JP4448780B2 - Positive resist composition and pattern forming method using the same - Google Patents

Description

  The present invention relates to a positive resist composition for microfabrication of semiconductor elements and the like that is sensitive to far ultraviolet rays, and more particularly to a positive resist composition for electron beam, X-ray or EUV exposure.

  In recent years, the degree of integration of integrated circuits has been increasing, and in the manufacture of semiconductor substrates such as VLSI, processing of ultra-fine patterns having a line width of less than half a micron has been required.

  Non-Patent Document 1 discloses a positive resist composition containing a copolymer of hydroxystyrene and t-butyl acrylate, and Patent Documents 1 to 3 disclose a positive resist composition containing acid-decomposable polyhydroxystyrene. ing. Patent Document 4 discloses a resist containing a copolymer of an α-hydroxyacrylate monomer and hydroxystyrene.

  However, in resists containing resins with aromatic rings such as styrene skeleton suitable for lithography using these electron beams, etc., further improvements in sensitivity, resolution, pattern shape, line edge roughness, etc., along with improvements in required performance Was desired.

Japanese Patent Laid-Open No. 10-53621 JP 2002-323768 A JP 2003-177537 A JP 2003-322970 A Bulletin of International Society of Optical Engineering (Proc. SPIE), 1995, Vol. 2483, p. 53

  Therefore, the object of the present invention can be suitably used in ultra-microlithography processes such as the manufacture of VLSI and high-capacity microchips and other photofabrication processes, and actinic rays or radiation, particularly electron beams, It is to provide a positive resist composition having good sensitivity, resolving power, pattern shape, and line edge roughness by irradiation with X-rays or EUV.

  As a result of intensive studies on the constituent materials of the positive chemical amplification resist composition, the present inventor has found that the object of the present invention can be achieved by the following constitution, and has reached the present invention.

  (1) (A) Resin having a repeating unit represented by general formula (I) and a repeating unit represented by general formula (II) whose dissolution rate in an alkaline developer is increased by the action of an acid, (B) A positive resist composition containing a compound that generates an acid upon irradiation with actinic rays or radiation, and (C) a solvent.

In the formula (I), R ₁ represents a hydrogen atom or a hydrocarbon group. R ₂ represents a hydrocarbon group represented by any one of the following general formulas (pI) to (pV) . X represents a single bond or a carbonyl group.

R ₃ represents a hydrogen atom, a methyl group or a halogen atom. R ₄ represents a hydrocarbon group which may have a hydrogen atom or a hetero atom.
However, at least one of R ₂ and R ₄ is a group that decomposes by the action of an acid.

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 having 1 to 4 carbon atoms or an alicyclic hydrocarbon group . However, at least one of R _{12 to} R ₁₄ and any one of R ₁₅ and R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl having 1 to 4 carbon atoms.
Group, or represents 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 having 1 to 4 carbon atoms or an alicyclic hydrocarbon group .
R ₂₂ to R ₂₅ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms, or represents an alicyclic hydrocarbon group, provided that at least one of R ₂₂ to R ₂₅ is Represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

(2) The positive resist composition as described in (1) above , wherein in the formula (I), R ₂ represents a hydrocarbon group represented by the general formula (pI) or (pII).
(3) The positive resist composition as described in (1) or (2) above, wherein in formula (I), X is a single bond and R ₁ is a hydrogen atom.
(4) The R ₄ in the repeating unit represented by the general formula (II) is a group represented by the following formula (A), and is described in any one of the above (1) to (3) Positive resist composition.

  In general formula (A), L represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aralkyl group. Z represents an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group. Z and L may be bonded to each other to form a 5- or 6-membered ring.

(5) R ₄ in the repeating unit represented by the general formula (II) is a group represented by the formula (A), and Z is a cycloalkyl group, an aralkyl group, or a cyclic hydrocarbon structure as a substituent. The positive resist composition as described in (4) above, wherein the positive resist composition is an alkyl group.

(6) R ₄ in the repeating unit represented by the general formula (II) is a tertiary alkoxycarbonyl group, a tertiary alkoxycarbonylalkyl group, a tertiary alkyl group, or a group represented by the following formula (B). The positive resist composition as described in any one of (1) to (3) above.

R ₅ and R ₆ each independently represents a hydrogen atom or an alkyl group, and R ₇ represents an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group. W represents a single bond or a divalent organic group, and Y represents a single bond, —O—, —CO ₂ —, —OCO—, —CO—, —S— or —SO ₂ —.

(7) The positive resist composition as described in any one of (1) to (6) above, which further comprises (E) an organic basic compound.
(8) The positive resist composition as described in any one of (1) to (7) above, wherein the solvent (C) contains propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether.
(9) A resist film is formed from the positive resist composition according to any one of (1) to (8) above , and the resist film is irradiated with an electron beam, X-rays or EUV, and developed with an alkali developer. The pattern formation method characterized by including the process to do.
Although this invention is invention which concerns on said (1)-(9), hereafter, other matters are also demonstrated.

  With the positive resist composition of the present invention, a good pattern can be formed with good sensitivity and resolution by irradiation with actinic rays or radiation, particularly electron beam, X-ray or EUV.

  Hereinafter, the components used in the present invention will be described in detail.

In addition, in the description of the group (atomic group) in this specification, the description which does not describe substitution and non-substitution includes what 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) whose dissolution rate in an alkaline developer is increased by the action of an acid
Resin (A) is a resin (acid-decomposable) having a repeating unit represented by general formula (I) and a repeating unit represented by general formula (II) whose dissolution rate in an alkaline developer is increased by the action of an acid. Resin).

  First, the repeating unit represented by the general formula (I) will be described.

In the formula (I), R ₁ represents a hydrogen atom or a hydrocarbon group. R ₂ represents a hydrocarbon group. X represents a single bond or a carbonyl group.
The hydrocarbon group as R ₁ and R ₂ is, for example, an alkyl group (preferably having 1 to 20 carbon atoms) and a cycloalkyl group (preferably having 3 to 20 carbon atoms) which may have a substituent. Can be mentioned. Moreover, you may have hetero atoms, such as an oxygen atom, in the chain | strand of an alkyl group. For example, methyl group, linear or branched propyl group, linear or branched butyl group, linear or branched pentyl group, linear, branched or cyclic hexyl group, adamantyl, norbornyl, butyrolactone, cyclohexanelactone, norbornane lactone, etc. Can do.
Examples of the substituent that the alkyl group may have as R ₁ and R ₂ include a carboxylic acid group and an oxo group.

The monomer corresponding to the repeating unit represented by the formula (I) is, for example, described in “Adhesion Technology” Vol.14, No4. (1995) Vol. 37, p2, published by the Adhesion Society of Japan, starting from the corresponding acrylic compound. It can be synthesized by the method.
Specific examples of the repeating unit represented by the general formula (I) are shown below, but are not limited thereto.

  Moreover, resin (A) contains the repeating unit represented by general formula (II).

R ₃ represents a hydrogen atom, a methyl group or a halogen atom. R ₄ represents a hydrocarbon group which may have a hydrogen atom or a hetero atom. The substitution position of —OR ₄ is preferably the para position.

The hydrocarbon group which may have a hetero atom as R ₄ is preferably a hydrocarbon group having 1 to 10 carbon atoms, such as an alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, an acyl group, Examples include an acyloxy group, an alkylsulfonyl group, and an arylsulfonyl group.

  Resin (A) is a resin whose dissolution rate in an alkaline developer is increased by the action of an acid, and has a group (acid-decomposable group) that is decomposed by the action of an acid and becomes alkali-soluble. This acid-decomposable group is present in at least one of the repeating unit of the general formula (I) and the repeating unit represented by the general formula (II), but may be contained in other repeating units.

When the repeating unit of the general formula (I) has an acid-decomposable group, the hydrocarbon group as R ₂ constitutes the acid-decomposable group as COOR ₂ in the general formula (I).
When the repeating unit of the general formula (II) has an acid-decomposable group, the hydrocarbon group as R ₄ constitutes the acid-decomposable group as OR ₄ in the general formula (II).

Examples of such acid-decomposable groups include groups represented by -COOA ⁰ and -O-B ⁰ groups. Further Examples of the group containing these, include groups represented by -R ⁰ -COOA ^0, or -A _r -O-B ^0.
Here, A ⁰ is -C (R ⁰¹ ) (R ⁰² ) (R ⁰³ ), -Si (R ⁰¹ ) (R ⁰² ) (R ⁰³ ), -C (R ⁰⁴ ) (R ⁰⁵ ) -O-R ⁰⁶ group or lactone group. B ⁰ represents a —A ⁰ or —CO—O—A ⁰ group.
^{R 01, R 02, R 03} , R 04 and R ⁰⁵ may also be different from, and each of the same, represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an aralkyl group or an aryl group, R ⁰⁶ Represents an alkyl group, a cyclic alkyl group or an aryl group. However, at least two of R ^{01 to} R ⁰³ are groups other than hydrogen atoms, and two groups of R ^{01 to} R ⁰³ and R ^{04 to} R ⁰⁶ are bonded to form a ring. Also good. R ⁰ represents a single bond or a divalent or higher valent aliphatic or aromatic hydrocarbon group which may have a substituent, and —Ar— may have a monocyclic or polycyclic substituent. An aromatic group having a valence of 2 or more is shown.

Here, 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. Those having 3 to 30 carbon atoms such as propyl group, cyclobutyl group, cyclohexyl group and adamantyl group are preferred, and the alkenyl group has 2 to 4 carbon atoms such as vinyl group, propenyl group, allyl group and butenyl group. Those having 6 to 14 carbon atoms such as phenyl, xylyl, toluyl, cumenyl, naphthyl, and anthracenyl groups are preferable. Examples of the cyclic alkyl group include those having 3 to 30 carbon atoms, specifically, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group, tricyclodecanyl group, Examples include a cyclopentenyl group, a nobornane epoxy group, a menthyl group, an isomenthyl group, a neomenthyl group, a tetracyclododecanyl group, and a steroid residue. Examples of the aralkyl group include those having 7 to 20 carbon atoms, which may have a substituent. Examples include a benzyl group, a phenethyl group, and a cumyl group.

Substituents include hydroxyl groups, halogen atoms (fluorine, chlorine, bromine, iodine), nitro groups, cyano groups, the above alkyl groups, methoxy groups, ethoxy groups, hydroxyethoxy groups, propoxy groups, hydroxypropoxy groups, n -Alkoxy groups such as butoxy group, isobutoxy group, sec-butoxy group, t-butoxy group, alkoxycarbonyl groups such as methoxycarbonyl group, ethoxycarbonyl group, aralkyl groups such as benzyl group, phenethyl group, cumyl group, and aralkyloxy groups Acyl group such as formyl group, acetyl group, butyryl group, benzoyl group, cyanamyl group, valeryl group, acyloxy group such as butyryloxy group, alkenyl group, alkenyl such as vinyloxy group, propenyloxy group, allyloxy group, butenyloxy group, etc. Oxy group, allee above It can be exemplified group, an aryloxy group such as phenoxy group, aryloxycarbonyl group such as benzoyloxy group.
Examples of the lactone group include those having the following structure.

In the above formula, R ^a , R ^b and R ^c each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n represents an integer of 2 to 4.

When R ₂ in formula (I) constitutes an acid-decomposable group as COOR ₂ , R ₂ is preferably any one 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 having 1 to 4 carbon atoms or an alicyclic hydrocarbon group. However, at least one of R _{12 to} R ₁₄ and any one of R ₁₅ and 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 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 is a fat Represents a cyclic 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 (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an acyl group, an acyloxy group, a cyano group, a 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, a cyclododecanyl group, and a tricyclodecanyl group.

Examples of the substituent for these alicyclic hydrocarbon groups include an alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group, and an alkoxycarbonyl group.
The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. To express.
Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom, and an alkoxy group.
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.

When the hydrocarbon group optionally having a hetero atom of R ₄ in the general formula (II) forms an acid-decomposable group as OR ₄ , R ₄ is a tertiary alkoxycarbonyl group (preferably having 5 carbon atoms). -14) A tertiary alkoxycarbonylalkyl group (preferably having 6 to 15 carbon atoms), a tertiary alkyl group (preferably having 4 to 13 carbon atoms), or the following general formula (A) or (B) It is preferably a group.

  The group represented by the general formula (A) will be described.

In general formula (A), L represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aralkyl group. Z represents an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group. Z
And L may combine with each other to form a 5- or 6-membered ring.

  The alkyl group and cycloalkyl group of L and Z may have a substituent, and preferably a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, Examples thereof include linear, branched or cyclic groups having 1 to 20 carbon atoms such as a pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group, dodecyl group, adamantyl group and the like.

  Preferable substituents that the alkyl group and cycloalkyl group as L and Z may have include a hydroxyl group, a halogen atom, a nitro group, a cycloalkyl group, a heterocyclic residue such as a pyrrolidone residue, and the like. In addition, about the cyclic structure of the cycloalkyl group as L and Z, an alkyl group can further be mentioned as a substituent. The number of carbon atoms of the substituent is preferably 12 or less.

  The aralkyl group of L and Z preferably has 7 to 15 carbon atoms, and examples thereof include a benzyl group and a phenethyl group.

  The aryl group for Z preferably has 6 to 14 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.

  Examples of the substituent that the aralkyl group and aryl group may have include a hydroxyl group, a halogen atom, a nitro group, an alkyl group, and a cycloalkyl group. Examples of the aralkyl group having a substituent include a hydroxybenzyl group. Can be mentioned. The range of the carbon number of the substituent that the aralkyl group as L or Z and the aryl group as Z may have is preferably 12 or less.

  The group as Z preferably has a cyclic carbon structure, that is, a cycloalkyl group, an aralkyl group, an aryl group, or an alkyl group having a cyclic carbon structure as a substituent, and a cycloalkyl group, an aralkyl group or a substituent. An alkyl group having a cyclic carbon structure is more preferable.

  Examples of the 5- or 6-membered ring formed by combining Z and L with each other include a tetrahydropyran ring and a tetrahydrofuran ring.

  Specific examples of the group represented by the general formula (A) are shown below, but are not limited thereto.

  Next, the group represented by the general formula (B) will be described.

In the formula (B), R ₅ and R ₆ each independently represent a hydrogen atom or an alkyl group, and R ₇ represents an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group. W represents a single bond or a divalent organic group, and Y represents a single bond, —O—, —CO ₂ —, —OCO—, —CO—, —S— or —SO ₂ —.

In the formula (B), R ₅ and R ₆ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, W represents a divalent organic group, R ₇ is a chain alkyl group which may have a substituent having a total carbon number of 11 to 20, a cyclic alkyl group which may have a substituent of a total carbon number of 11 to 20, and a substituent having a total carbon number of 11 to 30 And an aralkyl group that may have a substituent having a total carbon number of 12 to 30.

In the general formula (B), the alkyl groups as R ₅ and R ₆ are specifically methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t- C1-C4 alkyl groups, such as a butyl group, are mentioned.
The divalent organic group as W preferably has a substituent, and may be a linear, branched or cyclic alkylene group, an arylene group, a heteroarylene group, an aralkylene group, and —S—, — C (═O) —, —N (R ₈ ) —, —SO—, —SO ₂ —, —CO ₂ —, —N (R ₈ ) SO ₂ — or a divalent combination of two or more of these groups. Can be mentioned. Here, R ₈ can include a hydrogen atom or an alkyl group (specific examples of the alkyl group include those similar to the above R ₅ ). The carbon number of the divalent organic group as W is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less.

R ₇ is an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, or an aralkyl group which may have a substituent. It is.
The alkyl group includes a substituent and preferably has a total carbon number of 1 to 20, more preferably 11 to 20, and still more preferably 11 to 18, and may be linear or branched. For example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group, i-pentyl group, t-pentyl group, n -Hexyl group, i-hexyl group, t-hexyl group, n-heptyl group, i-heptyl group, t-heptyl group, n-octyl group, i-octyl group, t-octyl group, n-nonyl group, i -Nonyl group, t-nonyl group, n-decyl group, i-decyl group, t-decyl group, n-undecyl group, i-undecyl group, n-dodecyl group, i-dodecyl group, n-tridecyl group, i -Tridecyl group, n-tetradecyl group, i- Tradecyl group, n-pentadecyl group, i-pentadecyl group, n-hexadecyl group, i-hexadecyl group, n-heptadecyl group, i-heptadecyl group, n-octadecyl group, i-octadecyl group, n-nonadecyl group, i- Nonadecyl group etc. can be mentioned.

The cycloalkyl group includes a substituent and preferably has a total carbon number of 1 to 20, more preferably 11 to 20, still more preferably 11 to 18, and a ring formed of up to 20 carbon atoms. It may be a cyclic alkyl having a substituent, for example, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cycloundecyl group, cyclododecyl group. Group, cyclotridecyl group, cyclotridecyl group, cyclotetradecyl group, cyclopentadecyl group, cyclohexadecyl group, cycloheptadecyl group, cyclooctadecyl group, cyclononadecyl group, 4-cyclohexylcyclohexyl group, 4-n-hexyl Cyclohexyl group, Pentanylcyclohexyl group Hexyloxy cyclohexyl group, penta oxy cyclohexyl group can be mentioned. Substituted cyclic alkyl groups other than those listed here can also be used within the above ranges.

The aryl group represented by R ₇ includes a substituent and preferably has a total carbon number of 1 to 30, more preferably 11 to 30, and still more preferably 11 to 25. For example, a phenyl group, a tolyl group, a xylyl group. Group, ethylphenyl group, propylphenyl group, methoxyphenyl group, ethoxyphenyl group, propyloxyphenyl group, 4-cyclopentylphenyl group, 4-cyclohexylphenyl group, 4-cycloheptenylphenyl group, 4-cyclooctanylphenyl group 2-cyclopentylphenyl group, 2-cyclohexylphenyl group, 2-cycloheptenylphenyl group, 2-cyclooctanylphenyl group, 3-cyclopentylphenyl group, 3-cyclohexylphenyl group, 3-cycloheptenylphenyl group, 3 -Cyclooctanylphenyl group, 4-cyclopent Ruoxyphenyl group, 4-cyclohexyloxyphenyl group, 4-cycloheptenyloxyphenyl group, 4-cyclooctanyloxyphenyl group, 2-cyclopentyloxyphenyl group, 2-cyclohexyloxyphenyl group, 2-cycloheptenyloxy Phenyl group, 2-cyclooctanyloxyphenyl group, 3-cyclopentyloxyphenyl group, 3-cyclohexyloxyphenyl group, 3-cycloheptenyloxyphenyl group, 3-cyclooctanyloxyphenyl group, 4-n-pentylphenyl Group, 4-n-hexylphenyl group, 4-n-heptenylphenyl group, 4-n-octanylphenyl group, 2-n-pentylphenyl group, 2-n-hexylphenyl group, 2-n-heptenyl Phenyl group, 2-n-octanylphenyl group, 3-n -Pentylphenyl group, 3-n-hexylphenyl group, 3-n-heptenylphenyl group, 3-n-octanylphenyl group, 2,6-di-isopropylphenyl group, 2,3-di-isopropylphenyl group 2,4-di-isopropylphenyl group, 3,4-di-isopropylphenyl group, 3,6-di-t-butylphenyl group, 2,3-di-t-butylphenyl group, 2,4-di -T-butylphenyl group, 3,4-di-t-butylphenyl group, 2,6-di-n-butylphenyl group, 2,3-di-n-butylphenyl group, 2,4-di-n -Butylphenyl group, 3,4-di-n-butylphenyl group, 2,6-di-i-butylphenyl group, 2,3-di-i-butylphenyl group, 2,4-di-i-butyl Phenyl group, 3,4-di-i-butylphenyl group, 2, -Di-t-amylphenyl group, 2,3-di-t-amylphenyl group, 2,4-di-t-amylphenyl group, 3,4-di-t-amylphenyl group, 2,6-di -I-amylphenyl group, 2,3-di-i-amylphenyl group, 2,4-di-i-amylphenyl group, 3,4-di-i-amylphenyl group, 2,6-di-n -Pentylphenyl group, 2,3-di-n-pentylphenyl group, 2,4-di-n-pentylphenyl group, 3,4-di-n-pentylphenyl group, 4-adamantylphenyl group, 2-adamantyl Phenyl group, 4-isobornylphenyl group, 3-isobornylphenyl group, 2-isobornylphenyl group, 4-cyclopentyloxyphenyl group, 4-cyclohexyloxyphenyl group, 4-cycloheptenyloxyphenyl group, 4- Crooctanyloxyphenyl group, 2-cyclopentyloxyphenyl group, 2-cyclohexyloxyphenyl group, 2-cycloheptenyloxyphenyl group, 2-cyclooctanyloxyphenyl group, 3-cyclopentyloxyphenyl group, 3-cyclohexyloxy Phenyl group, 3-cycloheptenyloxyphenyl group, 3-cyclooctanyloxyphenyl group, 4-n-pentyloxyphenyl group, 4-n-hexyloxyphenyl group, 4-n-heptenyloxyphenyl group, 4 -N-octanyloxyphenyl group, 2-n-pentyloxyphenyl group, 2-n-hexyloxyphenyl group, 2-n-heptenyloxyphenyl group, 2-n-octanyloxyphenyl group, 3-n -Pentyloxyphenyl group, 3-n-hexyloxyph Enyl group, 3-n-heptenyloxyphenyl group, 3-n-octanyloxyphenyl group, 2,6-di-isopropyloxyphenyl group, 2,3-di-isopropyloxyphenyl group, 2,4-di -Isopropyloxyphenyl group, 3,4-di-isopropyloxyphenyl group, 2,6-di-t-butyloxyphenyl group, 2,3-di-t-butyloxyphenyl group, 2,4-di-t -Butyloxyphenyl group, 3,4-di-t-butyloxyphenyl group, 2,6-di-n-butyloxyphenyl group, 2,3-di-n-butyloxyphenyl group, 2,4-di -N-butyloxyphenyl group, 3,4-di-n-butyloxyphenyl group, 2,6-di-i-butyloxyphenyl group, 2,3-di-i-butyloxyphenyl group, 2,4 -Di-i- Tiloxyphenyl group, 3,4-di-i-butyloxyphenyl group, 2,6-di-t-amyloxyphenyl group, 2,3-di-t-amyloxyphenyl group, 2,4-di- t-amyloxyphenyl group, 3,4-di-t-amyloxyphenyl group, 2,6-di-i-amyloxyphenyl group, 2,3-di-i-amyloxyphenyl group, 2,4- Di-i-amyloxyphenyl group, 3,4-di-i-amyloxyphenyl group, 2,6-di-n-pentyloxyphenyl group, 2,3-di-n-pentyloxyphenyl group, 2, 4-di-n-pentyloxyphenyl group, 3,4-di-n-pentyloxyphenyl group, 4-adamantyloxyphenyl group, 3-adamantyloxyphenyl group, 2-adamantyloxyphenyl group, 4-isoboro Examples include a ruoxyphenyl group, a 3-isoboronyloxyphenyl group, a 2-isoboronyloxyphenyl group, and the like. These may be further substituted within the above range. Not limited.

The aralkyl group in R ₇ includes a substituent and preferably has 2 to 30 carbon atoms, more preferably 12 to 30 carbon atoms, still more preferably 12 to 25 carbon atoms, and examples thereof include a phenylethyl group and triphenylethyl group. Group, xylylphenylethyl group, ethylphenylethyl group, propylphenylethyl group, 4-cyclopentylphenylethyl group, 4-cyclohexylphenylethyl group, 4-cycloheptenylphenylethyl group, 4-cyclooctanylphenylethyl group, 2-cyclopentylphenylethyl group, 2-cyclohexylphenylethyl group, 2-cycloheptenylphenylethyl group, 2-cyclooctanylphenylethyl group, 3-cyclopentylphenylethyl group, 3-cyclohexylphenylethyl group, 3-cycloheptene Tenylphenylethyl 3-cyclooctanylphenylethyl group, 4-cyclopentyloxyphenylethyl group, 4-cyclohexyloxyphenylethyl group, 4-cycloheptenyloxyphenylethyl group, 4-cyclooctanyloxyphenylethyl group, 2-cyclopentyloxy Phenylethyl group, 2-cyclohexyloxyphenylethyl group, 2-cycloheptenyloxyphenylethyl group, 2-cyclooctanyloxyphenylethyl group, 3-cyclopentyloxyphenylethyl group, 3-cyclohexyloxyphenylethyl group, 3- Cycloheptenyloxyphenylethyl group, 3-cyclooctanyloxyphenylethyl group, 4-n-pentylphenylethyl group, 4-n-hexylphenylethyl group, 4-n-heptenylphenylethyl group, 4-n -Octanylphenylethyl group, 2-n-pentylphenylethyl group, 2-n-hexylphenylethyl group, 2-n-heptenylphenylethyl group, 2-n-octanylphenylethyl group, 3-n-pentyl Phenylethyl group, 3-n-hexylphenylethyl group, 3-n-heptenylphenylethyl group, 3-n-octanylphenylethyl group, 2,6-di-isopropylphenylethyl group, 2,3-di- Isopropylphenylethyl group, 2,4-di-isopropylphenylethyl group, 3,4-di-isopropylphenylethyl group, 2,6-di-t-butylphenylethyl group, 2,3-di-t-butylphenyl Ethyl group, 2,4-di-t-butylphenylethyl group, 3,4-di-t-butylphenylethyl group, 2,6-di-n-butylpheny Ethyl group, 2,3-di-n-butylphenylethyl group, 2,4-di-n-butylphenylethyl group, 3,4-di-n-butylphenylethyl group, 2,6-di-i- Butylphenylethyl group, 2,3-di-i-butylphenylethyl group, 2,4-di-i-butylphenylethyl group, 3,4-di-i-butylphenylethyl group, 2,6-di- t-amylphenylethyl group, 2,3-di-t-amylphenylethyl group, 2,4-di-t-amylphenylethyl group, 3,4-di-t-amylphenylethyl group, 2,6- Di-i-amylphenylethyl group, 2,3-di-i-amylphenylethyl group, 2,4-di-i-amylphenylethyl group, 3,4-di-i-amylphenylethyl group, 2, 6-di-n-pentylphenylethyl group, 2,3-di- -Pentylphenylethyl group, 2,4-di-n-pentylphenylethyl group, 3,4-di-n-pentylphenylethyl group, 4-adamantylphenylethyl group, 3-adamantylphenylethyl group, 2-adamantylphenyl Ethyl group, 4-isobornylphenylethyl group, 3-isobornylphenylethyl group, 2-isobornylphenylethyl group, 4-cyclopentyloxyphenylethyl group, 4-cyclohexyloxyphenylethyl group, 4-cyclohept Tenenyloxyphenylethyl group, 4-cyclooctanyloxyphenylethyl group, 2-cyclopentyloxyphenylethyl group, 2-cyclohexyloxyphenylethyl group, 2-cycloheptenyloxyphenylethyl group, 2-cyclooctanyloxyphenylethyl Group, 3-si Clopentyloxyphenylethyl group, 3-cyclohexyloxyphenylethyl group, 3-cycloheptenyloxyphenylethyl group, 3-cyclooctanyloxyphenylethyl group, 4-n-pentyloxyphenylethyl group, 4-n-to Xyloxyphenylethyl group, 4-n-heptenyloxyphenylethyl group, 4-n-octanyloxyphenylethyl group, 2-n-pentyloxyphenylethyl group, 2-n-hexyloxyphenylethyl group, 2- n-heptenyloxyphenylethyl group, 2-n-octanyloxyphenylethyl group, 3-n-pentyloxyphenylethyl group, 3-n-hexyloxyphenylethyl group, 3-n-heptenyloxyphenylethyl group , 3-n-octanyloxyphenylethyl group, 2,6- -Isopropyloxyphenylethyl group, 2,3-di-isopropyloxyphenylethyl group, 2,4-di-isopropyloxyphenylethyl group, 3,4-diisopropyloxyphenylethyl group, 2,6-di-t- Butyloxyphenylethyl group, 2,3-di-t-butyloxyphenylethyl group, 2,4-di-t-butyloxyphenylethyl group, 3,4-di-t-butyloxyphenylethyl group, 2, 6-di-n-butyloxyphenylethyl group, 2,3-di-n-butyloxyphenylethyl group, 2,4-di-n-butyloxyphenylethyl group, 3,4-di-n-butyloxy Phenylethyl group, 2,6-di-i-butyloxyphenylethyl group, 2,3-di-i-butyloxyphenylethyl group, 2,4-di-i-butyl Xylphenylethyl group, 3,4-di-i-butyloxyphenylethyl group, 2,6-di-t-amyloxyphenylethyl group, 2,3-di-t-amyloxyphenylethyl group, 2,4 -Di-t-amyloxyphenylethyl group, 3,4-di-t-amyloxyphenylethyl group, 2,6-di-i-amyloxyphenylethyl group, 2,3-di-i-amyloxyphenyl group Ethyl group, 2,4-di-i-amyloxyphenylethyl group, 3,4-di-i-amyloxyphenylethyl group, 2,6-di-n-pentyloxyphenylethyl group, 2,3-di -N-pentyloxyphenylethyl group, 2,4-di-n-pentyloxyphenylethyl group, 3,4-di-n-pentyloxyphenylethyl group, 4-adamantyloxyphenylethyl group , 3-adamantyloxyphenylethyl group, 2-adamantyloxyphenylethyl group, 4-isoboronyloxyphenylethyl group, 3-isoboronyloxyphenylethyl group, 2-isoboronyloxyphenylethyl group, or the above Examples include those in which an alkyl hydrogen atom is replaced by a methyl group, a propyl group, a butyl group or the like.

Further, as further substituents of the above groups, hydroxyl groups, halogen atoms (fluorine, chlorine, bromine, iodine), nitro groups, cyano groups, the above alkyl groups, methoxy groups, ethoxy groups, hydroxyethoxy groups, propoxy groups・ Hydroxypropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, alkoxy group such as t-butoxy group, alkoxycarbonyl group such as methoxycarbonyl group, ethoxycarbonyl group, benzyl group, phenethyl group, cumyl group, etc. Aralkyl groups, aralkyloxy groups, acyl groups such as formyl group, acetyl group, butyryl group, benzoyl group, cyanamyl group, valeryl group, acyloxy groups such as butyryloxy group,
Examples of the alkenyl group include alkenyloxy groups such as vinyloxy group, propenyloxy group, allyloxy group, and butenyloxy group, aryloxy groups such as aryl group and phenoxy group, and aryloxycarbonyl groups such as benzoyloxy group. .

The substituent for R ₇ is preferably an aryl group having 11 to 25 carbon atoms or an aralkyl group having 12 to 25 carbon atoms. These substituents may further have a substituent, as long as the total carbon number of the substituted aryl group or the substituted aralkyl group is within this range.

  Specific examples of the group represented by the general formula (B) are shown below, but are not limited thereto.

The resin (A) preferably further contains a polyhydroxystyrene repeating unit.
The position of the hydroxy group in the polyhydroxystyrene repeating unit may be any, but the para position is preferred.

  Resin (A) has addition polymerizable unsaturated bonds such as acrylic esters, methacrylic esters, acrylamides, methacrylamides, allyl compounds, vinyl ethers, vinyl esters other than the above repeating units. The repeating unit derived from a compound can be contained.

In the resin (A), the content of the repeating unit represented by the general formula (I) is preferably from 5 to 80 mol%, more preferably from 10 to 60 mol%, further preferably from all repeating units constituting the resin. Is 20 to 50 mol%.
The content of the repeating unit represented by the general formula (II) is preferably from 5 to 90 mol%, more preferably from 10 to 80 mol%, still more preferably from 30 to 70 mol% in all repeating units constituting the resin. It is.
As for the content rate of a polyhydroxystyrene repeating unit, 10-80 mol% is preferable in all the repeating units which comprise resin, More preferably, it is 20-70 mol%, More preferably, it is 30-70 mol%.
As for the content rate of the repeating unit which has an acid-decomposable group, 10-60 mol% is preferable in all the repeating units which comprise resin, More preferably, it is 20-55 mol%, More preferably, it is 30-50 mol%.

When -COOR ₂ in the formula (I) is an acid-decomposable group is preferably R ₄ in formula (II) is a hydrogen atom.
When —OR ₄ in the formula (II) is an acid-decomposable group, it is preferable to contain a polyhydroxystyrene repeating unit together with the repeating unit represented by the formula (I).

  The weight average molecular weight of the resin (A) can be measured as a polystyrene equivalent molecular weight (Mw) by gel permeation chromatography (GPC), preferably 2,000 to 1,000,000, and 3,000 to 100,000 is more preferable, and 5,000 to 50,000 is particularly preferable. That is, the molecular weight is preferably 2,000 or more in terms of suppressing resist film slippage, and is preferably 1,000,000 or less in terms of solubility and resolution.

  Resin (A) can be synthesized according to a conventional method (for example, radical polymerization). For example, as a general synthesis method, monomer species are charged into a reaction vessel in a batch or in the course of reaction, and if necessary, a reaction solvent such as ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, methyl ethyl ketone, Dissolve in a solvent that can dissolve various monomers, such as ketones such as methyl isobutyl ketone, ester solvents such as ethyl acetate, and propylene glycol monomethyl ether acetate described later, and then use nitrogen, argon, etc. Polymerization is started using a commercially available radical initiator (azo initiator, peroxide, etc.) as necessary under an active gas atmosphere. If desired, an initiator is added or added in portions, and after completion of the reaction, it is put into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. The concentration of the reaction is 20% by mass or more, preferably 30% by mass or more, and more preferably 40% by mass or more. The reaction temperature is 10 ° C to 150 ° C, preferably 30 ° C to 120 ° C, more preferably 50-100 ° C.

  The total amount of the resin is preferably 40 to 99.99% by mass, more preferably 50 to 99.97% by mass, based on the total solid content of the composition.

  Although the specific example of resin (A) is given, it is not limited to these.

[2] Compound (B) that generates acid upon irradiation with actinic rays or radiation
The resist composition of the present invention contains a compound (a photoacid generator) that generates an acid upon irradiation with actinic rays or radiation.

  As the photoacid generator used in the present invention, it is used as a photoinitiator for photocationic polymerization, a photoinitiator for radical photopolymerization, a photodecolorant for dyes, a photochromic agent, a microresist, or the like. A compound that generates an acid upon irradiation with actinic rays or radiation such as known light (200 to 400 nm ultraviolet light, far ultraviolet light, particularly KrF excimer laser light), electron beam, X-ray, EUV, and the like, and a mixture thereof are appropriately selected. Can be used.

Examples of other photoacid generators used in the present invention include diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, onium salts such as arsonium salts, organic halogen compounds, organic metals / organics. Examples include halides, photoacid generators having an o-nitrobenzyl type protecting group, compounds that generate photosulfonic acids by photolysis, such as iminosulfonates, disulfone compounds, diazoketosulfones, diazodisulfone compounds, etc. Can do.
Moreover, the group which generate | occur | produced the acid by these light, or the compound which introduce | transduced the compound into the principal chain or side chain of the polymer can be used.

  Furthermore, VNRPillai, Synthesis, (1), 1 (1980), A. Abad etal, Tetrahedron Lett., (47) 4555 (1971), DHR Barton etal, J. Chem. Soc., (C), 329 (1970) ), A compound capable of generating an acid by light described in US Pat. No. 3,779,778, European Patent 126,712 and the like can also be used.

Among the compounds that decompose upon irradiation with actinic rays or radiation to generate an acid, a photoacid generator that is particularly effectively used will be described below.
(1) An iodonium salt represented by the following general formula (PAG3) or a sulfonium salt represented by the general formula (PAG4).

Here, the formulas Ar ¹ and Ar ² each independently represent an aryl group.
R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ each independently represents an alkyl group, a cycloalkyl group or an aryl group.

Z ⁻ represents a counter anion, for example, a perfluoroalkanesulfonic acid anion such as BF ₄ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , SiF ₆ ²⁻ , ClO ₄ ⁻ , CF ₃ SO ₃ ⁻ , penta Examples include, but are not limited to, condensed polynuclear aromatic sulfonate anions such as fluorobenzene sulfonate anion and naphthalene-1-sulfonate anion, anthraquinone sulfonate anion, and sulfonate group-containing dyes.

Two of R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ and Ar ¹ and Ar ² may be bonded via a single bond or a substituent.

  Specific examples include the following compounds, but are not limited thereto.

In the above, Ph represents a phenyl group.
The above onium salts represented by the general formula (PAG3) or (PAG4) are known, such as US Pat. Nos. 2,807,648 and 4,247,473, and JP-A-53-101,331. It can be synthesized by the method described in 1.

  (2) A disulfone derivative represented by the following general formula (PAG5) or an iminosulfonate derivative represented by the general formula (PAG6).

In the formula, Ar ³ and Ar ⁴ each independently represent an aryl group. R ²⁰⁶ represents an alkyl group, a cycloalkyl group or an aryl group. A represents an alkylene group, an alkenylene group, or an arylene group.

  Specific examples include the following compounds, but are not limited thereto.

  (3) A diazodisulfone derivative represented by the following general formula (PAG7).

Here, R represents an alkyl group, a cycloalkyl group, or an aryl group.
Specific examples include the following compounds, but are not limited thereto.

The addition amount of the photoacid generator is usually used in the range of 0.001 to 30% by mass, preferably 0.3 to 20% by mass, more preferably 0.5 to 0.5%, based on the solid content in the composition. It is used in the range of 10% by mass.
The addition amount of the photoacid generator is preferably 0.001% by mass or more from the viewpoint of sensitivity, and is preferably 30% by mass or less from the viewpoint of light absorption, profile, and process (especially baking) margin of the resist.

[3] Surfactant (component D)
The positive resist composition of the present invention comprises a surfactant, preferably a fluorine-based and / or silicon-based surfactant (a fluorine-based surfactant and a silicon-based surfactant, an interface containing both fluorine and silicon atoms). It is preferable to contain any one or two or more of the active agents.
When the positive resist composition of the present invention contains the above-mentioned surfactant, it is particularly effective when using an exposure light source of 250 nm or less, particularly 220 nm or less, and when the line width of the pattern is narrower, and good sensitivity. In addition, it is possible to provide a resist pattern with less adhesion and development defects with resolution.
As these surfactants, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540 No. 7, JP-A-7-230165, JP-A-8-62834, JP-A-9-54432, JP-A-9-5988, JP-A 2002-277862, US Pat. No. 5,405,720. , No. 5,360,692, No. 5,529,881, No. 5,296,330, No. 5,543,098, No. 5,576,143, No. 5,294,511, No. 5,824,451. The following commercially available surfactants can also be used as they are.
Examples of commercially available surfactants that can be used include F-top EF301, EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176, F189, R08 (Dainippon Ink Chemical Co., Ltd.), 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.
As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block linked body) or a poly (block linked body of oxyethylene and oxypropylene) group, 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.

  As surfactants that can be used in addition to the above-mentioned fluorine-based and / or silicon-based surfactants, for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl Polyoxyethylene alkyl ethers such as ether, polyoxyethylene alkyl allyl ethers such as polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmi Sorbitan fatty acid esthetics such as tate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate Polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan tristearate Nonionic surfactants and the like.

(D) The amount of the surfactant used is preferably 0.0001 to 2% by mass, more preferably 0.001 to 1% by mass, particularly preferably the total amount of the positive resist composition (excluding the solvent). 0.01 to 1% by mass.

[4] Organic basic compound (E component)
The resist composition of the present invention preferably contains an organic basic compound. The organic basic compound is preferably a compound that is more basic than phenol. Of these, nitrogen-containing basic compounds are preferable, and examples thereof include structures represented by the following (A) to (E).

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, And R ²⁵⁰ and R ²⁵¹ may combine with each other to form a ring. These may have a substituent. Examples of the alkyl group and cycloalkyl group having a substituent include an aminoalkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and 1 to 20 carbon atoms. Or a cycloalkyl group having 3 to 20 carbon atoms is preferred.
These may contain an oxygen atom, a sulfur atom, or a nitrogen atom in the alkyl chain.

(Wherein R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶ each independently represents an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6 carbon atoms).
Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms of different chemical environments in one molecule, and particularly preferably both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom. Or a compound having an alkylamino group.
Preferred examples include guanidine, aminopyridine, aminoalkylpyridine, aminopyrrolidine, indazole, pyrazole, pyrazine, pyrimidine, purine, imidazoline, pyrazoline, piperazine, piperidine, aminomorpholine, aminoalkylmorpholine and the like. These may have a substituent, and preferred substituents include amino group, aminoalkyl group, alkylamino group, aminoaryl group, arylamino group, alkyl group, alkoxy group, acyl group, acyloxy group, aryl Group, aryloxy group, nitro group, hydroxyl group, cyano group and the like.

Preferable specific examples of the nitrogen-containing basic compound include guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2- Dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, 4-aminoethylpyridine, 3-aminopyrrolidine, piperazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4- Amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2- Minopiperidine, 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p-tolylpyrazole, pyrazine, 2- (aminomethyl) -5 Methylpyrazine, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine, 1,5-diazabicyclo [ 4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2.2.2] octane, 2,4,5- Triphenylimidazole, N-methylmorpholine, N-ethylmorpholine, N-hydroxyethylmorpholine, N-benzylmorpholine, cyclohexane Examples thereof include tertiary morpholine derivatives such as silmorpholinoethylthiourea (CHMETU), hindered amines described in JP-A-11-52575 (for example, those described in the publication [0005]), and the like. Absent.

Particularly preferred examples are 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2. 2.2] Octane, 4-dimethylaminopyridine, hexamethylenetetramine, 4,4-dimethylimidazoline, pyrroles, pyrazoles, imidazoles, pyridazines, pyrimidines, tertiary morpholines such as CHMETU, bis (1, And hindered amines such as 2,2,6,6-pentamethyl-4-piperidyl) sebagate.
Among them, 1,5-diazabicyclo [4.3.0] non-5-ene, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,4-diazabicyclo [2.2.2] Octane, 4-dimethylaminopyridine, hexamethylenetetramine, CHMETU, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebagate are preferred.

  A nitrogen-containing basic compound is used individually or in combination of 2 or more types. The usage-amount of a nitrogen-containing basic compound is 0.001-10 mass% normally with respect to solid content of the whole composition of the resist composition of this invention, Preferably it is 0.01-5 mass%. In order to obtain a sufficient addition effect, 0.001% by mass or more is preferable, and 10% by mass or less is preferable in terms of sensitivity and developability of the non-exposed area.

[5] Other Additives The positive resist composition of the present invention further promotes solubility in acid-decomposable dissolution inhibiting compounds, dyes, plasticizers, photosensitizers, and developers as necessary. A compound etc. can be contained.

[6] Solvent (component C)
The resist composition of the present invention is dissolved in a solvent that dissolves each of the above components and coated on a support. Solvents used here include ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate , Propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), propylene carbonate, toluene, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, pyruvin Acid ethyl, propyl pyruvate, N, N-dimethylformamide, dimethyl sulfoxide, N-methyl Pyrrolidone, tetrahydrofuran and the like are preferable to use these solvents singly or in combination.

Among these, preferable solvents include propylene glycol monomethyl ether acetate, 2-heptanone, γ-butyrolactone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether And propylene carbonate, butyl acetate, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate, N-methylpyrrolidone and tetrahydrofuran.
A resist composition having a total solid content concentration of the resist component of usually 3 to 25% by mass, preferably 5 to 22% by mass, and more preferably 7 to 20% by mass is prepared using a solvent.

  In addition, it is preferable to use a mixed solvent from the viewpoint of in-plane uniformity, storage stability, density dependency, development defects, and the like.

  As a preferable mixed solvent, a mixed solvent of a solvent of the following group A and at least one solvent selected from group B and C, a mixed solvent of a solvent of group D and at least one solvent selected from group E and F Can be mentioned.

Group A: Propylene glycol monomethyl ether acetate Group B: Propylene glycol monomethyl ether, ethyl lactate C group: γ-butyrolactone, propylene carbonate

Group D: 2-heptanone Group E: Propylene glycol monomethyl ether, ethyl lactate, butyl acetate Group F: γ-butyrolactone, propylene carbonate

The mass ratio (A: B) of the group A solvent and the group B solvent is preferably 90:10 to 15:85, more preferably 85:15 to 20:80, and still more preferably 80:20. ~ 25: 75.
The use mass ratio (A: C) of the solvent of the group A and the solvent of the group C is preferably 99.9: 0.1 to 75:25, more preferably 99: 1 to 80:20, and still more preferably. Is 97: 3-85: 15.
When combining the three types of solvents A, B, and C, the mass ratio of the solvent in the group C is preferably 0.1 to 25% by mass, more preferably 1 to 20% by mass, based on the total solvent. More preferably, it is 3-17 mass%.
The above preferred mixed solvent may be added with other solvents. Generally the addition amount of such other solvent is 30 mass parts or less with respect to 100 mass parts of mixed solvents.

The usage-amount of the solvent of D group is 30 mass% or more normally with respect to all the solvents, Preferably it is 40 mass% or more, More preferably, it is 50 mass% or more.
The usage-amount of the solvent of E group is 5-70 mass% normally with respect to all the solvents, Preferably it is 10-60 mass%, More preferably, it is 15-50 mass%.
The usage-amount of the solvent of F group is 0.1-25 mass% normally with respect to all the solvents, Preferably it is 1-20 mass%, More preferably, it is 3-15 mass%.
The other solvent is usually 20% by mass or less, preferably 10% by mass or less.

Specifically, the following combinations can be mentioned.
Propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether,
Propylene glycol monomethyl ether acetate / ethyl lactate,
Propylene glycol monomethyl ether acetate / γ-butyrolactone,
Propylene glycol monomethyl ether acetate / propylene carbonate, propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / γ-butyrolactone,
Propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / propylene carbonate,
Propylene glycol monomethyl ether acetate / ethyl lactate / γ-butyrolactone,
Propylene glycol monomethyl ether acetate / ethyl lactate / propylene carbonate,
2-heptanone / propylene glycol monomethyl ether,
2-heptanone / ethyl lactate,
2-heptanone / γ-butyrolactone,
2-heptanone / propylene carbonate,
2-heptanone / propylene glycol monomethyl ether / γ-butyrolactone,
2-heptanone / propylene glycol monomethyl ether / propylene carbonate, 2-heptanone / ethyl lactate / γ-butyrolactone,
2-Heptanone / ethyl lactate / propylene carbonate Further, ethyl lactate / butyl acetate (as mass ratio, usually 10/90 to 90/10, preferably 30/70 to 70/30) can also be mentioned.

Such a positive resist composition of the present invention is applied onto a substrate to form a thin film. The film thickness of this coating film is preferably 0.2 to 1.2 μm.
Examples of the substrate that can be used include a normal BareSi substrate, an SOG substrate, and a substrate having an inorganic antireflection film described below.
If necessary, a commercially available inorganic or organic antireflection film can be used.

As the antireflection film, an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, α-silicon, and an organic film type made of a light absorber and a polymer material can be used. The former requires equipment such as a vacuum deposition apparatus, a CVD apparatus, and a sputtering apparatus for film formation. Examples of the organic antireflection film include a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin described in JP-B-7-69611, an alkali-soluble resin, a light absorber, and maleic anhydride copolymer described in US Pat. No. 5,294,680. A reaction product of a coalescence and a diamine type light absorbing agent, a resin binder described in JP-A-6-186863 and a methylolmelamine thermal crosslinking agent, a carboxylic acid group, an epoxy group and a light-absorbing group described in JP-A-6-118656. An acrylic resin-type antireflection film in the same molecule, a composition comprising methylol melamine and a benzophenone-based light absorber described in JP-A-8-87115, and a low-molecular light absorber added to a polyvinyl alcohol resin described in JP-A-8-179509 And the like.
Further, as the organic antireflection film, DUV30 series, DUV-40 series, ARC25, AC-2, AC-3, AR19, AR20, etc., manufactured by Brewer Science can be used.

  Appropriate use of the resist solution on a substrate (eg, silicon / silicon dioxide coating) used for the manufacture of precision integrated circuit elements (on a substrate provided with the antireflection film if necessary), spinner, coater, etc. A good resist pattern can be obtained by coating and drying by various coating methods, forming a resist film, exposing through a predetermined mask, preferably baking and developing. Here, the exposure light is preferably a KrF excimer laser (248 nm), EUV (Extreme Ultraviolet), X-ray, or electron beam.

  Examples of the alkaline developer include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia, primary amines such as ethylamine and n-propylamine, diethylamine, di- Secondary amines such as n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium such as tetramethylammonium hydroxide and tetraethylammonium hydroxide Alkaline aqueous solutions (usually 0.1 to 10% by mass) of cyclic amines such as salts, pyrrole and pihelidine can be used. Furthermore, an appropriate amount of alcohol or surfactant may be added to the alkaline aqueous solution.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example. In the following, Examples 2, 3, 4, 10 and 14 are reference examples.

Synthesis of Resin (4) 4-Acetoxystyrene and (α-hydroxymethyl) acrylic acid-2-methyl-2-adamantyl ester were charged at a ratio of 60/40 (molar ratio), dissolved in propylene glycol monomethyl ether, and solid 450 g of a solution having a partial concentration of 22% by mass was prepared. 8 mol% of Wako Pure Chemical Industries, Ltd. polymerization initiator V-601 was added to this solution, and this was dripped at 40 g of propylene glycol monomethyl ether heated at 80 degreeC over 6 hours in nitrogen atmosphere. The reaction liquid was stirred for 2 hours after completion | finish of dripping. After completion of the reaction, the reaction solution was cooled to room temperature, crystallized in 5 L of methanol, and the precipitated white powder was collected by filtration. After adding 500 ml of methanol again, 10 g of dimethylaminopyridine was added, and the mixture was heated and stirred at 65 ° C. for 5 hours. After neutralizing the reaction solution with 1 / 10N hydrochloric acid, the white powder crystallized and precipitated in 5 L of distilled water was collected by filtration, then reslurried with 1 L of distilled water, and the resin (4) exemplified above as the target product. , 50 g was recovered.
The composition ratio (molar ratio) of the polymer determined from NMR was 57/43. Moreover, the weight average molecular weight of standard polystyrene conversion calculated | required by the gel permeation chromatography (GPC) measurement was 9600.

  The same resin composition (1) to (3), (5) to (7), (9), (10), (12), ( 14) to (16) and (19) were synthesized. In the following table, the composition ratio of repeating units is the order from the left of the structural formula.

(Preparation and evaluation of positive resist composition)
[Example 1]
A solution containing each component described as Example 1 in Table 2 was prepared, and a solution microfiltered with a membrane filter having a 0.1 μm aperture was applied onto a 6-inch silicon wafer using a spin coater Mark 8 manufactured by Tokyo Electron. C. for 90 seconds to obtain a uniform film having a thickness of 0.30 .mu.m.

(2) Production of positive resist pattern and its evaluation This resist film was irradiated with an electron beam using an electron beam drawing apparatus (HL750 manufactured by Hitachi, Ltd., acceleration voltage 50 KeV). After irradiation, it was baked at 110 ° C. for 90 seconds, immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution for 60 seconds, rinsed with water for 30 seconds and dried. The obtained pattern was evaluated by the following method.
(2-1) Sensitivity The cross-sectional shape of the obtained pattern was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.). The sensitivity was defined as the minimum irradiation energy when resolving a 0.15 μm line (line: space = 1: 1).
(2-2) Resolving power The resolving power was defined as the limiting resolving power (the line and space were separated and resolved) at the irradiation dose showing the above sensitivity.
(2-3) Pattern shape The cross-sectional shape of the 0.15 μm line pattern at the irradiation amount showing the above sensitivity was observed using a scanning electron microscope (S-4300, manufactured by Hitachi, Ltd.), and was rectangular, slightly tapered, Three-point evaluation of the taper was performed.
(2-4) Line edge roughness The resist composition prepared above was applied onto a silicon wafer, baked at 110 ° C. for 60 seconds, and coated with a film thickness of 150 nm.

  The wafer thus obtained was exposed using an electron beam direct drawing apparatus (50 KeV) while changing the exposure amount. After heating in a clean room at 130 ° C. for 90 seconds, the film was developed with a tetramethylammonium hydroxide developer (2.38 mass%) for 60 seconds, rinsed with distilled water and dried to obtain a pattern.

  About the range of the edge of 5 μm in the longitudinal direction of the 120 nm line pattern obtained by electron beam drawing, the distance from the reference line where the edge should be is measured by the side length SEM (S-9220, manufactured by Hitachi, Ltd.) at 50 points. The standard deviation was obtained and 3σ was calculated. A smaller value indicates better performance.

[Examples 2 to 14 and Comparative Examples 1 and 2]
Using each component shown in Table 2, a pattern was formed by resist preparation, coating, and electron beam irradiation in the same manner as in Example 1, and evaluation was performed.

  In Comparative Example 1, a copolymer of hydroxystyrene / acrylic acid-2-methyl-2-adamantyl ester (copolymerization molar ratio: 57/43, weight average molecular weight 9600) was used as the resin R1.

The symbol of each component in Table 2 shows the following.
The resin and the photoacid generator are those exemplified above.
[Surfactant]
1: MegaFuck F176 (Dainippon Ink Chemical Co., Ltd.) (Fluorine)
2: Megafuck R08 (Dainippon Ink Chemical Co., Ltd.)
(Fluorine and silicone)
3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.)
4: Polyoxyethylene nonylphenyl ether 5: Troisol S-366 (manufactured by Troy Chemical Co., Ltd.)

[Basic compounds]
E1: N, N-diethylaniline E2: N, N-bis (hydroxyethyl) aniline E3: trioctylamine E4: triphenylimidazole E5: antipyrine E6: 2,6-diisopropylaniline

〔solvent〕
S1: Propylene glycol monomethyl ether acetate S2: Propylene glycol monomethyl ether S3: γ-butyrolactone S4: Ethyl lactate S5: Butyl acetate S6: 2-Heptanone S7: Cyclohexanone

  As is apparent from the results in Table 2, it can be seen that the composition of the present invention is excellent in various properties.

Claims (9)

(A) a resin having a repeating unit represented by the general formula (I) and a repeating unit represented by the general formula (II) whose dissolution rate in an alkaline developer is increased by the action of an acid, (B) active light or A positive resist composition comprising a compound that generates an acid upon irradiation with radiation, and (C) a solvent.

In the formula (I), R ₁ represents a hydrogen atom or a hydrocarbon group. R ₂ represents a hydrocarbon group represented by any one of the following general formulas (pI) to (pV) . X represents a single bond or a carbonyl group.

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 having 1 to 4 carbon atoms or an alicyclic hydrocarbon group. However, at least one of R _{12 to} R ₁₄ and any one of R ₁₅ and R ₁₆ represents an alicyclic hydrocarbon group.
R _{17 to} R ₂₁ each independently represents a hydrogen atom, a linear or branched alkyl having 1 to 4 carbon atoms.
Represents 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 having 1 to 4 carbon atoms or an alicyclic hydrocarbon group.
R ₂₂ to R ₂₅ each independently represents a linear or branched alkyl group having 1 to 4 carbon atoms, or represents an alicyclic hydrocarbon group, provided that at least one of R ₂₂ to R ₂₅ is Represents an alicyclic hydrocarbon group. R ₂₃ and R ₂₄ may be bonded to each other to form a ring.

R ₃ represents a hydrogen atom, a methyl group or a halogen atom. R ₄ represents a hydrocarbon group which may have a hydrogen atom or a hetero atom.
However, at least one of R ₂ and R ₄ is a group that decomposes by the action of an acid. In formula (I), R ₂ Represents a hydrocarbon group represented by the general formula (pI) or (pII). The positive resist composition according to claim 1, wherein In the formula (I), X is a single bond, R ₁ The positive resist composition according to claim 1, wherein is a hydrogen atom. The positive resist composition according to claim 1 , wherein R ₄ in the repeating unit represented by the general formula (II) is a group represented by the following formula (A).

In general formula (A), L represents a hydrogen atom, an alkyl group, a cycloalkyl group, or an aralkyl group. Z represents an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group. Z and L may be bonded to each other to form a 5- or 6-membered ring. R ₄ in the repeating unit represented by the general formula (II) is a group represented by the formula (A), and Z is a cycloalkyl group, an aralkyl group, or an alkyl group having a cyclic hydrocarbon structure as a substituent. The positive resist composition according to claim 4 , wherein: R ₄ in the repeating unit represented by the general formula (II) is a tertiary alkoxycarbonyl group, a tertiary alkoxycarbonylalkyl group, a tertiary alkyl group, or a group represented by the following formula (B). The positive resist composition according to claim 1 .

R ₅ and R ₆ each independently represents a hydrogen atom or an alkyl group, and R ₇ represents an alkyl group, a cycloalkyl group, an aryl group or an aralkyl group. W represents a single bond or a divalent organic group, and Y represents a single bond, —O—, —CO ₂ —, —OCO—, —CO—, —S— or —SO ₂ —. The positive resist composition according to any one of claims 1 to 6 , further comprising (E) an organic basic compound. (C) Solvent contains propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether, The description in any one of Claims 1-7 characterized by the above-mentioned.
The positive resist composition described above. A process comprising: forming a resist film from the positive resist composition according to claim 1; irradiating the resist film with an electron beam, X-rays or EUV; and developing with an alkali developer. A characteristic pattern forming method.