JP2008107817A - Resist composition and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition which has high sensitivity, high resolution and reduction line edge roughness in the fine process of a semiconductor element using a high energy line, X-ray, electron beam or EUV light, suppresses outgassing, and achieves good sensitivity and dissolution contrast even in EUV exposure. <P>SOLUTION: The resist composition includes: a low molecular weight polymer having a group capable of generating an alkali-soluble group under an action of an acid; and a compound having a cationic moiety of a specific structure and capable of generating an acid under an action of actinic rays or radiation, wherein the compound may be a compound having a specific sulfonium cation and capable of generating an acid under an action of actinic rays or radiation. A pattern forming method using the resist composition is also provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a resist composition that is suitably used in an ultramicrolithography process such as the manufacture of VLSI and high-capacity microchips and other photofabrication processes. More specifically, the present invention relates to a photoresist that can form a highly refined pattern using electron beams, X-rays, EUV light, etc., and is suitably used for ultrafine processing of semiconductor elements using electron beams, X-rays, EUV light. And a pattern forming method using the same.

  Conventionally, in the manufacturing process of semiconductor devices such as IC and LSI, fine processing by lithography using a photoresist composition has been performed. In recent years, with the high integration of integrated circuits, the formation of ultrafine patterns in the sub-micron region and quarter-micron region has been required. Along with this, there is a tendency to shorten the exposure wavelength from g-line to i-line and further to KrF excimer laser light.

In addition to the excimer laser light, the development of lithography using electron beams, X-rays, or EUV light is also progressing. Among these, lithography using EUV as a light source is positioned as a powerful pattern forming technology of the next generation or the next generation, and intensive research is being conducted. The required performance of the resist used includes high sensitivity, high resolution, and good line edge roughness. However, since the above performance is in a trade-off relationship, it is important how to satisfy these simultaneously. Here, the line edge roughness means that when the pattern is viewed from directly above because the resist pattern and the edge of the substrate interface vary irregularly in the direction perpendicular to the line direction due to the characteristics of the resist. Say that the edge looks uneven. The unevenness is transferred by an etching process using a resist as a mask, and the electrical characteristics are deteriorated, so that the yield is lowered. In particular, line edge roughness is an extremely important improvement problem in an ultrafine region of 0.25 μm or less. Such a problem is equally important in lithography using X-rays or electron beams.

In addition to the above requirements, when a light source such as an electron beam, X-ray, or EUV is used, a resist decomposed by a low-boiling compound such as a solvent or high energy in order to perform exposure under vacuum. The problem of outgassing, in which the material volatilizes and contaminates the exposure apparatus, has also become important. In recent years, various studies have been conducted on the reduction of outgas, and a top trap layer is provided to suppress volatilization of low molecular weight compounds (see, for example, Patent Document 1) or radical traps to suppress polymer decomposition. Various attempts have been made, such as adding an agent (see, for example, Patent Document 2), but it is also desired to devise an outgas reduction method for the acid generator.

  Until now, as a resist suitable for a lithography process using electron beam, X-ray, or EUV light, a chemically amplified resist mainly utilizing an acid catalyst reaction has been used from the viewpoint of high sensitivity. In resists, a chemically amplified resist composition comprising a phenolic polymer that is insoluble or hardly soluble in an alkaline aqueous solution and soluble in an alkaline aqueous solution by the action of an acid and an acid generator as a main component has been studied. I came. However, the conventional photoresist having a polymer compound as a base material has a problem that the molecular shape is reflected in the pattern shape and the line edge roughness.

On the other hand, in recent years, low molecular materials have attracted attention from the viewpoint of pattern miniaturization and low line edge roughness, and in particular, molecular resists using a single molecule as a binder have been proposed. For example, a phenolic compound derivative having a specific structure (for example, see Patent Documents 1 and 2), a calixarene having a specific structure (for example, refer to Patent Documents 2 and 3), a calix resorcinarene (for example, Patent Documents 3 and 3) 4), and a resist composition using a phenolic dendrimer (see, for example, Patent Document 5) having calixresorcinarene as a mother nucleus.
In Patent Document 6, a specific sulfonium salt is studied for a polystyrene resin-containing resist having a general molecular weight in order to improve the pattern shape and edge roughness as well as sensitivity and resolution.

However, it has been pointed out that the use of such a molecular material makes the pattern collapse prominent in the ultrafine region, and no effective solution has yet been found.
Further, in the present situation, there has been no sufficient study on the suppression of outgas, which is regarded as a particularly important required performance in lithography using an electron beam or EUV.

JP 2003-183227 A JP-A-10-120610 JP-A-11-322656 JP 2003-321423 A JP-A-10-310545 JP 2003-149800 A

  The objective of this invention is solving the subject of the performance improvement technique in the microfabrication of the semiconductor element which uses actinic rays or radiations, such as a high energy ray, an X-ray, an electron beam, or EUV light. In particular, as a low-molecular compound that is expected to have high resolution in the ultrafine region, a polymer with a certain weight average molecular weight reduced is used to eliminate the problem of pattern collapse generally seen in molecular resists. Resist composition that satisfies high sensitivity, line edge roughness (LER) and outgas suppression while maintaining resolution and pattern collapse reduction, and has good sensitivity and dissolution contrast even with EUV exposure, and pattern formation using the same To provide a method.

The present invention is as follows.
As a result of intensive studies, the present inventors have a low molecular weight polymer containing a group that generates an alkali-soluble group by the action of an acid and a cationic site having a specific structure, and generate an acid by the action of actinic rays or radiation. This was achieved by a resist composition comprising a compound and a compound that generates a compound having a specific structure by the action of actinic rays or radiation.

That is, the present invention is achieved by the following configuration.
(1) (B) a polymer having a group decomposable by the action of an acid and having a weight average molecular weight of 1,000 to 5,000 whose solubility in an alkaline developer is increased by the action of an acid
(Z) A resist composition comprising a compound having a sulfonium cation having a structure represented by the general formula (Z-I).

In general formula (Z-I),
Y ^{1 to} Y ¹³ each independently represent a hydrogen atom or a substituent, and adjacent ones may be bonded to each other to form a ring.
Z represents a single bond or a divalent linking group.

(2) (A) The resist composition according to (1), which contains a compound that generates a compound having a structure represented by the following general formula (AI) upon irradiation with actinic rays or radiation.
_{Q 1 -X 1 -NH-X 2} -Q 2 (A-I)
In general formula (AI), Q ₁ and Q ₂ each independently represents a monovalent organic group. However, either Q ₁ or Q ₂ contains a proton acceptor functional group. Q ₁ and Q ₂ may combine to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ and X ₂ each independently represent —CO— or —SO ₂ —.

(3) The compound having a structure represented by the general formula (AI) includes a compound having a structure represented by the following general formula (A-II): (1) or (2) The resist composition described in 1.
_{Q 1 -X 1 -NH-X 2} -A- (X 3) n -B-Q 3 (A-II)
In general formula (A-II), Q ₁ and Q ₃ each independently represents a monovalent organic group. However, _one of Q ₁ and Q ₃ contains a proton acceptor functional group. Q ₁ and Q ₃ may combine to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ , X ₂ and X ₃ each independently represent —CO— or —SO ₂ —.
A represents a divalent linking group.
B represents a single bond, an oxygen atom, or —N (Qx) —.
Qx represents a hydrogen atom or a monovalent organic group.
When B is —N (Qx) —, Q ₃ and Qx may combine to form a ring.
n represents 0 or 1.

(4) The resist composition as described in any one of (1) to (3) above, further containing a nitrogen-containing basic compound.
(5) The resist composition as described in any one of (1) to (4) above, wherein a surfactant is further added.
(6) A pattern forming method comprising a step of forming a photosensitive film from the resist composition according to any one of (1) to (5) above, and exposing and developing the photosensitive film.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a photosensitive composition with less pattern collapse on a low line edge roughness, and a pattern forming method using the same.

Hereinafter, the present invention will be described in detail.
In addition, in the description of a group (atomic group) in this specification, the description which does not describe substituted and unsubstituted includes what has a substituent with what does not have 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).

  The photosensitive composition of the present invention, more preferably a resist composition, has an alkali-soluble group and an acid-decomposable group, increases alkali solubility by the action of an acid, and has a weight average molecular weight of 1,000 to 5, 000 polymer (B), a compound (Z) having a sulfonium cation having a structure represented by the general formula (ZI), and represented by the following general formula (AI) by irradiation with actinic rays or radiation. The compound (A) which generate | occur | produces the compound which has this structure is contained.

[1] (B) a polymer having a group having a weight-average molecular weight of 1,000 to 5,000 having a group that can be decomposed by the action of an acid and whose solubility in an alkali developer increases by the action of an acid (hereinafter referred to as “(B) Ingredients ").
A resin (acid-decomposable resin) that is decomposed by an acid used in the photosensitive composition of the present invention and has increased solubility in an alkaline developer is a main chain or side chain of the resin, or a main chain and side chain. Both are resins having an acid-decomposable group (hereinafter also referred to as “acid-decomposable group”). Among these, a resin having a group capable of decomposing with an acid in the side chain is more preferable.
A group preferable as a group that can be decomposed by an acid is a group in which a hydrogen atom of a —COOH group or —OH group is substituted with a group capable of leaving with an acid.

In the present invention, the acid-decomposable group is an acetal group or a tertiary ester group.
In the resin used in the present invention, the molar ratio of the alkali-soluble group to the acid-decomposable group in the resin is usually 80/20 to 20/80, preferably 70/30 to 30/70, particularly preferably 60. / 40 to 40/60.
The base resin in the case where these acid-decomposable groups are bonded as side chains is an alkali-soluble resin having —OH or —COOH groups in the side chains. For example, the alkali-soluble resin mentioned later can be mentioned.

The alkali dissolution rate of these alkali-soluble resins is preferably 170 A / second or more as measured with 0.261 N tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferably, it is 330 A / second or more (A is angstrom).
From this point of view, particularly preferred alkali-soluble resins are o-, m-, p-poly (hydroxystyrene) and copolymers thereof, hydrogenated poly (hydroxystyrene), halogen or alkyl-substituted poly (hydroxystyrene). Hydroxystyrene structural units such as a part of poly (hydroxystyrene), O-alkylated or O-acylated product, styrene-hydroxystyrene copolymer, α-methylstyrene-hydroxystyrene copolymer, hydrogenated novolak resin, etc. It is an alkali-soluble resin.

  Preferred examples of the repeating unit having an acid-decomposable group in the present invention include t-butoxycarbonyloxystyrene, 1-alkoxyethoxystyrene, (meth) acrylic acid tertiary alkyl ester, and the like. Alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate are more preferred.

  In addition, the component (B) used in the present invention is an acid soluble in an alkali-soluble resin as disclosed in European Patent No. 254853, JP-A-2-25850, JP-A-3-223860, JP-A-4-251259, and the like. It can be obtained by reacting a precursor of a group capable of decomposing with an acid, or copolymerizing an alkali-soluble monomer having a group capable of decomposing with an acid with various monomers.

  When the resist composition of the present invention is irradiated with KrF excimer laser light, electron beam, X-ray, or high energy light (EUV, etc.) having a wavelength of 50 nm or less, the resin of component (B) is a repeating unit having an aromatic group In particular, the resin (B1) having a hydroxystyrene repeating unit is preferable. More preferably, hydroxystyrene / hydroxystyrene copolymer protected with an acid-decomposable group and hydroxystyrene / (meth) acrylic acid tertiary alkyl ester are preferred.

  As the resin (B1) containing a hydroxystyrene repeating unit, a resin having a repeating unit represented by the following general formula (II) and a repeating unit represented by the general formula (III) is particularly preferable.

R ₀₁ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group.
L ₁ and L ₂ may be the same or different and each represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aralkyl group.
M represents a single bond or a divalent linking group.
Q represents an alicyclic group or an aromatic ring group which may contain an alkyl group, a cycloalkyl group, or a hetero atom.
At least two of Q, M, and L ₁ may combine to form a 5-membered or 6-membered ring.
A represents a halogen atom, a cyano group, an acyl group, an alkyl group, an alkoxy group, an acyloxy group, or an alkoxycarbonyl group, and an acyl group, an acyloxy group, or an alkoxycarbonyl group that is a group having a carbonyl group is particularly preferable.
m and n independently represent an integer of 0 to 4. However, m and n are preferably not 0 at the same time.

  Moreover, as resin (B1) containing a hydroxystyrene repeating unit, the repeating unit represented by general formula (II), the repeating unit represented by general formula (III), and the repeating unit represented by general formula (IV) It may be a resin having

R ₀₁ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group.
B represents a halogen atom, a cyano group, an acyl group, an alkyl group, an alkoxy group, an acyloxy group or an alkoxycarbonyl group.
p represents an integer of 0 to 5.

  The substituent that the benzene ring in the repeating unit represented by the general formula (II) has is a group (acid-decomposable group) that is decomposed by the action of an acid to generate a hydroxyl group (an alkali-soluble group). Hydroxystyrene units are produced, and the resin is a resin with increased solubility in an alkaline developer.

R ₀₁ each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group, and preferably has 20 or less carbon atoms.
The alkyl group or cycloalkyl group in R ₀₁ preferably has 20 or less carbon atoms, and is a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, cyclopentyl group. Hexyl group, cyclohexyl group, octyl group, dodecyl group and the like. These groups may have a substituent, for example, an alkoxy group, a hydroxyl group, a halogen atom, a nitro group, an acyl group, an acyloxy group, an acylamino group, a sulfonylamino group, an alkylthio group, an arylthio group, an aralkylthio group, a thiophene. Examples include carbonyloxy groups, thiophenemethylcarbonyloxy groups, and heterocyclic residues such as pyrrolidone residues, and those having 8 or less carbon atoms are preferred. CF ₃ group, alkoxycarbonylmethyl group, alkylcarbonyloxymethyl group, hydroxymethyl group, alkoxymethyl group and the like are more preferable.
Examples of the halogen atom for R ₀₁ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferred.
As the alkyl group contained in the alkoxycarbonyl group in R _01, the same alkyl groups represented by R ₀₁ are preferred.

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

The divalent linking group as M contains, for example, an alkylene group, a cycloalkylene group, an alkenylene group, an arylene group, —OCO—, —COO—, or —CON (R ₀ ) —, and a plurality thereof. A linking group. R ₀ is a hydrogen atom or an alkyl group.

The alkyl group and cycloalkyl group as Q are the same as the above groups as L ₁ and L ₂ .
As the alicyclic group or aromatic ring group which may contain a hetero atom as Q,
Examples of the cycloalkyl group and aryl group as L ₁ and L ₂ described above include 3 to 15 carbon atoms.
Examples of the alicyclic group or aromatic ring group containing a hetero atom include thiirane, cyclothiolane, thiophene, furan, pyrrole, benzothiophene, benzofuran, benzopyrrole, triazine, imidazole, benzimidazole, triazole, thiadiazole, thiazole, pyrrolidone, and the like. Is a structure generally called a heterocycle (a ring formed from carbon and a heteroatom, or a ring formed from a heteroatom).

As a 5-membered or 6-membered ring that may be formed by combining at least two of Q, M, and L ₁ , at least two of Q, M, and L ₁ are combined to form, for example, a propylene group and a butylene group In this case, a 5-membered or 6-membered ring containing an oxygen atom is formed.

As the group represented by -M-Q, 1 to 30 carbon atoms, more preferably from 5 to 20 carbon atoms, for _{example, -OC (L 1) (L} 2) a group represented by O-M-Q The following may be mentioned.

The acyl group as A is, for example, an acyl group having 2 to 8 carbon atoms. Specifically, a formyl group, an acetyl group, a propanoyl group, a butanoyl group, a pivaloyl group, a benzoyl group and the like can be preferably exemplified. .
The alkyl group as A is, for example, an alkyl group having 1 to 8 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a hexyl group, and an octyl group. Can be preferably mentioned.
The alkoxy group as A is, for example, the above alkoxy group having 1 to 8 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, and a cyclohexyloxy group. .
Examples of the acyloxy group or alkoxycarbonyl group as A include groups corresponding to the above acyl group and alkoxy group.

  Each of the above groups may have a substituent, and preferred substituents include a hydroxyl group, a carboxyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), an alkoxy group (methoxy group, ethoxy group, Propoxy group, butoxy group, etc.). As for the cyclic structure, examples of the substituent further include an alkyl group (preferably having 1 to 8 carbon atoms).

  m and n independently represent an integer of 0 to 4. m and n are each preferably 0 to 2, and more preferably 1.

  Specific examples of the repeating unit represented by the general formula (II) are shown below, but are not limited thereto.

  Specific examples of the repeating unit represented by the general formula (III) are shown below, but are not limited thereto.

R ₀₁ in the general formula (IV) independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, a halogen atom, a cyano group, or an alkoxycarbonyl group, preferably having 20 or less carbon atoms, The same as R ₀₁ in (II) or (III).
The acyl group, alkyl group, alkoxy group, acyloxy group or alkoxycarbonyl group as B in the general formula (IV) is the same as each group as A in the general formula (II).
p represents an integer of 1 to 5, preferably 0 to 2, and more preferably 1.

  Specific examples of the repeating unit represented by the general formula (IV) are shown below, but are not limited thereto.

  The resin (B) may contain a repeating unit represented by the general formula (V).

Ra to Rc each independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a cyano group or an alkyl group.
X ₁ represents a hydrogen atom or an organic group.

  The alkyl group as Ra to Rc is preferably an alkyl group having 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, and a propyl group.

The organic group as X ₁ preferably has 1 to 40 carbon atoms and may be an acid-decomposable group or a non-acid-decomposable group.

Examples of the non-acid-decomposable group include the same organic groups as those in the non-acid-decomposable group as R ₂ . (Because it is an organic group, it does not contain a halogen atom.) In addition, for example, an alkyl group, a cycloalkyl group, an alkenyl group, an aryl group, an alkyloxy group (excluding -O-tertiary alkyl), an acyl group, a cycloalkyloxy Group, alkenyloxy group, aryloxy group, alkylcarbonyloxy group, alkylamidomethyloxy group, alkylamido group, arylamidomethyl group, arylamido group and the like.
The non-acid-decomposable group is preferably an acyl group, an alkylcarbonyloxy group, an alkyloxy group, a cycloalkyloxy group, an aryloxy group, an alkylamidooxy group, or an alkylamido group, more preferably an acyl group or an alkylcarbonyl group. An oxy group, an alkyloxy group, a cycloalkyloxy group, and an aryloxy group;
In the non-acid-decomposable group, the alkyl group is preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, or a t-butyl group. As the alkyl group, those having 3 to 10 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclohexyl group and adamantyl group are preferable, and as the alkenyl group, carbon number such as vinyl group, propenyl group, allyl group and butenyl group. Those having 2 to 4 carbon atoms are preferable, those having 2 to 4 carbon atoms such as vinyl group, propenyl group, allyl group and butenyl group are preferable as alkenyl groups, and phenyl group, xylyl group and toluyl group are preferable as aryl groups. And those having 6 to 14 carbon atoms such as cumenyl group, naphthyl group and anthracenyl group are preferable. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a hydroxyethoxy group, a propoxy group, a hydroxypropoxy group, an n-butoxy group, an isobutoxy group, or a sec-butoxy group.

As the organic group of the acid-decomposable group for X ₁ , for example, —C (R _11a ) (R _12a ) (R _13a ), —C (R _14a ) (R _15a ) (OR _16a ), —CO—OC ( R _11a ) (R _12a ) (R _13a ) can be mentioned.
R _{11a to} R _13a each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group. R _14a and R _15a each independently represents a hydrogen atom or an alkyl group. R _16a is an alkyl group, a cycloalkyl group, an alkenyl group,
Represents an aralkyl group or an aryl group. Two of R _11a , R _12a and R _13a , or two of R _14a , R _15a and R _16a may be bonded to form a ring.
Note that a group having an acid-decomposable group can be introduced into X ₁ by modification. In this way, X ₁ introduced with the acid decomposable group is, for example, as follows.
-[C ( _R17a ) ( _R18a )] _p- CO-OC ( _R11a ) ( _R12a ) ( _R13a ) _R17a and _R18a each independently represents a hydrogen atom or an alkyl group. p is an integer of 1 to 4.

The organic group as X ₁ is preferably an acid-decomposable group having at least one cyclic structure selected from alicyclic, aromatic and bridged alicyclic, and an aromatic group (particularly a phenyl group). Or a structure containing an alicyclic or bridged alicyclic structure represented by the following general formulas (pI) to (pVI).

In the formula, R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z forms an alicyclic hydrocarbon group together with a carbon atom. Represents the atomic group necessary to do.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{12 to} R ₁₄ , or Either R ₁₅ or R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{17 to} R ₂₁ Represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or alicyclic hydrocarbon group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R _{22 to} R ₂₅ Represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In the general formulas (pI) to (pVI), the alkyl group in R _{12 to} R ₂₅ may be substituted or unsubstituted, and is a linear or branched alkyl group having 1 to 4 carbon atoms. Represents. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group.
Further, the further substituent of the alkyl group includes an alkoxy group having 1 to 4 carbon atoms, a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl group, acyloxy group, cyano group, hydroxyl group, A carboxy group, an alkoxycarbonyl group, a nitro group, etc. can be mentioned.

The alicyclic hydrocarbon group in R _{11 to} R _{25 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These alicyclic hydrocarbon groups may have a substituent.
Below, the structural example of an alicyclic part is shown among alicyclic hydrocarbon groups.

  In the present invention, preferred examples of the alicyclic moiety include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclohexyl group, cycloheptyl. Group, cyclooctyl group, cyclodecanyl group and cyclododecanyl group. More preferred are an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.

Examples of the substituent that the alicyclic hydrocarbon group may have include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group.
The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, more preferably a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. Can be mentioned. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
The alkyl group, alkoxy group, and alkoxycarbonyl group may further have a substituent. Examples of such a substituent include an alkoxy group having 1 to 4 carbon atoms (methoxy group, ethoxy group, butoxy group). Group), hydroxy group, oxo group, alkylcarbonyl group (preferably 2 to 5 carbon atoms), alkylcarbonyloxy group group (preferably 2 to 5 carbon atoms), alkoxycarbonyl group (preferably 2 to 5 carbon atoms) And halogen atoms (chlorine atom, bromine atom, fluorine atom, etc.).

In addition, the resin (B) contains an alkali-soluble group such as a phenolic hydroxyl group, a carboxyl group, a sulfonic acid group, a hexafluoroisopropanol group (—C (CF ₃ ) ₂ ) in order to maintain good developability for an alkali developer. Other suitable polymerizable monomers may be copolymerized so that (OH) can be introduced, and other hydrophobic polymerizable monomers such as alkyl acrylates and alkyl methacrylates may be copolymerized to improve film quality. May be.

The content of the repeating unit represented by the general formula (II) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, and particularly preferably 10 to 40 mol% in all repeating units constituting the resin. It is.
The content of the repeating unit represented by the general formula (III) is preferably 40 to 90 mol%, more preferably 45 to 80 mol%, particularly preferably 50 to 75 mol% in all repeating units constituting the resin. It is.

The content of the repeating unit represented by the general formula (IV) is preferably 5 to 50 mol%, more preferably 10 to 40 mol%, particularly preferably 15 to 30 mol% in all repeating units constituting the resin. It is.
The content of the repeating unit represented by the general formula (V) is preferably 0 to 30 mol%, more preferably 0 to 20 mol%, and particularly preferably 0 to 10 mol% in all repeating units constituting the resin. It is.

The content of the repeating unit having an alkali-soluble group such as a hydroxyl group, a carboxy group, or a sulfonic acid group is preferably 1 to 99 mol%, more preferably 3 to 95 mol%, particularly preferably in all repeating units constituting the resin. 5 to 90 mol%.
The content of the repeating unit having an acid-decomposable group is preferably 3 to 95 mol%, more preferably 5 to 90 mol%, and particularly preferably 10 to 85 mol% in all repeating units constituting the resin.

The weight average molecular weight of the resin (B1) is 1,000 to 5,000, preferably 1,500 to 4,000, more preferably 2,000 to 3,000, in terms of polystyrene by GPC method. is there. When the weight average molecular weight is 1000 or more, the collapse performance is improved, and when it is 5000 or less, the sensitivity, resolution, and LER are improved.
The dispersity (Mw / Mn) of the resin (B1) is preferably 1.0 to 3.0, more preferably 1.05 to 2.0, and even more preferably 1.1 to 1.7. .
Moreover, you may use resin (B1) in combination of 2 or more types.

  Specific examples of the resin (B1) are shown below, but are not limited thereto.

In the above specific example, tBu represents a t-butyl group.
The content of the group that can be decomposed by an acid is determined by the number of groups (B) that can be decomposed by an acid in the resin and the number of alkali-soluble groups that are not protected by a group capable of leaving by an acid (S). B + S). The content is preferably 0.01 to 0.7, more preferably 0.05 to 0.50, and still more preferably 0.05 to 0.40.

In addition, the resin as the component (B) may be a resin having a monocyclic or polycyclic alicyclic hydrocarbon structure, which is decomposed by the action of an acid and has increased solubility in an alkali developer.
As a resin that has a monocyclic or polycyclic alicyclic hydrocarbon structure, decomposes by the action of an acid, and increases its solubility in an alkaline developer (hereinafter also referred to as “alicyclic hydrocarbon-based acid-decomposable resin”) , At least selected from the group consisting of repeating units having a partial structure containing an alicyclic hydrocarbon represented by the following general formula (pI) to general formula (pVI) and repeating units represented by the following general formula (II-AB) It is preferable that it is resin containing 1 type.

In general formulas (pI) to (pVI),
R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z is an atom necessary for forming a cycloalkyl group together with a carbon atom. Represents a group.
R _{12 to} R ₁₆ each independently represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms, provided that at least one of R _{12 to} R ₁₄ , or R ₁₅ , Any of R ₁₆ represents a cycloalkyl group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group, provided that at least one of R _{17 to} R ₂₁ is cyclo Represents an alkyl group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or cycloalkyl group having 1 to 4 carbon atoms.
R _{22 to} R ₂₅ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a cycloalkyl group, provided that at least one of R _{22 to} R ₂₅ is cyclo Represents an alkyl group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

In the formula (II-AB),
R ₁₁ ′ and R ₁₂ ′ each independently represents a hydrogen atom, a cyano group, a halogen atom or an alkyl group.
Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

The general formula (II-AB) is more preferably the following general formula (II-A) or general formula (II-B).

In the formulas (II-A) and (II-B),
R ₁₃ ′ to R ₁₆ ′ each independently represents a hydrogen atom, a halogen atom, a cyano group, —COOH, —COOR ₅ , a group that decomposes by the action of an acid, —C (═O) —XA′—R. ₁₇ ′ represents an alkyl group or a cycloalkyl group.
Wherein, R ₅ represents an alkyl group, a cycloalkyl group, or -Y group shown below.
X represents an oxygen atom, a sulfur atom, -NH -, - NHSO ₂ - or an -NHSO ₂ NH-.
A ′ represents a single bond or a divalent linking group.
Further, at least two of R ₁₃ ′ to R ₁₆ ′ may be bonded to form a ring. n represents 0 or 1.
R ₁₇ ′ represents —COOH, —COOR ₅ , —CN, a hydroxyl group, an alkoxy group, —CO—NH—R ₆ , —CO—NH—SO ₂ —R ₆ or the following —Y group.
R ₆ represents an alkyl group or a cycloalkyl group.

  The -Y group;

In the —Y group, R ₂₁ ′ to R ₃₀ ′ each independently represents a hydrogen atom or an alkyl group. a and b represent 1 or 2;

In the general formulas (pI) to (pVI), the alkyl group in R _{12 to} R ₂₅ represents a linear or branched alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group.
In addition, examples of the substituent that each alkyl group and alkoxy group may have include an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), an acyl group, and an acyloxy group. Group, cyano group, hydroxyl group, carboxy group, alkoxycarbonyl group, nitro group and the like.

The cycloalkyl group in R _{11 to} R ₂₅ or the cycloalkyl group formed by Z and the carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The carbon number is preferably 6-30, and particularly preferably 7-25. These cycloalkyl groups may have a substituent.

  Preferred cycloalkyl groups include adamantyl group, noradamantyl group, decalin residue, tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecanyl group, A cyclododecanyl group can be mentioned. More preferable examples include an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.

Examples of the substituent for these cycloalkyl groups include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. As said alkoxy group, a C1-C4 methoxy group, an ethoxy group, a propoxy group, a butoxy group etc. can be mentioned. Examples of the substituent that the alkyl group, alkoxy group, alkoxycarbonyl group and the like may further have include a hydroxyl group, a halogen atom, and an alkoxy group.

  The structures represented by the general formulas (pI) to (pVI) in the resin can be used for protecting alkali-soluble groups. Examples of the alkali-soluble group include various groups known in this technical field.

  Specific examples include a carboxylic acid group, a sulfonic acid group, a phenol group, and a thiol group, and a carboxylic acid group and a sulfonic acid group are preferable.

  As the alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI) in the above resin, the hydrogen atom of the carboxyl group is preferably substituted with the structure represented by the general formula (pI) to (PVI). Structure.

  As the repeating unit having an alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI), a repeating unit represented by the following general formula (pA) is preferable.

Here, R represents a hydrogen atom, a halogen atom, or a linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R may be the same or different.
A represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, or a urea group, or a combination of two or more groups. Represents.
Ra represents any group of the above formulas (pI) to (pVI).

  The repeating unit represented by the general formula (pA) is most preferably a repeating unit of 2-alkyl-2-adamantyl (meth) acrylate and dialkyl (1-adamantyl) methyl (meth) acrylate.

  Specific examples of the repeating unit represented by the general formula (pA) are shown below.

In the general formula (II-AB), R ₁₁ ′ and R ₁₂ ′ each independently represent a hydrogen atom, a cyano group, a halogen atom, or an alkyl group.
Z ′ represents an atomic group for forming an alicyclic structure containing two bonded carbon atoms (C—C).

Examples of the halogen atom in R ₁₁ ′ and R ₁₂ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

The alkyl group in R ₁₁ ′, R ₁₂ ′, and R ₂₁ ′ to R ₃₀ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms. It is a linear or branched alkyl group, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a t-butyl group.

  Examples of the further substituent in the above alkyl group include a hydroxyl group, a halogen atom, a carboxy group, an alkoxy group, an acyl group, a cyano group, and an acyloxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group having 1 to 4 carbon atoms. Examples of the acyl group include a formyl group and an acetyl group, and examples of the acyloxy group include an acetoxy group.

The atomic group for forming the alicyclic structure of Z ′ is an atomic group that forms a repeating unit of an alicyclic hydrocarbon which may have a substituent in a resin, and among them, a bridged type alicyclic group. An atomic group for forming a bridged alicyclic structure forming a cyclic hydrocarbon repeating unit is preferred.

Examples of the skeleton of the alicyclic hydrocarbon formed include the same alicyclic hydrocarbon groups as R _{11 to} R _{25 in} the general formulas (pI) to (pVI).

The alicyclic hydrocarbon skeleton may have a substituent. Examples of such a substituent include R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or (II-B).

  Among the repeating units having the bridged alicyclic hydrocarbon, the repeating unit represented by the general formula (II-A) or (II-B) is more preferable.

In the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention, the acid-decomposable group may be contained in the aforementioned —C (═O) —XA′—R ₁₇ ′, or may be represented by the general formula (II- AB) may be included as a substituent for Z ′.

The structure of the acid-decomposable group is represented by —C (═O) —X ₁ —R ₀ .
In the formula, R ₀ is a tertiary alkyl group such as t-butyl group or t-amyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxy. 1-alkoxyethyl group such as ethyl group, 1-methoxymethyl group, alkoxymethyl group such as 1-ethoxymethyl group, 3-oxoalkyl group, tetrahydropyranyl group, tetrahydrofuranyl group, trialkylsilyl ester group, 3- An oxocyclohexyl ester group, a 2-methyl-2-adamantyl group, a mevalonic lactone residue and the like can be mentioned. X ₁ has the same meaning as X above.

Examples of the halogen atom in R ₁₃ ′ to R ₁₆ ′ include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

The alkyl group in R ₅ , R ₆ and R ₁₃ ′ to R ₁₆ ′ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a linear chain having 1 to 6 carbon atoms. Or a branched alkyl group, more preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a t-butyl group.

Examples of the cycloalkyl group in R ₅ , R ₆ , and R ₁₃ ′ to R ₁₆ ′ are monocyclic cyclic alkyl groups and bridged hydrocarbons, such as cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, 2-methyl-2-adamantyl group, norbornyl group, boronyl group, isobornyl group, tricyclodecanyl group, dicyclopentenyl group, nobornane epoxy group, menthyl group, isomenthyl group, neomenthyl group, tetracyclododecanyl group, etc. Can be mentioned.

Examples of the ring formed by combining at least two of R ₁₃ ′ to R ₁₆ ′ include rings having 5 to 12 carbon atoms such as cyclopentene, cyclohexene, cycloheptane, and cyclooctane.

Examples of the alkoxy group for R ₁₇ ′ include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group having 1 to 4 carbon atoms.

  Examples of further substituents in the alkyl group, cycloalkyl group, and alkoxy group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group, an acyloxy group, an alkyl group, and a cycloalkyl group. . Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. Examples of the acyl group include a formyl group and an acetyl group. Examples thereof include an acetoxy group.

  Examples of the alkyl group and cyclic hydrocarbon group include those listed above.

The divalent linking group of A ′ is one or two selected from the group consisting of an alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, and a urea group. Combinations of the above groups can be mentioned.

In the alicyclic hydrocarbon-based acid-decomposable resin according to the present invention, the group decomposed by the action of an acid has a partial structure containing the alicyclic hydrocarbon represented by the general formula (pI) to the general formula (pVI). It can be contained in at least one type of repeating unit among the repeating unit having, the repeating unit represented by the general formula (II-AB), and the repeating unit of the copolymerization component described later.

Various substituents of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or the general formula (II-B) are atomic groups for forming an alicyclic structure in the general formula (II-AB). It can also be a substituent of the atomic group Z for forming a bridged alicyclic structure.

  Although the following specific examples are mentioned as a repeating unit represented by the said general formula (II-A) or general formula (II-B), This invention is not limited to these specific examples.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a lactone group and is represented by any one of the following general formula (Lc) or the following general formulas (V-1) to (V-5). It is more preferable to have a repeating unit having a group having a lactone structure. Further, a group having a lactone structure may be directly bonded to the main chain.

In general formula (Lc), Ra ₁ , Rb ₁ , Rc ₁ , Rd ₁ and Re ₁ each independently represent a hydrogen atom or an alkyl group. m and n each independently represents an integer of 0 to 3, and m + n is 2 or more and 6 or less.

In the general formulas (V-1) to (V-5), R _{1b to} R _5b each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylsulfonylimino group, or an alkenyl group. Represents. Two of R _{1b to} R _5b may combine to form a ring.

R _{1 to} Re ₁ alkyl groups in general formula (Lc) and R _{1b to} R _5b alkyl groups, alkoxy groups, alkoxycarbonyl groups, alkyls in general formulas (V-1) to (V-5) Examples of the alkyl group in the sulfonylimino group include linear and branched alkyl groups, which may have a substituent. Preferable substituents that may be included include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group, an acyloxy group, and a cycloalkyl group.

As the repeating unit having a group having a lactone structure represented by general formula (Lc) or any one of general formulas (V-1) to (V-5), the above general formula (II-A) or (II- B) wherein at least one of R ₁₃ ′ to R ₁₆ ′ has a group represented by general formula (Lc) or general formula (V-1) to (V-5) (for example, R in —COOR ₅ ) ₅ represents a group represented by general formula (Lc) or general formulas (V-1) to (V-5)), or 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. As a preferable substituent which the alkyl group of R _b0 may have, as a preferable substituent which the alkyl group as R _1b in the general formulas (V-1) to (V-5) may have. What was illustrated previously is mentioned.

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.

  A ′ represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these.

B ₂ represents a group represented by any one of general formula (Lc) and general formulas (V-1) to (V-5).

  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 alicyclic hydrocarbon-based acid-decomposable resin of the present invention may contain a repeating unit having a group represented by the following general formula (VII) having an adamantane skeleton.

In general formula (VII), R _{2c to} R _4c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R _{2c to} R _4c represents a hydroxyl group.

  The group represented by the general formula (VII) is preferably a dihydroxy body or a monohydroxy body, and more preferably a dihydroxy body.

As the repeating unit having a group represented by the general formula (VII), at least one of R ₁₃ ′ to R ₁₆ ′ in the general formula (II-A) or (II-B) is the above general formula (VII ) (For example, R _{5 in} —COOR ₅ represents a group represented by the general formula (VII)), or a repeating unit represented by the following general formula (AII). it can.

In general formula (AII), R _1c represents a hydrogen atom or a methyl group.
R _{2c to} R _4c each independently represents a hydrogen atom or a hydroxyl group. However, at least one of R _{2c to} R _4c represents a hydroxyl group. Those in which two of R _{2c to} R _4c are hydroxyl groups are preferred.

  Specific examples of the repeating unit having the structure represented by the general formula (AII) are given below, but the present invention is not limited thereto.

The alicyclic hydrocarbon-based acid-decomposable resin of the present invention may contain a repeating unit represented by the following general formula (VIII).

In the general formula (VIII), Z ₂ represents —O— or —N (R ₄₁ ) —. R ₄₁ represents a hydrogen atom, a hydroxyl group, an alkyl group, or —OSO ₂ —R ₄₂ . R ₄₂ represents an alkyl group, a cycloalkyl group or a camphor residue. The alkyl group of R ₄₁ and R ₄₂ may be substituted with a halogen atom (preferably a fluorine atom) or the like.

Examples of the repeating unit represented by the general formula (VIII) include the following specific examples.
The present invention is not limited to these.

  The alicyclic hydrocarbon-based acid-decomposable resin of the present invention preferably has a repeating unit having an alkali-soluble group, and more preferably has a repeating unit having a carboxyl group. By containing this, the resolution in contact hole applications increases. The repeating unit having a carboxyl group includes a repeating unit in which a carboxyl group is directly bonded to the main chain of the resin, such as a repeating unit of acrylic acid or methacrylic acid, or a carboxyl group in the main chain of the resin through a linking group. Any of the bonded repeating units is preferable, and the linking group may have a monocyclic or polycyclic hydrocarbon structure. Most preferred are acrylic acid and methacrylic acid.

  In addition to the above repeating structural units, the alicyclic hydrocarbon-based acid-decomposable resin of the present invention has a dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolving power that is a general necessary characteristic of a resist. Various repeating structural units can be contained for the purpose of adjusting heat resistance, sensitivity, and the like.

  Examples of such repeating structural units include, but are not limited to, repeating structural units corresponding to the following monomers.

  As a result, performance required for the alicyclic hydrocarbon-based acid-decomposable resin, in particular, (1) solubility in coating solvent, (2) film-forming property (glass transition point), (3) alkali developability, (4 Fine adjustments such as () film slippage (selection of hydrophilicity / hydrophobicity, alkali-soluble group), (5) adhesion of unexposed part to substrate, (6) dry etching resistance, etc. are possible.

  As such a monomer, for example, a compound having one addition polymerizable unsaturated bond selected from acrylic acid esters, methacrylic acid esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, etc. Etc.

  In addition, any addition-polymerizable unsaturated compound that can be copolymerized with monomers corresponding to the above various repeating structural units may be copolymerized.

  In alicyclic hydrocarbon-based acid-decomposable resins, the molar ratio of each repeating structural unit is the resist's dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution that is a general required performance of resists. In order to adjust heat resistance, sensitivity, etc., it is set appropriately.

Preferred embodiments of the alicyclic hydrocarbon-based acid-decomposable resin of the present invention include the following.
(1) What contains the repeating unit which has a partial structure containing the alicyclic hydrocarbon represented by the said general formula (pI)-(pVI) (side chain type).
(2) Containing repeating units represented by general formula (II-AB) (main chain type) However,
Examples of (2) include the following.
(3) Those having a repeating unit represented by the general formula (II-AB), a maleic anhydride derivative and a (meth) acrylate structure (hybrid type).
In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having an acid-decomposable group is preferably 10 to 60 mol%, more preferably 20 to 50 mol%, still more preferably 25 in all repeating structural units. -40 mol%.

  In the present invention, the repeating unit having an acid-decomposable group preferably contains at least one methacrylate repeating unit and at least one acrylic ester repeating unit. The molar ratio of acrylic acid ester to methacrylic acid ester is generally 10/90 to 90/10, preferably 20/80 to 80/20, more preferably 30/70 to 70/30, most preferably 40 / 60-60 / 40.

  In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit having a partial structure containing the alicyclic hydrocarbon represented by the general formulas (pI) to (pVI) is 30 to 70 in all the repeating structural units. The mol% is preferable, more preferably 35 to 65 mol%, and still more preferably 40 to 60 mol%.

In the alicyclic hydrocarbon-based acid-decomposable resin, the content of the repeating unit represented by the general formula (II-AB) is preferably 10 to 60 mol%, more preferably 15 to 55 mol% in all repeating structural units. More preferably, it is 20-50 mol%.

In addition, the content of the repeating structural unit based on the monomer of the further copolymer component in the resin can also be appropriately set according to the performance of the desired resist. 99 mol% with respect to the total number of moles of the repeating structural unit having a partial structure containing the alicyclic hydrocarbon represented by (pVI) and the repeating unit represented by the above general formula (II-AB) The following is preferable, More preferably, it is 90 mol% or less, More preferably, it is 80 mol% or less.

The alicyclic hydrocarbon-based acid-decomposable resin used in the present invention is in accordance with a conventional method (for example, radical polymerization).
Can be synthesized. For example, as a general synthesis method, monomer species are charged into a reaction vessel in a batch or in the course of reaction, and if necessary, a reaction solvent such as ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, methyl ethyl ketone, A ketone such as methyl isobutyl ketone, an ester solvent such as ethyl acetate, and the composition of the present invention such as propylene glycol monomethyl ether acetate described below are dissolved in a solvent that dissolves uniformly and then nitrogen, argon, etc. Polymerization is started using a commercially available radical initiator (azo initiator, peroxide, etc.) as necessary under an inert gas atmosphere. 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 20% by mass or more, preferably 30% by mass or more, and more preferably 40% by mass or more. The reaction temperature is 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 50-100 ° C.
In the photosensitive composition of the present invention, component B usually preferably has an acid-decomposable group having 4 or more carbon atoms. More preferably, it has 10 or more carbon atoms, and particularly preferably has an acid-decomposable group having 12 or more carbon atoms.
The compound of a component (B) can be used individually by 1 type or in combination of 2 or more types.

[2] (Z) A compound having a sulfonium cation having a structure represented by the general formula (Z-I) (hereinafter also referred to as “compound (Z)” or “(Z) component”)

In general formula (Z-I),
Y ^{1 to} Y ¹³ each independently represent a hydrogen atom or a substituent, and adjacent ones may be bonded to each other to form a ring.
Z represents a single bond or a divalent linking group.
In the general formula (ZI), the substituent of Y ^{1 to} Y ¹³ may be any one and is not particularly limited. For example, a halogen atom, an alkyl group, a cycloalkyl group (bicycloalkyl group, trialkyl) Cycloalkyl groups), alkenyl groups (including cycloalkenyl groups and bicycloalkenyl groups), alkynyl groups, aryl groups, heterocyclic groups (also referred to as heterocyclic groups), cyano groups, hydroxyl groups, nitro groups, Carboxyl group, alkoxy group (including cycloalkoxy group), aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group (including cycloalkoxycarbonyloxy group), aryloxycarbonyloxy Group, amino group (including anilino group), ammonio group, acyl Mino group, aminocarbonylamino group, alkoxycarbonylamino group (including cycloalkoxycarbonylamino group), aryloxycarbonylamino group, sulfamoylamino group, alkyl, cycloalkyl or arylsulfonylamino group, mercapto group, alkylthio group ( Cycloalkylthio group), arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl, cycloalkyl or arylsulfinyl group, alkyl, cycloalkyl or arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group (Including cycloalkoxycarbonyl group), carbamoyl group, aryl or heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group Phosphinylamino group, a phosphono group, a silyl group, a hydrazino group, a ureido group, a boronic acid group (-B (OH) _2), phosphato group (-OPO (OH) _2), a sulfato group (-OSO ₃ H), Other known substituents can be mentioned.
Alcoholic hydroxyl groups are preferred as further substituents that these groups may have.

Y ^{1 to} Y ¹³ are preferably a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group (including a bicycloalkyl group or a tricycloalkyl group), an alkenyl group (including a cycloalkenyl group or a bicycloalkenyl group), alkynyl Group, aryl group, cyano group, hydroxyl group, carboxyl group, alkoxy group (including cycloalkoxy group), aryloxy group, acyloxy group, carbamoyloxy group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group (cycloalkoxy group) Carbonylamino group), aryloxycarbonylamino group, sulfamoylamino group, alkyl, cycloalkyl or arylsulfonylamino group, alkylthio group (including cycloalkylthio group), arylthio group, sulfamoy Group, (including cycloalkoxy group) alkyl, cycloalkyl or aryl-sulfonyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an imido group, a silyl group, a ureido group.

Y ^{1 to} Y ¹³ are more preferably a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group (including a bicycloalkyl group or a tricycloalkyl group), a cyano group, a hydroxyl group, or an alkoxy group (including a cycloalkoxy group). ), Acyloxy group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group (including cycloalkoxycarbonylamino group), alkyl, cycloalkyl or arylsulfonylamino group, alkylthio group (including cycloalkylthio group), sulfamoyl group, An alkyl, cycloalkyl or arylsulfonyl group, an alkoxycarbonyl group (including a cycloalkoxycarbonyl group), and a carbamoyl group;

Y ^{1 to} Y ¹³ are particularly preferably a hydrogen atom, an alkyl group, a cycloalkyl group (including a bicycloalkyl group and a tricycloalkyl group), a cyano group, a hydroxyl group, an alkoxy group (including a cycloalkoxy group), and an alkyl group. A sulfonyl group.
Examples of the ring formed by bonding the adjacent ones of Y ^{1 to} Y ¹³ include aromatic, non-aromatic hydrocarbon rings, heterocyclic rings, and polycyclic condensed rings obtained by further combining these, For example, benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, fluorene ring, triphenylene ring, naphthacene ring, biphenyl ring, pyrrole ring, furan ring, thiophene ring, imidazole ring, oxazole ring, thiazole ring, pyridine ring, pyrazine ring, Pyrimidine ring, pyridazine ring, indolizine ring, indole ring, benzofuran ring, benzothiophene ring, isobenzofuran ring, quinolidine ring, quinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinoxazoline ring, isoquinoline ring, carbazole ring, phenant Lysine ring, acridine ring, Ntororin ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, phenothiazine ring, phenazine ring, and the like.

Examples of the divalent linking group in Z include, for example, an alkylene group, an arylene group, an ether group, a thioether group, an amino group, —CH═CH—, —C≡C—, a carbonyl group, a sulfide group, a sulfone group, and a sulfoxide group. , -COO-, -CONH-, -SO ₂ NH-, -CF _2- , -CF ₂ CF _2- , -OCF ₂ O-, -CF ₂ OCF _2-
, -SS-, -CH ₂ SO ₂ CH _2- , -CH ₂ COCH _2- , -COCF ₂ CO-, -COCO-, -OCOO-, -OSO ₂ O-.
Z is preferably a single bond, an alkylene group (preferably a methylene group), an ether group, a thioether group, a carbonyl group, a sulfide group, a sulfone group, —COO—, —CONH—, —SO ₂ NH—, —CF ₂ —. , —CF ₂ CF ₂ —, —COCO—, more preferably a single bond, an ether group, a thioether group, a carbonyl group, a sulfide group, or a sulfone group, and particularly preferably a single bond or a sulfone group.

The compound of component (Z) has a counter anion. The counter anion is preferably an organic anion. An organic anion is an anion having at least one carbon atom. Furthermore, the organic anion is preferably a non-nucleophilic 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.
Examples of the non-nucleophilic anion include a sulfonate anion, a carboxylate anion, a sulfonylimide anion, a bis (alkylsulfonyl) imide anion, and a tris (alkylsulfonyl) methyl anion.

Examples of the non-nucleophilic sulfonate anion include an aliphatic sulfonate anion, an aromatic sulfonate anion, a camphor sulfonate anion, and the like. Examples of the non-nucleophilic 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, for example, Methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, 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, etc. .

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.
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 1 to 5 carbon atoms), cycloalkyl group (preferably 3 to 15 carbon atoms), aryl group (preferably 6 to 14 carbon atoms), alkoxycarbonyl group (Preferably having 2 to 7 carbon atoms), acyl group (preferably having 2 to 12 carbon atoms), alkoxycarbonyloxy group (preferably having 2 to 7 carbon atoms) and the like can be mentioned. 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 groups 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.
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 as in the aromatic sulfonate anion. Atoms, alkyl groups, cycloalkyl groups, alkoxy groups, alkylthio groups and the like can be mentioned.
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 the substituent for these alkyl groups include a halogen atom, an alkyl group substituted with a halogen atom, an alkoxy group, and an alkylthio group.
Examples of other non-nucleophilic anions include fluorinated phosphorus, fluorinated boron, and fluorinated antimony.

The counter anion of the compound of component (Z) is preferably a sulfonate anion, and more preferably an aromatic sulfonate anion.
Specific examples of counter anions include methane sulfonate anion, trifluoromethane sulfonate anion, pentafluoroethane sulfonate anion, heptafluoropropane sulfonate anion, perfluorobutane sulfonate anion, perfluorohexane sulfonate anion, perfluoro. Octane sulfonate anion, pentafluorobenzene sulfonate anion, 3,5-bistrifluoromethylbenzene sulfonate anion, 2,4,6-triisopropylbenzene sulfonate anion, perfluoroethoxyethane sulfonate anion, 2, 3, 5 , 6-tetrafluoro-4-dodecyloxybenzenesulfonate anion, p-toluenesulfonate anion, pentafluorobenzenesulfonate anion, camphorsulfonate anion and the like.
The counter anion that the compound of the (Z) component has together with the sulfonium cation represented by the general formula (ZI) may be monovalent or divalent. When the counter anion is divalent or more, the compound of the (Z) component can have two or more sulfonium cations represented by the general formula (Z-I).

The content of the component (Z) is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, and further preferably 1 to 7%, based on the total solid content of the positive resist composition. % By mass.
The compound of component (Z) is an acid generator that generates an acid upon irradiation with actinic rays or radiation.
(Z) The compound of a component can be used individually by 1 type or in combination of 2 or more types.
Specific examples of the sulfonium salt (Z) represented by the general formula (Z-I) are shown below, but are not limited thereto.

[3] (A) Compound (hereinafter also referred to as “compound (A)”) which generates a compound represented by the following general formula (AI) upon irradiation with actinic rays or radiation.
_{Q 1 -X 1 -NH-X 2} -Q 2 (A-I)
In general formula (AI),
Q ₁ and Q ₂ each independently represents a monovalent organic group. However, either Q ₁ or Q ₂ contains a proton acceptor functional group. Q ₁ and Q ₂ may combine to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ and X ₂ each independently represent —CO— or —SO ₂ —.
The monovalent organic group as Q ₁ and Q _{2 in the} general formula (AI) preferably has 1 to 40 carbon atoms, such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, An alkenyl group etc. can be mentioned. When a proton acceptor functional group is present, it may be present at the end of a monovalent organic group such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group, in the chain, or in a side chain.

The alkyl group in Q ₁ and Q ₂ may further have a substituent, preferably a linear or branched alkyl group having 1 to 30 carbon atoms, and an oxygen atom, sulfur atom, nitrogen in the alkyl chain You may have an atom. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-dodecyl group, n-tetradecyl group, n-octadecyl group, etc. And a branched alkyl group such as isopropyl group, isopropyl group, isobutyl group, t-butyl group, neopentyl group, 2-ethylhexyl group.

The cycloalkyl group in Q ₁ and Q ₂ may further have a substituent, preferably a cycloalkyl group having 3 to 20 carbon atoms, and has an oxygen atom and a nitrogen atom in the ring. Also good. Specific examples include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like.
The aryl group in Q ₁ and Q ₂ may further have a substituent, and preferably an aryl group having 6 to 14 carbon atoms, such as a phenyl group and a naphthyl group.

The aralkyl group in Q ₁ and Q ₂ may further have a substituent, and preferably an aralkyl group having 7 to 20 carbon atoms, such as benzyl group, phenethyl group, naphthylmethyl group, naphthylethyl. Groups.
The alkenyl group in Q ₁ and Q ₂ may further have a substituent, and examples thereof include a group having a double bond at an arbitrary position of the alkyl group.

  Examples of further substituents that each of the above groups may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), and an aryl group. (Preferably 6 to 14 carbon atoms), alkoxy group (preferably 1 to 10 carbon atoms), acyl group (preferably 2 to 20 carbon atoms), acyloxy group (preferably 2 to 10 carbon atoms), alkoxycarbonyl group ( Preferably, it has 2 to 20 carbon atoms, and an aminoacyl group (preferably 2 to 10 carbon atoms).

  As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having 1 to 10 carbon atoms). As for the aminoacyl group, examples of the substituent further include an alkyl group (preferably having a carbon number of 1 to 10). Examples of the alkyl group having a substituent include perfluoroalkyl groups such as a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, and a perfluorobutyl group.

One of the monovalent organic groups of Q ₁ and Q ₂ has a proton acceptor functional group. The proton acceptor functional group is a group that can electrostatically interact with a proton or a functional group having a lone pair of electrons, such as a functional group having a macrocyclic structure such as a cyclic polyether, or π A functional group having a nitrogen atom having a lone electron pair with little conjugation contribution can be given. Examples of the nitrogen atom having a lone electron pair with little contribution of π conjugation include a nitrogen atom having a partial structure represented by the following general formula.

Preferable partial structures of the proton acceptor functional group include, for example, crown ether, azacrown ether, tertiary amine, secondary amine, primary amine, pyridine, imidazole, pyrazine, aniline structure and the like. The number of carbon atoms is preferably 4 to 30, and examples of the group having such a structure include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. The alkyl group, cycloalkyl group, aryl group, aralkyl group and alkenyl group are the same as those mentioned above.
These groups may further have a substituent.

  Examples of further substituents that each of the above groups may have include, for example, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxy group, a carbonyl group, a cycloalkyl group (preferably having 3 to 10 carbon atoms), and an aryl group. (Preferably 6 to 14 carbon atoms), alkoxy group (preferably 1 to 10 carbon atoms), acyl group (preferably 2 to 20 carbon atoms), acyloxy group (preferably 2 to 10 carbon atoms), alkoxycarbonyl group ( Preferably, it has 2 to 20 carbon atoms, and an aminoacyl group (preferably 2 to 20 carbon atoms). As for the cyclic structure in the aryl group, cycloalkyl group and the like, examples of the substituent further include an alkyl group (preferably having 1 to 20 carbon atoms). As for the aminoacyl group, examples of the substituent further include an alkyl group (preferably having 1 to 20 carbon atoms).

The proton acceptor functional group may be substituted with an organic group having a bond that is cleaved by an acid. Examples of the organic group having a bond that can be cleaved by an acid include an amide group, an ester group (preferably a tertiary alkyloxycarbonyl group), an acetal group (preferably a 1-alkyloxy-alkyloxy group), and a carbamoyl group. Group, carbonate group and the like.
Examples of the structure in which Q ₁ and Q ₂ are bonded to form a ring and the formed ring has a proton acceptor functional group include, for example, an organic group of Q ₁ and Q ₂ is further an alkylene group, an oxy group And a structure bonded with an imino group or the like.

In general formula (AI), it is preferable that at least one of X ₁ and X ₂ is —SO ₂ —.
The compound represented by the general formula (AI) preferably has a structure represented by the following general formula (A-II).
_{Q 1 -X 1 -NH-X 2} -A- (X 3) n -B-Q 3 (A-II)
In general formula (A-II),
Q ₁ and Q ₃ each independently represents a monovalent organic group. However, _one of Q ₁ and Q ₃ has a proton acceptor functional group. Q ₁ and Q ₃ may combine to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ , X ₂ and X ₃ each independently represent —CO— or —SO ₂ —.
A represents a divalent linking group.
B represents a single bond, an oxygen atom, or —N (Qx) —.
Qx represents a hydrogen atom or a monovalent organic group.
When B is —N (Qx) —, Q ₃ and Qx may combine to form a ring.
n represents 0 or 1.
Q ₁ has the same meaning as Q _{1 in} formula (AI).
Examples of the organic group of Q ₃ include the same organic groups as Q ₁ and Q ₂ in formula (AI).

The divalent linking group in A is preferably a divalent linking group having a fluorine atom having 1 to 8 carbon atoms, for example, 1 to 8 carbon atoms, preferably 2 to 6 carbon atoms, more preferably carbon number. Examples thereof include an alkylene group having 2 to 4 fluorine atoms and a phenylene group having fluorine atoms. More preferred is an alkylene group having a fluorine atom. The alkylene chain may have a linking group such as an oxygen atom or a sulfur atom. The alkylene group is preferably an alkylene group in which 30 to 100% of the number of hydrogen atoms are substituted with fluorine atoms, more preferably a perfluoroalkylene group, and particularly preferably a perfluoroethylene group, a perfluoropropylene group, or a perfluorobutylene group. .

The monovalent organic group in Qx is preferably an organic group having 4 to 30 carbon atoms, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and an alkenyl group. Examples of the alkyl group, cycloalkyl group, aryl group, aralkyl group, and alkenyl group are the same as those for Q ₁ and Q ₂ .

In the general formula (A-II), X ₁ , X ₂ and X ₃ are preferably —SO ₂ —.
Hereinafter, although the specific example of a compound represented by general formula (AI) is shown, this invention is not limited to this.

The compound that generates the compound represented by the general formula (AI) by irradiation with actinic rays or radiation is a sulfonium salt compound of the compound represented by the general formula (AI) or the general formula (AI). The iodonium salt compound of the compound represented is preferable.
The compound that generates the compound represented by the general formula (AI) by irradiation with actinic rays or radiation is more preferably a compound represented by the following general formula (A1) or (A2).

In general formula (A1),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
X ⁻ represents an anion of the compound represented by the general formula (AI). In the anion of the compound represented by the general formula (AI), the nitrogen atom represented by the general formula (AI) is a negative ion.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1 to 30, preferably 1
~ 20.

It is also possible to form the two members ring structure of the R ₂₀₁ to R _203, an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Specific examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include a compound (A1a) described later.
, (A1b), and (A1c), the corresponding groups.
In addition, the compound which has two or more structures represented by general formula (A1) may be sufficient. For example, the general formula at least one of R ₂₀₁ to R ₂₀₃ of a compound represented by (A1) is at least one bond between the structure of R ₂₀₁ to R ₂₀₃ of another compound represented by formula (A1) It may be a compound.

More preferred components (A1) include compounds (A1a), (A1b), and (A1c) described below.
Compound (A1a) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (A1), arylsulfonium compound, i.e., a compound having arylsulfonium as a cation.
In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or R ₂₀₁
Part of the to R ₂₀₃ is an aryl group with the remaining being an alkyl group or a cycloalkyl group.
Examples of the arylsulfonium compound include a triarylsulfonium compound, a diarylalkylsulfonium compound, a diarylcycloalkylsulfonium compound, an aryldialkylsulfonium compound, an aryldicycloalkylsulfonium compound, and an arylalkylcycloalkylsulfonium compound.

  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 that the arylsulfonium compound has as necessary is preferably a linear or branched alkyl group having 1 to 15 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, sec- Examples thereof include a butyl group and a t-butyl group.
The cycloalkyl group that the arylsulfonium compound has as necessary is preferably a cycloalkyl group having 3 to 15 carbon atoms, and examples thereof include a cyclopropyl group, a cyclobutyl group, and a cyclohexyl group.

Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are 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, most preferably They are a C1-C4 alkyl group and a C1-C4 alkoxy group. The substituent may be substituted on any one of three R ₂₀₁ to R _203, or may be substituted on 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 (A1b) will be described.
The compound (A1b) is a compound in which R _{201 to} R ₂₀₃ in the general formula (A1) each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring having a hetero atom.

The aromatic ring-free organic group 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, An alkoxycarbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group. The alkyl group as R ₂₀₁ to R ₂₀₃ may be linear, it may be either branched, preferably a straight-chain or branched alkyl group (e.g., methyl group having 1 to 20 carbon atoms, an ethyl group, a propyl Group, butyl group, pentyl group). The alkyl group as R ₂₀₁ to R ₂₀₃ is a straight-chain or branched 2-oxoalkyl group, an alkoxycarbonylmethyl group are preferred.

The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is preferably, and a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl). The cycloalkyl group as R ₂₀₁ to R ₂₀₃ is a 2-oxocycloalkyl group is more preferable.
The linear or branched 2-oxoalkyl group as R _{201 to} R ₂₀₃ may have a double bond in the chain, and preferably has> C═O at the 2-position of the alkyl group. The group can be mentioned.

The 2-oxocycloalkyl group as R _{201 to} R ₂₀₃ may have a double bond in the chain, and preferably includes a group having> C═O at the 2-position of the cycloalkyl group. be able to.
The alkoxy group in the alkoxycarbonylmethyl group as R ₂₀₁ to R _203, preferably may be mentioned alkoxy groups having 1 to 5 carbon atoms (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentoxy group).

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), an alkoxycarbonyl group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group. .
The compound (A1c) is a compound represented by the following general formula (A1c), and is a compound having an arylacylsulfonium salt structure.

In general formula (A1c):
_R213 represents an aryl group, preferably a phenyl group or a naphthyl group.
As the preferred substituents that have an aryl group as R _213, an alkyl group, an alkoxy group, an acyl group, a nitro group, a hydroxyl group, an alkoxycarbonyl group and a carboxy group.
R ₂₁₄ and R ₂₁₅ each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
Y ₂₀₁ and Y ₂₀₂ each independently represents an alkyl group, a cycloalkyl group, an aryl group, or a vinyl group.

X ⁻ represents an anion of the compound represented by the general formula (AI).
R ₂₁₃ and R ₂₁₄ may be bonded to form a ring structure, R ₂₁₄ and R ₂₁₅ may be bonded to form a ring structure, and Y ₂₀₁ and Y ₂₀₂ are bonded to each other. To form a ring structure. These ring structures may contain an oxygen atom, a sulfur atom, an ester bond, or an amide bond. Examples of the group R ₂₁₃ and R _214, R ₂₁₄ and R _215, Y ₂₀₁ and Y ₂₀₂ are formed by combined include a butylene group and a pentylene group.

The alkyl group as R ₂₁₄ , R ₂₁₅ , Y ₂₀₁ and Y ₂₀₂ is preferably a linear or branched alkyl group having 1 to 20 carbon atoms. The alkyl group as Y ₂₀₁ and Y ₂₀₂ is a 2-oxoalkyl group having> C═O at the 2-position of the alkyl group, an alkoxycarbonylalkyl group (preferably an alkoxy group having 2 to 20 carbon atoms), or a carboxyalkyl group. More preferred.
The cycloalkyl group as R ₂₁₄ , R ₂₁₅ , Y ₂₀₁ and Y ₂₀₂ is preferably a cycloalkyl group having 3 to 20 carbon atoms.

The aryl group as Y ₂₀₁ and Y ₂₀₂ is preferably a phenyl group or a naphthyl group.
Y ₂₀₁ and Y ₂₀₂ are preferably an alkyl group having 4 or more carbon atoms, more preferably an alkyl group having 4 to 6, and further preferably 4 to 12.
In addition, at least one of R ₂₁₄ or R ₂₁₅ is preferably an alkyl group, and more preferably both R ₂₁₄ and R ₂₁₅ are alkyl groups.

In general formula (A2),
_R204 and _R205 each independently represents an aryl group, an alkyl group or a cycloalkyl group.
X ⁻ represents an anion of the compound represented by the general formula (AI).
The aryl group of R ₂₀₄ and R _205, a phenyl group, a naphthyl group, more preferably a phenyl group. The aryl group of R ₂₀₄ and R ₂₀₅ 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.

The alkyl group as _R204 and _R205 may be either linear or branched, and is preferably a linear or branched alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group). Group, butyl group, pentyl group).
The cycloalkyl group as R ₂₀₄ and R ₂₀₅ can preferably be mentioned a cycloalkyl group having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, norbornyl). _R204 and _R205 may have a substituent. Examples of the substituent that R ₂₀₄ and R ₂₀₅ may have include, 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, 6 to 6 carbon atoms). 15), alkoxy groups (for example, having 1 to 15 carbon atoms), halogen atoms, hydroxyl groups, phenylthio groups and the like.

  The compound (A) is preferably a compound represented by the general formula (A1), and more preferably a compound represented by the general formulas (A1a) to (A1c).

  Hereinafter, although the specific example of a compound (A) is given, this invention is not limited to this.

  Compound (A) may be used alone or in combination of two or more.

The content of the compound (A) in the positive resist composition of the present invention is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, based on the solid content of the composition.
Compound (A) can be easily synthesized by using a general sulfonic acid esterification reaction or sulfonamidation reaction. For example, one sulfonyl halide part of a bissulfonyl halide compound is selectively reacted with an amine or alcohol containing a partial structure represented by the general formula (AI) to form a sulfonamide bond or a sulfonate bond Then, the other sulfonyl halide moiety can be hydrolyzed, or the cyclic sulfonic acid anhydride can be opened by an amine or alcohol containing a partial structure represented by the general formula (AI). . An amine or alcohol containing a partial structure represented by the general formula (AI) is an amine, an alcohol such as (R′O ₂ C) ₂ O or an anhydride such as R′O ₂ CCl, acid It can be synthesized by reacting with a chloride compound.

<Other ingredients>
[4] (G) Nitrogen-containing basic compound In the present invention, it is preferable to use the nitrogen-containing basic compound (G) from the viewpoint of improving performance such as resolution and improving storage stability.
Preferable structures of the nitrogen-containing basic compound include structures represented by the following general formulas (A) to (E).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl having 1 to 20 carbons, a cycloalkyl group having 3 to 20 carbons or an aryl group having 6 to 20 carbons, R ²⁵⁰ and R ²⁵¹ may combine with each other to form a ring. These may have a substituent. Examples of the alkyl group and cycloalkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, an aminocycloalkyl group having 3 to 20 carbon atoms, and 1 to 1 carbon atoms. A 20 hydroxyalkyl group or a C 3-20 hydroxycycloalkyl group is preferred.
These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.
In the formula, R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represent an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms.

  Preferable compounds include guanidine, aminopyrrolidine, pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine, and piperidine, and may have a substituent. More preferred compounds include compounds having an imidazole structure, diazabicyclo structure, onium hydroxide structure, onium carboxylate structure, trialkylamine structure, aniline structure or pyridine structure, alkylamine derivatives having a hydroxyl group and / or an ether bond, hydroxyl groups and / or Or the aniline derivative which has an ether bond etc. can be mentioned.

  Examples of the compound having an imidazole structure include imidazole, 2,4,5-triphenylimidazole, benzimidazole, and the like. 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. ] Undec-7-ene. 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. The compound having an onium carboxylate structure is a compound having an onium hydroxide structure in which the anion moiety 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 aniline compounds include 2,6-diisopropylaniline and N, N-dimethylaniline. 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. However, when the amount of component (B) used is 0.05% by mass or more, the basic substance may or may not be used. When using a basic compound, the amount of its use is 0.001-10 mass% normally based on solid content of a resist composition, Preferably it is 0.01-5 mass%. In order to obtain a sufficient addition effect, 0.001% by mass or more is preferable, and 10% by mass or less is preferable in terms of sensitivity and developability of the non-exposed area.

[5] (H) Fluorine and / or silicon-based surfactant The resist composition of the present invention further comprises a fluorine-based and / or silicon-based surfactant (fluorine-based surfactant and silicon-based surfactant, fluorine atom Or a surfactant containing both silicon atoms), or preferably two or more.
When the resist composition of the present invention contains fluorine and / or a silicon-based surfactant, when using an exposure light source of 250 nm or less, particularly 220 nm or less, good sensitivity and resolution, and less adhesion and development defects. A resist pattern can be provided.

  Examples of these fluorine and / or silicon surfactants 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 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), Surflon S-382, SC101, 102, 103, 104, 105, 106 (Asahi Glass Co., Ltd.), Troisol S-366 (Troy Chemical Co., Ltd.), etc. Fluorine type surfactant or silicon type surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

  In addition to the known surfactants described above, surfactants are derived from fluoroaliphatic compounds produced by the telomerization method (also referred to as the telomer method) or the oligomerization method (also referred to as the oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

  As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. It may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block link) or poly (block link of oxyethylene and oxypropylene) may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups, Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (Ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate) copolymer, acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group Coalesce, etc. Can.

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

[6] Organic solvent The 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, dimethyl sulfoxide, N-methylpyrrolidone, tetrahydrofuran, etc.
The solvent used in the present invention is preferably a solvent having at least one ketone structure.
Examples of the solvent having a ketone structure include a chain ketone solvent and a cyclic ketone solvent, and a compound having a total carbon number of 5 to 8 is preferable because of good coatability.

Examples of chain ketone solvents include 2-heptanone, methyl ethyl ketone, and methyl isobutyl ketone, with 2-heptanone being preferred.
Examples of the cyclic ketone solvent include cyclopentanone, 3-methyl-2-cyclopentanone, cyclohexanone, 2-methylcyclohexanone, 2,6-dimethylcyclohexanone, cycloheptanone, cyclooctanone, and isophorone. Are cyclohexanone and cycloheptanone.

The solvent is preferably used as a solvent having a ketone structure alone or as a mixed solvent with other solvents. Examples of the solvent to be mixed (combined solvent) include propylene glycol monoalkyl ether carboxylate, alkyl lactate, propylene glycol monoalkyl ether, alkyl alkoxypropionate, and lactone compound.
Examples of the propylene glycol monoalkyl ether carboxylate include propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, propylene glycol monoethyl ether acetate and the like.

Examples of the alkyl lactate include methyl lactate and ethyl lactate.
Examples of the propylene glycol monoalkyl ether include propylene glycol monomethyl ether and propylene glycol monoethyl ether.
Examples of the alkyl alkoxypropionate include methyl methoxypropionate, ethyl methoxypropionate, methyl ethoxypropionate, and ethyl ethoxypropionate.

Examples of the lactone compound include γ-butyrolactone.
Preferred examples of the combined solvent include propylene glycol monoalkyl ether carboxylate, alkyl lactate, and propylene glycol monoalkyl ether. More preferable examples of the combined solvent include propylene glycol monomethyl ether acetate.

By mixing the ketone solvent and the combined solvent, substrate adhesion, developability, DOF, and the like are improved.
The ratio (mass ratio) of the ketone solvent and the combined solvent is preferably 10/90 to 95/5, more preferably 20/80 to 80/20, still more preferably 30/70 to 70/30.

Moreover, you may mix the high boiling point solvent of 200 degreeC or more of boiling points, such as ethylene carbonate and a propylene carbonate, from a viewpoint of improving film thickness uniformity and development defect performance.
The addition amount of these high-boiling solvents is usually 0.1 to 15% by mass, preferably 0.5 to 10% by mass, and more preferably 1 to 5% by mass in the total solvent.
In the present invention, the solvent is used alone, preferably two or more kinds of solvents, and the solid content concentration is usually 1 to 20% by mass, preferably 1 to 10% by mass, more preferably 1 to 10% by mass. An 8 mass% resist composition is prepared.

[7] Other Additives The resist composition of the present invention further promotes solubility in dyes, plasticizers, surfactants other than the above component (H), photosensitizers, and developers as necessary. The compound to be made can be contained.

In the present invention, a surfactant other than the (H) fluorine-based and / or silicon-based surfactant may be added. Specifically, nonionic interfaces such as polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan aliphatic esters, polyoxyethylene sorbitan aliphatic esters, etc. Mention may be made of activators.
These surfactants may be added alone or in some combination.

[8] Pattern Forming Method The resist composition of the present invention is used by dissolving the above components in a predetermined organic solvent, preferably the mixed solvent, and applying the solution on a predetermined support as follows.
For example, a photosensitive composition is formed by applying and drying a resist composition on a substrate (eg, silicon / silicon dioxide coating) used in the manufacture of precision integrated circuit elements by an appropriate application method such as a spinner or a coater. To do.

The photosensitive film is irradiated with actinic rays or radiation through a predetermined mask, preferably baked (heated) and developed. Thereby, a good pattern can be obtained.
Exposure (immersion exposure) may be performed by filling a liquid having a higher refractive index than air between the photosensitive film and the lens during irradiation with actinic rays or radiation. Thereby, resolution can be improved.
Examples of the actinic ray or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, etc., but preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157 nm), X-ray, electron beam, etc., more preferably KrF excimer laser (248 nm), EUV ( 13 nm), an electron beam.

  In the development step, an alkaline developer is used as follows. As an alkaline developer of the resist composition, inorganic hydroxides such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, 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, etc. Alkaline aqueous solutions such as quaternary ammonium salts, cyclic amines 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.

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

<Compound (Z)>
<Synthesis Example 1: Synthesis of 10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonate (Z-1)>
10 g of thioxanthen-9-one was stirred in 40 ml of trifluoroacetic acid, and a solution prepared by mixing 5.4 ml of 30% aqueous hydrogen peroxide and 10.8 ml of trifluoroacetic acid was slowly added under ice cooling. Thereafter, the mixture was stirred for 30 minutes under ice cooling, and then stirred at room temperature for 1 hour. Further, the reaction solution was poured into water, and the precipitated crystals were collected by filtration. The obtained crystals were recrystallized from acetonitrile to obtain 4.6 g of a sulfoxide form. 3 g of the sulfoxide compound was stirred in 20 ml of toluene, and 3.7 ml of trifluoroacetic anhydride and 2.2 ml of nonafluorobutanesulfonic acid were added under ice cooling. The reaction was gradually warmed to room temperature and stirred for 1 hour. Diisopropyl ether was added to the reaction solution to precipitate crystals, and recrystallized with a mixed solvent of ethyl acetate and diisopropyl ether to give 10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonate (Z-1). 3.9g was obtained.
¹ H-NMR (400 MHz, CDCl ₃ ) σ2.38 (s, 3H), 7.34 (d, 2H), 7.72 (m, 2H), 7.95 (m, 4H), 8.28 (m, 2H), 8.63 (d , 2H)

<Synthesis Example 2: Synthesis of 10-tolyl-9-oxothioxanthenium 3,5-bistrifluoromethylbenzenesulfonate (Z-2)>
To 1.5 g of 10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonate (Z-1) obtained in Synthesis Example 1, 10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonic acid 1.5 g of salt is dissolved in a methanol / water = 1/1 solution and passed through an ion exchange resin (Amberlite IRA402Cl in which anion is replaced with OH with NaOH water), 1 g of 3,5-bistrifluoromethylbenzenesulfonic acid And extracted with chloroform to obtain 1.7 g of 10-tolyl-9-oxothioxanthenium 3,5-bistrifluoromethylbenzenesulfonate (Z-2) whose salt was changed.
¹ H-NMR (400 MHz, CDCl ₃ ) σ2.37 (s, 3H), 7.34 (d, 2H), 7.79 (m, 3H), 7.93 (m, 4H), 8.34 (m, 4H), 8.62 (d , 2H)

<Synthesis Example 3: Synthesis of 2-acetyl-10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonate (Z-8)>
15 g of thiosalicylic acid and 20 g of 4-bromoacetophenone were stirred in 170 ml of dimethylformamide in the presence of 12 g of sodium carbonate and 0.2 g of copper catalyst for 6 hours at 170 ° C. Then, the reaction solution was poured into an aqueous hydrochloric acid solution and collected by filtration. The obtained crystals were recrystallized from acetonitrile to obtain 16 g of sulfide. 10 g of the obtained sulfide was stirred in 60 g of polyphosphoric acid at 60 degrees for 5 hours, and then poured into ice water. The crystals were collected by filtration, washed with an aqueous sodium hydrogen carbonate solution and water, and recrystallized with ethanol to obtain 5 g of 2-acetyl-9H-thioxan-9-one. Further, 3 g of the obtained 2-acetyl-9H-thioxan-9-one was stirred in 12 ml of trifluoroacetic acid under ice-cooling, and a mixed solution of 1.4 ml of 30% hydrogen peroxide and 2.7 ml of trifluoroacetic acid was slowly added. added. After the addition, the mixture was stirred for 30 minutes under ice cooling, followed by stirring at room temperature for 1 hour to complete the reaction. The reaction solution was poured into water, and separated with ethyl acetate and an aqueous sodium hydroxide solution, and the organic layer was distilled off under reduced pressure to obtain 3.6 g of a sulfoxide form. It was stirred in 15 g of toluene, 3.3 ml of trifluoroacetic anhydride and 1.9 ml of nonafluorobutanesulfonic acid were added under ice cooling, and the mixture was stirred at room temperature for 30 minutes and at room temperature for 1 hour. Diisopropyl ether is added to the reaction solution for crystallization, and the resulting crystal is recrystallized with a mixed solvent of ethyl acetate and diisopropyl ether to give 2-acetyl-10-tolyl-9-oxothioxanthenium nonafluorobutanesulfonic acid. 1 g of salt (A8) was obtained.
¹ H-NMR (400 MHz, CDCl ₃ ) σ2.39 (s, 3H), 2.74 (s, 3H), 7.37 (d, 2H), 7.72 (m, 2H), 7.97 (m, 2H), 8.19 (m , 1H), 8.39 (m, 2H), 8.67 (d, 1H), 9.09 (s, 1H)

<Synthesis Example 4: Synthesis of (Z-40)>
20 g of thianthrene was refluxed in 300 ml of acetic acid, and 36 ml of diluted nitric acid was slowly added dropwise thereto. After reacting for 5 hours, the reaction solution was poured into 1.2 l of water to precipitate crystals. The crystals were filtered and recrystallized from acetonitrile to obtain 12 g of thianslene-S-oxide.
¹ H-NMR (400 MHz, CDCl ₃ ) σ7.42 (t, 2H), 7.56 (t, 2H), 7.63 (d, 2H), 7.93 (d, 2H)
Thianthrene-S-oxide (2 g) was dissolved in 10 ml of toluene and cooled on ice. Thereto, 2.8 ml of trifluoroacetic anhydride and 1.2 ml of nonafluorobutanesulfonic acid were added and stirred for 1 hour. Diisopropyl ether was added and the supernatant was removed, followed by purification with a silica gel column (chloroform / methanol = 19/1) to obtain 4.4 g of 5- (p-tolyl) thianthrenium nonafluorobutanesulfonate.
¹ H-NMR (400 MHz, CDCl ₃ ) σ 2.34 (s, 3H), 7.08 (d, 2H), 7.22 (d, 2H), 7.78 (m, 6H),
8.65 (d, 2H)

2 g of 5- (p-tolyl) thianthrenium nonafluorobutanesulfonate was suspended in 6 ml of trifluoroacetic acid, and 0.75 ml of 30% aqueous hydrogen peroxide was added dropwise at room temperature. Then, it stirred at 80 degreeC for 1 hour, water and chloroform were added and liquid separation was performed. After the chloroform layer was distilled off under reduced pressure, purification was performed with a silica gel column (chloroform / methanol = 19/1) to obtain 1.2 g of (Z-40).
¹ H-NMR (400 MHz, CDCl ₃ ) σ2.47 (s, 3H), 7.47 (d, 2H), 7.66 (d, 2H), 7.98 (t, 2H), 8.04 (t, 2H), 8.40 (d , 2H), 8.43 (d, 2H)

<Synthesis Example 5: Synthesis of (Z-73)>
1 g of thianslene-S-oxide was mixed with 1.1 ml of ethoxybenzene and cooled on ice. Thereto were added 1.2 ml of trifluoroacetic anhydride and 0.71 ml of nonafluorobutanesulfonic acid, and the mixture was stirred for 15 minutes. Diisopropyl ether was added and the supernatant was removed, followed by separation with chloroform and water. The chloroform layer was distilled off under reduced pressure to obtain 2.5 g of 5- (p-ethoxybenzene) thianthrenium nonafluorobutanesulfonate.
¹ H-NMR (400 MHz, CDCl ₃ ) σ1.38 (t, 3H), 4.00 (q, 2H), 6.92 (d, 2H), 7.29 (d, 2H), 7.75 (m, 6H), 8.56 (d , 2H)

2.5 g of 5- (p-ethoxybenzene) thianthrenium nonafluorobutanesulfonate was suspended in 10 ml of trifluoroacetic acid and cooled on ice. Thereto was added dropwise 0.89 ml of 30% hydrogen peroxide and stirred for 1 hour. After the reaction, the reaction solution was poured into water, and further chloroform was added for liquid separation. The chloroform layer was distilled off under reduced pressure, and recrystallization was performed with a mixed solvent of diisopropyl ether and ethyl acetate to obtain 1.3 g of (Z-73).
¹ H-NMR (400 MHz, CDCl ₃ ) σ1.47 (t, 3H), 4.20 (q, 2H), 7.26 (d, 2H), 7.91 (m, 6H), 7.98 (m, 2H), 8.39 (d , 2H)

  Compounds other than the above among (Z-1) to (Z-105) were synthesized in the same manner. On the other hand, the compounds (Z-106) to (Z-122) were synthesized by a known method described in JP-A No. 2003-149800 and the like.

<Compound (B)>
The structure, weight average molecular weight, degree of dispersion, and composition ratio (molar ratio) of the compound (B) used in the examples are shown below.

<Compound (A)>
(Synthesis Example of Compound A-1)
Into a 1000 mL three-necked flask equipped with a 100 mL dropping funnel and a nitrogen introducing tube, 34.4 g (200 mmol) of sulfanilamide was added, dissolved in 200 mL of 10% NaOH, stirred with ice cooling, and 55.3 g of 1-octanesulfonyl chloride (from the dropping funnel) 200 mmol) was added dropwise over 1 hour. After dropping, the mixture was stirred for 1 hour under ice-cooling, and the ice bath was further removed, followed by stirring at room temperature for 3 hours. Concentrated hydrochloric acid was added dropwise to the reaction solution to neutralize it, and the precipitated white solid was filtered. This solid was recrystallized from water / methanol to obtain 45.1 g of the following compound as plate-like crystals.

16.1 g (46.9 mmol) of triphenylsulfonium bromide and 12.4 g (53.5 mmol) of silver oxide were added to 150 mL of methanol and stirred at room temperature for 2 hours. The silver salt was removed by filtration, 16.34 g (46.9 mmol) of the above compound was added to the filtrate, and the mixture was further stirred for 1 hour. After removing the solvent, 200 mL of chloroform was added and the organic layer was washed with water. The solvent was removed and dried to obtain 20.9 g of a white solid.
¹ H-NMR (400 MHz, CD ₃ OD) δ 0.93 (t, 3H), 1.34-1.46 (m, 10H), 1.81 (quin, 2H), 3.24 (t, 2H), 6.78 (d, 2H), 7.66-7.78 (m, 17H)

(Synthesis Example of Compound A-6)
8.01 g (23.34 mmol) of triphenylsulfonium bromide and 5.68 silver oxide
g (24.51 mmol) was added to 100 mL of methanol and stirred at room temperature for 2 hours. The silver salt was removed by filtration, and 5.0 g (23.34 mmol) of the above compound sulfaacetamide was added to the filtrate, and the mixture was further stirred for 1 hour. The solvent was removed and dried to obtain 10.0 g of a white solid.
¹ H-NMR (400 MHz, CD ₃ OD) δ 1.84 (s, 3H), 6.63 (d, 2H), 7.63 (d, 2H), 7.78-7.87 (m, 15H)

(Synthesis Example of Compound A-8)
Under a nitrogen stream, a mixture of 5.0 g (15.8 mmol) of 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonyldifluoride and 50 mL of THF was ice-cooled. A mixed solution of 1.66 g (16.6 mmol) of methylpiperazine, 10 mL of triethylamine, and 50 mL of THF was added dropwise over 60 minutes. The mixture was stirred for 1 hour under ice cooling, and further stirred at room temperature for 1 hour. The organic layer was washed successively with water, a saturated aqueous ammonium chloride solution and water, and the organic layer was dried over sodium sulfate. The solvent is concentrated and trifluoromethanesulfonamide 2.36 is added to the residue.
g (15.8 mmol) and 10 mL of triethylamine were added, transferred to a pressure-resistant glass tube, and stirred at 100 ° C. for 20 hours in a sealed tube. 100 mL of chloroform was added, the organic layer was washed with water, and the organic layer was dried over sodium sulfate to obtain a brown oil. Methanol 25mL, 1.5N-HCl 60mL was made neutral to this, and the depositing white solid was filtered, and the following compound 5.65g was obtained.

4.0 g of this solid was dissolved in a mixed solvent of 100 mL of methanol and 40 mL of 1M NaOH, 2.61 g (7.61 mmol) of triphenylsulfonium bromide was added, and the mixture was stirred at room temperature for 3 hours. 200 mL of chloroform was added, the organic layer was washed with water, the solvent was removed, and the residue was purified by column chromatography (SiO ₂ , chloroform / methanol = 10/1) to obtain the target compound (4.56 g) as a white solid.
¹ H-NMR (400 MHz, CDCl ₃ ) δ 2.32 (s, 3H), 2.50 (m, 4H), 3.55 (m, 4H), 7.65-7.80 (m, 15H)
¹⁹ F-NMR (400 MHz, CDCl ₃ ) δ -118.5 (m, 2F), -112.3 (m, 2F), -111.1 (m, 2F), -78.6 (m3F)

  Other compounds were synthesized in the same manner.

[Example]
i) Preparation of resist composition (Example 1)
Component B (RA-1): 1.255 g
Acid generator (Z-4): 0.0759 g
A component (A-38): 0.02g
Surfactant (W-4): 0.002 g
Was dissolved in the solvent shown in Table 1 below to prepare a solution having a solid content concentration of 6.5% by mass. This solution was filtered through a 0.1 μm polytetrafluoroethylene filter to obtain a resist solution.
Resist solutions of other examples and comparative examples were also obtained in the same manner as described above.

(Ii) Pattern fabrication and evaluation (EB)
Using a spin coater, the positive resist solution prepared as described above is uniformly applied on a silicon wafer that has been subjected to hexamethyldisilazane treatment, and is heated and dried at 120 ° C. for 90 seconds to obtain a positive film having a thickness of 0.15 μm. A mold resist film was formed. The resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750 manufactured by Hitachi, Ltd., acceleration voltage 50 KeV). After irradiation, it was baked at 110 ° C. for 90 seconds, immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds and dried. The obtained pattern was evaluated by the following method.

[sensitivity]
The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4800, manufactured by Hitachi, Ltd.). The minimum irradiation energy when resolving a 150 nm line (line: space = 1: 1) was defined as sensitivity.

[resolution]
The line size (line: space = 1: 1) in which separation resolution is recognized even when a part of the pattern is tilted at the irradiation amount exhibiting the above sensitivity is defined as the critical resolution size,
This was defined as resolution.

[Line edge roughness (LER)]
The distance from the reference line where there should be an edge using a scanning electron microscope (S-9220, manufactured by Hitachi, Ltd.) at any 30 points in the length direction of 50 μm of the 150 nm line pattern at the irradiation dose showing the sensitivity described above. Was measured, the standard deviation was obtained, and 3σ was calculated. A smaller value means better performance.

[Dimension before collapse]
The pattern size (line: space = 1: 1) in which separation resolution was recognized without any pattern collapse at the above-mentioned sensitivity was defined as the dimension before collapse, and an index of the degree of collapse suppression It was. A smaller value means better performance.
[Outgas]
Evaluation was performed based on the variation rate of the film thickness when the minimum irradiation energy was applied when resolving the 150 nm line (line: space = 1: 1).
Outgas: ((film thickness before exposure) − (film thickness after exposure)) / (film thickness before exposure) × 100
Here, the film thickness after exposure refers to the film thickness immediately after exposure, and is the film thickness before entering the PEB or alkali development step. A smaller value means better performance.

  The abbreviations shown in Tables 1 to 3 are shown below.

<Resin>

  <Acid generator>

<Basic compound>
N-1: Trioctylamine N-2: 1,5-diazabicyclo [4.3.0] -5-nonene N-3: 2,4,6-triphenylimidazole

<Surfactant>
W-1: Megafuck F176 (manufactured by Dainippon Ink & Chemicals, Inc.)
W-2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.)
W-3: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)
W-4: Polyoxyethylene lauryl ether

<Solvent>
S-1: Propylene glycol monomethyl ether acetate S-2: Propylene glycol monomethyl ether S-3: Ethyl lactate S-4: Cyclohexanone

  As shown in Tables 1 to 3, the resist composition of the present invention improves the outgas performance without degrading the resolution, LER, and pattern collapse performance of the resist composition of the comparative example. I understand that.

Using the resist compositions of Examples 1, 2, 4, 6, 8, and Comparative Examples 1 and 2, a resist film was obtained in the same manner as in Example 1. EUV light (wavelength: 13.5 nm) was applied to the resulting resist film.
The surface exposure was performed while changing the exposure amount by 0.5 mJ in the range of 0 to 20.0 mJ, and further baked at 110 ° C. for 90 seconds. Then, using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, the dissolution rate at each exposure amount was measured to obtain a sensitivity curve. In this sensitivity curve, the exposure amount when the dissolution rate of the resist is saturated was taken as sensitivity, and the dissolution contrast (γ value) was calculated from the gradient of the linear portion of the sensitivity curve. The larger the γ value, the better the dissolution contrast. These results were considered as Examples 38 to 42 and Comparative Examples 9 and 10, respectively.
The evaluation results are shown in Table 4.

  From the results in Table 4, it can be seen that the composition of the present invention has good sensitivity and dissolution contrast even by EUV exposure.

Claims (4)

(B) a polymer having a weight-average molecular weight of 1,000 to 5,000 having a group that can be decomposed by the action of an acid and having increased solubility in an alkaline developer by the action of the acid;
(Z) A resist composition comprising a compound having a sulfonium cation having a structure represented by the general formula (Z-I).

In general formula (Z-I),
Y ^{1 to} Y ¹³ each independently represent a hydrogen atom or a substituent, and adjacent ones may be bonded to each other to form a ring.
Z represents a single bond or a divalent linking group. 2. The resist composition according to claim 1, further comprising (A) a compound that generates a compound having a structure represented by the following general formula (AI) upon irradiation with actinic rays or radiation.
_{Q 1 -X 1 -NH-X 2} -Q 2 (A-I)
In general formula (AI), Q ₁ and Q ₂ each independently represents a monovalent organic group. However, either Q ₁ or Q ₂ contains a proton acceptor functional group. Q ₁ and Q ₂ may combine to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ and X ₂ each independently represent —CO— or —SO ₂ —. 3. The resist composition according to claim 1, wherein the compound having a structure represented by the general formula (AI) is a compound having a structure represented by the following general formula (A-II): object.
_{Q 1 -X 1 -NH-X 2} -A- (X 3) n -B-Q 3 (A-II)
In general formula (A-II), Q ₁ and Q ₃ each independently represents a monovalent organic group. However, _one of Q ₁ and Q ₃ contains a proton acceptor functional group. Q ₁ and Q ₃ may combine to form a ring, and the formed ring may have a proton acceptor functional group.
X ₁ , X ₂ and X ₃ each independently represent —CO— or —SO ₂ —.
A represents a divalent linking group.
B represents a single bond, an oxygen atom, or —N (Qx) —.
Qx represents a hydrogen atom or a monovalent organic group.
When B is —N (Qx) —, Q ₃ and Qx may combine to form a ring.
n represents 0 or 1.   A pattern forming method comprising: forming a resist film from the resist composition according to claim 1; and exposing and developing the resist film.