JP2010061087A - Positive resist composition for electron beam, x-ray or euv, and pattern forming method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive resist composition minimized in the performance fluctuation resulting from fluctuation of a baking condition, and a pattern forming method using the same. <P>SOLUTION: The resist composition for electron beam, X-ray or EUV includes: (A) a resin which is decomposed by the effect of acid and increased in the rate of solution to alkali aqueous solution; (B) a compound which generates an acid by irradiation with active ray or radiant ray; (C) a compound having nitrogenous basic group or quaternary ammonium group, which has a volatilization volume of 10% or less when held at 120°C for 15 minutes; and (D) an organic solvent. The concentration of the whole solid component in the composition is 1.0 to 4.5 mass%, and the total quantity of the compound which generates an acid by irradiation with active ray or radiant ray (B) is at least 10 mass% relative to the whole solid component in the composition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a positive resist composition suitably used in an ultramicrolithography process such as the manufacture of VLSI and high-capacity microchips and other photo-publishing processes. More particularly, the present invention relates to a positive type photoresist that can form a high-definition pattern using an electron beam, X-ray, EUV light or the like, and is used for fine processing of a semiconductor element using an electron beam, X-ray, or EUV light. The present invention relates to a positive resist composition that can be suitably used and a pattern forming method using the same.

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

Lithography using an electron beam or EUV light is positioned as a next-generation or next-generation pattern forming technique, and a positive resist with high sensitivity is desired.
In particular, high sensitivity is an important issue for shortening the wafer processing time. A chemically amplified positive resist generally comprises a resin in which an alkali-soluble group is protected with an acid-decomposable group to make it insoluble in alkali, a photoacid generator, and a basic compound. The photoacid generator is decomposed by exposure to generate an acid, the acid decomposes the acid-decomposable group while diffusing in the resist film, and the resin is alkali-solubilized. Therefore, in order to increase sensitivity, it is desirable to increase the amount of acid generated and to diffuse the acid to promote the deprotection reaction.
On the other hand, acid diffusion leads to image blurring and degrades image performance such as resolution. The basic compound functions to quench the acid and suppress excessive acid diffusion. Therefore, in order to achieve both sensitivity and resolution, it is necessary to achieve both suppression of acid diffusion and promotion of deprotection.
In particular, when an extremely fine pattern is to be formed, the aspect ratio of the resist pattern to be formed (resist pattern height / resist pattern width) must be kept below a certain value to prevent pattern collapse. Therefore, it is necessary to reduce the thickness of the resist film.

As described below, in Patent Documents 1 to 3, a resist composition containing a basic compound having a carboxyl group is described. From the viewpoint of the resist film thickness and the content of the photoacid generator, It is considered that this is not a system in which the volatility of the volatile compound becomes a problem.
Patent Documents 1 and 2 describe a photosensitive composition to which an amine compound selected from imidazole, alanine, adenine, and adenosine compound is added in order to suppress sensitivity, resolution, and phase separation in a film state in patterning by KrF exposure. Disclosure.
Patent Document 3 discloses a radiation-sensitive resin composition containing a compound having a nitrogen-containing basic group and an acidic group such as phenylalanine and nicotinic acid in order to improve developability, pattern shape, and resolution in patterning by KrF exposure. Disclosure.

JP-A-6-266111 Japanese Patent Laid-Open No. 7-146558 Japanese Patent Laid-Open No. 5-289340

In addition, in a system in which a large amount of a photoacid generator is added for high sensitivity and the resist film thickness is thin, the basic compound is very volatile at the time of baking (prebaking) before exposure. There has been a problem that the resist image performance fluctuates due to a change in the amount remaining in the resist film. Increasing the molecular weight of the basic compound is an effective means for reducing volatility, but the image performance may be greatly impaired due to an increase in the added mass.
An object of the present invention is to solve the problem of performance improvement technology in microfabrication of a semiconductor device using actinic rays or radiation, particularly electron beam, X-ray or EUV light, and a thin resist film (for example, film thickness) Is a positive resist composition having a small performance fluctuation due to fluctuations in baking conditions and a pattern forming method using the same.

The present inventor has found that the addition of a specific compound (component (C) below) functions to control acid diffusion and can reduce performance fluctuations due to fluctuations in baking conditions despite having a relatively low molecular weight. The present invention has been reached.
The present invention is as follows.

(1) (A) a resin that is decomposed by the action of an acid to increase the dissolution rate in an alkaline aqueous solution;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) a compound having a nitrogen-containing basic group or a quaternary ammonium group having a volatilization amount of 10% or less when held at 120 ° C. for 15 minutes, and
(D) a composition containing an organic solvent,
The concentration of total solids in the composition is 1.0 to 4.5 wt%,
(B) The positive amount for electron beam, X-ray or EUV, characterized in that the total amount of compounds generating an acid upon irradiation with actinic rays or radiation is at least 10% by mass with respect to the total solid content in the composition Type resist composition.

  (2) The positive resist composition for electron beam, X-ray or EUV according to (1) above, wherein the component (C) is a compound having a nitrogen-containing basic group and a carboxyl group.

  (3) The molecular weight of the compound having a nitrogen-containing basic group and a carboxyl group is 100 to 500, and the content of the compound having the nitrogen-containing basic group and the carboxyl group is (B) actinic rays or radiation The positive resist composition for electron beam, X-ray or EUV according to (2) above, wherein the molar amount of the compound that generates an acid upon irradiation is 0.1 to 0.5 times mole. object.

  (4) The electron according to any one of (1) to (3) above, wherein the compound that generates an acid upon irradiation with actinic rays or radiation is a compound represented by the following general formula (I): A positive resist composition for X-ray, X-ray or EUV.

In general formula (I),
R ^{1 to} R ¹³ each independently represents a hydrogen atom or a substituent.
Z is a single bond or a divalent linking group.
X ⁻ represents a counter anion.

  (5) The resin that decomposes by the action of an acid and increases the dissolution rate in an alkaline aqueous solution has a repeating unit represented by the following general formula (II) and a repeating unit represented by the general formula (III) The positive resist composition for electron beam, X-ray or EUV according to any one of (1) to (4) above.

In general formulas (II) and (III):
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, an aryloxy 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 when there are a plurality thereof, they may be the same or different.
m and n each independently represents an integer of 0 to 4.

  (6) (A) The weight average molecular weight of the resin that is decomposed by the action of an acid to increase the dissolution rate in an alkaline aqueous solution is 1500 to 5000, according to any one of the above (1) to (5) The positive resist composition for electron beam, X-ray or EUV described.

  (7) A step of forming a resist film using the positive resist composition as described in any one of (1) to (6) above, and exposing and developing with an electron beam, X-rays or EUV light. A pattern forming method.

  INDUSTRIAL APPLICABILITY According to the present invention, a positive resist composition having a small performance variation due to variations in baking conditions and a pattern forming method using the same can be provided.

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).

[1] Resin (A) which decomposes by the action of an acid and increases the solubility in an alkali developer
Resins that are decomposed by the acid used in the positive resist composition of the present invention and have increased solubility in an alkaline developer (hereinafter also referred to as “acid-decomposable resins”) are resin main chains or side chains, or The resin having a group (acid-decomposable group) that decomposes by the action of an acid to generate an alkali-soluble group in both the main chain and the side chain. Among these, a resin having an acid-decomposable group in the side chain is more preferable.

A preferable group as the acid-decomposable group is a group in which a hydrogen atom of an alkali-soluble group such as a —COOH group or a —OH group is substituted with a group capable of leaving with an acid.
In the present invention, the acid-decomposable group is preferably an acetal group or a tertiary ester group.

  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, when formed as a resist film, is preferably 80 kg / sec or more as measured with 0.261N tetramethylammonium hydroxide (TMAH) (23 ° C.). Particularly preferably, it is 160 Å / second or more.

The acid-decomposable resin preferably contains a repeating unit having an aromatic group, and particularly preferably an acid-decomposable resin having a hydroxystyrene repeating unit (hereinafter also referred to as “resin (A1)”). More preferably, hydroxystyrene / hydroxystyrene copolymer protected with an acid-decomposable group and hydroxystyrene / (meth) acrylic acid tertiary alkyl ester are preferred.
Specific examples of the resin (A1) 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.

  As the resin (A1), 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.

In general formulas (II) and (III):
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, an aryloxy 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 when there are a plurality thereof, they may be the same or different.
m and n each independently represents an integer of 0 to 4. However, m and n are preferably not 0 at the same time.

Further, as the resin (A1), a repeating unit represented by the general formula (II), the general formula (III)
And a resin having a repeating unit represented by formula (IV). In this case, m = n = 0 may be used.

In general formula (IV),
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). This produces hydroxystyrene units. This increases the solubility of the resin in an alkaline developer.

In the general formulas (II) to (IV), 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. It is.
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, alkoxy group, hydroxyl group, halogen atom, nitro group, acyl group, acyloxy group, acylamino group, sulfonylamino group, alkylthio group, arylthio group, aralkylthio group, 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.
Further, it is preferable that either one of L _1, L ₂ is a hydrogen atom.

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 .
Examples of the aryloxy group as Q include a phenoxy group, a naphthoxy group, and a terphenyloxy group.
Examples of the alicyclic group or aromatic ring group which may contain a hetero atom as Q include the cycloalkyl group and aryl group as L ₁ and L ₂ described above, preferably 3 to 15 carbon atoms. It is.
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 ,
Examples include a case where at least two of Q, M, and L ₁ are bonded to form, for example, a propylene group or a butylene group to form a 5-membered or 6-membered ring containing an oxygen atom.

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 cyano 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).
Examples of the acyl group, alkyl group, alkoxy group, acyloxy group or alkoxycarbonyl group as B in the general formula (IV) include the same groups as A in the general formula (II). An acyloxy group and an alkoxycarbonyl group are preferable, and an acyloxy group is more preferable. Among acyloxy groups (represented by the general formula —O—CO—R _A , where R _A is an alkyl group), those having 1 to 6 carbon atoms in _RA are preferred, and those having 1 to 3 carbon atoms in _RA. Are more preferable, and those in which R _A has 1 carbon atom (that is, an acetoxy group) are particularly preferable.
p represents an integer of 0 to 5, preferably 0 to 2, more preferably 1 to 2, and still more preferably 1.

  Each of the above groups may have a substituent, and preferred substituents include a hydroxyl group, a carboxyl group, a cyano 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).

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

  The resin (A1) may have a repeating unit represented by the following general formula (V).

In general formula (V),
R _{a to} R _c 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.

In general formula (V), the alkyl group as R _{a to} R _c 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.

Non-acid-decomposable groups include, for example, alkyl groups, cycloalkyl groups, alkenyl groups, aryl groups, alkyloxy groups (excluding -O-tertiary alkyl), acyl groups, cycloalkyloxy groups, alkenyloxy groups. 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, and aryl groups having 6 to 14 carbon atoms such as phenyl group, xylyl group, toluyl group, cumenyl group, naphthyl group, and anthracenyl group are preferable. As the alkoxy group, 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, and a sec-butoxy group is preferable.

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 represents 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 any of the following general formulas (pI) to (pV).

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 (pV), the alkyl group in R _{12 to} R ₂₅ may be either substituted or unsubstituted, and 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.).

Further, the resin (A1) 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 0 to 50 mol%, more preferably 10 to 40 mol%, and 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 carboxy group or a sulfonic acid group other than a hydroxyl group is preferably 0 to 10 mol%, more preferably 1 to 8 mol%, in all repeating units constituting the resin. Most preferably, it is 2-6 mol%.
The content of the repeating unit having an acid-decomposable group is preferably 5 to 60 mol%, more preferably 10 to 55 mol%, and particularly preferably 10 to 50 mol% in all repeating units constituting the resin (A1). It is.

  The synthesis of the resin (A1) is a precursor of a group that can be decomposed with an acid into an alkali-soluble resin, as described in European Patent No. 254853, JP-A-2-258500, 3-223860, and 4-251259. It can be synthesized by a known synthesis method such as a method of reacting the above, or a method of copolymerizing a monomer having a group decomposable with an acid with various monomers.

The weight average molecular weight of the resin (A1) is preferably 15000 or less, more preferably 1,000 to 10,000, still more preferably 1,500 to 5,000, particularly preferably as a polystyrene equivalent value by GPC method. 2,000 to 3,000.
The dispersity (Mw / Mn) of the resin (A1) 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 (A1) in combination of 2 or more types.

  Specific examples of the resin (A1) are shown below, but are not limited thereto.

  In the positive resist composition of the present invention, the blending amount of the acid-decomposable resin in the composition is preferably 45 to 90% by mass, more preferably 55 to 85% by mass, and even more, based on the total solid content of the composition. Preferably it is 60-80 mass%.

[2] Compound that generates acid upon irradiation with actinic ray or radiation (acid generator) (B)
As an acid generator, photo-initiator of photocation polymerization, photo-initiator of photo-radical polymerization, photo-decoloring agent of dyes, photo-discoloring agent, or irradiation with actinic ray or radiation used for micro-resist etc. Known compounds that generate acids and mixtures thereof can be appropriately selected and used.

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

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

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

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

In the general formula (ZI),
R ₂₀₁ , R ₂₀₂ and R ₂₀₃ each independently represents an organic group.
The carbon number of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ is generally 1 to 30, preferably 1
~ 20.
Two of R _{201 to} R ₂₀₃ may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester bond, an amide bond, or a carbonyl group. The two of the group formed by bonding of the R ₂₀₁ to R _203, there can be mentioned an alkylene group (e.g., butylene, pentylene).
Z ⁻ represents a non-nucleophilic anion.

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

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

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

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

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

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

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

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

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

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

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

  Examples of the sulfonylimide anion include saccharin anion.

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

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

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

Examples of the organic group as R ₂₀₁ , R ₂₀₂ and R ₂₀₃ include the corresponding groups in the compounds (ZI-1), (ZI-2) and (ZI-3) described later.

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

  More preferable (ZI) components include compounds (ZI-1), (ZI-2), and (ZI-3) described below.

The compound (ZI-1) is at least one of the aryl groups R ₂₀₁ to R ₂₀₃ in formula (ZI), arylsulfonium compounds, namely, compounds containing an arylsulfonium as a cation.

In the arylsulfonium compound, all of R _{201 to} R ₂₀₃ may be an aryl group, or R ₂₀₁
Some of to R ₂₀₃ is an aryl group and the remainder may be an alkyl group or a cycloalkyl group.

  Examples of the arylsulfonium compound include triarylsulfonium compounds, diarylalkylsulfonium compounds, aryldialkylsulfonium compounds, diarylcycloalkylsulfonium compounds, and aryldicycloalkylsulfonium compounds.

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

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

Aryl group, alkyl group of R ₂₀₁ to R _203, cycloalkyl group, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms), an aryl group (for example, 6 to 14 carbon atoms) , An alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, or a phenylthio group may be substituted. Preferred substituents are linear or branched alkyl groups having 1 to 12 carbon atoms, cycloalkyl groups having 3 to 12 carbon atoms, and linear, branched or cyclic alkoxy groups having 1 to 12 carbon atoms, more preferably carbon. These are an alkyl group having 1 to 4 carbon atoms and an alkoxy group having 1 to 4 carbon atoms. The substituent may be substituted with any one of the three R _{201 to} R ₂₀₃ , or may be substituted with all three. When R _{201 to} R ₂₀₃ are an aryl group, the substituent is preferably substituted at the p-position of the aryl group.

Next, the compound (ZI-2) will be described.
Compound (ZI-2) is a compound in which R _{201 to} R ₂₀₃ in formula (ZI) each independently represents an organic group having no aromatic ring. Here, the aromatic ring includes an aromatic ring containing a hetero atom.

The organic group having no aromatic ring as R ₂₀₁ to R ₂₀₃ generally has 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms.

R _{201 to} R ₂₀₃ are each independently preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, 2-oxocycloalkyl group, alkoxy group. A carbonylmethyl group, particularly preferably a linear or branched 2-oxoalkyl group.

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

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

  The alkoxy group in the alkoxycarbonylmethyl group is preferably an alkoxy group having 1 to 5 carbon atoms (methoxy group, ethoxy group, propoxy group, butoxy group, pentoxy group).

R _{201 to} R ₂₀₃ may be further substituted with a halogen atom, an alkoxy group (for example, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.

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

In general formula (ZI-3),
R _1c to R _5c each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group or a halogen atom.
R _6c and R _7c each independently represents a hydrogen atom, an alkyl group or a cycloalkyl group.
R _x and R _y independently represents an alkyl group, a cycloalkyl group, an allyl group or a vinyl group.

Any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y may be bonded to each other to form a ring structure, and this ring structure includes an oxygen atom and a sulfur atom. , An ester bond and an amide bond may be included. Examples of the group formed by combining any two or more of R _{1c to} R _5c , R _6c and R _7c , and R _x and R _y include a butylene group and a pentylene group.

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

The alkyl group as R _1c to R _7c may be linear or branched may be any of, for example, alkyl group having 1 to 20 carbon atoms, preferably 1 to 12 linear or branched alkyl group having a carbon number ( Examples thereof include a methyl group, an ethyl group, a linear or branched propyl group, a linear or branched butyl group, and a linear or branched pentyl group. Examples of the cycloalkyl group include cyclohexane having 3 to 8 carbon atoms. An alkyl group (for example, a cyclopentyl group, a cyclohexyl group) can be mentioned.

The alkoxy group as R _{1c to} R _{5c may} be linear, branched or cyclic, for example, an alkoxy group having 1 to 10 carbon atoms, preferably a linear or branched alkoxy group having 1 to 5 carbon atoms. (For example, methoxy group, ethoxy group, linear or branched propoxy group, linear or branched butoxy group, linear or branched pentoxy group), C3-C8 cyclic alkoxy group (for example, cyclopentyloxy group, cyclohexyloxy group) ).

Preferably, any of R _{1c to} R _5c is a linear or branched alkyl group, a cycloalkyl group, or a linear, branched or cyclic alkoxy group, and more preferably the sum of the carbon number of R _{1c to} R _5c. Is 2-15. Thereby, solvent solubility improves more and generation | occurrence | production of a particle is suppressed at the time of a preservation | save.

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

Examples of the 2-oxoalkyl group and 2-oxocycloalkyl group include a group having> C═O at the 2-position of the alkyl group or cycloalkyl group as R _{1c to} R _7c .

Examples of the alkoxy group in the alkoxycarbonylmethyl group include the same alkoxy groups as in R _{1c to} R _5c .

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

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

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

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

Aryl group, alkyl group of R ₂₀₄ to R _207, cycloalkyl groups may have a substituent. Aryl group, alkyl group of R ₂₀₄ to R _207, the cycloalkyl group substituent which may be possessed by, for example, an alkyl group (for example, 1 to 15 carbon atoms), a cycloalkyl group (for example, 3 to 15 carbon atoms ), An aryl group (for example, having 6 to 15 carbon atoms), an alkoxy group (for example, having 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.

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

  Examples of the compound that generates an acid upon irradiation with actinic rays or radiation that can be used further include compounds represented by the following general formulas (ZIV), (ZV), and (ZVI).

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

Of the compounds that generate an acid upon irradiation with actinic rays or radiation, compounds represented by general formulas (ZI) to (ZIII) are more preferable.
Further, as a compound that generates an acid by radiation of actinic rays or radiation, a compound that generates an acid having one sulfonic acid group or imide group is preferable, and a compound that generates monovalent perfluoroalkanesulfonic acid, more preferably, Or a compound generating an aromatic sulfonic acid substituted with a monovalent fluorine atom or a group containing a fluorine atom, or a compound generating an imido acid substituted with a monovalent fluorine atom or a group containing a fluorine atom Even more preferably, it is a sulfonium salt of fluorinated substituted alkane sulfonic acid, fluorine substituted benzene sulfonic acid or fluorine substituted imido acid. The acid generator that can be used is particularly preferably a fluorinated substituted alkane sulfonic acid, a fluorinated substituted benzene sulfonic acid or a fluorinated substituted imido acid whose pKa of the generated acid is pKa = -1 or less, and the sensitivity is improved. .

  Among the compounds that generate an acid upon irradiation with actinic rays or radiation, particularly preferred examples are given below.

  As the acid generator, a compound represented by the general formula (I) (acid generator A1) is particularly preferable.

In general formula (I),
R ^{1 to} R ¹³ each independently represents a hydrogen atom or a substituent. Z is a single bond or a divalent linking group.
X ⁻ represents a counter anion.

In the general formula (I), at least one of R ^{1 to} R ¹³ is preferably a substituent containing an alcoholic hydroxyl group. When at least one of R ^{1 to} R ¹³ is a substituent containing an alcoholic hydroxyl group (the alcoholic hydroxyl group represents a hydroxyl group bonded to a carbon atom of an alkyl group), R ^{1 to} R ¹³ are represented by —W—Y. Is done. Y is an alkyl group substituted with a hydroxyl group, and W is a single bond or a divalent linking group.

The alkyl group of Y is methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl Group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group Preferably ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group and sec-butyl group, more preferably ethyl group, propyl group and isopropyl group. Y particularly preferably contains a —CH ₂ CH ₂ OH structure.

  The divalent linking group represented by W is not particularly limited, and examples thereof include an alkoxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an acylamino group, an aminocarbonylamino group, Alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, alkylthio group, arylthio group, sulfamoyl group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxy Examples thereof include a divalent group in which an arbitrary hydrogen atom in a monovalent group such as a carbonyl group, an alkoxycarbonyl group, or a carbamoyl group is replaced with a single bond.

  W is preferably a single bond, an alkoxy group, an acyloxy group, an acylamino group, an alkyl and arylsulfonylamino group, an alkylthio group, an alkylsulfonyl group, an acyl group, an alkoxycarbonyl group, and any hydrogen atom in the carbamoyl group replaced with a single bond. It is a divalent group, more preferably a divalent group in which any hydrogen atom in a single bond, acyloxy group, alkylsulfonyl group, acyl group or alkoxycarbonyl group is replaced with a single bond.

When R ^{1 to} R ¹³ are substituents containing an alcoholic hydroxyl group, the number of carbon atoms contained is preferably 2 to 10, more preferably 2 to 6, and particularly preferably 2 to 4. .
The substituent containing an alcoholic hydroxyl group as R ^{1 to} R ¹³ may have two or more alcoholic hydroxyl groups. The number of alcoholic hydroxyl groups having a substituent containing an alcoholic hydroxyl group as R ^{1 to} R ¹³ is 1 to 6, preferably 1 to 3, and more preferably 1. preferable.
The number of alcoholic hydroxyl groups of the compound represented by the general formula (I) is 1 to 10 in total, preferably 1 to 6, more preferably 1 in total for R ^{1 to} R ^13. It is three from.

When R ^{1 to} R ¹³ do not contain an alcoholic hydroxyl group, R ^{1 to} R ¹³ are each independently a hydrogen atom or a substituent, and any substituent may be used without any particular limitation. Atoms, alkyl groups (including cycloalkyl groups, bicycloalkyl groups, and tricycloalkyl groups), alkenyl groups (including cycloalkenyl groups and bicycloalkenyl groups), alkynyl groups, aryl groups, and heterocyclic groups (referred to as heterocyclic groups) Cyano group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group ( Anilino group), ammonio group, acylamino group, aminocarbonyl group Group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, mercapto group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl and aryl Sulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxycarbonyl group, alkoxycarbonyl group, carbamoyl group, aryl and heterocyclic azo group, imide group, phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino Group, phosphono group, silyl group, hydrazino group, ureido group, boronic acid group (—B (OH) ₂ ), phosphato group (—OPO (OH) ₂ ), sulfato group (—OSO ₃ H), and other known ones Substituents are mentioned as examples.

In addition, two adjacent R ^{1 to} R ¹³ may be combined to form a ring (aromatic or non-aromatic hydrocarbon ring or heterocyclic ring. These may be further combined to form a polycyclic fused ring. 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, Phenanthridine ring, acridine ring, Ntororin ring, thianthrene ring, chromene ring, xanthene ring, phenoxathiin ring, a phenothiazine ring and a phenazine ring.) May also be formed.

When R ^{1 to} R ¹³ do not contain an alcoholic hydroxyl group, R ^{1 to} R ¹³ are preferably a hydrogen atom or a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group), an alkenyl group ( (Including cycloalkenyl groups and bicycloalkenyl groups), alkynyl groups, aryl groups, cyano groups, carboxyl groups, alkoxy groups, aryloxy groups, acyloxy groups, carbamoyloxy groups, acylamino groups, aminocarbonylamino groups, alkoxycarbonylamino groups , Aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, alkylthio group, arylthio group, sulfamoyl group, alkyl and arylsulfonyl group, aryloxycarbonyl group, alkoxycarbonyl , A carbamoyl group, an imido group, a silyl group, a ureido group.

When R ^{1 to} R ¹³ do not contain an alcoholic hydroxyl group, R ^{1 to} R ¹³ are more preferably a hydrogen atom or a halogen atom, an alkyl group (including a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group), a cyano group. , Alkoxy group, acyloxy group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, alkyl and arylsulfonylamino group, alkylthio group, sulfamoyl group, alkyl and arylsulfonyl group, alkoxycarbonyl group and carbamoyl group.
Further, when R ^{1 to} R ¹³ do not contain an alcoholic hydroxyl group, R ^{1 to} R ¹³ are particularly preferably a hydrogen atom or an alkyl group (including a cycloalkyl group, a bicycloalkyl group and a tricycloalkyl group), a halogen atom, An alkoxy group;

In general formula (I), at least one of R ^{1 to} R ¹³ contains an alcoholic hydroxyl group, and preferably at least one of R ^{9 to} R ¹³ contains an alcoholic hydroxyl group.

Z represents a single bond or a divalent linking group, and examples of the divalent linking group include an alkylene group, an arylene group, a carbonyl group, a sulfonyl group, a carbonyloxy group, a carbonylamino group, a sulfonylamide group, an ether group, and a thioether. Group, amino group, disulfide group, acyl group, alkylsulfonyl group, —CH═CH—, —C≡C—, aminocarbonylamino group, aminosulfonylamino group, etc., which may have a substituent. These substituents are the same as the substituents shown for R ^{1 to} R ¹³ above. Z preferably has a single bond, alkylene group, arylene group, ether group, thioether group, amino group, —CH═CH—, —C≡C—, aminocarbonylamino group, aminosulfonylamino group, etc. A substituent, more preferably a single bond, an ether group or a thioether group, particularly preferably a single bond.

The compound represented by the general formula (I) has a counter anion X ⁻ . As an anion, an organic anion is desirable. An organic anion represents an anion containing 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 alkyl sulfonate anion, an aryl sulfonate anion, and a camphor sulfonate anion. Examples of the non-nucleophilic carboxylate anion include an alkylcarboxylate anion, an arylcarboxylate anion, and an aralkylcarboxylate anion.

The alkyl moiety in the alkyl sulfonate anion may be an alkyl group or a cycloalkyl group, and preferably an alkyl group having 1 to 30 carbon atoms and a cycloalkyl group having 3 to 30 carbon atoms, such as a methyl group or an ethyl group. Group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group Tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group and the like.
The aryl group in the aryl 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 alkyl sulfonate anion and aryl 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 May include 2 to 7 carbon atoms, an acyl group (preferably 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferably 2 to 7 carbon atoms), and the like. About the aryl group and ring structure which each group has, an alkyl group (preferably C1-C15) can further be mentioned as a substituent.

  Examples of the alkyl moiety in the alkylcarboxylate anion include the same alkyl group and cycloalkyl group as in the alkylsulfonate anion. Examples of the aryl group in the arylcarboxylate anion include the same aryl groups as in the arylsulfonate 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 alkyl group, cycloalkyl group, aryl group and aralkyl group substituent in the alkylcarboxylate anion, arylcarboxylate anion and aralkylcarboxylate anion include, for example, the same halogen atom, alkyl group as in the arylsulfonate anion, A cycloalkyl group, an alkoxy group, an alkylthio group, etc. 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 X ⁻ of the compound represented by the general formula (I) is preferably a sulfonate anion, and more preferably an aryl 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, 2,4,6-trimethylbenzenesulfonate anion, and the like.

  200-2000 are preferable and, as for the molecular weight of the compound represented by general formula (I), 400-1000 are especially preferable.

  The compound represented by the general formula (I) is a method in which a benzene derivative containing a hydroxyl group protected by a protecting group as a substituent and a cyclic sulfoxide compound are condensed to form a sulfonium salt, and the protecting group of the hydroxyl group is deprotected, etc. Can be synthesized.

  In the figure, W is a divalent linking group, R is an alkylene group, and P is a protecting group.

Examples of acids used for the reaction of sulfoniumation include methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, pentanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, p-ethylbenzenesulfonic acid, Nonafluorobutanesulfonic acid and the like can be mentioned, and the conjugate base of the acid used becomes the anion of sulfonium. Examples of the condensing agent used in the sulfoniumation reaction include acid anhydrides, such as trifluoroacetic acid anhydride, polyphosphoric acid, methanesulfonic acid anhydride, trifluoromethanesulfonic acid anhydride, p-toluenesulfonic acid anhydride, nona. Examples include strong acid anhydrides such as fluorobutanesulfonic anhydride, tetrafluorosuccinic anhydride, hexafluoroglutaric anhydride, chlorodifluoroacetic anhydride, pentafluoropropionic anhydride, heptafluorobutanoic anhydride.
Examples of the hydroxyl-protecting group P include ethers and esters, and examples include methyl ether, aryl ether, benzyl ether, acetic acid ester, benzoic acid ester, and carbonic acid ester.
The counter anion X ⁻ can be converted into a desired anion by passing through an ion exchange resin and adding a conjugate acid of the target anion.

Although the specific example of a compound represented by general formula (I) below is shown, it is not limited to these.

An acid generator can be used individually by 1 type or in combination of 2 or more types.
In this invention, content of an acid generator is at least 10 mass% with respect to the total solid of a composition, Preferably it is 10-50 mass%, More preferably, it is 20-50 mass%, More preferably Is 22-50% by mass, particularly preferably 25-50% by mass, most preferably 25-40% by mass.

In ArF or KrF exposure, the photo-energy photoacid generator incident on the resist is absorbed, and the photoacid generator in an excited state is decomposed to generate an acid. Therefore, the absorption rate of incident light is determined by the molecular extinction coefficient of the photoacid generator and the concentration of the photoacid generator. On the other hand, from the viewpoint of the pattern shape, the light absorption rate of the resist is increased and the transmittance is about Since it is known that the resist pattern shape deteriorates when it is less than 70%, the concentration of the photoacid generator is naturally limited.
In contrast, in EUV or EB exposure, the energy per incident photon or electron is very high compared to conventional ArF or KrF exposure, and the absorption rate of the energy hardly depends on the chemical structure of the resist. Therefore, it is considered that there is no restriction on the photoacid generator concentration from the transmittance.
On the other hand, it has been found that when the photoacid generator concentration is increased, the photoacid generators aggregate with each other, resulting in a decrease in acid generation efficiency and deterioration in stability. In the present invention, the conventional ArF and KrF resists are effectively used by optimizing the solid content concentration even with a high concentration of photoacid generator, which could not be used due to problems of transmittance and aggregation of the photoacid generator. I found out that I can do it. Although this was a completely unexpected effect, the resist film was maintained by maintaining an appropriate concentration of the photoacid generator in the state of the resist solution (this point relates to the “total solid content concentration” described later). It is considered that a stable dispersed state has been maintained even after it has been made.

[3] Compound having nitrogen-containing basic group or quaternary ammonium group (compound (C))
The present inventor has found that by using a specific compound (C), even in a thin film and low Tg resist film system, the additive can be left in the film. Despite the molecular weight, we succeeded in reducing performance fluctuations due to changes in baking conditions.
In the present invention, the volatilization amount when held at 120 ° C. for 15 minutes is defined as a value obtained by standardizing the amount of mass decrease before and after the measurement target compound is held in the temperature environment, normalized by the initial mass. However, it is preferable to measure using a thermogravimetric analyzer (TGA).

Under relatively thick film conditions where the resist film thickness exceeds 100 nm, the additive added to the resist solution remains in the resist film after coating and heating regardless of its volatility, but the film thickness is 80 nm or less. It was found that volatilization by coating and heating becomes a significant problem in thin film systems. Furthermore, it has been clarified that in a system in which a low molecular weight component such as an acid generator coexists in an amount of 10% by mass or more, the Tg of the resist film is lowered and the volatilization amount is increased.
In order for the additive to function effectively in the resist film, it is preferable that 20% or more of the added additive remains, more preferably 50% or more, and particularly preferably 70% or more. It is. Here, the residual amount can be measured by, for example, forming a resist film, redissolving the resist with methanol, and quantifying the amount of additive contained in the resist by HPLC.
In the present invention, a compound having a nitrogen-containing basic group or a quaternary ammonium group has a volatilization amount of 10% or less, preferably 5% or less, particularly preferably 1% when held alone at 120 ° C. for 15 minutes. It is as follows. There is no particular lower limit.

Examples of the nitrogen-containing basic group possessed by the compound (C) include those in the compound (C1) described later.
Specific examples of the compound (C) are shown below, but are not limited thereto.

The molecular weight of the compound (C) is preferably 100 to 500, more preferably 130 to 400, and still more preferably 150 to 300.
The content of the compound (C) is preferably 1.0 to 8.0% by mass, more preferably 1.5 to 5.0% by mass, still more preferably based on the total solid content of the composition. Is 2.0-4.0 mass%.
The content of the compound (C) is preferably 0.1 to 0.5 times the mole of the total amount of the compound generating an acid upon irradiation with actinic rays or radiation, more preferably 0.15. It is -0.4 times mole, Most preferably, it is 0.2-0.3 times mole.

The compound (C) is more preferably a compound (C1) having a nitrogen-containing basic group and a carboxyl group.
Hereinafter, this compound will be described in detail.

The nitrogen-containing basic group of the compound (C1) preferably has, for example, a conjugate acid having a pKa of 4 or more, more preferably 10 or more. There is no particular upper limit, but it is preferably 14 or less.
Preferable examples of the nitrogen-containing basic group include groups having structures represented by the following formulas (A) to (E).

In the formula (A), R ²⁵⁰ , R ²⁵¹ and R ²⁵² each independently represent a hydrogen atom, an alkyl group (
Preferably, it has 1 to 20 carbon atoms, a cycloalkyl group (preferably 3 to 20 carbon atoms) or an aryl group (preferably 6 to 20 carbon atoms), wherein R ²⁵⁰ and R ²⁵¹ are bonded to each other to form a ring. It may be formed. R ²⁵⁰ , R ²⁵¹ and R ²⁵² are not all hydrogen atoms at the same time.
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 alkylene chain.

In the formula (E), R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represents an alkyl group (preferably having 1 to 6 carbon atoms) or a cycloalkyl group (preferably having 3 to 6 carbon atoms).

A plurality of nitrogen-containing basic groups and carboxyl groups may be present in each molecule, and the nitrogen-containing basic group is preferably 1 to 5, more preferably 1 to 3, particularly preferably 1 in one molecule. is there. The carboxyl group is preferably 1 to 5, more preferably 1 to 3, particularly preferably 1 or 2 in one molecule. The number of nitrogen-containing basic groups and the number of carboxyl groups may be the same or different, but preferably the number of nitrogen-containing basic groups is less than or equal to the number of carboxyl groups, more preferably the same number.
The nitrogen-containing basic group and the carboxyl group are preferably connected by a linking group having 1 to 10 atoms, more preferably connected by a linking group having 1 to 6 atoms, and particularly preferably 2 to 3 atoms. Are connected by a linking group. More specifically, the linking group is preferably a group having a linear, branched or cyclic hydrocarbon structure.
In addition to C and H, the atoms constituting the linking group include other atoms such as O and S, and the linking group may comprise -S- and C (= O) O-.
The nitrogen-containing basic group is preferably a secondary, tertiary or cyclic amine, more preferably a tertiary or cyclic amine.

The compound (C1) preferably further contains a hydroxyl group and a halogen atom, and particularly preferably has a hydroxyl group.
Compound (C1) may be used alone or in combination of two or more.

The molecular weight of the compound (C1) is preferably 100 to 500, more preferably 130 to 400, and still more preferably 150 to 300.
Compound (C1) takes the form of zwitterions in the system, and may be, for example, a compound having N ⁺ and COO ⁻ in the resist composition.
The content of the compound (C1) is preferably 1.0 to 8.0% by mass, more preferably 1.5 to 5.0% by mass, still more preferably based on the total solid content of the composition. Is 2.0-4.0 mass%.
The content of the compound (C1) is preferably 0.1 to 0.5 times the mole of the total amount of the compound capable of generating an acid upon irradiation with actinic rays or radiation, more preferably 0.15. It is -0.4 times mole, Most preferably, it is 0.2-0.3 times mole.

  Although the specific example of a compound (C1) is given to the following, it is not limited to these.

  Compound (C1) may be commercially available from Aldrich or the like, or may be synthesized by a known method.

[4] Basic compound having no carboxyl group (C2)
Along with the compound (C1), the resist composition of the present invention may contain a basic compound (C2) having no carboxyl group in order to reduce the change in performance over time from exposure to heating. The basic compound (C2) plays a role of quenching the deprotection reaction by the acid generated by exposure, and its diffusibility and basicity affect the substantial acid diffusibility. The basic compound (C2) is preferably a compound having a higher basicity than the phenolic hydroxyl group.

  Examples of the basic compound (C2) include basic compounds having structures represented by the following formulas (A) to (E).

In the formula (A), R ²⁵⁰ , R ²⁵¹ and R ²⁵² each independently represent a hydrogen atom, an alkyl group (
Preferably, it has 1 to 20 carbon atoms, a cycloalkyl group (preferably 3 to 20 carbon atoms) or an aryl group (preferably 6 to 20 carbon atoms), wherein R ²⁵⁰ and R ²⁵¹ are bonded to each other to form a ring. It may be formed.
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 alkylene chain.

In the formula (E), R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ are each independently an alkyl group (preferably having 1 to 6 carbon atoms) or a cycloalkyl group (preferably having 3 to 6 carbon atoms). Indicates.

These basic compounds (C2) are used alone or in combination of two or more.
The molecular weight of the basic compound (C2) is preferably 250 to 1000, more preferably 250 to 800, and still more preferably 400 to 800.
Content of basic compound (C2) is 1.0-8.0 mass% with respect to the total solid of this composition as a total amount of compound (C1) and basic compound (C2). More preferably, it is 1.5-5.0 mass%, More preferably, it is 2.0-4.0 mass%.

[5] Solid content concentration and solvent (D)
The resist composition of the present invention is prepared by dissolving the above components in a solvent.
In the constitution of the present invention, the total solid content concentration in the resist composition is generally 1.0 to 4.5% by mass, preferably 2.0 to 4.0% by mass, more preferably 2.0 to 3%. 0.0% by mass.
The total solid content corresponds to the composition obtained by removing the solvent, and corresponds to the mass of the dried coating film formed from the composition.

Solvents for preparing the resist composition 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, and other organic solvents Preferably, more preferably cyclohexanone, .gamma.-butyrolactone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, and particularly preferably propylene glycol monomethyl ether.
The solvent may be a single solvent or a mixed solvent in which two or more are mixed.
Of the total amount of solvent, it is particularly preferable to contain 50% by mass or more of propylene glycol monomethyl ether, most preferably 50 to 80% by mass. As the solvent used in combination with propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone and ethyl lactate are preferable, and propylene glycol monomethyl ether acetate is most preferable.

  In addition to the above components, the resist composition of the present invention may contain the following components.

[6] Fluorine-based and / or silicon-based surfactant (E)
The resist composition of the present invention further includes any one of fluorine-based and / or silicon-based surfactants (fluorine-based surfactants and silicon-based surfactants, surfactants containing both fluorine atoms and silicon atoms). Or it is preferable to contain 2 or more types.

  When the resist composition of the present invention contains fluorine and / or a silicon-based surfactant, it is possible to provide a resist pattern with less adhesiveness and development defects with good sensitivity and resolution.

  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 EFTOP EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430 and 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, and 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, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.

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

Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (Dainippon Ink Chemical Co., Ltd.). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy) (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 surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, based on the total solid content of the resist composition.

[7] Dissolution inhibiting compound (F) having a molecular weight of 3000 or less, which is decomposed by the action of an acid to increase the solubility in an alkaline developer.
Hereinafter, it is also referred to as “component (F)” or “dissolution inhibitor compound”.
(F) As a dissolution-inhibiting compound having a molecular weight of 3000 or less that decomposes by the action of an acid and increases its solubility in an alkaline developer, the transmittance of 220 nm or less is not lowered, so Proceeding of SPIE, 2724, 355 (1996) An alicyclic or aliphatic compound containing an acid-decomposable group is preferred, such as a cholic acid derivative containing an acid-decomposable group described in 1).

When the resist composition of the present invention is irradiated with an electron beam, it preferably contains a structure in which the phenolic hydroxyl group of the phenol compound is substituted with an acid-decomposable group. As a phenol compound, what contains 1-9 phenol frame | skeleton is preferable, More preferably, it contains 2-6 pieces.

  The molecular weight of the dissolution inhibiting compound in the present invention is 3000 or less, preferably 300 to 3000, and more preferably 500 to 2500.

  The addition amount of the dissolution inhibiting compound is preferably 3 to 50% by mass, more preferably 5 to 40% by mass, based on the total solid content of the resist composition.

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

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

The dissolution accelerating compound for the developer that can be used in the present invention is a low molecular weight compound having a molecular weight of 1,000 or less and having two or more phenolic OH groups or one or more carboxyl groups. When it has a carboxyl group, an alicyclic or aliphatic compound is preferable.

  A preferable addition amount of these dissolution promoting compounds is 2 to 50% by mass, and more preferably 5 to 30% by mass with respect to the resin of the component (A). 50 mass% or less is preferable at the point of development residue suppression and the pattern deformation prevention at the time of image development.

  Such a phenol compound having a molecular weight of 1,000 or less can be obtained by, for example, the method described in JP-A-4-1222938, JP-A-2-28531, US Pat. No. 4,916,210, European Patent 219294, and the like. It can be easily synthesized by those skilled in the art with reference.

  Specific examples of alicyclic or aliphatic compounds having a carboxyl group include carboxylic acid derivatives having a steroid structure such as cholic acid, deoxycholic acid, lithocholic acid, adamantane carboxylic acid derivatives, adamantane dicarboxylic acid, cyclohexane carboxylic acid, cyclohexane Examples thereof include, but are not limited to, dicarboxylic acids.

  In the present invention, a surfactant other than the above (E) 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.

[9] Pattern Forming Method The resist composition of the present invention is applied on a support such as a substrate to form a resist film. The thickness of this resist film is preferably 20 to 100 nm, more preferably 40 to 80 nm.
As a method of coating on the substrate, spin coating is preferable, and the rotation speed is preferably 1000 to 3000 rpm.

For example, a resist composition is applied onto a substrate (eg, silicon / silicon dioxide coating) used for manufacturing a precision integrated circuit element by an appropriate application method such as a spinner or a coater, and dried to form a resist film. . In addition, a known antireflection film can be applied in advance.
The resist film is irradiated with an electron beam, X-rays or EUV, preferably baked (heated) and developed. Thereby, a good pattern can be obtained.
The baking temperature after exposure is preferably 70 to 140 ° C., and the baking time is preferably 30 to 120 seconds.

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 and the like 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.

Synthesis Example 1 (Synthesis of Resin (RB-19))
p-Acetoxystyrene and (4′-hydroxyphenyl) methacrylate were charged at a ratio (molar ratio) of 60/40 and dissolved in tetrahydrofuran to prepare 100 mL of a solution having a solid content concentration of 20% by mass. To this solution was added 3 mol% of methyl mercaptopropionate and 4 mol% of polymerization initiator V-65 manufactured by Wako Pure Chemical Industries, Ltd., and this was added dropwise to 10 mL of tetrahydrofuran heated to 60 ° C. over 4 hours in a nitrogen atmosphere. did. After completion of the dropwise addition, the reaction solution was heated for 4 hours, 1 mol% of V-65 was added again, and the mixture was stirred for 4 hours. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 3 L of hexane, and the precipitated white powder was collected by filtration.
The composition ratio of the polymer determined from C ¹³ NMR was 58/42. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by GPC measurement was 2200, and dispersion degree (Mw / Mn) was 1.30.
The obtained resin was vacuum-dried and then dissolved in 100 ml of dehydrated THF (tetrahydrofuran). Thereto, 10 ml of cyclohexyl vinyl ether was added and stirred, and 100 mg of p-toluenesulfonic acid was added and reacted for 3 hours. The reaction solution was neutralized by adding 1 ml of triethylamine, 200 ml of ethyl acetate was added, 500 ml of distilled water was further added, and liquid separation and washing were repeated three times. The ethyl acetate layer was reprecipitated with hexane to obtain the target resin RB-19 (composition molar ratio (43/15/32/10), weight average molecular weight 2500, dispersity 1.30. Its glass transition temperature was converted to DSC. Measurement showed 110 ° C.

  Other resins were synthesized by the same method.

[Examples 1 to 22 and Comparative Examples 1 to 25]
<Measurement of additive volatilization>
Measurement was carried out under the following conditions using a differential thermal calorimeter TG / DTA6200 manufactured by Seiko Instruments Inc.
Atmosphere: Nitrogen, gas flow rate 100mL / min
Sample pan: Al
Sample amount: 10mg
Reference: Blank measurement program:
Start: 30 ℃
Limit: 125 ° C
Temperature rising rate: 20 ° C./min Holding time: 15 minutes In the above, the sample was held at 120 ° C. for 15 minutes. The sample mass before and after the measurement was compared, and the TGA volatilization amount under the conditions was determined. The results are shown in Table 2.

<Quantification of remaining amount in resist film>
The components shown in Table 1 were dissolved in a mixed solvent (propylene glycol monomethyl ether acetate (PGMEA): propylene glycol monomethyl ether (PGME) = 6: 4 (mass ratio)), and this was dissolved in polytetrafluoro with a pore size of 0.1 μm. A positive resist composition having a total solid concentration shown in Table 1 is prepared by filtration through an ethylene filter, and uniformly applied onto a hexamethyldisilazane-treated silicon substrate using a spin coater at 120 ° C. After heating and drying on a hot plate for 60 seconds to form a resist film having a predetermined thickness shown in Table 1, the resist film is redissolved with methanol, and the amount of additive contained in the resist film is determined by HPLC. Quantified.
That is, the amount when the additive is present in the prescribed amount is defined as 100%, and is expressed as a ratio of the amount of additive contained in the resist film after baking at 120 ° C. for 60 seconds.
Condition 2 shows the case where the solid content concentration is outside the scope of the present invention as a reference.
The results are shown in Table 2.

“%” Described in Table 1 is “mass%”.
The addition amount “%” of each component is based on the total solid content. The amount of the resin used is an amount obtained by subtracting the solid content of other components such as a photoacid generator and an additive when the total solid content of the resist composition is 100% by mass.
Each resist contains 0.1% by mass of a surfactant (Megafac F176 (manufactured by Dainippon Ink & Chemicals, Inc.) (fluorine)) in the total solid content of the resist composition.

  In addition, the comparative additives (A-1), (A-2) and (A-3) in the table are as follows.

[Examples (II-1) to (II-32) and Comparative Examples (II-1) to (II-2)]
<Resist preparation>
The components shown in Table 3 below were dissolved in a mixed solvent (A1: B1 = 6: 4 (mass ratio)), which was filtered through a polytetrafluoroethylene filter having a pore size of 0.1 μm, and the total solid shown in Table 3 Partial concentration positive resist compositions were prepared and evaluated as follows.
The mass% of each component described in Table 3 is based on the total solid content.
Each resist contains 0.1% by mass of the surfactant W-1 in the total solid content of the resist composition.
The amount of the resin used is an amount obtained by subtracting the solid content of other components such as a photoacid generator and an additive when the total solid content of the resist composition is 100% by mass.
Thereafter, the volatilization amount of the compound (C) used in the examples is all within the range of the volatilization amount defined in the present invention.

<Resist evaluation>
The prepared positive resist composition was uniformly coated on a silicon substrate subjected to hexamethyldisilazane treatment using a spin coater, and then heated and dried on a hot plate at 120 ° C. for 60 seconds to obtain a film having a thickness of 60 nm. A resist film was formed.
This resist film was irradiated with an electron beam projection lithography apparatus (acceleration voltage 50 keV) manufactured by Nikon Corporation, and surface exposure was performed while changing the exposure amount by 1 μC / cm ^{2 in} the range of 0 to 40 μC / cm ² . This resist film was further baked at 120 ° C. for 90 seconds. Thereafter, development was performed for 30 seconds using an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution, and the exposure amount at which the film thickness was 0 was determined by fitting.
In the same manner, different treatments were performed except that the baking after electron beam irradiation was 80 ° C. for 90 seconds, and the exposure amount at which the same film thickness was 0 was obtained by fitting.

<Quantification of volatilization>
A positive resist composition is uniformly applied on a silicon substrate subjected to hexamethyldisilazane treatment using a spin coater, and is heated and dried on a hot plate at 120 ° C. for 90 seconds to form a resist film having a thickness of 60 nm. Then, the resist was redissolved with methanol, and the amount of additive contained in the resist was quantified by HPLC.
That is, the amount when the additive is present in a prescribed amount is defined as 100%, and is expressed as a ratio of the additive amount contained in the resist after baking at 120 ° C. for 90 seconds.

(Acid-decomposable resin)
The structure, molecular weight, and dispersity of the acid-decomposable resin used in the examples are shown below. The ratio of the repeating unit is a molar ratio.

[Acid generator]
The acid generators shown in Table 3 correspond to those exemplified above.
[Basic compounds]

[Surfactant]
W-1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
〔solvent〕
A1: Propylene glycol monomethyl ether acetate (PGMEA)
B1: Propylene glycol monomethyl ether (PGME)

Moreover, about the composition of Example (II-7), when an additive was quantified by the said volatilization amount determination method, a residual rate was 98% (additive: T-55), and in comparative example (II-2). It was 5% (additive: A-2).
The residual ratio when a resist film having a thickness of 250 nm was formed was 100% for the composition of Example (II-7) and 72% for the composition of Comparative Example (II-2). .
From the above results, it is shown that the additive of the present invention is suppressed in volatility and can suppress sensitivity fluctuations even when baking conditions fluctuate.

  Similar effects can be obtained in EUV and X-ray lithography.

Claims (7)

(A) a resin that decomposes by the action of an acid and increases the dissolution rate in an aqueous alkali solution;
(B) a compound that generates an acid upon irradiation with actinic rays or radiation,
(C) a compound having a nitrogen-containing basic group or a quaternary ammonium group having a volatilization amount of 10% or less when held at 120 ° C. for 15 minutes, and
(D) a composition containing an organic solvent,
The total solid content in the composition is 1.0 to 4.5% by mass, and (B) the total amount of the compound that generates acid upon irradiation with actinic rays or radiation is the total solid content in the composition. A positive resist composition for electron beam, X-ray or EUV, characterized in that the content is at least 10% by mass with respect to the content.   The positive resist composition for electron beam, X-ray or EUV according to claim 1, wherein the component (C) is a compound having a nitrogen-containing basic group and a carboxyl group.   The molecular weight of the compound having a nitrogen-containing basic group and a carboxyl group is 100 to 500, and the content of the compound having the nitrogen-containing basic group and the carboxyl group is (B) by irradiation with actinic rays or radiation. 3. The positive resist composition for electron beam, X-ray or EUV according to claim 2, wherein the molar amount is 0.1 to 0.5 times the number of moles of the total amount of the compound generating an acid. The electron beam, X-ray or EUV according to any one of claims 1 to 3, wherein the compound that generates an acid upon irradiation with actinic rays or radiation is a compound represented by the following general formula (I): Positive resist composition.

In general formula (I),
R ^{1 to} R ¹³ each independently represents a hydrogen atom or a substituent.
Z is a single bond or a divalent linking group.
X ⁻ represents a counter anion. The resin which decomposes by the action of an acid and increases the dissolution rate in an alkaline aqueous solution has a repeating unit represented by the following general formula (II) and a repeating unit represented by the general formula (III): Item 5. A positive resist composition for electron beam, X-ray or EUV according to any one of Items 1 to 4.

In general formulas (II) and (III):
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, an aryloxy 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 when there are a plurality thereof, they may be the same or different.
m and n each independently represents an integer of 0 to 4.   (A) The weight average molecular weight of resin which decomposes | disassembles by the effect | action of an acid and the dissolution rate with respect to aqueous alkali solution increases is 1500-5000, The electron beam in any one of Claims 1-5, X A positive resist composition for wire or EUV.   A pattern forming method comprising: forming a resist film using the positive resist composition according to claim 1, and exposing and developing with an electron beam, X-ray or EUV light.