JP2002303978A - Positive type resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive type resist composition which is suitable for use in microphotofabrication using far ultraviolet light, particularly ArF excimer laser light and which has high sensitivity and small density dependency and is less liable to surface roughening in etching. SOLUTION: The positive type resist composition contains (A) two resins each having an alicyclic hydrocarbon group in a side chain and having a velocity of dissolution in an alkali developing solution increased by the action of an acid and (B) a compound which generates an acid when irradiated with active light or radiation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive resist composition used in an ultra microlithography process such as the production of an ultra LSI or a high-capacity micro chip, or other photofabrication processes.

[0002]

2. Description of the Related Art In recent years, the degree of integration of integrated circuits has been increasing more and more, and in the manufacture of semiconductor substrates such as VLSIs, processing of ultrafine patterns having a line width of less than half a micron is required. It has become In order to meet the need, the wavelength used in an exposure apparatus used for photolithography is becoming shorter and shorter, and now it is considered to use excimer laser light (XeCl, KrF, ArF, etc.) having a short wavelength among far ultraviolet rays. Up to now.
A chemically amplified resist is used for forming a pattern in lithography in this wavelength region.

In general, chemically amplified resists can be broadly classified into three types: so-called two-component, 2.5-component and three-component resists. The two-component system combines a compound that generates an acid by photolysis (hereinafter referred to as a photoacid generator) and a binder resin. The binder resin is a resin having in its molecule a group (also referred to as an acid-decomposable group) that decomposes under the action of an acid to increase the solubility of the resin in an alkaline developer. The 2.5-component system further contains a low-molecular compound having an acid-decomposable group in such a two-component system. The three-component system contains a photoacid generator, an alkali-soluble resin, and the above low molecular compound.

The above-mentioned chemically amplified resist is suitable for a photoresist for irradiating ultraviolet rays or far ultraviolet rays, but among them, it is necessary to further meet the required characteristics in use. As a photoresist composition for an ArF light source, a resin having an alicyclic hydrocarbon moiety introduced therein for the purpose of imparting dry etching resistance has been proposed. However, such a phenomenon that the development with an aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH), which has been widely used as a resist developing solution in the past, becomes difficult, and the resist is peeled off from the substrate during the development. Can be seen. In response to such a resist hydrophobization, measures such as mixing an organic solvent such as isopropyl alcohol with a developing solution have been studied, and although tentative results have been obtained, the swelling of the resist film and the process become complicated. This does not necessarily mean that the problem has been solved. In the approach of improving the resist, many measures have been taken to supplement various hydrophobic alicyclic hydrocarbon sites by introducing a hydrophilic group.

JP-A-9-73173 discloses an alkali-soluble group protected by a structure containing an alicyclic group, and an acid containing a structural unit capable of leaving the alkali-soluble group by an acid to render it alkali-soluble. A resist material using a sensitive compound is described.

[0006] However, the conventional positive resist composition has a sensitivity in microphotofabrication using far ultraviolet light, particularly ArF excimer laser light.
Good results have not been obtained in terms of density dependence and surface roughness during etching.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a high-sensitivity, low-density, and high-density photo-fabrication device that can be suitably used in microphotofabrication using deep ultraviolet light, particularly ArF excimer laser light. An object of the present invention is to provide a positive resist composition having a low dependence and having a small surface roughness during etching.

[0008]

Means for Solving the Problems As a result of intensive studies on the constituent materials of the positive type chemically amplified resist composition, the present inventors have achieved the object of the present invention by using a specific acid-decomposable resin. This led to the present invention. That is,
The above object is achieved by the following constitutions.

(1) (A) As a resin having an aliphatic cyclic hydrocarbon group in a side chain and having a dissolution rate in an alkali developing solution increased by the action of an acid, a repeating unit represented by the following general formula (Ia): A positive resist composition comprising a resin containing a repeating unit represented by the general formula (Ib) and a resin generating an acid upon irradiation with actinic rays or radiation. .

[0010]

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In the formulas (Ia) and (Ib), R₁Independently
A represents a hydrogen atom or an alkyl group, and A represents a linking group. formula
In (Ia), R₁₁Represents an alkyl group having 1 to 4 carbon atoms,
Z forms an alicyclic hydrocarbon group with a carbon atom.
Represents the required atomic group. In the formula (Ib), R₁₂~ R₁₄Is each
Each independently represents a hydrocarbon group, provided that R₁₂~ R ₁₄Of which
At least one represents an alicyclic hydrocarbon group.

(2) The positive resist composition according to (1), further comprising (C) a fluorine-based and / or silicon-based surfactant. (3) The positive resist composition according to (1) or (2), further comprising (D) an organic basic compound.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, components used in the present invention will be described in detail. [1] (A) A resin whose dissolution rate in an alkali developer is increased by the action of an acid (also referred to as “acid-decomposable resin”).
In the present invention, the acid-decomposable resin is represented by the above general formula (Ia)
The resin (Aa) containing a repeating unit represented by the general formula (Ib) and the resin (Aa) containing a repeating unit represented by the general formula (Ib)
b) is used together.

In the formulas (Ia) and (Ib), R ₁ independently represents a hydrogen atom or an alkyl group. As the alkyl group for R ₁ , preferably an alkyl group having 1 to 4 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group) And particularly preferably a hydrogen atom or a methyl group. A
Represents a linking group, and is generally a single bond, an alkylene group, a substituted alkylene group, an ether group, a thioether group,
It represents a single group selected from the group consisting of a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, and a urea group, or a combination of two or more groups. A
Has preferably 10 or less carbon atoms.
Examples of the alkylene group for A include groups represented by the following formula. — [C (Rf) (Rg)] r ₁ — In the above formula, Rf and Rg represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, and they may be the same or different. Good. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group and a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group and an isopropyl group. 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. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r ₁ is an integer of ₁ to 10.

In the formula (Ia), R ₁₁ is an alkyl group having 1 to 4 carbon atoms (methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl). ), And Z represents an atomic group necessary for forming an alicyclic hydrocarbon group together with a carbon atom.

In the formula (Ib), R₁₂~ R₁₄Are each independently
Represents a hydrocarbon group, provided that R₁₂~ R ₁₄At least
One represents an alicyclic hydrocarbon group.

The hydrocarbon group other than the alicyclic hydrocarbon group represented by R _{12 to} R ₁₄ is preferably a linear or branched alkyl group having 1 to 15 carbon atoms (particularly preferably having 1 to 4 carbon atoms).

The alicyclic hydrocarbon group represented by R _{12 to} R _{14 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. Its carbon number is 6 ~
It is preferably 30 and particularly preferably 7 to 25 carbon atoms.
These alicyclic hydrocarbon groups may have a substituent. Below, the structural example of an alicyclic part among alicyclic hydrocarbon groups is shown.

[0019]

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[0020]

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[0021]

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In the present invention, preferred examples of the alicyclic moiety include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, and a cyclohexyl group. , Cycloheptyl group, cyclooctyl group,
Examples thereof include a cyclodecanyl group and a 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 of these alicyclic hydrocarbon groups include an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, and a carbonyl group (＝ O). As the alkyl group, a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group is preferable,
More preferably, it represents a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group, and an isopropyl group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. As the alkoxy group, a methoxy group, an ethoxy group, a propoxy group,
Examples thereof include those having 1 to 4 carbon atoms such as a butoxy group.

Hereinafter, specific examples of the monomer corresponding to the repeating unit represented by formula (Ia) or (Ib) will be shown.

[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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The acid-decomposable resin (A) of the present invention may further contain a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by the following general formulas (pIII) to (pV).

[0035]

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(In the above formula, R ₁₅ and R ₁₆ each independently represent a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that R ₁₅ and R ₁₆ Any one of ₁₆ represents an alicyclic hydrocarbon group, and R _{17 to} R ₂₁ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group. Where R
At least one of ₁₇ to R ₂₁ represents an alicyclic hydrocarbon group. Further, any one of R ₁₉ and R ₂₁ has 1 to 4 carbon atoms,
Represents a linear or branched alkyl group or an alicyclic hydrocarbon group. R _{22 to} R ₂₅ each independently represent a group having 1 to 4 carbon atoms;
It represents a linear or branched alkyl group 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 (pIII) to (pV), R
The alkyl group for _{15 to} R ₂₅ represents a linear or branched alkyl group having 1 to 4 carbon atoms, which may be substituted or unsubstituted. 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,
Examples include a sec-butyl group and a t-butyl group. Further, as a further substituent of the above alkyl group, one having 1 carbon atom
And 4 to 4 alkoxy groups, halogen atoms (fluorine atom, chlorine atom, bromine atom, iodine atom), acyl group, acyloxy group, cyano group, hydroxyl group, carboxy group, alkoxycarbonyl group, nitro group and the like.

The general formulas (pIII) to (p)
The structure represented by V) can be used for protecting an alkali-soluble group. Examples of the alkali-soluble group include various groups known in this technical field. Specific examples include a carboxylic acid group, a sulfonic acid group, a phenol group, and a thiol group, and a carboxylic acid group and a sulfonic acid group are preferable. General formula (pIII) to above resin
As the alkali-soluble group protected by the structure represented by (pV), the following general formulas (pVIII) to (pX) are preferable.
And the groups represented by I).

[0039]

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Here, R _{15 to} R ₂₅ are the same as defined above. In the above resin, the compound represented by the general formula (pIII)
As the repeating unit having an alkali-soluble group protected by the structure represented by (pV), a repeating unit represented by the following general formula (pA) is preferable.

[0041]

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Here, R represents a hydrogen atom, a halogen atom, or a substituted or unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of Rs may be the same or different. A is a compound represented by the formula (Ia) (I
Same as in b). Ra is determined by the above formula (pII
I) represents any group of (pV).

Specific examples of the repeating unit represented by formula (pA) are shown below, but it should not be construed that the invention is limited thereto.

[0044]

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[0045]

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The acid-decomposable resin of the present invention can further contain a repeating unit having a lactone structure represented by the following general formula (IV).

[0047]

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[0048] In the general formula (IV), R ₁ a represents a hydrogen atom or a methyl group. W ₁ represents a single bond, an alkylene group, an ether group, a thioether group, a carbonyl group, or a combination of two or more groups selected from the group consisting of an ester group. _{Ra 1, Rb 1, Rc 1} , Rd 1, Re 1 each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. m and n each independently represent an integer of 0 to 3;
Is 2 or more and 6 or less.

Examples of the alkyl group having 1 to 4 carbon atoms of Ra _{1 to} Re ₁ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group and a t-butyl group. Can be mentioned.

In the general formula (IV), examples of the alkylene group represented by W ₁ include groups represented by the following formula. — [C (Rf) (Rg)] r ₁ — In the above formula, Rf and Rg represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, and they may be the same or different. Good. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group and a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group and an isopropyl group. 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. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r ₁ is an integer of ₁ to 10.

Further substituents on the above alkyl group include carboxyl group, acyloxy group, cyano group, alkyl group, substituted alkyl group, halogen atom, hydroxyl group, alkoxy group, substituted alkoxy group, acetylamide group, alkoxycarbonyl group, An acyl group is exemplified. Here, examples of the alkyl group include lower alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a cyclopropyl group, a cyclobutyl group, and a cyclopentyl group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. Examples of the substituent of the substituted alkoxy group include 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. Examples of the acyloxy group include an acetoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom.

Hereinafter, specific examples of the monomer corresponding to the repeating structural unit represented by the general formula (IV) will be shown, but it should not be construed that the invention is limited thereto.

[0053]

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[0054]

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[0055]

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In the specific example of the above general formula (IV), (IV-17) to (IV-17)
(IV-36) is preferred. Further, as the structure of the general formula (IV), those having an acrylate structure are preferable from the viewpoint that edge roughness is improved.

Further, the following general formulas (V-1) to (V-4)
And a repeating unit having a group represented by any of the above.

[0058]

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In the general formulas (V-1) to (V-4),
R _{1b to} R _5b each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group or an alkenyl group which may have a substituent. Two of R _{1b to} R _5b may combine to form a ring.

In the general formulas (V-1) to (V-4),
Examples of the alkyl group for R _{1b to} R _5b include a linear or branched alkyl group, and may have a substituent. The linear or branched alkyl group has 1 to 1 carbon atoms.
Twelve linear or branched alkyl groups are preferred,
More preferably, it is a linear or branched alkyl group having 1 to 10 carbon atoms, and still more preferably, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, -Butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group,
Decyl group. The cycloalkyl group in R _{1b to} R _5b is preferably a cycloalkyl group having 3 to 8 carbon atoms such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and the like. The alkenyl group in R _{1b to} R _5b is preferably an alkenyl group having 2 to 6 carbon atoms such as a vinyl group, a propenyl group, a butenyl group, and a hexenyl group. Examples of the ring formed by combining two members out of R _{1b to} R _5b include a 3- to 8-membered ring such as a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, and a cyclooctane ring. The general formula (V-1)
R _{1b to} R _5b in (V-4) may be connected to any of the carbon atoms constituting the cyclic skeleton.

Preferred substituents which the alkyl group, cycloalkyl group and alkenyl group may have are an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom). Atom), an acyl group having 2 to 5 carbon atoms, an acyloxy group having 2 to 5 carbon atoms, a cyano group, a hydroxyl group, a carboxy group, an alkoxycarbonyl group having 2 to 5 carbon atoms, and a nitro group.

The repeating units having groups represented by formulas (V-1) to (V-4) include compounds represented by the following formula (AI)
And the like.

[0063]

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In the general formula (AI), R _b0 represents a hydrogen atom, a halogen atom, or a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. Preferred substituents which the alkyl group of _Rb0 may have are those represented by the general formulas (V-1) to (V-1).
Preferred examples of the substituent which may be possessed by the alkyl group as R _1b in (V-4) include those exemplified above. Examples of the halogen atom for R _b0 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R
_b0 is preferably a hydrogen atom. A ′ represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent group obtained by combining these. B ₂ represents a group represented by any one of formulas (V-1) to (V-4). In A ′, examples of the combined divalent group include those represented by the following formulas.

[0065]

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In the above formula, Rab and Rbb represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, and they may be the same or different. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group and a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group and an isopropyl group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom, and an alkoxy group having 1 to 4 carbon atoms. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r
1 represents an integer of 1 to 10, preferably an integer of 1 to 4.
m represents an integer of 1 to 3, preferably 1 or 2.

Hereinafter, specific examples of the repeating unit represented by the general formula (AI) are shown, but the present invention is not limited thereto.

[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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[0073]

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[0074]

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Further, the acid-decomposable resin of the present invention may further contain a repeating unit represented by the following general formula (VI).

[0076]

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In the general formula (VI), A ₆ is a single bond, an alkylene group, a cycloalkylene group, an ether group, a thioether group, a carbonyl group, an ester group, or a combination of two or more groups. Represents R _6a represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, or a halogen atom.

In the general formula (VI), examples of the alkylene group represented by A ₆ include groups represented by the following formula. -[C (Rnf) (Rng)] r- In the above formula, Rnf and Rng are a hydrogen atom, an alkyl group,
Represents a substituted alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, which may be the same or different. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group and a butyl group, and more preferably selected from a methyl group, an ethyl group, a propyl group and an isopropyl group. 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. Examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. r is an integer of 1 to 10. General formula (VI)
In the above, examples of the cycloalkylene group for A ₆ include those having 3 to 10 carbon atoms, and a cyclopentylene group,
Examples thereof include a cyclohexylene group and a cyclooctylene group.

The bridged alicyclic ring containing Z ₆ may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (preferably having 1 to 4 carbon atoms), an alkoxycarbonyl group (preferably having 1 to 5 carbon atoms), an acyl group (eg, a formyl group and a benzoyl group), and an acyloxy group ( For example, a propylcarbonyloxy group, a benzoyloxy group), an alkyl group (preferably having 1 to 4 carbon atoms), a carboxyl group, a hydroxyl group, an alkylsulfonylsulfamoyl group (such as —CONHSO ₂ CH ₃ ) are exemplified. still,
The alkyl group as a substituent may be further substituted with a hydroxyl group, a halogen atom, an alkoxy group (preferably having 1 to 4 carbon atoms), or the like.

In the general formula (VI), the oxygen atom of the ester group bonded to A ₆ may be bonded at any position of the carbon atom constituting the bridged alicyclic ring structure including Z _6. Good.

The following are specific examples of the repeating unit represented by the general formula (VI), but the invention is not limited thereto.

[0082]

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[0083]

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Further, it may contain a repeating unit having a group represented by the following formula (VII).

[0085]

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In the general formula (VII), R ₂ c to R ₄ c each independently represent a hydrogen atom or a hydroxyl group. Provided that at least one of R ₂ c to R ₄ c represents a hydroxyl group.

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

As the repeating unit having a group represented by the general formula (VII), a repeating unit represented by the following general formula (AII) can be exemplified.

[0089]

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[0090] In formula (AII), R ₁ c represents a hydrogen atom or a methyl group. R ₂ c~R ₄ c represents a hydrogen atom or a hydroxyl group independently. Provided that at least one of R ₂ c to R ₄ c represents a hydroxyl group.

Specific examples of the repeating unit having the structure represented by formula (AII) will be shown below, but it should not be construed that the invention is limited thereto.

[0092]

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The acid-decomposable resins (Aa) and (Ab) may have, in addition to the above-mentioned repeating structural units, dry etching resistance, standard developer suitability, substrate adhesion, resist profile,
Further, various recurring structural units can be contained for the purpose of adjusting resolution, heat resistance, sensitivity and the like, which are general necessary characteristics of the resist.

Examples of such a repeating structural unit include, but are not limited to, repeating structural units corresponding to the following monomers. Thereby, the performance required for the acid-decomposable resin, in particular, (1) solubility in a coating solvent, (2) film-forming property (glass transition point),
Fine adjustment of (3) alkali developability, (4) film loss (hydrophobicity, selection of alkali-soluble group), (5) adhesion of unexposed portion to substrate, (6) dry etching resistance, etc. becomes possible. . As such monomers, for example, acrylates, methacrylates, acrylamides,
Examples thereof include compounds having one addition-polymerizable unsaturated bond selected from methacrylamides, allyl compounds, vinyl ethers, vinyl esters, and the like.

Specifically, the following monomers can be mentioned. Acrylic esters (preferably alkyl acrylates having 1 to 10 carbon atoms in the alkyl group): methyl acrylate, ethyl acrylate, propyl acrylate,
Amyl acrylate, cyclohexyl acrylate, ethyl hexyl acrylate, octyl acrylate, tert-octyl acrylate, chloroethyl acrylate, 2-hydroxyethyl acrylate 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane Monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate and the like.

Methacrylic esters (preferably alkyl methacrylate having an alkyl group having 1 to 10 carbon atoms): methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate,
Cyclohexyl methacrylate, benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, 5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, penta Erythritol monomethacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate and the like.

Acrylamides: acrylamide, N-
Alkyl acrylamide (the alkyl group has 1 carbon atom
And 10 such as methyl, ethyl, propyl, butyl, t-butyl, heptyl, octyl, cyclohexyl, and hydroxyethyl. ), N, N-dialkylacrylamide (alkyl group having 1 to 10 carbon atoms, for example, methyl group, ethyl group, butyl group, isobutyl group, ethylhexyl group,
A cyclohexyl group, etc.), N-hydroxyethyl-
N-methylacrylamide, N-2-acetamidoethyl-N-acetylacrylamide and the like.

Methacrylamides: methacrylamide,
N-alkyl methacrylamide (an alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group,
Butyl group, ethylhexyl group, hydroxyethyl group, cyclohexyl group, etc.), N, N-dialkylmethacrylamide (alkyl group includes ethyl group, propyl group, butyl group, etc.), N-hydroxyethyl-N-
Methyl methacrylamide and the like.

Allyl compounds: allyl esters (eg, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate, etc.), allyloxyethanol etc.

Vinyl ethers: alkyl vinyl ethers (eg, hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether,
-Methyl-2,2-dimethylpropyl vinyl ether,
2-ethylbutyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether,
Dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether and the like.

Vinyl esters: vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valate, vinyl caproate, vinyl chloroacetate, vinyl dichloroacetate, vinyl methoxy acetate, vinyl butoxy acetate, vinyl Acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate and the like.

Dialkyl itaconates: dimethyl itaconate, diethyl itaconate, dibutyl itaconate and the like. Dialkyl esters or monoalkyl esters of fumaric acid; dibutyl fumarate;

Others crotonic acid, itaconic acid, maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleilenitrile and the like.

In addition, as long as it is an addition-polymerizable unsaturated compound copolymerizable with the monomer corresponding to the above-mentioned various repeating structural units, it may be copolymerized.

In the acid-decomposable resin, the molar ratio of each repeating structural unit depends on the dry etching resistance of the resist, the suitability for a standard developing solution, the substrate adhesion, the resist profile, and the resolving power, heat resistance, which is a general required performance of the resist. It is set as appropriate to adjust properties, sensitivity, and the like.

In the acid-decomposable resin (Aa), the compound represented by the general formula (Ia)
The content of the repeating unit represented by is preferably 30 to 70 mol%, more preferably 35 to 70 mol% of all the repeating structural units.
６５65 mol%, more preferably 40-60 mol%. In the acid-decomposable resin (Ab), the content of the repeating unit represented by the general formula (Ib) is 30% in all the repeating structural units.
It is preferably from 70 to 70 mol%, more preferably from 35 to 65 mol%, and still more preferably from 40 to 60 mol%. In the acid-decomposable resins (Aa) and (Ab), general formulas (pIII) to (p
The content of the repeating unit having a partial structure containing an alicyclic hydrocarbon represented by V) is 30 to
70 mol% is preferable, more preferably 35 to 65 mol%, and still more preferably 40 to 60 mol%. In the acid-decomposable resins (Aa) and (Ab), the compounds represented by the general formulas (IV) to (VI)
The content of the repeating unit (I) is preferably from 5 to 70 mol%, more preferably from 10 to 65 mol%, even more preferably from 15 to 60 mol%, based on the total repeating structural units. In the acid-decomposable resins (Aa) and (Ab), a repeating unit represented by the general formula (Ia) or (Ib), (pII
The content of the repeating unit having an acid-decomposable group containing a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by I) to (pV) is 30 to 70 mol% in all repeating structural units. It is preferably 35 to 65 mol%, more preferably 40 to 60 mol%.

The total amount of the acid-decomposable resins (Aa) and (Ab) based on the total solid content of the composition of the present invention is generally 5%.
It is 0 to 99.99% by weight, preferably 60 to 99.97. The range of the weight ratio between the acid-decomposable resins (Aa) and (Ab) is generally 99: 1 to 1:99, preferably 9: 1.
0:10 to 10:90, more preferably 80:20 to 2
0:80.

The acid-decomposable resin used in the present invention 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 at once or in the middle of a reaction, and this is reacted with a reaction solvent as necessary, for example, ethers such as tetrahydrofuran, 1,4-dioxane, diisopropyl ether, methyl ethyl ketone, Ketones such as methyl isobutyl ketone, ester solvents such as ethyl acetate, and further dissolved in a solvent that dissolves the composition of the present invention such as propylene glycol monomethyl ether acetate described below, and then homogenized. Under an inert gas atmosphere, if necessary, heating is performed, and polymerization is started using a commercially available radical initiator (such as an azo initiator or a peroxide).
If desired, an initiator is added or added in portions, and after completion of the reaction, the mixture is poured into a solvent and a desired polymer is recovered by a method such as powder or solid recovery. Reaction concentration is 20% by weight
It is preferably at least 30% by weight, more preferably at least 40% by weight. Reaction temperature is 10 ° C. to 150
° C, preferably from 30 ° C to 120 ° C, more preferably from 50 to 100 ° C.

The weight average molecular weight of the resin according to the present invention is G
It is preferably from 1,000 to 200,000 in terms of polystyrene according to the PC method. When the weight average molecular weight is less than 1,000, heat resistance and dry etching resistance are deteriorated, so that it is not preferable. When the weight average molecular weight exceeds 200,000, the developability is deteriorated and the viscosity becomes extremely high, so that the film forming property is deteriorated. And so on, which produces very unfavorable results. When the composition of the present invention is for ArF exposure,
It is preferable that the resin does not have an aromatic ring from the viewpoint of transparency to light. In addition, having no alicyclic group in the main chain of the resin,
This is preferable because the contact hole can be easily removed and the defocus latitude (the allowable range of defocus) can be significantly improved.

In the positive photoresist composition for deep ultraviolet exposure according to the present invention, the amount of all the resins according to the present invention in the total composition is from 40 to 99.
It is preferably 99% by weight, more preferably 50 to 99.9.
7% by weight.

[2] (B) Compound that Generates Acid by Irradiation with Actinic Ray or Radiation (Photoacid Generator) The photoacid generator used in the present invention includes a photoinitiator for photocationic polymerization and a photoradical polymerization. Known photoinitiators, photodecolorants of dyes, photochromic agents, or known light (ultraviolet light of 400 to 200 nm, far ultraviolet light, particularly preferably g-line, h-line, X-rays, KrF excimer laser light), ArF excimer laser light, electron beams, X-rays, compounds generating an acid by a molecular beam or an ion beam, and mixtures thereof can be appropriately selected and used.

For example, onium salts such as diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts and arsonium salts;
Organic halogen compound, organic metal / organic halide, o
A photoacid generator having a nitrobenzyl-type protecting group; a compound represented by photolysis such as iminosulfonate that generates sulfonic acid; a disulfone compound; a diazoketosulfone; and a diazodisulfone compound.
Further, a group in which an acid is generated by such light or a compound in which a compound is introduced into a main chain or a side chain of a polymer can be used.

Further, VNRPillai, Synthesis, (1), 1 (198
0), A. Abad etal, Tetrahedron Lett., (47) 4555 (1971),
Compounds that generate an acid by light described in DHR Barton et al., J. Chem. Soc., (C), 329 (1970), U.S. Pat. No. 3,779,778, and EP 126,712 can also be used.

Among the compounds capable of decomposing upon irradiation with actinic rays or radiation to generate an acid, other photoacid generators which are used particularly effectively will be described below. (1) The following general formula (PAG) substituted with a trihalomethyl group
The oxazole derivative represented by 1) or the general formula (PAG)
An S-triazine derivative represented by 2).

[0115]

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In the formula, R ²⁰¹ is a substituted or unsubstituted aryl group or alkenyl group, and R ²⁰² is a substituted or unsubstituted aryl group, alkenyl group, alkyl group, —C (Y) ₃
Show Y represents a chlorine atom or a bromine atom. Specific examples include the following compounds, but the present invention is not limited thereto.

[0117]

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(2) An iodonium salt represented by the following formula (PAG3) or a sulfonium salt represented by the following formula (PAG4).

[0119]

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The formulas Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. R ²⁰³ , R ²⁰⁴ ,
R ²⁰⁵ each independently represents a substituted or unsubstituted alkyl group or aryl group.

Z ^- represents a counter anion, for example, B
F ₄ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , SiF ₆ ²⁻ , Cl
Condensed polynuclear aromatic sulfonic acid anions such as perfluoroalkanesulfonic acid anions such as O ₄ ⁻ and CF ₃ SO ₃ ⁻ , pentafluorobenzenesulfonic acid anion and naphthalene-1-sulfonic acid anion, anthraquinonesulfonic acid anion and sulfonic acid group Dyes and the like may be included, but are not limited thereto.

In addition, 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.

[0124]

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[0125]

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[0126]

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[0127]

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[0128]

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[0129]

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[0130]

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[0131]

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[0132]

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[0133]

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In the above, Ph represents a phenyl group.
The onium salts represented by the general formulas (PAG3) and (PAG4) are known and can be synthesized, for example, by the methods described in U.S. Pat. Nos. 2,807,648 and 4,247,473 and JP-A-53-101,331. .

(3) Disulfone derivatives represented by the following formula (PAG5) or iminosulfonate derivatives represented by the following formula (PAG6).

[0136]

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

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

[0139]

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[0140]

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[0141]

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[0142]

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[0143]

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

[0145]

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Here, R represents a linear, branched or cyclic alkyl group or an optionally substituted aryl group. Specific examples include the following compounds, but are not limited thereto.

[0147]

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[0148]

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The amount of the photoacid generator is usually in the range of 0.001 to 30% by weight, preferably 0.3 to 20% by weight, more preferably 0 to 30% by weight, based on the solid content in the composition. It is used in the range of 0.5 to 10% by weight. If the amount of the photoacid generator is less than 0.001% by weight, the sensitivity is low. If the amount is more than 30% by weight, the light absorption of the resist becomes too high, and the profile deteriorates and the process (particularly baking) ) The margin is undesirably narrow. [3] Other Additives The positive resist composition of the present invention may further contain an acid-decomposable dissolution inhibiting compound, a dye, a plasticizer, a surfactant, if necessary.
A photosensitizer, an organic basic compound, a compound that promotes solubility in a developer, and the like can be contained.

The positive resist composition of the present invention preferably contains (C) a fluorine-based and / or silicon-based surfactant. The positive resist composition of the present invention preferably contains one or more of a fluorine-based surfactant, a silicon-based surfactant and a surfactant containing both a fluorine atom and a silicon atom. . When the positive resist composition of the present invention contains the above-mentioned acid-decomposable resin and the above-mentioned surfactant, it is particularly effective when the line width of the pattern is narrower, and the development defects are further improved. As these surfactants, for example, JP-A-62-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950
No., JP-A-63-34540, JP-A-7-230165, JP-A-8-62
No. 834, JP-A-9-54432, JP-A-9-5988, U.S. Pat.
05720, 5360692, 5529881, 5296330,
The surfactants described in 5436098, 5576143, 5294511 and 5824451 can be mentioned, and the following commercially available surfactants can be used as they are. As commercially available surfactants that can be used, for example, F-top EF301, EF303,
(Manufactured by Shin-Akita Chemical Co., Ltd.), Florard FC430, 431 (manufactured by Sumitomo 3M Limited), Megafac F171, F173, F176, F18
9, R08 (Dainippon Ink Co., Ltd.), Surflon S-382,
SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.),
Fluorinated surfactants such as Troysol S-366 (manufactured by Troy Chemical Co., Ltd.) and silicon-based surfactants can be mentioned. Also, polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used as a silicon-based surfactant.

The amount of the surfactant is usually 0.001 to 2% by weight, preferably 0.01 to 1% by weight, based on the solid content in the composition of the present invention. These surfactants may be added alone or in some combination.

Examples of the surfactant that can be used in addition to the above include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether. Polyoxyethylene alkyl allyl ethers such as ethylene alkyl ethers, polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostea Fatty acid esters such as sorbitan monosorbate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, polyoxyethylene Nonionics such as fatty acid esters of polyoxyethylene sorbitan such as rubitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Surfactants and the like. The amount of these other surfactants is usually 2 parts by weight or less, preferably 1 part by weight or less, per 100 parts by weight of the solids in the composition of the present invention.

The preferred (D) organic basic compound which can be used in the present invention is a compound which is more basic than phenol. Among them, a nitrogen-containing basic compound is preferable.

[0154]

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Here, R²⁵⁰, R²⁵¹And R²⁵²Are each
Independently, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms,
1-6 aminoalkyl groups, hydroxy having 1-6 carbon atoms
Alkyl group or substituted or unsubstituted 6 to 20 carbon atoms
An aryl group, where R ²⁵¹And R²⁵²Are connected to each other
To form a ring.

[0156]

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(Wherein R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R
²⁵⁶ independently represent an alkyl group having 1 to 6 carbon atoms.) Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms having different chemical environments in one molecule,
Particularly preferred are compounds containing both a substituted or unsubstituted amino group and a ring structure containing a nitrogen atom, or compounds having an alkylamino group. Preferred specific examples include substituted or unsubstituted guanidine, substituted or unsubstituted aminopyridine, substituted or unsubstituted aminoalkylpyridine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted indazol, substituted or unsubstituted Pyrazole, substituted or unsubstituted pyrazine,
Substituted or unsubstituted pyrimidine, substituted or unsubstituted purine, substituted or unsubstituted imidazoline, substituted or unsubstituted pyrazoline, substituted or unsubstituted piperazine, substituted or unsubstituted aminomorpholine, substituted or unsubstituted amino And alkyl morpholine. Preferred substituents are an amino group, an aminoalkyl group, an alkylamino group, an aminoaryl group, an arylamino group, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, an aryloxy group, a nitro group,
A hydroxyl group and a cyano group.

Preferred specific examples of the nitrogen-containing basic compound include guanidine, 1,1-dimethylguanidine,
1,3,3, -tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine,
-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-amino Ethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine, 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] nona-
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, cyclohexylmorpholinoethylthiourea (CHMET
U) and other tertiary morpholine derivatives, JP-A-11-5257
No. 5 hindered amines (for example, those described in the gazette [0005]) and the like, but are not limited thereto.

Particularly preferred specific 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] Tertiary morpholines such as octane, 4-dimethylaminopyridine, hexamethylenetetramine, 4,4-dimethylimidazoline, pyrroles, pyrazoles, imidazoles, pyridazines, pyrimidines, CHMETU, etc., and bis Hindered amines such as (1,2,2,6,6-pentamethyl-4-piperidyl) sebagate and the like can be mentioned. 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 is preferred.

These nitrogen-containing basic compounds are used alone or in combination of two or more. The amount of the nitrogen-containing basic compound to be used is generally 0.001 to 10% by weight, preferably 0.01 to 5% by weight, based on the solid content of the entire photosensitive resin composition. If the amount is less than 0.001% by weight, the effect of the addition of the nitrogen-containing basic compound cannot be obtained. On the other hand, if it exceeds 10% by weight, the sensitivity tends to decrease and the developability of the unexposed portion tends to deteriorate.

The positive resist composition of the present invention is dissolved in a solvent capable of dissolving each of the above components and applied on a support. As the solvent used here, 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, lactic acid Ethyl, methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-
Dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable, and these solvents are used alone or in combination.

Among the above, preferred solvents are propylene glycol monomethyl ether acetate,
Heptanone, γ-butyrolactone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate , N-methylpyrrolidone and tetrahydrofuran.

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

As the anti-reflection film, an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, α-silicon, and an organic film type comprising a light absorbing agent 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. As the organic antireflection film, for example, Japanese Patent Publication No. 7-69
No. 611, consisting of a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin, an alkali-soluble resin, and a light absorbing agent; a reaction product of a maleic anhydride copolymer and a diamine type light absorbing agent described in US Pat. No. 5,294,680; No. 6,118,631 containing a resin binder and a methylolmelamine-based thermal crosslinking agent; Japanese Patent Application Laid-Open No. 6-118656, an acrylic resin type antireflection film having a carboxylic acid group, an epoxy group and a light absorbing group in the same molecule; JP-A-8-87115, comprising a methylolmelamine and a benzophenone-based light-absorbing agent;
No. 79509 in which a low molecular weight light absorbing agent is added to a polyvinyl alcohol resin. As an organic anti-reflection film, DUV3 manufactured by Brewer Science Co., Ltd.
0 series, DUV-40 series, ARC25, Shipley's AC-2, AC-3, AR19, AR20
Etc. can also be used.

The resist solution is coated on a substrate (eg, silicon / silicon dioxide coating) used for manufacturing precision integrated circuit elements (on a substrate provided with the antireflection film if necessary), a spinner, a coater, and the like. After coating by an appropriate coating method such as that described above, exposure through a predetermined mask, baking and development can provide a good resist pattern. Here, the exposure light is preferably 150
It is light having a wavelength of nm to 250 nm. Specifically, Kr
F excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157
nm), X-rays, electron beams and the like.

Examples of the 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;
Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like An alkaline aqueous solution such as a quaternary ammonium salt, a cyclic amine such as pyrrole, or pyrhelidine can be used. Further, an appropriate amount of an alcohol or a surfactant may be added to the above alkaline aqueous solution.

[0167]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples.

[Synthesis of acid-decomposable resin (Aa)] 2-Ethyl-2-adamantyl methacrylate, butyrolactone methacrylate and methacrylic acid were charged at a ratio of 50/45/5 and dissolved in methyl isobutyl ketone, and the solid content was 30%. A solution (100 mL) was prepared. To this solution was added 4 mol% of V-601 manufactured by Wako Pure Chemical Industries, and this was added dropwise to 10 mL of methyl isobutyl ketone heated to 70 ° C over 4 hours under a nitrogen atmosphere. After completion of the dropwise addition, the reaction solution was heated and stirred for 4 hours. After completion of the reaction, the reaction solution is cooled to room temperature,
Mixed solvent 1 of distilled water / isopropyl alcohol = 1/1
The white powder crystallized and precipitated in L was washed with 1 L of methanol to recover the target resin (1a). C ¹³ NMR
Was 43/50/7.
The weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 8,900. Resins having the composition ratios and molecular weights shown in the following table were synthesized in the same manner as in the above Synthesis Examples.
The repeating units 1, 2, 3, and 4 are in order from the left in the structural formula.

[0169]

[Table 1]

The structures of the resins (1a) to (15a) are shown below.

[0171]

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[0172]

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[0173]

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[0174]

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[Synthesis of Acid-Decomposable Resin (Ab)] Inadamantyl methacrylate, a methacrylate having the following structure,
Methacrylic acid was charged at a ratio of 46/40/14 and dissolved in methyl ethyl ketone.
mL was prepared.

[0176]

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To this solution was added V-601 manufactured by Wako Pure Chemical Industries, 1 mol.
1% and 2 mol% of 2-ethylhexyl mercaptopropionate were added dropwise to 10 mL of methyl isobutyl ketone heated to 70 ° C. over 4 hours under a nitrogen atmosphere. After completion of the dropwise addition, the reaction solution was heated and stirred for 4 hours.
After completion of the reaction, the reaction solution was cooled to room temperature, and the white powder precipitated and crystallized in 1 L of a mixed solvent of distilled water / isopropyl alcohol = 1/1 was washed with 1 L of methanol to obtain the target resin (1b). Collected. The polymer composition ratio determined from C ¹³ NMR was 45/40/15. The weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 12,100. Resins having the composition ratios and molecular weights shown in the following table were synthesized in the same manner as in the above synthesis examples. The repeating units 1, 2, 3, and 4 are in order from the left in the structural formula.

[0178]

[Table 2]

The structures of the resins (1b) to (15b) are shown below.

[0180]

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[0181]

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[0182]

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[0183]

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[0184]

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Examples 1 to 15 and Comparative Example 1 (Preparation and Evaluation of Positive Resist Composition) The components shown in Table 3 synthesized in the above Synthesis Examples were blended, and the respective components were mixed at a solid content of 14% by weight. After dissolving in propylene glycol monomethyl ether acetate, the solution was filtered through a 0.1 μm microfilter to prepare positive resist compositions of Examples 1 to 15 and Comparative Example 1.

[0186]

[Table 3]

As the surfactant, W1: Megafac F176 (manufactured by Dainippon Ink and Chemicals, Inc.)
(Fluorine) W2: Megafac R08 (Dai Nippon Ink Co., Ltd.)
(Fluorine and silicone type) W3: Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) W4: Polyoxyethylene nonylphenyl ether W5: Troysol S-366 (Troy Chemical Co., Ltd.)
Made).

As the amine, 1 represents 1,5-diazabicyclo [4.3.0] -5-nonene (DBN);
2 is bis (1,2,2,6,6-pentamethyl-4-
Piperidyl) sebagate 3 is tri-n-butylamine 4
Is triphenylimidazole 5 is antipyrine 6
Represents 2,6-diisopropylaniline.

First, DUV30 manufactured by Brewer Science was applied on a silicon wafer using a spin coater at 1600 nm and dried, and then the obtained positive photoresist composition was applied thereon and dried at 140 ° C. for 90 seconds. A positive photoresist film having a thickness of about 0.4 μm was formed, and an ArF excimer laser (wavelength 193) was formed thereon.
Exposure was performed with a 1/2 pitch contact hole pattern (mask size of 0.15 μm) while changing the exposure amount using an ArF stepper (manufactured by ISI, Inc., nm, NA = 0.6). A heat treatment after exposure is performed at 120 ° C. for 90 seconds,
It was developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide and rinsed with distilled water to obtain a resist pattern profile. Observe the resist pattern of the silicon wafer thus obtained with a scanning microscope,
The resist was evaluated as follows.

[Sensitivity]: The minimum exposure for reproducing a contact hole having a diameter of 0.15 μm is defined as the sensitivity, and the relative exposure when the resist exposure in Example 1 is set to 1.0 is the relative sensitivity (for other resists). (Exposure amount / exposure amount of Example 1).

[Dependency on coarse / dense]: 0.15 μm contact hole (dense pattern: pitch 1/1 and pitch 1 /
2) and the isolated contact hole pattern (sparse pattern: pitch 1/10)
The overlapping range of the depth of focus allowing ± 10% was determined. The larger the range, the better. [Surface Roughness During Etching]: A 0.15 μm contact hole pattern was formed with CHF ₃ / O ₂ = 8/2 plasma for 6 times.
Etching was performed for 0 second, and the cross section and surface of the obtained sample were observed with an SEM, and a pinhole-shaped defect (the lower layer of the non-processed portion would be etched) was x, and the surface roughness occurred. No defect was generated, however, a hole having deformation of the hole was rated as Δ, and a sample having a small surface roughness and no deformation of the hole was rated as ○. Table 4 shows the results.

[0192]

[Table 4]

As is clear from the results shown in Table 4, the positive resist composition of the present invention has high sensitivity, is highly dependent on density, has small surface roughness during etching, and is excellent.

[0194]

According to the present invention, it is possible to provide a positive resist composition which has high sensitivity, low dependency on density and low surface roughness during etching. The positive resist composition of the present invention can be suitably used for microfabrication using far ultraviolet light, particularly ArF excimer laser light.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G03F 7/004 504 G03F 7/004 504 H01L 21/027 H01L 21/30 502R F-term (Reference) 2H025 AA00 AA01 AB16 AC04 AC08 AD03 BE00 BG00 BJ10 CC04 CC20 FA04 FA12 FA17 4J002 BG071 CH012 EH047 ER028 EU028 EU036 EU048 EU078 EU128 EU138 EU148 EU186 EU208 EU216 EU238 EV216 EV296 FD317 GP03 4J100 AJ02R AL08P AL08B ALBARBAQBA08BA03BA03 BA03R03 BA08 BC07R BC07S BC07T BC09P BC09Q BC09R BC09S BC53Q BC53R BC53S JA38

Claims (3)

[Claims] (1) An aliphatic cyclic hydrocarbon group having (A) an aliphatic cyclic hydrocarbon group in a side chain.
And the dissolution rate in an alkaline developer is
As an increasing resin, a resin represented by the following general formula (Ia)
A resin containing a repeating unit and represented by the general formula (Ib)
A resin containing a repeating unit, and (B) an actinic ray or
Contain compounds that generate acid upon irradiation
A positive resist composition comprising: Embedded imageIn the formulas (Ia) and (Ib), R₁Is independently a hydrogen atom or
A represents an alkyl group, and A represents a linking group. In the formula (Ia),
R₁₁Represents an alkyl group having 1 to 4 carbon atoms, and Z represents a carbon atom
Required to form an alicyclic hydrocarbon group with
Represents In the formula (Ib), R₁₂~ R₁₄Are each independently carbonized
Represents a hydrogen group, provided that R₁₂~ R ₁₄At least one of
Represents an alicyclic hydrocarbon group. 2. The positive resist composition according to claim 1, further comprising (C) a fluorine-based and / or silicon-based surfactant. 3. The positive resist composition according to claim 1, further comprising (D) an organic basic compound.