples include 2-thiapropylene and 2-thiabutylene.
Cycloaliphatic groups include monocyclic aliphatic groups such as cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene, norbornylene, isobornylene, adamantylene, bicyclooctylene, tricyclodecanylene, tetracyclododecanylene. , Hexacycloheptadecanylene, spirononylene, spirodecanylene, spiroundecanylene, spirododecanylene, and the like, and the cycloaliphatic groups may contain S, O, and N atoms. Often, it contains S atoms.

In the general formula (2), L may be bonded to any one of R ^{a1 to} R ^a3 to form a ring. Specifically, the following structures are exemplified, but the present invention is not limited to these.

In the formula, R ^P represents an alkyl group or a cycloalkyl group, preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group,
Neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, cyclo Examples thereof include a propyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, and a boronyl group.

  According to the present invention, by adding a compound having an episulfide structure, the refractive index of the resist film is increased, and a further fine pattern can be formed as a resist for a high refractive index medium.

  Among these compounds having an episulfide structure, from the viewpoint of improving the refractive index of the negative resist composition, preferably a compound having one or more S atoms, more preferably 2 to 10 S atoms, particularly preferably. It is a compound having 3 to 8 S atoms. From the viewpoint of reducing development defects and good pattern collapse margin, n is preferably 2 or more, preferably 2 to 6, and more preferably 3 or 4 from the viewpoint of function as a crosslinking agent or synthesis.

  Examples of the compound having an episulfide structure used in the present invention include the following compounds, but the present invention is not limited thereto.

  2,3-epithiopropylthioethane, 2,3-epithiopropyloxypropane, 4-ethyl-1,2-epithiocyclohexane, 1-epithioethyl-3-thiapentane, 2,3-epithiopropylphenyl ether.

Bis (2,3-epithiopropyl) sulfide, bis (2,3-epithiopropylthio) methane, 1,2-bis (2,3-epithiopropylthio) ethane, 1,2-bis (2, 3-epithiopropylthio) propane, 1,3-bis (2,3-epithiopropylthio) propane, 1,3-bis (2,3-epithiopropylthio) -2-methylpropane, 1,4 -Bis (2,3-epithiopropylthio) butane, 1,4-bis (2,3epithiopropylthio) -2-methylbutane, 1- (2,3-epithiopropyl) -2- (1, 2-epithiocyclohexyl lu 4-oxy) ethane, 1,3-bis (2,3-epithiopropylthio) butane, 1,5-bis (2,3-epithiopropylthio) pentane, 1,5- Bis (2,3-epithiopropylthio ) -2-methylpentane, 1,5-bis (2,3-epithiopropylthio) -3-thiapentane, 1,6-bis (2,3-epithiopropylthio) hexane, 1,6-bis ( 2,3-epithiopropylthio) -2-methylhexane, 1,1-bis (epithioethyl) methane, 1- (epithioethyl) -1- (2,3-epithiopropyl) methane, 1,1-bis ( 2,3-epithiopropyl) methane, 1- (epithioethyl) -1- (2,3-epithiopropyl) ethane, 1,2-bis (2,3-epithiopropyl) ethane, 1- (epithioethyl) -3- (2,3-epithiopropyl) butane, 1,3-bis (2,3-epithiopropyl) propane, 1- (epithioethyl) -4- (2,3-epithiopropyl) pentane, , 4-bis ( , 3-epithiopropyl) butane, 1- (epithioethyl) -5- (2,3-epithiopropyl) hexane, 1- (epithioethyl) -2- (3,4-epithiobutylthio) ethane, 1- (Epithioethyl) -2- [2- (3,4-epithiobutylthio) ethylthio] ethane, 3,8-bis (2,3-epithiopropylthio) -3,6-trithiaoctane, bis (2 , 3-epithiopropyl) disulfide, bis (2,3-epithiopropyl) trisulfide, bis (2,3-epithiopropyldithio) methane, bis (2,3-epithiopropyldithio) ethane, bis ( 2,3-epithiopropyldithioethyl) sulfide, bis (2,3-epithiopropyldithioethyl) disulfide, 1,2-bis (2,3-epithiopropylthio) Tan, 1,3-bis (2,3-epithiopropylthio) propane, 1,2-bis (2,3-epithiopropylthio) propane, 1- (2,3-epithiopropylthio) -2 -(2,3-epithiopropylthiomethyl) propane, 1,4-bis (2,3-epithiopropylthio) butane, 1,3-bis (2,3-epithiopropylthio) butane, 1- (2,3-epithiopropylthio) -3- (2,3-epithiopropylthiomethyl) butane, 1,5-bis (2,3-epithiopropylthio) pentane, 1- (2,3- Epithiopropylthio) -4- (2,3-epithiopropylthiomethyl) pentane, 1,6-bis (2,3-epithiopropylthio) hexane, 1- (2,3-epithiopropylthio) -5- (2,3-epithiopropylthio Til) hexane, 1- (2,3-epithiopropylthio) -2-[(2-2,3-epithiopropylthioethyl) thio] ethane, 1- (2,3-epithiopropylthio)- 2-[[2- (2-2,3-epithiopropylthioethyl) thioethyl] thio] ethane, bis (2,3-epithiopropyl) ether, bis (2,3-epithiopropyloxy) methane, 1,2-bis (2,3-epithiopropyloxy) ethane, 1,3-bis (2,3-epithiopropyloxy) propane, 1,2-bis (2,3-epithiopropyloxy) propane 1- (2,3-epithiopropyloxy) -2- (2,3-epithiopropyloxymethyl) propane, 1,4-bis (2,3-epithiopropyloxy) butane, 1,3- Bis (2,3-Epithi Propyloxy) butane, 1- (2,3-epithiopropyloxy) -3- (2,3-epithiopropyloxymethyl) butane, 1,5-bis (2,3-epithiopropyloxy) pentane, 1- (2,3-epithiopropyloxy) -4- (2,3-epithiopropyloxymethyl) pentane, 1,6-bis (2,3-epithiopropyloxy) hexane, 1- (2, 3-epithiopropyloxy) -5- (2,3-epithiopropyloxymethyl) hexane, 1- (2,3-epithiopropyloxy) -2-[(2-2,3-epithiopropyloxy) Ethyl) oxy] ethane, 1- (2,3-epithiopropyloxy) -2-[[2- (2-2,3-epithiopropyloxyethyl) oxyethyl] oxy] ethane.

Tris (2,3-epithiopropylthiomethyl) methane, 1,2,3-tris (2,3-epithiopropylthio) propane, 2,2-bis (2,3-epithiopropylthio) -1 , 3-bis (2,3-epithiopropylthiomethyl) propane, 2,2-bis (2,3-epithiopropylthiomethyl) -1- (2,3-epithiopropylthio) butane, 1, 5-bis (2,3-epithiopropylthio) -2-10 (2,3-epithiopropylthiomethyl) -3-thiapentane, 1,5-bis (2,3-epithiopropylthio) -2 , 4-Bis (2,3-epithiopropylthiomethyl) -3-thiapentane, 1- (2,3-epithiopropylthio) -2,2-bis (2,3-epithiopropylthiomethyl)- 4-thiahexane, 1,5,6-tris 2,3-epithiopropylthio) -4- (2,3-epithiopropylthiomethyl) -3-thiahexane, 1,8-bis (2,3-epithiopropylthio) -4- (2,3 -Epithiopropylthiomethyl) -3,6-dithiaoctane, 1
, 8-bis (2,3-epithiopropylthio) -4,5-bis (2,3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithio) Propylthio) -4,4-bis (2,3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithiopropylthio) -2,5-bis (2 , 3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithiopropylthio) -2,4,5-tris (2,3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,1,1-tris [{2- (2,3-epithiopropylthio) ethyl} thiomethyl] -2- (2,3-epithiopropylthio) ethane, 1,1 , 2,2-Tetrakis [{2- (2,3-Epithi Propylthio) ethyl} thiomethyl] ethane, 1,11-bis (2,3-epithiopropylthio) -4,8-bis (2,3-epithiopropylthiomethyl) -3,6,9-trithiaundecane 1,11-bis (2,3-epithiopropylthio) -4,7-bis (2,3-epithiopropylthiomethyl) -3,6,9-trithiaundecane, 1,11-bis ( 2,3-epithiopropylthio) -5,7-bis (2,3-epithiopropylthiomethyl) -3,6,9-trithiaundecane, tetrakis (2,3-epithiopropyl) methane, , 1,1-tris (2,3-epithiopropyl) propane, 1,3-bis (2,3-epithiopropyl) -1- (2,3-epithiopropyl) -2-thiapropane, 1, 5-bis (2,3-epithio Propyl) -2,4-bis (2,3-epithiopropyl) -3- Chiapentan.

Tetrakis (2,3-epithiopropyloxymethyl) methane, 1,1,1-tris (2,3-epithiopropyloxymethyl) propane, 1,5-bis (2,3-epithiopropyloxy)- 2- (2,3-epithiopropyloxymethyl) -3-thiapentane, 1,5-bis (2,3-epithiopropyloxy) -2,4-bis (2,3-epithiopropyloxymethyl) -3-thiapentane, 1- (2,3-epithiopropyloxy) -2,2-bis (2,3-epithiopropyloxymethyl) -4-thiahexane, 1,5,6-tris (2,3 -Epithiopropyloxy) -4- (2,3-epithiopropyloxymethyl) -3-thiahexane, 1,8-bis (2,3-epithiopropyloxy) -4- (2,3-epithio Propyl Xymethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithiopropyloxy) -4,5bis (2,3-epithiopropyloxymethyl) -3,6-dithiaoctane, 1,8 -Bis (2,3-epithiopropyloxy) -4,4-bis (2,3-epithiopropyloxymethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithiopropyloxy) ) -2,4,5-tris (2,3-epithiopropyloxymethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithiopropyloxy) -2,5-bis (2 , 3-epithiopropyloxymethyl) -3,6-dithiaoctane, 1,9-bis (2,3-epithiopropyloxy) -5- (2,3-epithiopropyloxymethyl) -5-[( 2-2,3-epi Opropyloxyethyl) oxymethyl] -3,7-dithianonane, 1,10-bis (2,3-epithiopropyloxy) -5,6-bis [(2-2,3-epithiopropyloxyethyl) Oxy] -3,6,9-trithiadecane, 1,11-bis (2,3-epithiopropyloxy) -4,8-bis (2,3-epithiopropyloxymethyl) -3,6,9- Trithiaundecane, 1,11-bis (2,3-epithiopropyloxy) -5,7-bis (2,3-epithiopropyloxymethyl) -3,6,9-trithiaundecane, 1,11 -Bis (2,3-epithiopropyloxy) -5,7-[(2-2,3-epithiopropyloxyethyl) oxymethyl] -3,6,9-trithiaundecane, 1,11-bis (2,3-epithiop (Lopyloxy) -4,7-bis (2,3-epithiopropyloxymethyl) -3,6,9-trithiaundecane, tetrakis (2,3-epithiopropylthiomethyl) methane, tetrakis (2,3- Epithiopropyldithiomethyl) methane, 1,1,1-tris (2,3-epithiopropylthiomethyl) propane, 1,2,3-tris (2,3-epithiopropyldithio) propane, 1,5 -Bis (2,3-epithiopropylthio) -2- (2,3-epithiopropylthiomethyl) -3-thiapentane, 1,5-bis (2,3-epithiopropylthio) -2,4 -Bis (2,3-epithiopropylthiomethyl) -3-thiapentane, 1,6-bis (2,3-epithiopropyldithiomethyl) -2- (2,3-epithiopropyldithioethylthio) ) -4-thiahexane, 1- (2,3-epithiopropylthio) -2,2-bis (2,3-epithiopropylthiomethyl) -4-thiahexane, 1,5,6-tris (2, 3-epithiopropylthio) -4- (2,3-epithiopropylthiomethyl) -3-thiahexane, 1,8-bis (2,3-epithiopropylthio) -4- (2,3-epi Thiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithiopropylthio) -4,5bis (2,3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithiopropylthio) -4,4-bis (2,3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epi Thiopropylthio) -2,4,5-tris 2,3-epithiopropylthiomethyl) -3,6-dithiaoctane, 1,8-bis (2,3-epithiopropylthio) -2,5-bis (2,3-epithiopropylthiomethyl)- 3,6-dithiaoctane, 1,9-bis (2,3-epithiopropylthio) -5- (2,3-epithiopropylthiomethyl) -5-[(2-2,3-epithiopropylthio Ethyl) thiomethyl] -3,7-dithianonane, 1,10-bis (2,3-epithiopropylthio) -5,6-bis [(2-2,3-epithiopropylthioethyl) thio] -3 , 6,9-trithiadecane, 1,11-bis (2,3-epithiopropylthio) -4,8-bis (2,3-epithiopropylthiomethyl) -3,6,9-trithiaundecane, 1,11-bis (2,3-epithiopro Pyrthio) -5,7-bis (2,3-epithiopropylthiomethyl) -3,6,9-trithiaundecane, 1,11-bis (2,3-epithiopropylthio) -5,7- [(2-2,3-epithiopropylthioethyl) thiomethyl] -3,6,9-trithiaundecane, 1,11-bis (2,3-epithiopropylthio) -4,7-bis (2 , 3-epithiopropylthiomethyl) -3,6,9-trithiaundecane.

  Tetra [2- (2,3-epithiopropylthio) acetylmethyl] methane, 1,1,1-tri [2- (2,3-epithiopropylthio) acetylmethyl] propane, tetra [2- (2 , 3-epithiopropylthiomethyl) acetylmethyl] methane, 1,1,1-tri [2- (2,3-epithiopropylthiomethyl) acetylmethyl] propane.

  1,3-bis (epithioethyl) cyclopentane, 1,3-bis (2,3-epithiopropyl) cyclopentane, 1,3-bis (2,3-epithiopropyloxy) cyclopentane, 1,3- Bis (2,3-epithiopropylthio) cyclopentane, 1,3-bis (2,3-epithiopropyloxymethyl) cyclopentane, 1,3-bis (2,3-epithiopropylthiomethyl) cyclo Pentane, 1,3-bis (epithioethyl) cyclohexane, 1,4-bis (epithioethyl) cyclohexane, 1,3-bis (2,3-epithiopropyl) cyclohexane, 1,4-bis (2,3-epithio) Propyl) cyclohexane, 1,3-bis (2,3-epithiopropyloxy) cyclohexane, 1,4-bis (2,3-epithiopropyloxy) ) Cyclohexane, 1,3-bis (2,3-epithiopropylthio) cyclohexane, 1,4-bis (2,3-epithiopropylthio) cyclohexane, 1,3-bis (2,3-epithiopropyl) Oxymethyl) cyclohexane, 1,4-bis (2,3-epithiopropyloxymethyl) cyclohexane, 1,3-bis (2,3-epithiopropylthiomethyl) cyclohexane, 1,4-bis (2,3 -Epithiopropylthiomethyl) cyclohexane, 1,3,5-tris (2,3-epithiopropyl) cyclohexane, 1,3-cyclohexanedicarboxylic acid-bis (2,3-epithiopropylthio) ester, 1, 4-cyclohexanedicarboxylic acid-bis (2,3-epithiopropylthio) ester, 1,3,5-cyclohexanetrica Bon acid - tris (2,3-epithiopropylthio) ester.

2,4-bis (epithioethyl) tetrahydrothiophene, 2,5-bis (epithioethyl) tetrahydrothiophene, 2,4-bis (2,3-epithiopropyl) tetrahydrothiophene, 2,5-bis (2,3-epi Thiopropyl) tetrahydrothiophene, 2,4-bis (2,3-epithiopropyloxy) tetrahydrothiophene, 2,5-bis (2,3-epithiopropyloxy) tetrahydrothiophene, 2,4-bis (2, 3-epithiopropylthio) tetrahydrothiophene, 2,5-bis (2,3-epithiopropylthio) tetrahydrothiophene, 2,4-bis (2,3-epithiopropyloxymethyl) tetrahydrothiophene, 2,5 -Bis (2,3-epithiopropyloxymethyl) tetrahydrothiophene, 2 4- bis (2,3-epithiopropylthiomethyl) tetrahydrothiophene, 2,5-bis (2,3-epithiopropylthiomethyl) tetrahydrothiophene.

  2,5-bis (epithioethyl) tetrahydro-2H-thiopyran, 2,6-bis (epithioethyl) tetrahydro-2H-thiopyran, 2,5-bis (2,3-epithiopropyl) tetrahydro-2H-thiopyran, 2, 6-bis (2,3-epithiopropyl) tetrahydro-2H-thiopyran, 2,5-bis (2,3-epithiopropyloxy) tetrahydro-2H-thiopyran, 2,6-bis (2,3-epi Thiopropyloxy) tetrahydro-2H-thiopyran, 2,5-bis (2,3-epithiopropylthio) tetrahydro-2H-thiopyran, 2,6-bis (2,3-epithiopropylthio) tetrahydro-2H- Thiopyran, 2,5-bis (2,3-epithiopropyloxymethyl) tetrahydro-2H-thiopyran, 2,6 Bis (2,3-epithiopropyloxymethyl) tetrahydro-2H-thiopyran, 2,5-bis (2,3-epithiopropylthiomethyl) tetrahydro-2H-thiopyran, 2,6-bis (2,3- (Epithiopropylthiomethyl) tetrahydro-2H-thiopyran, 2,4,6-tris (2,3-epithiopropyl) tetrahydro-2H-thiopyran.

  2,5-bis (epithioethyl) -1,4-dithiane, 2,5-bis (2,3-epithiopropyl) -1,4-dithiane, 2,5-bis (2,3-epithiopropyloxy) Methyl) -1,4-dithiane, 2,5-bis (2,3-epithiopropylthiomethyl) -1,4-dithiane, 2,5-bis [{2- (2,3-epithiopropylthiol) ) Ethyl} thiomethyl] -1,4-dithiane.

  4-epithioethyl-1,2-epithiocyclopentane, 4-epithioethyl-1,2-epithiocyclohexane, 4-epoxy-1,2-epithiocyclopentane, 4-epoxy-1,2-epithiocyclohexane.

  Bis [4- (epithioethyl) cyclohexyl] methane, bis [4- (2,3-epithiopropyl) cyclohexyl] methane, bis [4- (2,3-epithiopropyloxy) cyclohexyl] methane, bis [4- (2,3-epithiopropylthio) cyclohexyl] methane, bis [4- (2,3-epithiopropyloxymethyl) cyclohexyl] methane, bis [3,5-bis (2,3-epithiopropyl) cyclohexane -1-yl] methane, 2,2-bis [4- (2,3-epithiopropylthiomethyl) cyclohexyl] propane, 2,2-bis [4- (epithioethyl) cyclohexyl] propane, 2,2-bis [4- (2,3-epithiopropyl) cyclohexyl] propane, 2,2-bis [4- (2,3-epithiopropyloxy) ) Cyclohexyl] propane, 2,2-bis [4- (2,3-epithiopropylthio) cyclohexyl] propane, 2,2-bis [4- (2,3-epithiopropyloxymethyl) cyclohexyl] propane, 2,2-bis [4- (2,3-epithiopropylthiomethyl) cyclohexyl] propane, bis [3,5-bis (2,3-epithiopropyl) cyclohexane-1-yl]] propane.

Bis [4- (epithioethyl) cyclohexyl] sulfide, bis [4- (2,3-epithiopropyl) cyclohexyl] sulfide, bis [4- (2,3-epithiopropyloxy) cyclohexyl] sulfide, bis [4- (2,3-epithiopropylthio) cyclohexyl] sulfide, bis [4- (2,3-epithiopropyloxymethyl) cyclohexyl] sulfide, bis [4- (2,3-epithiopropylthiomethyl) cyclohexyl] Sulfide, bis [3,5-bis (2,3-epithiopropyl) cyclohexane-1-yl] sulfide.

  Bis [4- (epithioethyl) cyclohexyl] sulfone, bis [4- (2,3-epithiopropyl) cyclohexyl] sulfone, bis [4- (2,3-epithiopropyloxy) cyclohexyl] sulfone, bis [4- (2,3-epithiopropylthio) cyclohexyl] sulfone, bis [4- (2,3-epithiopropyloxymethyl) cyclohexyl] sulfone, bis [4- (2,3-epithiopropylthiomethyl) cyclohexyl] Sulfon.

  1,3-bis (epithioethyl) benzene, 1,4-bis (epithioethyl) benzene, 1,3-bis (2,3-epithiopropyl) benzene, 1,4-bis (2,3-epithiopropyl) Benzene, 1,3-bis (2,3-epithiopropyloxy) benzene, 1,4-bis (2,3-epithiopropyloxy) benzene, 1,3-bis (2,3-epithiopropylthio) ) Benzene, 1,4-bis (2,3-epithiopropylthio) benzene, 1,3-bis (2,3-epithiopropyloxymethyl) benzene, 1,4-bis (2,3-epithio) Propyloxymethyl) benzene, 1,3-bis (2,3-epithiopropylthiomethyl) benzene, 1,4-bis (2,3-epithiopropylthiomethyl) benzene, 1,3,5-tris ( 2 3-epithiopropylthio) benzene.

  Bis [4- (epithioethyl) phenyl] methane, bis [4- (2,3-epithiopropyl) phenyl] methane, bis [4- (2,3-epithiopropyloxy) phenyl] methane, bis [4- (2,3-epithiopropyloxymethyl) phenyl] methane, bis {4- (2,3-epithiopropylthio) phenyl} methane, bis [4- (2,3-epithiopropylthiomethyl) phenyl] Methane, bis [3,5-bis (2,3-epithiopropyl) phenyl] sulfide.

  2,2-bis [4- (epithioethyl) phenyl] propane, 2,2-bis [4- (2,3-epithiopropyl) phenyl] propane, 2,2-bis [4- (2,3-epi Thiopropyloxy) phenyl] propane, 2,2-bis {4- (2,3-epithiopropylthio) phenyl} propane, 2,2-bis {4- (2,3-epithiopropyloxymethyl) phenyl } Propane, 2,2-bis {4- (2,3-epithiopropylthiomethyl) phenyl} propane.

  Bis [4- (epithioethyl) phenyl] sulfide, bis [4- (2,3-epithiopropyl) phenyl] sulfide, bis {4- (2,3-epithiopropyloxy) phenyl} sulfide, bis {4- (2,3-epithiopropylthio) phenyl} sulfide, bis {4- (2,3-epithiopropyloxymethyl) phenyl} sulfide, bis {4- (2,3-epithiopropylthiomethyl) phenyl} Sulfide.

  Bis [4- (epithioethyl) phenyl] sulfone, bis [4- (2,3-epithiopropyl) phenyl] sulfone, bis [4- (2,3-epithiopropyloxy) phenyl] sulfone, bis {4- (2,3-epithiopropylthio) phenyl} sulfone, bis [4- (2,3-epithiopropyloxymethyl) phenyl] sulfone, bis [4- (2,3-epithiopropylthiomethyl) phenyl] Sulfon.

  4,4′-bis (epithioethyl) biphenyl, 4,4′-bis (2,3-epithiopropyl) biphenyl, 4,4′-bis (2,3-epithiopropyloxy) biphenyl, 4,4 ′ -Bis (2,3-epithiopropylthio) biphenyl, 4,4'-bis (2,3-epithiopropyloxymethyl) biphenyl, 4,4'-bis (2,3-epithiopropylthiomethyl) Biphenyl.

  Examples of the compound having an episulfide structure particularly preferably used in the present invention include the following compounds.

A compound having an episulfide structure may be used alone or in combination.
The compound having an episulfide structure preferably has a molecular weight of 100 to 10,000.
The compound having an episulfide structure is 0.5 to 50% by mass, preferably 1 to 30% by mass, and more preferably 2 to 20% by mass with respect to the alkali-soluble resin.

  A compound having an episulfide structure can be synthesized from a reaction of a corresponding epoxy compound or a ring-opened derivative thereof with potassium thiocyanate or thiourea as described below.

(B) Alkali-soluble resin The negative resist composition of the present invention contains an alkali-soluble resin.
The alkali-soluble resin is composed of a group having solubility in an alkali developer (hereinafter also referred to as “alkali-soluble group”) and other functional groups such as a crosslinking agent or a carboxyl group or a hydroxy group in the resin by the action of an acid. Or a hydroxyl group in the crosslinking agent or resin by the action of an acid. And other functional groups that react with other functional groups (hereinafter also referred to as “alkali-soluble / reactive groups”).

Alkali-soluble group, reactive group, repeating unit having alkali-soluble / reactive group An alkali-soluble resin is composed of a group that is polymerized by radical polymerization or the like (hereinafter also referred to as “polymerizable group”), an alkali-soluble group, and a reactive group. Having a repeating unit formed by a polymerizable monomer having or having a repeating unit formed by a polymerizable monomer having a polymerizable group and an alkali-soluble group, and a polymerizable group and a reactive group It preferably has a repeating unit formed by a polymerizable monomer, or has a repeating unit formed by a polymerizable monomer having a polymerizable group and an alkali-soluble / reactive group.

  The repeating unit is preferably represented by the following general formula (I-1) or (I-2).

In general formula (I-1),
R ¹² , R ¹³ and R ¹⁴ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
R ¹¹ represents a hydrogen atom, an organic group having an alkali-soluble group and / or a reactive group, or an organic group having an alkali-soluble / reactive group.
In general formula (I-2),
Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).
R ¹⁵ and R ¹⁶ each independently represents a hydrogen atom, an organic group having an alkali-soluble group and / or a reactive group, or an organic group having an alkali-soluble / reactive group.

  The general formula (I-2) is preferably the following general formulas (I-2′-1) to (I-2′-3).

In general formulas (I-2′-1) to (I-2′-3),
R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² and R ²³ are each independently an organic group having a hydrogen atom, alkali-soluble group and / or reactive group, or alkali-soluble / reactive Represents an organic group having a functional group.
m represents an integer of 0 or more.

The organic group in R ¹¹ and R ^{15 to} R ²³ is preferably a linear or branched aliphatic group, monocyclic or polycyclic aliphatic group which may have a substituent. . The linear or branched aliphatic group, monocyclic or polycyclic aliphatic group may contain an ether structure or an ester structure, an alkali-soluble group, a reactive group, or an alkali-soluble / reactive group. A plurality of groups may be bonded.

  The organic group may be a group in which a linear or branched aliphatic group and a monocyclic or polycyclic aliphatic group are connected as shown below. In the formula, examples of the structure having a polymerizable group include a methacrylic acid skeleton, a tricyclodecane skeleton, and a polynorbornane skeleton, but the present invention is not limited thereto.

Where
A represents a single bond or a linear or branched aliphatic group.
B represents a single bond or a monocyclic or polycyclic aliphatic group.
R ′ is an alkali-soluble group.
R ″ is a reactive group.
One of R ′ and R ″ may be an alkali-soluble / reactive group, and the other may be a hydrogen atom.
n 'and n "are an integer of 1 or more, n ^a and n ^b is an integer of 0 or more, when m is an integer of at least 0 .n ^a and ^{n b} is an integer of 2 or more, A and B N ′ and n ″ are preferably 1 to 2 and n ^a = 1 and n ^b = 0, n ^a = 0 and n ^b = 1 or n ^a = n ^b = 1. preferable.

  A is preferably a linear or branched aliphatic group having 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms. Examples of such linear or branched aliphatic groups include chain alkylene groups such as the following (A1) to (A18). A (2 + n) -valent group obtained by removing n hydrogen atoms from these alkylene groups is also included in A.

  Examples of the repeating unit in which a polymerizable group, an alkali-soluble group, a reactive group, and an alkali-soluble / reactive group are bonded via A include the following structures.

In the above structure,
R ^12, R ¹³ and R ¹⁴ are the in the general formula (I-1), is the same as the R ^12, R ¹³ and R ^14.
When there are a plurality of R ′, each independently represents an alkali-soluble group.
When there are a plurality of R ″, each independently represents a reactive group.
One of R ′ and R ″ may be an alkali-soluble / reactive group, and the other may be a hydrogen atom.

  The B is preferably a monocyclic or polycyclic aliphatic group having 5 to 30 carbon atoms, more preferably 6 to 25 carbon atoms. Examples of such monocyclic or polycyclic aliphatic groups include alicyclic alkylene groups such as the following (B1) to (B37). In addition, (2 + n) -valent groups obtained by removing n hydrogen atoms from these alkylene groups are also included in B. From the viewpoint of etching resistance, a polycyclic aliphatic group is more preferable.

  Examples of the repeating unit in which a polymerizable group, an alkali-soluble group, a reactive group, and an alkali-soluble / reactive group are bonded via B include the following structures.

In the above structure,
When there are a plurality of R ′, each independently represents an alkali-soluble group.
When there are a plurality of R ″, each independently represents a reactive group.
One of R ′ and R ″ may be an alkali-soluble / reactive group, and the other may be a hydrogen atom.
n ′ and n ″ represent an integer of 0 or more, provided that n ′ + n ″ is 1 or more.

  A and B may combine to form an organic group.

Alkali-soluble group In the above structure, the alkali-soluble group of R ′ includes an organic group containing a polyfluorinated alcohol structure, an organic group containing a carboxylic acid structure, an organic group containing a sulfonamide structure in the following compounds: Organic group containing furfuryl alcohol structure, organic group containing amic acid structure, organic group containing carbamate structure, organic group containing tautomeric alcohol structure, organic group containing thiol structure, organic group containing ketone oxime structure, di Examples include an organic group containing a carbonylmethylene structure, an organic group containing an N-hydroxysuccinimide structure, and an organic group having a triazine skeleton.

In the polyfluorinated alcohol structure, R ^1b and R ^1c represent a hydrogen atom, a fluorine atom or a fluorine-substituted alkyl group, and may be the same or different. The fluorine-substituted alkyl group preferably has all hydrogen atoms of the alkyl group substituted with fluorine. R ^1b and R ^1c may be bonded to each other to form a ring. Examples of the polyfluorinated alcohol structure include the following structures.

  Furthermore, a carbonyl group, an amide group, a sulfone group, an ester group, or the like may be bonded to the sulfonamide structure. The structure is shown below.

In the above structure, R ^3a and R ^3b each independently represents a linear or branched alkyl group or a monocyclic or polycyclic alkyl group which may have a substituent. The substituent may include a hydroxyl group, an ether structure or an ester structure, and a hydrogen atom may be substituted with a fluorine atom. From the viewpoint of alkali solubility, these substituents are preferably linear or branched alkyl groups that may contain an ether or ester structure, and more preferably groups in which a hydrogen atom is substituted with a fluorine atom. Examples of R ^3a and R ^3b include a methyl group, an ethyl group, a 2-hydroxyethyl group, a 2-methoxyethyl group, a 2-methoxycarbonylethyl group, a 2-t-butoxycarbonylethyl group, a cyclopentyl group, a cyclohexyl group, A norbornyl group, an isobornyl group, a tricyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, a trifluoromethyl group, a nonafluorobutyl group, and the like.

When the alkali-soluble group is a polyfluorinated alcohol, carboxylic acid, furfuryl alcohol, tautomeric alcohol, thiol, ketone oxime, N-hydroxysuccinimide, or amic acid, these groups also act as reactive groups. This is an alkali-soluble / reactive group to be obtained.
Of these alkali-soluble groups, polyfluorinated alcohols, carboxylic acids, tautomeric alcohols, thiols, ketone oximes, N-hydroxysuccinimides, and amic acids are preferred from the viewpoint of reactive groups. From the viewpoint of suppression of swelling, polyfluorinated alcohols, carboxylic acids, and sulfonamides are more preferable.

Reactive Group In the above structure, examples of the reactive group R ″ include a carboxyl group, a hydroxyl group, an epoxy group, an oxetane group, and a methylol group in the following compounds.

  Of these reactive groups, the hydroxyl group and carboxyl group are alkali-soluble and reactive groups that can act as alkali-soluble groups.

In the above structure, R ^13a , R ^14a , R ^15a , R ^16a and R ^17a represent a single bond or an organic group (organic structure) that becomes a bond to the main chain of the resin. R ^14b , R ^14c , R ^14d , R ^15b and R ^17b each represents a linear or branched alkyl group or a monocyclic or polycyclic alkyl group which may have a substituent. The substituent may include a hydroxyl group, an ether structure or an ester structure, and a hydrogen atom may be substituted with a fluorine atom. Examples of R ^14b , R ^14c , R ^15c and R ^17b include a methyl group, an ethyl group, a 2-hydroxyethyl group, a 2-methoxyethyl group, a 2-methoxycarbonylethyl group, a 2-t-butoxycarbonylethyl group, A cyclopentyl group, a cyclohexyl group, a norbornyl group, an isobornyl group, a tricyclodecanyl group, a tetracyclododecanyl group, an adamantyl group, a trifluoromethyl group, and a nonafluorobutyl group. l is an integer of 1 to 5, and when ¹⁵ is 2 or more, R ^15b may be the same or different. R ^14a , R ^14b , R ^14c and R ^14d may be bonded to each other to form a ring structure, and R ^15a and R ^15b may be bonded to each other to form a ring structure.

  The structure of an epoxy group and an oxetane group is illustrated below.

^{Wherein, R 14a, R 14b, R} 15a , the structure R ^14a, R ^14b, is similar to the R ^15a.

  Of these reactive groups, a hydroxyl group or a carboxyl group is preferred from the viewpoint of reactivity with an episulfide compound.

When the reactive group is a hydroxyl group, the hydroxyl group may be protected with an acetal or ketal structure. Thus, by protecting the hydroxyl group with an acetal or ketal structure, the hydroxyl group is generated only in the exposed portion, and the dissolution contrast between the exposed portion and the unexposed portion is improved.
Next, such an acetal structure is illustrated.

  Among these partial structures, those having a small absorption at 193 nm and having no aromatic structure are preferable.

When the reactive group is a carboxyl group, the carboxyl group may form an ester structure (acid-decomposable group) with an acid-eliminable alkyl group. Since the carboxyl group forms an ester structure with the acid-eliminable alkyl group in this way, a carboxyl group that becomes a reactive group is generated only in the exposed area, thereby suppressing the dissolution rate of the entire resist film before exposure. Meanwhile, the substantial content of the carboxyl group which is a reactive group can be increased.
Next, such acid-decomposable groups are exemplified.

Although the structure of the repeating unit which has an alkali-soluble group, a reactive group, and an alkali-soluble / reactive group used for this invention is illustrated below, this invention is not limited to this.
Moreover, although the methacrylic acid structure is shown as a structure which has a polymeric group in the following examples, this invention is not limited to these. Examples of the structure having other polymerizable group include an acrylic acid structure, a maleic acid structure, an itaconic acid structure, a norbornene structure, a tricyclodecane structure, and a tetracyclododecane structure.

  The sulfonamide structure further includes the following structures in which the sulfone moiety and the amide moiety are reversed, and structures in which a carbonyl group, an amide group, a sulfone group, an ester group, and the like are bonded.

Repeating Unit Having Aliphatic Group The alkali-soluble resin may have a repeating unit having an aliphatic group. By having the repeating unit having an aliphatic group, the dissolution rate of the resist film can be adjusted and the etching resistance can be increased.

Examples of the aliphatic group include a linear or branched aliphatic group and a monocyclic or polycyclic aliphatic group. The aliphatic group is preferably a group consisting of a carbon atom and a hydrogen atom or a fluorine atom, not a group having solubility in an alkali developer, and a polycyclic aliphatic group is preferable from the viewpoint of etching resistance. .
Examples of the linear or branched aliphatic group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, Groups such as dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, etc., and monocyclic aliphatic groups include, for example, groups such as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc. Examples of the polycyclic aliphatic group include groups such as norbornyl, isobornyl, tricyclodecanyl, tetracyclododecanyl, hexacycloheptadecanyl, adamantyl, diamantyl, spirodecanyl, and spiroundecanyl.

  Examples of the repeating unit having an aliphatic group are shown below. In the following examples, a methacrylic acid structure is shown as the polymerizable group, but the present invention is not limited thereto.

Repeating Unit Having Lactone Structure The alkali-soluble resin may have a repeating unit having a lactone structure.
The lactone structure is opened by an alkaline developer to generate a carboxylic acid. The generated carboxylic acid has a function of increasing the solubility in an alkali developer. At this time, the exposed portion is cured by the reaction of the reactive group with the generated acid, and the amount of the developer is less attracted than the unexposed portion. Therefore, the solubility in an alkali developer due to the lactone structure is not as high as that of the unexposed area. By having a lactone structure by the above action, the dissolution contrast between the unexposed area and the exposed area is further improved, or swelling of the exposed area is suppressed, and improvement in resolution is expected.

  Any lactone structure can be used as long as it has a lactone structure, but a lactone structure having a 5- to 7-membered ring is preferable, and a bicyclo structure or a spiro structure is formed in the 5- to 7-membered lactone structure. Those in which the other ring structures are condensed are preferred. It is more preferable to have a repeating unit having a lactone structure represented by any of the following general formulas (LC1-1) to (LC1-16). Further, a group having a lactone structure may be directly bonded to the main chain. Preferred lactone structures are (LC1-1), (LC1-4), (LC1-5), (LC1-6), (LC1-13), and (LC1-14), particularly preferably (LC1-4 ). By using a specific lactone structure, line edge roughness and development defects are improved.

The lactone structure moiety may or may not have a substituent (Rb ₂ ). Preferred substituents (Rb ₂ ) include an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonyl group having 1 to 8 carbon atoms, and a carboxyl group. , Halogen atom, hydroxyl group, cyano group, acid-decomposable group and the like. More preferred are alkyl groups having 1 to 4 carbon atoms, cyano groups, and acid-decomposable groups. n2 represents an integer of 0 to 4. When n2 is 2 or more, a plurality of substituents (Rb ₂ ) may be the same or different, and a plurality of substituents (Rb ₂ ) may be bonded to form a ring.

  Examples of the repeating unit having a group having a lactone structure represented by any of the general formulas (LC1-1) to (LC1-16) include a repeating unit represented by the following general formula (AI).

In general formula (AI),
R _b0 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms. Preferable substituents that the alkyl group for R _b0 may have include a hydroxyl group and a halogen atom.
Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
R _b0 is preferably a hydrogen atom or a methyl group.
A _b represents a single bond, an alkylene group, a divalent linking group having a monocyclic or polycyclic alicyclic hydrocarbon structure, an ether group, an ester group, a carbonyl group, or a divalent linking group obtained by combining these. . Preferably a single bond, -Ab ₁ -CO ₂ - is a divalent linking group represented by. Ab ₁ is a linear, branched alkylene group, monocyclic or polycyclic cycloalkylene group, preferably a methylene group, an ethylene group, a cyclohexylene group, an adamantylene group or a norbornylene group.
V represents a group represented by any one of the general formulas (LC1-1) to (LC1-16).

  The repeating unit having a lactone structure usually has an optical isomer, but any optical isomer may be used. One optical isomer may be used alone, or a plurality of optical isomers may be mixed and used. When one kind of optical isomer is mainly used, the optical purity (ee) thereof is preferably 90 or more, more preferably 95 or more.

  Specific examples of the repeating unit having a group having a lactone structure are given below, but the present invention is not limited thereto.

The alkali-soluble resin has a repeating unit having an alkali-soluble group and a repeating unit having a reactive group, or has a repeating unit having an alkali-soluble / reactive group.
The alkali-soluble resin is preferably a copolymer having a repeating unit having an alkali-soluble group and a repeating unit having a reactive group, and the copolymer is preferably used alone.
In addition to the above repeating units, a copolymer of a repeating unit having an aliphatic group or a repeating unit having a lactone structure can also be used for the alkali-soluble resin.
The composition ratio of each component of the repeating unit varies depending on the structural unit to be used, but the repeating unit having an alkali-soluble group in all the repeating units is preferably 1 to 90 mol%, more preferably 15 to 80 mol%, Even more preferably 20 to 70 mol%, the repeating unit having a reactive group is preferably 10 to 90 mol%, more preferably 25 to 85 mol%, still more preferably 30 to 70 mol%, The repeating unit having an alkali-soluble / reactive group is preferably 1 to 90 mol%, more preferably 15 to 85 mol%, still more preferably 20 to 70 mol%, and the repeating unit having an aliphatic group is Preferably from 1 to 40 mol%, more preferably from 3 to 25 mol%, still more preferably from 5 to 20 mol%, and the repeating unit having a lactone structure But preferably 15 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 30 to 50 mol%.

The weight average molecular weight (Mw) of the alkali-soluble resin is 1000 to 100,000, preferably 1000 to 20000, more preferably 1000 to 10000, and particularly preferably 1000 to 8000. The value obtained by dividing the weight average molecular weight by the number average molecular weight (dispersion degree M
w / Mn) is 1 to 3, preferably 1 to 2.5, more preferably 1 to 1.8, and particularly preferably 1 to 1.5.

The alkali-soluble resin can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as that used in the resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.
The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred examples of the initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 5 to 50% by mass, preferably 10 to 30% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

  The content of the alkali-soluble resin is preferably 50 to 99.5% by mass, more preferably 70 to 99% by mass, based on the solid content of the negative resist composition, and 80 to 98% by mass. % Is more preferable.

(C) Compound that generates acid upon irradiation with actinic ray or radiation The negative resist composition of the present invention contains a compound that generates acid upon irradiation with actinic ray or radiation (hereinafter also referred to as “acid generator”). To do.
As the acid generator, photo-initiator of photocation polymerization, photo-initiator of photo-radical polymerization, photo-decoloring agent of dyes, photo-discoloring agent, or irradiation with actinic ray or radiation used for micro-resist etc. Known compounds that generate acids and mixtures 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.

  Preferred compounds among the acid generators include compounds represented by the following general formulas (ZI), (ZII), and (ZIII).

In the general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1 to 30, preferably 1
~ 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).
Z ⁻ represents a non-nucleophilic anion.

Examples of the non-nucleophilic anion as Z ⁻ include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

  A non-nucleophilic anion is an anion that has an extremely low ability to cause a nucleophilic reaction, and is an anion that can suppress degradation over time due to an intramolecular nucleophilic reaction. This improves the temporal stability of the resist.

  Examples of the sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, and a camphor sulfonate anion.

  Examples of the carboxylate anion include an aliphatic carboxylate anion, an aromatic carboxylate anion, and an aralkylcarboxylate anion.

  The aliphatic moiety in the aliphatic sulfonate anion may be an alkyl group or a cycloalkyl group, preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms such as methyl. Group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group , Tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group and the like.

  The aromatic group in the aromatic sulfonate anion is preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group, a tolyl group, and a naphthyl group.

The alkyl group, cycloalkyl group and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, and aryl group in the aliphatic sulfonate anion and aromatic sulfonate anion include, for example, a nitro group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), carboxyl group , Hydroxyl group, amino group, cyano group, alkoxy group (preferably having 1 to 15 carbon atoms), cycloalkyl group (preferably having 3 to 15 carbon atoms), aryl group (preferably having 6 to 14 carbon atoms), alkoxycarbonyl group ( Preferably 2 to 7 carbon atoms, acyl group (preferably 2 to 12 carbon atoms), alkoxycarbonyloxy group (preferably 2 to 7 carbon atoms), alkylthio group (preferably 1 to 15 carbon atoms), alkylsulfonyl group (Preferably having 1 to 15 carbon atoms), alkyliminosulfonyl group (preferably having 2 to 15 carbon atoms), aryl Ruoxysulfonyl group (preferably having 6 to 20 carbon atoms), alkylaryloxysulfonyl group (preferably having 7 to 20 carbon atoms), cycloalkylaryloxysulfonyl group (preferably having 10 to 20 carbon atoms), alkyloxyalkyloxy group (Preferably having 5 to 20 carbon atoms), a cycloalkylalkyloxyalkyloxy group (preferably having 8 to 20 carbon atoms), and the like. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) can further be mentioned as a substituent.

  Examples of the aliphatic moiety in the aliphatic carboxylate anion include the same alkyl group and cycloalkyl group as in the aliphatic sulfonate anion.

  Examples of the aromatic group in the aromatic carboxylate anion include the same aryl group as in the aromatic sulfonate anion.

  The aralkyl group in the aralkyl carboxylate anion is preferably an aralkyl group having 6 to 12 carbon atoms, such as a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group, and a naphthylmethyl group.

  The alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion may have a substituent. Examples of the substituent of the alkyl group, cycloalkyl group, aryl group and aralkyl group in the aliphatic carboxylate anion, aromatic carboxylate anion and aralkylcarboxylate anion include, for example, the same halogen atom and alkyl as in the aromatic sulfonate anion Group, cycloalkyl group, alkoxy group, alkylthio group and the like.

  Examples of the sulfonylimide anion include saccharin anion.

  The alkyl group in the bis (alkylsulfonyl) imide anion and tris (alkylsulfonyl) methyl anion is preferably an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, An isobutyl group, a sec-butyl group, a pentyl group, a neopentyl group, and the like can be given. Examples of substituents for these alkyl groups include halogen atoms, alkyl groups substituted with halogen atoms, alkoxy groups, alkylthio groups, alkyloxysulfonyl groups, aryloxysulfonyl groups, cycloalkylaryloxysulfonyl groups, and the like. Alkyl groups substituted with fluorine atoms are preferred.

  Examples of other non-nucleophilic anions include fluorinated phosphorus, fluorinated boron, and fluorinated antimony.

Examples of the non-nucleophilic anion of Z ⁻ include an aliphatic sulfonate anion in which the α-position of the sulfonic acid is substituted with a fluorine atom, an aromatic sulfonate anion substituted with a fluorine atom or a group having a fluorine atom, and an alkyl group. A bis (alkylsulfonyl) imide anion substituted with a fluorine atom and a tris (alkylsulfonyl) methide anion wherein an alkyl group is substituted with a fluorine atom are preferred. The non-nucleophilic anion is more preferably a perfluoroaliphatic sulfonic acid anion having 4 to 8 carbon atoms, a benzenesulfonic acid anion having a fluorine atom, still more preferably a nonafluorobutanesulfonic acid anion, a perfluorooctanesulfonic acid anion, It is a pentafluorobenzenesulfonic acid anion and 3,5-bis (trifluoromethyl) benzenesulfonic acid anion.

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include a compound (ZI-1) described later.
), (ZI-2) and (ZI-3).

In addition, the compound which has two or more structures represented by general formula (ZI) 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.

  More preferable (ZI) components 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 compounds, namely, compounds containing an arylsulfonium as a cation.

In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or R ₂₀₁
Some of to R ₂₀₃ is an aryl group and the remainder 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 a phenyl group or a naphthyl group, and more preferably a phenyl group. The aryl group may be an aryl group having a heterocyclic structure having an oxygen atom, a nitrogen atom, a sulfur atom or the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like. When the arylsulfonium compound has two or more aryl groups, the two or more aryl groups may be the same or different.

  The alkyl group or cycloalkyl group that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms and a cycloalkyl group having 3 to 15 carbon atoms, such as a methyl group, Examples thereof include an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, 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 linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, more preferably carbon. These are an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. 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 which R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group having no 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 or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.

The alkyl group and cycloalkyl group of R ₂₀₁ to R _203, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group). More preferred examples of the alkyl group include a 2-oxoalkyl group and an alkoxycarbonylmethyl group. More preferred examples of the cycloalkyl group include a 2-oxocycloalkyl group.

The 2-oxoalkyl group may be either linear or branched, and a group having> C = O at the 2-position of the above alkyl group is preferable.
The 2-oxocycloalkyl group is preferably a group having> C═O at the 2-position of the cycloalkyl group.

  The alkoxy group in the alkoxycarbonylmethyl group is preferably an alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, 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.
R _x and R _y 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 _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom and a sulfur atom. , An ester bond and an amide bond may be included. Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.
Zc ⁻ represents a non-nucleophilic anion, and examples thereof include the same non-nucleophilic anion as Z ^{− in} formula (ZI).

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 methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, and a linear or branched pentyl group. Examples of the cycloalkyl group include cyclohexane having 3 to 8 carbon atoms. An alkyl group (for example, a cyclopentyl group, a cyclohexyl group) can be mentioned.

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 of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, 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 and cycloalkyl group as R _x and R _y include the same alkyl group and cycloalkyl group as in R _{1c to} R _7c , such as a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxy group. A carbonylmethyl group is more preferred.

Examples of the 2-oxoalkyl group and 2-oxocycloalkyl 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 in R _{1c to} R _5c .

R _x and R _y are preferably an alkyl group or cycloalkyl group having 4 or more carbon atoms, more preferably 6 or more, and still more preferably 8 or more alkyl groups or cycloalkyl groups.

In general formulas (ZII) and (ZIII),
R ₂₀₄ to R ₂₀₇ each independently represents an aryl group, an alkyl group or a cycloalkyl group.

Phenyl group and a naphthyl group are preferred as the aryl group of R ₂₀₄ to R _207, more preferably a phenyl group. Aryl group R ₂₀₄ to R ₂₀₇ represents an oxygen atom, a nitrogen atom, may be an aryl group having a heterocyclic structure having a sulfur atom and the like. Examples of the aryl group having a heterocyclic structure include a pyrrole residue (a group formed by losing one hydrogen atom from pyrrole) and a furan residue (a group formed by losing one hydrogen atom from furan). Groups), thiophene residues (groups formed by the loss of one hydrogen atom from thiophene), indole residues (groups formed by the loss of one hydrogen atom from indole), benzofuran residues ( A group formed by losing one hydrogen atom from benzofuran), a benzothiophene residue (a group formed by losing one hydrogen atom from benzothiophene), and the like.

The alkyl group and cycloalkyl group in R ₂₀₄ to R _207, preferably a linear or branched alkyl group having 1 to 10 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group), carbon Examples thereof include cycloalkyl groups of several 3 to 10 (cyclopentyl group, cyclohexyl group, norbornyl group).

Aryl group, alkyl group of R ₂₀₄ to R _207, cycloalkyl groups may have a substituent. Aryl group, alkyl group of R ₂₀₄ to R _207, the cycloalkyl group substituent which may be possessed by, 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 (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

Z ⁻ represents a non-nucleophilic anion, and examples thereof include the same as the non-nucleophilic anion of Z ^{− in} formula (ZI).

  Examples of the acid generator further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI).

In general formulas (ZIV) to (ZVI),
Ar ₃ and Ar ₄ each independently represents an aryl group.
R ₂₀₈ , R ₂₀₉ and R ₂₁₀ each independently represents an alkyl group, a cycloalkyl group or an aryl group.
A represents an alkylene group, an alkenylene group or an arylene group.

Among the acid generators, compounds represented by the general formulas (ZI) to (ZIII) are more preferable.
Further, the acid generator is preferably a compound that generates an acid having one sulfonic acid group or imide group, more preferably a compound that generates monovalent perfluoroalkanesulfonic acid, or a monovalent fluorine atom or fluorine atom. A compound that generates an aromatic sulfonic acid substituted with a group containing fluorinated acid, or a compound that generates a monovalent fluorine atom or an imide acid substituted with a group containing a fluorine atom, and even more preferably, It is a sulfonium salt of a substituted alkanesulfonic acid, a fluorine-substituted benzenesulfonic acid, a fluorine-substituted imide acid or a fluorine-substituted methide acid. The acid generator that can be used is particularly preferably a fluorinated substituted alkane sulfonic acid, a fluorinated substituted benzene sulfonic acid or a fluorinated substituted imido acid whose pKa of the generated acid is pKa = -1 or less, and the sensitivity is improved. .

  Among acid generators, particularly preferred examples are given below.

An acid generator can be used individually by 1 type or in combination of 2 or more types.
The content of the acid generator in the negative resist composition is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, still more preferably, based on the total solid content of the negative resist composition. Is 1-7 mass%.

(D) Crosslinking agent The crosslinking agent that can be used in the present invention is preferably a compound represented by the following general formula (4), general formula (5), general formula (6), or general formula (7).

In the general formulas (4) to (7),
R ⁸ each independently represents a hydrogen atom or an alkyl group (preferably having 1 to 6 carbon atoms, specifically methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl Group, hexyl group and the like) or oxoalkyl group (preferably having 3 to 6 carbon atoms, specifically β-oxopropyl group, β-oxobutyl group, β-oxoheptyl group, β-oxohexyl group and the like).
R ⁹ is independently a hydrogen atom, a hydroxyl group, or an alkoxy group (preferably having 1 to 6 carbon atoms, specifically, a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butoxy group, an isobutoxy group, or a tertiary butoxy group. Group, pentyloxy group, hexyloxy group, etc.) or oxoalkyloxy group (preferably having 3 to 6 carbon atoms, specifically β-oxopropoxy group, β-oxobutoxy group, β-oxoheptyloxy group, β- Represents an oxohexyloxy group and the like.
R ¹⁰ represents an oxygen atom, a sulfur atom, an alkylene group (preferably having 1 to 3 carbon atoms, specifically a methylene group, an ethylene group, a propylene group, a 1-methylethylene group or the like) or a hydroxymethylene group.
a ₁ represents 1 or 2.
a ₂ represents 1 or 2.
b ₁ represents 0 or 1.
b ₂ represents 0 or 1.
However, a ₁ + b ₁ = 2 and a ₂ + b ₂ = 2.

The crosslinking agent can crosslink the alkali-soluble resin under an acid catalyst, forms a three-dimensional network structure, and becomes insoluble in an alkali developer.
Therefore, when a resist film is formed with a negative resist composition containing an alkali-soluble resin, a crosslinking agent, and an acid generator and exposed to light, an acid is generated from the acid generator in the exposed region, and further, heating is performed. When performed, the acid becomes a catalyst, and the alkali-soluble resin is crosslinked by the crosslinking agent. As a result, the exposed portion is insoluble in the developer, and a negative pattern can be obtained.

In the negative resist composition of the present invention, these crosslinking agent components may be used alone or in combination.
In the present invention, the content of the crosslinking agent is preferably 0.5 to 50% by mass, more preferably 1 to 30% by mass, and even more preferably 2 to 20% by mass with respect to the alkali-soluble resin. .

Basic Compound The negative resist composition of the present invention preferably contains a basic compound in order to reduce the change in performance over time from exposure to heating.
Preferred examples of the basic compound include compounds having structures represented by the following formulas (A) to (E).

In general formulas (A) to (E),
R ²⁰⁰ , R ²⁰¹ and R ²⁰² may be the same or different, and are a hydrogen atom, an alkyl group (preferably having 1 to 20 carbon atoms), a cycloalkyl group (preferably having 3 to 20 carbon atoms) or an aryl group (having a carbon number). 6-20), wherein R ²⁰¹ and R ²⁰² may combine with each other to form a ring.
About the said alkyl group, as an alkyl group which has a substituent, a C1-C20 aminoalkyl group, a C1-C20 hydroxyalkyl group, or a C1-C20 cyanoalkyl group is preferable.
R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ and R ²⁰⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms.
The alkyl groups in these general formulas (A) to (E) are more preferably unsubstituted.

  Preferred compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, piperidine and the like, and more preferred compounds include imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate Examples thereof include a compound having a structure, a trialkylamine structure, an aniline structure or a pyridine structure, an alkylamine derivative having a hydroxyl group and / or an ether bond, and an aniline derivative having a hydroxyl group and / or an ether bond.

Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, and benzimidazole. Examples of the compound having a diazabicyclo structure include 1,4-diazabicyclo [2,2,2] octane, 1,5-diazabicyclo [4,3,0] non-5-ene, and 1,8-diazabicyclo [5,4,0. ] Undecar 7-ene etc. are mentioned. Examples of the compound having an onium hydroxide structure include triarylsulfonium hydroxide, phenacylsulfonium hydroxide, sulfonium hydroxide having a 2-oxoalkyl group, specifically triphenylsulfonium hydroxide, tris (t-butylphenyl) sulfonium. Examples thereof include hydroxide, bis (t-butylphenyl) iodonium hydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiophenium hydroxide. As the compound having an onium carboxylate structure, an anion portion of the compound having an onium hydroxide structure is converted to a carboxylate, and examples thereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having a trialkylamine structure include tri (n-butyl) amine and tri (n-octyl) amine. Examples of the aniline compound include 2,6-diisopropylaniline, N, N-dimethylaniline, N, N-dibutylaniline, N, N-dihexylaniline and the like. Examples of the alkylamine derivative having a hydroxyl group and / or an ether bond include ethanolamine, diethanolamine, triethanolamine, and tris (methoxyethoxyethyl) amine. Examples of aniline derivatives having a hydroxyl group and / or an ether bond include N, N-bis (hydroxyethyl) aniline.
These basic compounds are used alone or in combination of two or more.

  The usage-amount of a basic compound is 0.001-10 mass% normally on the basis of solid content of a negative resist composition, Preferably it is 0.01-5 mass%.

  The use ratio of the acid generator and the basic compound in the composition is preferably acid generator / basic compound (molar ratio) = 2.5 to 300. In other words, the molar ratio is preferably 2.5 or more from the viewpoint of sensitivity and resolution, and is preferably 300 or less from the viewpoint of suppressing the reduction in resolution due to the thickening of the resist pattern over time until post-exposure heat treatment. The acid generator / basic compound (molar ratio) is more preferably 5.0 to 200, still more preferably 7.0 to 150.

Surfactant The negative resist composition of the present invention preferably further contains a surfactant, and a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant, silicon-based surfactant, fluorine atom) Or a surfactant having both silicon atoms and two or more of them.

  When the negative resist composition of the present invention contains the above-described surfactant, a resist pattern with less adhesion and development defects can be obtained with good sensitivity and resolution when using an exposure light source of 250 nm or less, particularly 220 nm or less. It becomes possible.

Examples of the fluorine-based and / or silicon-based surfactant include, for example, JP-A No. 62-36663, JP-A No. 61-226746, JP-A No. 61-226745, JP-A No. 62-170950, JP 63-34540 A, JP 7-230165 A, JP 8-62834 A, JP 9-54432 A, JP 9-5988 A, JP 2002-277862 A, US Patent Nos. 5,405,720, 5,360,692, 5,529,881, 5,296,330, 5,436,098, 5,576,143, 5,294,511, 5,824,451 Surfactant can be mentioned, The following commercially available surfactant can also be used as it is.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431, 4430 (manufactured by Sumitomo 3M Co., Ltd.),
Megafuck F171, F173, F176, F189, F113, F110, F177, F120, R08 (manufactured by Dainippon Ink and Chemicals), Surflon S-382, SC1
01, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (manufactured by Troy Chemical Co., Ltd.), GF-300, GF-150 (manufactured by Toagosei Chemical Co., Ltd.), Surflon S-393 (manufactured by Seimi Chemical Co., Ltd.), F-top EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351, 352, EF801, EF802, EF601 (manufactured by Gemco), PF636, PF656, PF6320, PF6520 Fluorosurfactant or silicon surfactant such as (manufactured by OMNOVA), FTX-204D, 208G, 218G, 230G, 204D, 208D, 212D, 218, 222D (manufactured by Neos) 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, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called 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 ₃ F ₇ group and (poly (oxy) And a copolymer of (ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate).

  In the present invention, other surfactants other than fluorine-based and / or silicon-based surfactants can also be used. 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 - DOO, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, may be mentioned polyoxyethylene sorbitan tristearate nonionic surfactants of polyoxyethylene sorbitan fatty acid esters such as such.

These surfactants may be used alone or in several combinations.
The amount of the surfactant used is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, based on the total amount of the negative resist composition (excluding the solvent).

Hydrophobic resin When a resist film comprising the negative resist composition of the present invention is exposed through an immersion medium, it is preferable to further add a hydrophobic resin (HR) to the negative resist composition. . As a result, hydrophobic resin (HR) is unevenly distributed on the surface of the resist film, and when the immersion medium is water, the receding contact angle of the resist film surface with respect to the water when the resist film is formed is improved, and the immersion water tracking is improved. Can be made. As the hydrophobic resin (HR), any resin can be used as long as the receding contact angle on the surface can be improved by adding it, but a resin having at least one of a fluorine atom and a silicon atom is preferable. The receding contact angle of the resist film is preferably 60 ° to 90 °, more preferably 70 ° or more. The addition amount can be adjusted as appropriate so that the receding contact angle of the resist film falls within the above range, but is preferably 0.1 to 10% by mass based on the total solid content of the negative resist composition, More preferably, it is 0.1-5 mass%. Hydrophobic resin (HR) is ubiquitous at the interface as described above, but unlike a surfactant, it does not necessarily have a hydrophilic group in the molecule, and polar / nonpolar substances are mixed uniformly. There is no need to contribute.

  The fluorine atom or silicon atom in the hydrophobic resin (HR) may be contained in the main chain of the resin or may be substituted on the side chain.

The hydrophobic resin (HR) is preferably a resin having an alkyl group having a fluorine atom, a cycloalkyl group having a fluorine atom, or an aryl group having a fluorine atom as a partial structure having a fluorine atom.
The alkyl group having a fluorine atom (preferably having 1 to 10 carbon atoms, more preferably 1 to 4 carbon atoms) is a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, It may have a substituent.
The cycloalkyl group having a fluorine atom is a monocyclic or polycyclic cycloalkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and may further have another substituent.
Examples of the aryl group having a fluorine atom include those in which at least one hydrogen atom of an aryl group such as a phenyl group or a naphthyl group is substituted with a fluorine atom, and may further have another substituent.

  Preferred examples of the alkyl group having a fluorine atom, the cycloalkyl group having a fluorine atom, or the aryl group having a fluorine atom include groups represented by the following general formulas (F2) to (F4). The present invention is not limited to this.

In general formulas (F2) to (F4),
R _{57 to} R ₆₈ each independently represents a hydrogen atom, a fluorine atom or an alkyl group. However, at least one of R _{57 to} R ₆₁ , R _{62 to} R ₆₄ and R _{65 to} R ₆₈ is a fluorine atom or an alkyl group in which at least one hydrogen atom is substituted with a fluorine atom (preferably having a carbon number of 1 ~ 4). R _{57 to} R ₆₁ and R _{65 to} R ₆₇ are preferably all fluorine atoms. R ₆₂ , R ₆₃ and R ₆₈ are preferably an alkyl group (preferably having 1 to 4 carbon atoms) in which at least one hydrogen atom is substituted with a fluorine atom, and preferably a perfluoroalkyl group having 1 to 4 carbon atoms. Further preferred. R ₆₂ and R ₆₃ may be connected to each other to form a ring.

Specific examples of the group represented by the general formula (F2) include a p-fluorophenyl group, a pentafluorophenyl group, and a 3,5-di (trifluoromethyl) phenyl group.
Specific examples of the group represented by the general formula (F3) include trifluoromethyl group, pentafluoropropyl group, pentafluoroethyl group, heptafluorobutyl group, hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2 -Methyl) isopropyl group, nonafluorobutyl group, octafluoroisobutyl group, nonafluorohexyl group, nonafluoro-t-butyl group, perfluoroisopentyl group, perfluorooctyl group, perfluoro (trimethyl) hexyl group, 2,2 1,3,3-tetrafluorocyclobutyl group, perfluorocyclohexyl group and the like. Hexafluoroisopropyl group, heptafluoroisopropyl group, hexafluoro (2-methyl) isopropyl group, octafluoroisobutyl group, nonafluoro-t-butyl group and perfluoroisopentyl group are preferable, and hexafluoroisopropyl group and heptafluoroisopropyl group are preferable. Further preferred.
Specific examples of the group represented by the general formula (F4) include, for example, —C (CF ₃ ) ₂ OH, —C (C ₂ F ₅ ) ₂ OH, —C (CF ₃ ) (CH ₃ ) OH, -CH (CF ₃₎ OH and the like, -C (CF _{3) 2} OH is preferred.

Hereinafter, although the specific example of the repeating unit which has a fluorine atom is shown, this invention is not limited to this.
In specific examples, X ₁ represents a hydrogen atom, —CH ₃ , —F or —CF ₃ .
X ₂ represents —F or —CF ₃ .

The hydrophobic resin (HR) is preferably a resin having an alkylsilyl structure (preferably a trialkylsilyl group) or a cyclic siloxane structure as a partial structure having a silicon atom.
Specific examples of the alkylsilyl structure or the cyclic siloxane structure include groups represented by the following general formulas (CS-1) to (CS-3).

In the general formulas (CS-1) to (CS-3),
R _{12 to} R ₂₆ each independently represents a linear or branched alkyl group (preferably having 1 to 20 carbon atoms) or a cycloalkyl group (preferably having 3 to 20 carbon atoms).
L < ₃ > -L < ₅ > represents a single bond or a bivalent coupling group. As the divalent linking group, an alkylene group, a phenyl group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a urethane group, or a urea group is used alone or in combination of two or more groups. A combination is mentioned.
n represents an integer of 1 to 5.

Hereinafter, although the specific example of the repeating unit which has a silicon atom is given, this invention is not limited to this.
In specific examples, X ₁ represents a hydrogen atom, —CH ₃ , —F or —CF ₃ .

Furthermore, the hydrophobic resin (HR) may have at least one group selected from the following groups (x) to (z).
(X) an alkali-soluble group,
(Y) a group that decomposes by the action of an alkali developer and increases the solubility in the alkali developer;
(Z) A group that decomposes by the action of an acid.

(X) Alkali-soluble groups include phenolic hydroxyl groups, carboxylic acid groups, fluorinated alcohol groups, sulfonic acid groups, sulfonamido groups, sulfonylimide groups, (alkylsulfonyl) (alkylcarbonyl) methylene groups, (alkylsulfonyl) ( Alkylcarbonyl) imide group, bis (alkylcarbonyl) methylene group, bis (alkylcarbonyl) imide group, bis (alkylsulfonyl) methylene group, bis (alkylsulfonyl) imide group, tris (alkylcarbonyl) methylene group, tris (alkylsulfonyl) And a group having a methylene group.
Preferred alkali-soluble groups include fluorinated alcohol groups (preferably hexafluoroisopropanol), sulfonimide groups, and bis (carbonyl) methylene groups.

Examples of the repeating unit having an alkali-soluble group (x) include a repeating unit in which an alkali-soluble group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a main group of the resin via a linking group. It is preferable to use a repeating unit in which an alkali-soluble group is bonded to the chain, and further introduce a polymerization initiator or chain transfer agent having an alkali-soluble group at the end of the polymer chain at the time of polymerization.
The content of the repeating unit having an alkali-soluble group (x) is preferably from 1 to 50 mol%, more preferably from 3 to 35 mol%, still more preferably from 5 to 20 mol%, based on all repeating units in the polymer.

  Specific examples of the repeating unit having an alkali-soluble group (x) are shown below, but the present invention is not limited thereto.

(Y) Examples of the group that decomposes by the action of an alkali developer and increases the solubility in the alkali developer include a group having a lactone structure, an acid anhydride, an acid imide group, and the like, and preferably a lactone group It is.
As the repeating unit having a group (y) that is decomposed by the action of an alkali developer and increases the solubility in the alkali developer, an alkali is added to the main chain of the resin, such as a repeating unit of an acrylate ester or a methacrylate ester. A polymerization initiator having a repeating unit to which a group (y) that decomposes by the action of the developer and increases the solubility in an alkali developer is bonded, or a group (y) that increases the solubility in an alkali developer Or introducing a chain transfer agent at the end of the polymer chain at the time of polymerization is preferred.
The content of the repeating unit having a group (y) whose solubility in an alkali developer is increased is preferably 1 to 40 mol%, more preferably 3 to 30 mol%, still more preferably based on all repeating units in the polymer. 5 to 15 mol%.

  Specific examples of the repeating unit having a group (y) that increases the solubility in an alkali developer include the same repeating units as those having a lactone structure exemplified in the component (B).

  In the hydrophobic resin (HR), examples of the repeating unit having a group (z) capable of decomposing by the action of an acid include the same repeating units having an acid-decomposable group as mentioned in the component (B). In the hydrophobic resin (HR), the content of the repeating unit having a group (z) that is decomposed by the action of an acid is preferably 1 to 80 mol%, more preferably 10 to 10%, based on all repeating units in the polymer. 80 mol%, more preferably 20 to 60 mol%.

  The hydrophobic resin (HR) may further have a repeating unit represented by the following general formula (III).

In general formula (III):
R ₄ represents a group having an alkyl group, a cycloalkyl group, an alkenyl group, or a cycloalkenyl group.
L ₆ represents a single bond or a divalent linking group.

In general formula (III), the alkyl group represented by R ₄ is preferably a linear or branched alkyl group having 3 to 20 carbon atoms.
The cycloalkyl group is preferably a cycloalkyl group having 3 to 20 carbon atoms.
The alkenyl group is preferably an alkenyl group having 3 to 20 carbon atoms.
The cycloalkenyl group is preferably a cycloalkenyl group having 3 to 20 carbon atoms.
The divalent linking group of L ₆ is preferably an alkylene group (preferably having 1 to 5 carbon atoms) or an oxy group.

When the hydrophobic resin (HR) has a fluorine atom, the fluorine atom content is preferably 5 to 80% by mass, and 10 to 80% by mass with respect to the molecular weight of the hydrophobic resin (HR). Is more preferable. Moreover, it is preferable that the repeating unit containing a fluorine atom is 10-100 mass% in hydrophobic resin (HR), and it is more preferable that it is 30-100 mass%.
When the hydrophobic resin (HR) has a silicon atom, the content of the silicon atom is preferably 2 to 50% by mass and preferably 2 to 30% by mass with respect to the molecular weight of the hydrophobic resin (HR). Is more preferable. Moreover, it is preferable that it is 10-100 mass% in hydrophobic resin (HR), and, as for the repeating unit containing a silicon atom, it is more preferable that it is 20-100 mass%.

  The weight average molecular weight of the hydrophobic resin (HR) in terms of standard polystyrene is preferably 1,000 to 100,000, more preferably 1,000 to 50,000, and even more preferably 2,000 to 15,000. is there.

  As with the component (B), the hydrophobic resin (HR) preferably has 0 to 10% by mass of residual monomer and oligomer components, and more preferably has few impurities such as metals. 0-5 mass% and 0-1 mass% are still more preferable. Thereby, a resist having no change over time such as foreign matter in liquid or sensitivity can be obtained. The molecular weight distribution (Mw / Mn, also referred to as dispersity) is preferably in the range of 1 to 5, more preferably 1 to 3, and still more preferably from the viewpoints of resolution, resist shape, resist pattern sidewall, roughness, and the like. It is the range of 1-2.

  As the hydrophobic resin (HR), various commercially available products can be used, or they can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, a monomer polymerization method in which a monomer species and an initiator are dissolved in a solvent and the polymerization is performed by heating, and a solution of the monomer species and the initiator is dropped into the heating solvent over 1 to 10 hours. The dropping polymerization method is added, and the dropping polymerization method is preferable. Examples of the reaction solvent include ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate, amide solvents such as dimethylformamide and dimethylacetamide, Furthermore, the solvent which melt | dissolves the composition of this invention like the below-mentioned propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, and cyclohexanone is mentioned. More preferably, the polymerization is performed using the same solvent as that used in the negative resist composition of the present invention. Thereby, generation | occurrence | production of the particle at the time of a preservation | save can be suppressed.

  The polymerization reaction is preferably performed in an inert gas atmosphere such as nitrogen or argon. As a polymerization initiator, a commercially available radical initiator (azo initiator, peroxide, etc.) is used to initiate the polymerization. As the radical initiator, an azo initiator is preferable, and an azo initiator having an ester group, a cyano group, or a carboxyl group is preferable. Preferred initiators include azobisisobutyronitrile, azobisdimethylvaleronitrile, dimethyl 2,2′-azobis (2-methylpropionate) and the like. The concentration of the reaction is 5 to 50% by mass, preferably 30 to 50% by mass. The reaction temperature is usually 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 60-100 ° C.

After completion of the reaction, it is allowed to cool to room temperature and purified. Purification can be accomplished by a liquid-liquid extraction method that removes residual monomers and oligomer components by combining water and an appropriate solvent, and a purification method in a solution state such as ultrafiltration that extracts and removes only those having a specific molecular weight or less. , Reprecipitation method that removes residual monomer by coagulating resin in poor solvent by dripping resin solution into poor solvent and purification in solid state such as washing filtered resin slurry with poor solvent A normal method such as a method can be applied. For example, the resin is precipitated as a solid by contacting a solvent (poor solvent) in which the resin is hardly soluble or insoluble in a volume amount of 10 times or less, preferably 10 to 5 times that of the reaction solution.

  The solvent (precipitation or reprecipitation solvent) used in the precipitation or reprecipitation operation from the polymer solution may be a poor solvent for the polymer, and may be a hydrocarbon, halogenated hydrocarbon, nitro, depending on the type of polymer. A compound, ether, ketone, ester, carbonate, alcohol, carboxylic acid, water, a mixed solvent containing these solvents, and the like can be appropriately selected for use. Among these, as a precipitation or reprecipitation solvent, a solvent containing at least an alcohol (particularly methanol or the like) or water is preferable.

  The amount of the precipitation or reprecipitation solvent used can be appropriately selected in consideration of efficiency, yield, and the like, but generally 100 to 10000 parts by mass, preferably 200 to 2000 parts by mass with respect to 100 parts by mass of the polymer solution, More preferably, it is 300-1000 mass parts.

  The temperature for precipitation or reprecipitation can be appropriately selected in consideration of efficiency and operability, but is usually about 0 to 50 ° C., preferably around room temperature (for example, about 20 to 35 ° C.). The precipitation or reprecipitation operation can be performed by a known method such as a batch method or a continuous method using a conventional mixing vessel such as a stirring tank.

  The precipitated or re-precipitated polymer is usually subjected to conventional solid-liquid separation such as filtration and centrifugation, and dried before use. Filtration is performed using a solvent-resistant filter medium, preferably under pressure. Drying is performed at a temperature of about 30 to 100 ° C., preferably about 30 to 50 ° C. under normal pressure or reduced pressure (preferably under reduced pressure).

  The resin may be once deposited and separated, and then dissolved again in a solvent, and the resin may be brought into contact with a hardly soluble or insoluble solvent. That is, after completion of the radical polymerization reaction, a solvent in which the polymer is hardly soluble or insoluble is brought into contact, the resin is precipitated (step a), the resin is separated from the solution (step b), and dissolved again in the solvent. (Step c), and then contact the resin solution A with a solvent in which the resin is hardly soluble or insoluble in a volume amount less than 10 times that of the resin solution A (preferably 5 times or less volume). This may be a method including precipitating a resin solid (step d) and separating the precipitated resin (step e).

  Specific examples of the hydrophobic resin (HR) are shown below. Table 1 below shows the molar ratio of the repeating units in each resin (corresponding to each repeating unit in order from the left), the weight average molecular weight, and the degree of dispersion.

Dissolution inhibitor The negative resist composition of the present invention may contain a dissolution inhibitor having a molecular weight of 3000 or less, which is decomposed by the action of an acid to increase the solubility in an alkaline developer.
As a dissolution inhibiting compound having a molecular weight of 3000 or less (hereinafter also referred to as “dissolution inhibiting compound”), which is decomposed by the action of an acid to increase the solubility in an alkaline developer, it does not lower the permeability of 220 nm or less, so Proceeding of SPIE 2724,355 (1996), an alicyclic or aliphatic compound containing an acid-decomposable group is preferred, such as a cholic acid derivative containing an acid-decomposable group. Examples of the acid-decomposable group and alicyclic structure are the same as those described for the component (B).
The molecular weight of the dissolution inhibiting compound in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.
The addition amount of the dissolution inhibiting compound is preferably 1 to 30% by mass and more preferably 2 to 20% by mass with respect to the solid content of the negative resist composition.

  Specific examples of the dissolution inhibiting compound are shown below, but the present invention is not limited thereto.

Carboxylic acid onium salt The negative resist composition in the present invention may contain a carboxylic acid onium salt.
Examples of the carboxylic acid onium salt include a carboxylic acid sulfonium salt, a carboxylic acid iodonium salt, and a carboxylic acid ammonium salt. In particular, as the carboxylic acid onium salt, an iodonium salt and a sulfonium salt are preferable. Furthermore, it is preferable that the carboxylate residue of the carboxylic acid onium salt of the present invention does not contain an aromatic group or a carbon-carbon double bond. As a particularly preferable anion moiety, a linear, branched, monocyclic or polycyclic alkylcarboxylic acid anion having 1 to 30 carbon atoms is preferable. More preferably, an anion of a carboxylic acid in which some or all of these alkyl groups are fluorine-substituted is preferable. The alkyl chain may contain an oxygen atom. This ensures transparency with respect to light of 220 nm or less, improves sensitivity and resolution, and improves density dependency and exposure margin.

  Fluoro-substituted carboxylic acid anions include fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, pentafluoropropionic acid, heptafluorobutyric acid, nonafluoropentanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorocyclohexanecarboxylic acid, 2 , 2-bistrifluoromethylpropionic acid anion and the like.

  These carboxylic acid onium salts can be synthesized by reacting sulfonium hydroxide, iodonium hydroxide, ammonium hydroxide and carboxylic acid with silver oxide in a suitable solvent.

  The content of the carboxylic acid onium salt in the composition is generally 0.1 to 20% by mass, preferably 0.5 to 10% by mass, more preferably 1 to 7% by mass, based on the total solid content of the composition. %.

Organic Solvent The negative resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent.
Examples of the organic solvent that can be used 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 -Dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, methoxybutanol, tetrahydrofuran, etc. It can be mentioned.

In this invention, you may use the mixed solvent which mixed the solvent which has a hydroxyl group in a structure, and the solvent which does not have a hydroxyl group as an organic solvent.
Examples of the solvent having a hydroxyl group include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethyl lactate, and the like. Propylene glycol monomethyl ether and ethyl lactate are preferred.
Examples of the solvent having no hydroxyl group include propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone, N, N-dimethylacetamide, dimethyl sulfoxide. Among these, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone, γ-butyrolactone, cyclohexanone, and butyl acetate are preferable, propylene glycol monomethyl ether acetate, ethyl ethoxypropionate 2-heptanone is more preferable.
The mixing ratio (mass ratio) of the solvent having a hydroxyl group and the solvent having no hydroxyl group is preferably 1/99 to 99/1, more preferably 10/90 to 90/10, and even more preferably 20/80 to 60/40. A mixed solvent containing 50% by mass or more of a solvent having no hydroxyl group is particularly preferable from the viewpoint of coating uniformity.

Other Additives The negative resist composition of the present invention may further contain a dye, a plasticizer, a photosensitizer, a compound that promotes solubility in a developer, and the like as necessary.
The dissolution accelerating compound for the developer that can be used in the present invention is a low molecular weight compound having a molecular weight of 1,000 or less and having two or more phenolic OH groups or one or more carboxy groups. When it has a carboxy group, an alicyclic or aliphatic compound is preferable.
The preferable addition amount of these dissolution promoting compounds is 2 to 50% by mass, and more preferably 5 to 30% by mass with respect to the component (B). The above range is preferable from the standpoint of development residue and pattern during development.
A phenol compound having a molecular weight of 1000 or less can be easily synthesized by those skilled in the art with reference to methods described in, for example, JP-A-4-1222938, JP-A-2-28531, U.S. Pat. No. 4,916,210 and European Patent 219294. it can.
Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

(how to use)
The negative resist composition of the present invention is preferably used at a film thickness of 30 to 250 nm, more preferably at a film thickness of 30 to 200 nm, from the viewpoint of improving resolution. Such a film thickness can be obtained by setting the solid content concentration in the negative resist composition to an appropriate range to give an appropriate viscosity and improving the coating property and film forming property.
The total solid concentration in the negative resist composition is generally 1 to 10% by mass, more preferably 1 to 8.0% by mass, and still more preferably 1.0 to 6.0% by mass.

The negative resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, filtering the solution, and then applying the solution on a predetermined support as follows.
The filter used for filter filtration is preferably made of polytetrafluoroethylene, polyethylene, or nylon of 0.1 microns or less, more preferably 0.05 microns or less, and still more preferably 0.03 microns or less.

For example, a negative resist composition is applied onto a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit element by an appropriate application method such as a spinner or a coater, and dried to form a resist film. Form.
The resist film is irradiated with actinic rays or radiation through a predetermined mask, preferably baked (heated), developed and rinsed. Thereby, a good pattern can be obtained.

Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., preferably 250 nm or less, more preferably 220 nm or less, particularly preferably 1 to 1. Far-ultraviolet light having a wavelength of 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc. ArF excimer laser, F ₂ Excimer laser, EUV (13 nm), and electron beam are preferable.

Before forming the resist film, an antireflection film may be coated on the substrate in advance.
As the antireflection film, any of an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and amorphous silicon, and an organic film type made of a light absorber and a polymer material can be used. 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.

Exposure (immersion exposure) may be performed by filling a liquid (immersion medium) having a higher refractive index than air between the resist film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved. As the immersion medium to be used, any liquid can be used as long as it has a higher refractive index than air, but pure water is preferred.

The immersion liquid used for the immersion exposure will be described below.
The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a refractive index temperature coefficient as small as possible so as to minimize distortion of the optical image projected onto the resist film. Is an ArF excimer laser (wavelength; 193 nm), it is preferable to use water from the viewpoints of availability and ease of handling in addition to the above-mentioned viewpoints.
Further, a medium having a refractive index of 1.5 or more can be used in that the refractive index can be further improved. This medium may be an aqueous solution or an organic solvent.

  When water is used as the immersion liquid, the surface tension of the water is decreased and the surface activity is increased, so that the resist film on the wafer is not dissolved and the influence on the optical coating on the lower surface of the lens element can be ignored. An additive (liquid) may be added in a small proportion. The additive is preferably an aliphatic alcohol having a refractive index substantially equal to that of water, and specifically includes methyl alcohol, ethyl alcohol, isopropyl alcohol and the like. By adding an alcohol having a refractive index substantially equal to that of water, even if the alcohol component in water evaporates and the content concentration changes, an advantage that the change in the refractive index of the entire liquid can be made extremely small can be obtained. On the other hand, when an opaque material or impurities whose refractive index is significantly different from that of water are mixed with 193 nm light, the optical image projected on the resist film is distorted. . Further, pure water filtered through an ion exchange filter or the like may be used.

The electrical resistance of water is desirably 18.3 MQcm or more, the TOC (organic substance concentration) is desirably 20 ppb or less, and deaeration treatment is desirably performed.
Moreover, it is possible to improve lithography performance by increasing the refractive index of the immersion liquid. From such a viewpoint, an additive for increasing the refractive index may be added to water, or heavy water (D ₂ O) may be used instead of water.

In order to prevent the resist film from directly contacting the immersion liquid between the resist film made of the negative resist composition of the present invention and the immersion liquid, the immersion liquid hardly soluble film (hereinafter also referred to as “top coat”). ) May be provided. The necessary functions for the top coat are suitability for application to the upper layer of the resist, radiation, especially transparency to 193 nm, and poor immersion liquid solubility. It is preferable that the top coat is not mixed with the resist and can be uniformly applied to the resist upper layer.
From the viewpoint of 193 nm transparency, the top coat is preferably a polymer that does not contain abundant aromatics. Specifically, the polymer contains a hydrocarbon polymer, an acrylate polymer, polymethacrylic acid, polyacrylic acid, polyvinyl ether, and silicon. Examples thereof include a polymer and a fluorine-containing polymer. The aforementioned hydrophobic resin (HR) is also suitable as a top coat. From the viewpoint of contaminating the optical lens when impurities are eluted from the top coat into the immersion liquid, it is preferable that the residual monomer component of the polymer contained in the top coat is small.

When peeling the top coat, a developer may be used, or a separate release agent may be used. As the release agent, a solvent having a small penetration into the resist film is preferable. It is preferable that the peeling process can be performed with an alkali developer in that the peeling process can be performed simultaneously with the resist film development process. From the viewpoint of peeling with an alkaline developer, the topcoat is preferably acidic, but may be neutral or alkaline from the viewpoint of non-intermixability with the resist film.
The resolution is improved when there is no difference in refractive index between the top coat and the immersion liquid. In the case of using water as an immersion liquid in an ArF excimer laser (wavelength: 193 nm), Ar
The top coat for F immersion exposure is preferably close to the refractive index of the immersion liquid. From the viewpoint of making the refractive index close to the immersion liquid, it is preferable to have fluorine atoms in the topcoat. A thin film is more preferable from the viewpoint of transparency and refractive index.

  The top coat is preferably not mixed with the resist film and further not mixed with the immersion liquid. From this viewpoint, when the immersion liquid is water, it is preferable that the solvent used for the top coat is a slightly water-insoluble medium that is hardly soluble in the solvent used for the negative resist composition. Furthermore, when the immersion liquid is an organic solvent, the topcoat may be water-soluble or water-insoluble.

The negative resist composition of the present invention may be applied to a multilayer resist process (particularly a three-layer resist process). The multilayer resist method includes the following processes.
(a) A lower resist layer made of an organic material is formed on a substrate to be processed.
(b) On the lower resist layer, an intermediate layer and an upper resist layer made of an organic material that crosslinks or decomposes upon irradiation are sequentially laminated.
(c) After forming a predetermined pattern in the upper resist layer, the intermediate layer, the lower layer and the substrate are sequentially etched.
As the intermediate layer, organopolysiloxane (silicone resin) or SiO ₂ coating solution (SOG) is generally used. As the lower layer resist, an appropriate organic polymer film is used, but various known photoresists may be used. For example, each series of the Fuji Film Arch FH series, FHi series, or Sumitomo Chemical PFI series can be illustrated.
The film thickness of the lower resist layer is preferably 0.1 to 4.0 μm, more preferably 0.2 to 2.0 μm, and particularly preferably 0.25 to 1.5 μm. A thickness of 0.1 μm or more is preferable from the viewpoint of antireflection and dry etching resistance, and a thickness of 4.0 μm or less is preferable from the viewpoint of aspect ratio and pattern collapse of the formed fine pattern.

In the development step, an alkaline developer is used as follows. Examples of the alkali developing solution for the negative resist composition include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia and other primary alkalis, and primary amines such as ethylamine and n-propylamine. Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide Alkaline aqueous solutions of cyclic amines such as quaternary ammonium salts such as pyrrole and pihelidine can be used.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline developer.
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.
Furthermore, alcohols and surfactants can be added in appropriate amounts to the alkaline aqueous solution.
As the rinsing liquid, pure water can be used, and an appropriate amount of a surfactant can be added.
Further, after the development process or the rinsing process, a process of removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid can be performed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to this.

Synthesis Example 1 (Synthesis of Resin (16))
Under a nitrogen stream, 6.83 g of cyclohexanone was placed in a three-necked flask and heated to 80 ° C. To this, 7.81 g of 2-hydroxyethyl methacrylate (manufactured by Wako Pure Chemical Industries), 6.93 g of 4,4-dimethyl-2-oxotetrahydrofuranyl methacrylate (manufactured by Aldrich)
3-hydroxyadamantyl methacrylate (manufactured by Idemitsu Kosan Co., Ltd.), 1.18 g, a polymerization initiator V-601 (manufactured by Wako Pure Chemical Industries, Ltd.), 5 mol% based on the total amount of monomers dissolved in 61.48 g of cyclohexanone was added dropwise over 6 hours. did. After completion of dropping, the reaction was further carried out at 80 ° C. for 2 hours. The reaction solution was allowed to cool and then added dropwise over 20 minutes to a mixture of 800 m of hexane / 200 ml of ethyl acetate. The precipitated powder was collected by filtration and dried, yielding 10.12 g of Resin (16). The composition ratio of the obtained resin was 60/34/6, the weight average molecular weight was 8000 in terms of standard polystyrene, and the dispersity (Mw / Mn) was 2.0.
Other resins were synthesized in the same manner. Hereinafter, the structures of the synthesized resins (1) to (23) are shown.

  Table 2 below shows the composition ratio (molar ratio, corresponding to each repeating unit in order from the left), weight average molecular weight, and degree of dispersion of resins (1) to (23).

Examples 1-31 and Comparative Examples 1-4
<Resist preparation>
The components shown in Table 3 below (for Examples 29-31, 0.1 g of hydrophobic resin (HR-22) was further added) were dissolved in a solvent, and a solution with a solid content concentration of 6% by mass was prepared for each. This was filtered through a 0.1 μm polyethylene filter to prepare a negative resist solution. The prepared negative resist composition was evaluated by the following method, and the results are shown in Table 3. In addition, about each component in Table 3, the ratio at the time of using multiple is a mass ratio.

<Image performance test>
Exposure condition (1)
For Examples 1 to 28 and Comparative Examples 1 to 4, an organic antireflection film ARC29A (Nissan Chemical Co., Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. did. A negative resist composition prepared thereon was applied, and baked at 130 ° C. for 60 seconds to form a 250 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser scanner (PAS5500 / 1100, NA0.75, σo / σi = 0.85 / 0.55, manufactured by ASML). Thereafter, heating was performed at 130 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.
Exposure condition (2)
This condition is to form a resist pattern by an immersion exposure method using pure water.
For Examples 29 to 31, an organic antireflection film ARC29A (manufactured by Nissan Chemical Industries, Ltd.) was applied on a silicon wafer and baked at 205 ° C. for 60 seconds to form a 78 nm antireflection film. A negative resist composition prepared thereon was applied, and baked at 130 ° C. for 60 seconds to form a 250 nm resist film. The obtained wafer was subjected to pattern exposure using an ArF excimer laser immersion scanner (NA 0.85). Ultra pure water was used as the immersion liquid. Thereafter, heating was performed at 130 ° C. for 60 seconds, followed by development with an aqueous tetramethylammonium hydroxide solution (2.38 mass%) for 30 seconds, rinsing with pure water, and spin drying to obtain a resist pattern.
Under the exposure conditions (1) and (2), the obtained resist pattern was evaluated for pattern shape and pattern collapse.
Pattern shape:
The exposure amount that reproduces a line-and-space 1/1 with a mask size of 130 nm was taken as the optimal exposure amount, and the profile at the optimal exposure amount was observed with a scanning electron microscope (SEM).
Pattern collapse:
The exposure amount that reproduces a 130 nm line and space 1: 1 mask pattern is the optimum exposure amount, and the dense pattern of line and space 1: 1 does not collapse at a finer mask size when exposed at the optimum exposure amount. The line width (CDmin) to be resolved into the limit pattern was defined as the limit pattern collapse line width (CDmin). The smaller the value, the finer pattern is resolved without falling, and the pattern collapse is less likely to occur.

  Hereinafter, abbreviations in the table are shown.

  [Episulfide compounds and comparative compounds]

  [Crosslinking agent]

[Basic compounds]
TPI: 2,4,5-triphenylimidazole TPSA: triphenylsulfonium acetate HEP: N-hydroxyethylpiperidine DIA: 2,6-diisopropylaniline DCMA: dicyclohexylmethylamine TPA: tripentylamine HAP: hydroxyantipyrine TBAH: tetrabutyl Ammonium hydroxide TMEA: Tris (methoxyethoxyethyl) amine PEA: N-phenyldiethanolamine TOA: Trioctylamine DBN: 1,5-diazabicyclo [4.3.0] non-5-ene PBI: 2-phenylbenzimidazole
DHA: N, N-dihexylaniline

[Surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.) (fluorine and silicon)
W-3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) (silicon-based)
W-4: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-5: PF656 (manufactured by OMNOVA, fluorine-based)
W-6: PF6320 (manufactured by OMNOVA, fluorine-based)

〔solvent〕
A1: Propylene glycol monomethyl ether acetate A2: 2-heptanone A3: Cyclohexanone A4: γ-Butyrolactone B1: Propylene glycol monomethyl ether B2: Ethyl lactate B3: Propylene carbonate

  From Table 3, it can be seen that the negative resist composition of the present invention is excellent in pattern shape and pattern collapse not only in normal exposure but also in immersion exposure.

Claims (8)

(A) a compound having at least one episulfide structure represented by the following general formula (1) (a three-membered ring structure comprising two C atoms and one S atom), (B) an alkali-soluble resin, and ( C) A negative resist composition comprising a compound that generates an acid upon irradiation with actinic rays or radiation.

The negative resist composition according to claim 1, wherein the compound of component (A) is a compound represented by the following general formula (2).

In general formula (2),
R ^{1a to} R ^1c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group.
L represents a single bond or a divalent organic group.
Q represents an O atom, an S atom, or an n-valent organic group.
R ^1a , R ^1b or R ^1c and L may be bonded to each other to form a ring.
n represents an integer of 1 or more. However, when Q is an O atom or an S atom, n = 2.
When n is an integer of 2 or more, a plurality of R ^{1a to} R ^1c and L may be the same or different.   The negative resist composition according to claim 2, wherein, in the general formula (2), Q has an S atom and / or L has an S atom.   The negative resist composition according to claim 2 or 3, wherein in the general formula (2), n is 2 or more.   The repeating unit having a group in which the resin of component (B) is soluble in an alkaline developer and reacts with a compound having at least one episulfide structure represented by the general formula (1) by the action of an acid The negative resist composition according to claim 1, comprising:   The negative resist composition according to claim 1, wherein the resin as the component (B) has a repeating unit having a carboxyl group and / or a hydroxyl group.   The negative resist composition according to claim 1, further comprising (D) a crosslinking agent.   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.