JP2001100421A - Positive type photoresist composition for exposure with far ultraviolet ray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a technical problem in enhancing performance peculiar to microphotofabrication using far ultraviolet light, particularly KrF or ArF excimer laser light and to obtain a positive type photoresist composition less liable to cause development defects and excellent in edge roughness. SOLUTION: The positive type photoresist composition contains a compound which generated an acid when irradiated with active light or radiation and a resin containing repeating units each containing a group represented by a specified structure and increasing its rate of dissolution in an alkali developing solution under the action of the acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photoresist composition for use in an ultra-microlithography process such as the production of an VLSI or a high-capacity microchip and 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 satisfy 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. For example,
When using 248 nm light of a KrF excimer laser, a hydroxystyrene-based polymer having a low light absorption is particularly used.
There has been proposed a resist composition using a polymer having an acetal group or a ketal group introduced as a protective group. JP-A-2-141636, JP-A-2-19847, JP-A-4
Japanese Patent Application Laid-Open No. 5-281745 and Japanese Patent Application Laid-Open No. 5-281745 are examples. In addition, similar compositions using a t-butoxycarbonyloxy group or a p-tetrahydropyranyloxy group as an acid-decomposable group are disclosed in JP-A-2-209977 and JP-A-3-209.
206458 and JP-A-2-19847.

As a photoresist composition for an ArF light source, a resin into which an alicyclic hydrocarbon moiety is introduced for the purpose of imparting dry etching resistance has been proposed. Because the system becomes extremely hydrophobic, development with an aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH), which has been widely used as a resist developer, becomes difficult, or the resist is peeled off from the substrate during development. Some phenomena such as getting lost are 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-10-10739 discloses an energy-sensitive resist containing a polymer obtained by polymerizing a monomer having an alicyclic structure such as a norbornene ring in its main chain, maleic anhydride, and a monomer having a carboxyl group. Materials are disclosed. JP-A-10-111569 discloses a radiation-sensitive resin composition containing a resin having an alicyclic skeleton in the main chain and a radiation-sensitive acid generator. JP-A-11-109632 describes that a resin containing a polar group-containing alicyclic functional group and an acid-decomposable group is used for a radiation-sensitive material.

[0007] The resin containing an acid-decomposable group used in a photoresist for exposure to far ultraviolet rays generally contains an aliphatic cyclic hydrocarbon group in the molecule at the same time. For this reason, the resin becomes hydrophobic, and there is a problem caused by the hydrophobicity. Various means for improving the above have been studied, but the above techniques still have many unsatisfactory points (especially in terms of developability), and improvements are desired.

Further, in recent years, with the demand for miniaturization of semiconductor chips, the design pattern of the fine semiconductor has been reduced to 0.13.
It reaches a fine region of about 0.35 μm. However, these compositions have a problem that the resolution of the pattern is hindered by factors such as the edge roughness of the line pattern. Here, the edge roughness refers to the top and bottom edges of a resist line pattern that fluctuate irregularly in a direction perpendicular to the line direction due to the characteristics of the resist. Means that the edge looks uneven.

[0009]

As described above, in the known technique of the conventional photoresist composition, development defects are observed, and further, roughness is observed at the edge of the pattern.
Since a stable pattern cannot be obtained, further improvement has been desired. Accordingly, an object of the present invention is to provide a deep ultraviolet light,
An object of the present invention is to solve the problem of the above-mentioned performance improvement technology inherent in microphotofabrication using an rF or ArF excimer laser beam. Specifically, the problem of development defect generation at the time of development is solved. Another object of the present invention is to provide a positive photoresist composition for deep ultraviolet exposure, which has improved edge roughness.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies on the constituent materials of the resist solution in the positive-type chemical amplification system, and as a result, the object of the present invention has been achieved 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 resin which contains a compound which generates an acid upon irradiation with actinic rays or radiation and a repeating unit containing a group represented by the following general formula (I), and whose dissolution rate in an alkali developing solution is increased by the action of an acid And a positive photoresist composition for deep ultraviolet exposure.

[0011]

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In the formula (I), R ₁ represents an organic group linked to the repeating unit, and R _{2 to} R ₄ each independently represent a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group, Represents an aryl group, an aralkyl group, or a cyclic alkyl group. However, R _{2 to} R ₄ may combine with each other to form a non-aromatic ring or an aromatic ring. X: R—SO ₃ , R: an aliphatic hydrocarbon group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. (2) The positive photoresist composition for deep ultraviolet exposure according to (1), wherein the resin contains a repeating unit represented by the following general formula (II).

[0013]

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In the formula (II), R _{2 to} R ₄ each independently represent a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group, an aryl group, an aralkyl group or a cyclic alkyl group. However, R _{2 to} R ₄ may combine with each other to form a non-aromatic ring or an aromatic ring. R ₅ to R ₇ each independently represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group.
R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, or a cyclic alkyl group which may have a substituent. However, R ₁₁ and R ₁₂ may combine with each other to form a cyclic alkyl ring. m: an integer of 0 to 10 A: represents a single bond or a divalent organic group.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the compounds used in the present invention will be described in detail. [1] A resin containing a repeating unit containing a group represented by the above general formula (I) and increasing the dissolution rate in an alkali developer by the action of an acid (also referred to as an acid-decomposable resin). The resin is characterized by having at least one group represented by the following general formula (I).

In the general formula (I), examples of the alkyl group of R _{2 to} R ₄ include a linear or branched alkyl group, which may have a substituent. As the linear or branched alkyl group, a linear or branched alkyl group having 1 to 12 carbon atoms is preferable, and a linear or branched alkyl group having 1 to 10 carbon atoms is more preferable. ,
More preferred are a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a pentyl group, a neopentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group. . Examples of the cyclic alkyl group include those having 3 to 30 carbon atoms, and may include a hetero atom such as an oxygen atom or a nitrogen atom. Specifically, cyclopropyl group, cyclopentyl group, cyclohexyl group, adamantyl group, norbornyl group, boronyl group, tricyclodecanyl group, dicyclopentenyl group, nobornane epoxy group, menthyl group, isomenthyl group, neomenthyl group, tetratetral Examples thereof include a cyclododecanyl group, a steroid residue, a tetrahydropyranyl group, and a morpholino group.

Examples of the alkenyl group include alkenyl groups having 2 to 6 carbon atoms, which may have a substituent.
Specifically, a vinyl group, a propenyl group, an allyl group, a butenyl group, a pentenyl group, a hexenyl group, a cyclopentenyl group, a cyclohexenyl group, a 3-oxocyclohexenyl group, a 3-oxocyclopentenyl group, a 3-oxoindenyl group, and the like. No. Among these, the cyclic alkenyl group may contain an oxygen atom. The aryl group includes those having 6 to 10 carbon atoms, and may have a substituent. Specific examples include a phenyl group, a tolyl group, and a naphthyl group.

Examples of the aralkyl group include a benzyl group, a phenethyl group, a naphthylmethyl group, a naphthylethyl group and a mesitylmethyl group.

Further substituents in the above-mentioned alkyl group, cyclic alkyl group, alkenyl group, aryl group and aralkyl group include carboxyl group, acyloxy group, cyano group, alkyl group, substituted alkyl group, aryl group, halogen atom, hydroxyl group. , An alkoxy group, an acetylamide group, an alkoxycarbonyl group, and an acyl group. 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 alkoxy group of the alkoxy group or the alkoxycarbonyl group include a methoxy group, an ethoxy group,
Examples thereof include those having 1 to 4 carbon atoms such as a propoxy group and a butoxy group. As the acyl group, an acetyl group,
And a propionyl 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.

R ₁ preferably represents a single bond, an ether group, an ester group, an amide group, an alkylene group, a substituted alkylene group, an arylene group, a substituted arylene group or a divalent group obtained by combining two or more thereof.

Examples of the alkylene group and substituted alkylene group include groups represented by the following formulas. -[C (R _a ) (R _b )] _r-wherein R _a and R _b are a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group, an aryl group, an aralkyl group, a cyclic alkyl group , A halogen atom, a hydroxyl group, or an alkoxy group, which may be the same or different. R
_a , an _optionally substituted alkyl group, alkenyl group, aryl group, aralkyl group, cyclic alkyl group,
Can be the same as the specific examples of R _{2 to} R ₄ described above. 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 represents an integer of 1 to 10.

The arylene group of the above arylene group and substituted arylene group includes those having 6 to 10 carbon atoms, and specific examples include a phenylene group, a tolylene group and a naphthylene group. Examples of the substituent of the substituted arylene group include a carboxyl group, an acyloxy group, a cyano group, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, an acetylamide group, an alkoxycarbonyl group, and an acyl group. 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 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.

R ₁ preferably has an alkylene structure and is bonded to the nitrogen atom in the formula (I) by a carbon atom of the alkylene.

The repeating unit containing a group represented by the above general formula (I) preferably includes a repeating unit represented by the above general formula (II).

In the formula (II), R _{2 to} R ₄ each independently represent a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group, an aryl group, an aralkyl group or a cyclic alkyl group. However, R _{2 to} R ₄ may combine with each other to form a non-aromatic ring or an aromatic ring. R ₅ to R ₇ each independently represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group.
R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, or a cyclic alkyl group which may have a substituent. However, R ₁₁ and R ₁₂ may combine with each other to form a cyclic alkyl ring. m: an integer of 0 to 10 A: represents a single bond or a divalent organic group.

As the alkyl group, alkenyl group, aryl group, aralkyl group, cyclic alkyl group, and halogen atom of R _{5 to} R _7, the same as those of the specific examples of R _{2 to} R ₄ can be exemplified. A can be the same as the specific examples of R ₁ described above.

Hereinafter, specific examples of the repeating unit containing the group represented by formula (I) will be shown. However, the content of the present invention is not limited to these.

[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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[0034]

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The acid-decomposable resin according to the present invention contains an acid
Contains groups that decompose when used (also called acid-decomposable groups)
You. The group decomposed by the action of an acid includes -COOA
⁰ , -OB⁰ The group shown by the group can be mentioned.
Further, as a group containing these, -R⁰ -COOA⁰ ,or
Is -A_r -OB⁰ The group shown by these is mentioned. here
A⁰ Is -C (R⁰¹) (R⁰²) (R⁰³), -Si
(R⁰¹) (R⁰²) (R ⁰³), -C (R⁰⁴) (R⁰⁵) -O
-R⁰⁶A lactone group or a lactone group. B⁰ Is -A⁰ or
Is -CO-OA⁰ Represents a group. R⁰¹, R⁰², R⁰³, R⁰⁴
And R⁰⁵May be the same or different,
Element atom, alkyl group, cycloalkyl group, alkenyl
A aralkyl group or an aryl group;⁰⁶Is
It represents an alkyl group, a cyclic alkyl group or an aryl group.
Where R⁰¹~ R⁰³At least two of which are other than hydrogen atoms
And R ⁰¹~ R⁰³, And R⁰⁴~ R⁰⁶Two of
May combine to form a ring. R⁰Is a single bond
Or a divalent or higher valent aliphatic which may have a substituent.
Represents an aromatic hydrocarbon group, -Ar- is a monocyclic or
A divalent or higher valent aromatic group which may have a polycyclic substituent;
Show.

The alkyl group preferably has 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group and a t-butyl group. Preferred are those having 3 to 10 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclohexyl group and adamantyl group, and alkenyl groups having 2 to 2 carbon atoms such as vinyl group, propenyl group, allyl group and butenyl group. Preferably, the aryl group has 6 to 1 carbon atoms such as phenyl, xylyl, toluyl, cumenyl, naphthyl and anthracenyl.
Four are preferred. Examples of the cyclic alkyl group include those having 3 to 30 carbon atoms, and specific examples thereof include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a norbornyl group, a boronyl group, a tricyclodecanyl group, and a dicyclodecanyl group. Examples thereof include a cyclopentenyl group, a nobornane epoxy group, a menthyl group, an isomenthyl group, a neomenthyl group, a tetracyclododecanyl group, and a steroid residue. As the aralkyl group, a compound having 7 to 7 carbon atoms
Twenty of them may be mentioned, and may have a substituent.
Examples thereof include a benzyl group, a phenethyl group, and a cumyl group.

As the substituent, a hydroxyl group, a halogen atom (fluorine, chlorine, bromine, iodine), a nitro group, a cyano group, the above-mentioned alkyl group, methoxy group, ethoxy group, hydroxyethoxy group, propoxy group, hydroxypropoxy group Alkoxy groups such as groups, n-butoxy group, isobutoxy group, sec-butoxy group, t-butoxy group, alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group, aralkyl groups such as benzyl group, phenethyl group and cumyl group, Aralkyloxy group, formyl group, acetyl group, butyryl group, benzoyl group, cyanyl group, acyl group such as valeryl group, acyloxy group such as butyryloxy group, the above alkenyl group, vinyloxy group, propenyloxy group, allyloxy group, butenyloxy group Alkenyloxy groups such as Serial aryl group, an aryloxy group such as phenoxy group, and an aryloxycarbonyl group such as benzoyloxy group. The lactone group has the following structure.

[0038]

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

When an ArF excimer laser is used as a light source for exposure, it is preferable to use a group represented by —C (＝ O) —X ₁ —R ₀ as a group decomposed by the action of an acid. Here, R ₀ is a t-butyl group, t
A tertiary alkyl group such as an amyl group, an isobornyl group, 1-
1-alkoxyethyl groups such as ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-cyclohexyloxyethyl group, 1-methoxymethyl group, 1-
Examples thereof include an alkoxymethyl group such as an ethoxymethyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a trialkylsilyl group, a 3-oxocyclohexyl group, and the above-mentioned lactone group. X ₁ represents an oxygen atom or a sulfur atom, preferably an oxygen atom.

The structure of the resin containing at least the group represented by the general formula (I) and the acid-decomposable group must be selected depending on the exposure light source. Exposure light source is wavelength 2
In the case of a KrF excimer laser beam of 48 nm, it is preferable to use a repeating unit having a benzene ring such as a styrene-based repeating unit as a main repeating unit contained in the resin. When the exposure light source is ArF excimer laser light having a wavelength of 193 nm, a repeating unit having a benzene ring cannot be used, and therefore, the main repeating unit contained in the resin contains an alicyclic structure in the main chain or side chain. Are preferred.

An acid-decomposable resin which is preferably used when the exposure light source is a KrF excimer laser beam having a wavelength of 248 nm will be described. The general formula (I) repeating units and acid matrix resin having a group decomposable in the side chain by the action of shown by, -OH or -COOH in the side chain, preferably -R ⁰ -COOH or -A _r -OH It is an alkali-soluble resin having a group.

The alkali dissolution rate of these alkali-soluble resins was measured using a 0.261N tetramethylammonium hydroxide (TMAH) (at 23 ° C.) and measured at 170 ° C.
A / sec or more is preferable. Particularly preferably 330A
Per second or more (where A is Angstroms). From the viewpoint of achieving a rectangular profile, an alkali-soluble resin having a high transmittance to far ultraviolet light or excimer laser light is preferable. Preferably, a 1 μm film thickness of 24
The transmittance at 8 nm is 35% or more. From such a viewpoint, particularly preferred alkali-soluble resins are o-, m-
Or p-poly (hydroxystyrene) and copolymers thereof, hydrogenated poly (hydroxystyrene), halogen- or alkyl-substituted poly (hydroxystyrene),
Part of poly (hydroxystyrene), O-alkylated or O-acylated product, styrene-hydroxystyrene copolymer, α-methylstyrene-hydroxystyrene copolymer and hydrogenated novolak resin.

The resin having a group decomposable with an acid used in the present invention is disclosed in EP 254853, JP-A-2-25.
No. 850, No. 3-223860, No. 4-251259
As disclosed in US Pat. No. 6,086,098, an alkali-soluble resin is reacted with a precursor of an acid-decomposable group, or an alkali-soluble resin monomer having an acid-decomposable group bonded thereto is copolymerized with various monomers. Can be obtained.

Specific examples of the acid-decomposable resin which can be preferably used when the exposure light source is a KrF excimer laser beam having a wavelength of 248 nm are shown below, but the present invention is not limited to these.

[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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When the exposure light source is ArF excimer laser light having a wavelength of 193 nm, it is preferable that the main repeating unit contained in the resin does not contain a benzene ring but contains an alicyclic structure in the main chain or side chain. Here, the alicyclic structure may be monocyclic or polycyclic. In particular,
Examples thereof include a group having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. The number of carbon atoms is preferably 6 to 30, especially 7 to 25.
Are preferred. These alicyclic hydrocarbon groups may have a substituent. Specific alicyclic structures include cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclodecane, cyclododecane and the following structures.

[0053]

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[0054]

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Among the above, cyclopentane, cyclohexane, (5), (6), (7), (9), (10),
(13), (14), (15), (23), (28),
(36), (37), (42) and (47) are preferred.

Examples of the substituent of these alicyclic structures include an alkyl group, a substituted 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 and a butyl group, and more preferably a methyl group, an ethyl group, a propyl group, and a substituent selected from the group consisting of an isopropyl group. Represent. As the substituent of the substituted alkyl group,
Examples 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.

Preferred examples of the acid-decomposable resin include the following resins. A repeating unit containing a group represented by the general formula (I),
A resin containing a repeating unit having an alicyclic structure in a side chain and a repeating unit having an acid-decomposable group. A repeating unit containing a group represented by the general formula (I),
And a resin containing a repeating unit having an acid-decomposable group containing an alicyclic structure. A repeating unit containing a group represented by the general formula (I),
And a resin containing a repeating unit having an alicyclic structure and an acid-decomposable group in a side chain.

As the resin of the embodiment, the following general formula (I)
The polymers represented by a) are preferred.

[0059]

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In the general formula (Ia), R _{2 to} R ₇ , R ₁₁ to
R ₁₂ , A and m have the same meanings as in general formula (I) or general formula (II), respectively. B ₁ represents a monovalent alicyclic group. Rx represents an acid-decomposable group. R ₁₀ may be hydrogen or substituted or unsubstituted having 1 to 4 carbon atoms. The monovalent alicyclic group for B ₁ represents a linear or branched alkyl group having the alicyclic structure shown above. In the formula, a plurality of R ₁₀ are the same even though each is the same.
Those that have become the basis of valence are mentioned. Examples of the acid-decomposable group for Rx include those described above.

As the resin of the embodiment, a polymer represented by the following general formula (Ib) is preferable.

[0062]

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In the general formula (Ib), R _{2 to} R ₇ , R ₁₁ to
R ₁₂ , A and m have the same meanings as in general formula (I) or general formula (II), respectively. R ₁₀ represents a hydrogen atom or 1 to
Represents a substituted or unsubstituted linear or branched alkyl group having 4 carbon atoms. A plurality of R ₁₀ in the formula may be the same or different. Y represents a single bond, an alkylene group, a substituted 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
Represents at least one of the groups represented by the following formulas (RaI) to (RaVI).

[0064]

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In the formulas (RaI) to (RaVI), R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-
Represents a butyl group, an isobutyl group or a sec-butyl group,
Z ₁ represents an atomic group necessary for forming an alicyclic group together with a carbon atom. R _{12 to} R ₁₆ each independently have 1 carbon atom
Represents up to four linear or branched alkyl groups or alicyclic groups, provided that at least one of R _{12 to} R ₁₄ , or any of R ₁₅ and R ₁₆ represents an alicyclic group. R _{17 to} R
₂₁ represents each independently a hydrogen atom, 1 to 4 carbon atoms, a linear or branched alkyl group or alicyclic group, provided that,
At least one of R _{17 to} R ₂₁ represents an alicyclic group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or an alicyclic group having 1 to 4 carbon atoms. R ₂₂ ~R
₂₅ independently represents a linear or branched alkyl group or an alicyclic group having 1 to 4 carbon atoms, provided that R _{22 to} R ₂₅
At least one of them represents an alicyclic group.

In the general formulas (RaI) to (RaVI), the alkyl group for R _{12 to} R ₂₅ may be substituted or unsubstituted, and may be a straight or branched chain having 1 to 4 carbon atoms. Represents an alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, and n-
Examples include a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. Further, as a further substituent of the alkyl group, 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, Examples include a carboxy group, an alkoxycarbonyl group, and a nitro group.

The alicyclic group for R _{11 to} R ₂₅ or the alicyclic 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 number of carbon atoms is preferably from 6 to 30, particularly preferably from 7 to 25. These alicyclic groups may have a substituent.

In the general formulas (RaI) to (RaVI), preferred examples of the alicyclic moiety include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, and a norbornyl group. Groups, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, 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.

The substituent of these alicyclic groups includes an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group and an alkoxycarbonyl group. As the alkyl group, a methyl group, an ethyl group,
A lower alkyl group such as a propyl group, an isopropyl group, and a butyl group is preferable, and a methyl group, an ethyl group, and more preferably
Represents a substituent selected from the group consisting of 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.

The polymer represented by the general formula (Ib) is
In addition to the acid-decomposable group represented by -COORa, it is preferable to include a repeating unit containing another acid-decomposable group. Examples of the repeating unit include a repeating unit containing the acid-decomposable group Rx of the polymer represented by the general formula (Ia).

The resin of the embodiment has the following general formula (I)
The polymers represented by c) are preferred.

[0072]

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In the general formula (Ic), R _{2 to} R ₇ , R ₁₁ to
R ₁₂ , A and m have the same meanings as in general formula (I) or general formula (II), respectively. B ₂ is 2 containing an alicyclic group
Represents a valent alkylene group or an alicyclic group. Rx represents an acid-decomposable group. R ₁₀ represents a hydrogen atom or a substituted or unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms. A plurality of R ₁₀ in the formula may be the same or different. The alicyclic group in B ₂ preferably has 6 to 30 carbon atoms, and particularly preferably has 7 to 25 carbon atoms, and the example of the alicyclic structure shown above is a divalent group. What has become. The alkylene group which forms a divalent group together with the alicyclic group may have 1 carbon atom.
Represents up to 4 substituted or unsubstituted linear or branched alkylene groups. Examples of the acid-decomposable group for Rx include those described above.

The purpose of the acid-decomposable resin is to adjust dry etching resistance, standard developer suitability, substrate adhesion, resist profile, and resolution, heat resistance, sensitivity, and the like, which are general requirements for resist. Can be used as a copolymer with various monomer repeating units.

Examples of such a repeating unit include repeating units corresponding to the following monomers, but are not limited thereto. Thereby, the performance required for the resin, particularly (1) solubility in a coating solvent, (2) film forming property (glass transition point), (3)
Alkali developability, (4) film loss (hydrophilic / hydrophobic, alkali-soluble group selection), (5) adhesion of unexposed portion to substrate,
(6) Fine adjustment of dry etching resistance becomes possible.
Examples of such a copolymerizable monomer include, for example, an acrylate, a methacrylate, an acrylamide, a methacrylamide, an allyl compound, a vinyl ether, and an addition-polymerizable unsaturated bond selected from vinyl esters. Compounds having one can be mentioned.

Specifically, for example, acrylates such as alkyl (the alkyl group has 1 to 1 carbon atoms)
Acrylates (for example, methyl acrylate, ethyl acrylate, propyl acrylate, amyl acrylate, cyclohexyl acrylate, ethylhexyl acrylate, octyl acrylate, acrylate-
t-octyl, chloroethyl acrylate, 2-hydroxyethyl acrylate 2,2-dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, Tetrahydrofurfuryl acrylate, etc.);

Methacrylic esters, for example, alkyl (alkyl having preferably 1 to 10 carbon atoms) methacrylate (for example, 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, pentaerythritol monomethacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, etc.);

Acrylamides, for example, acrylamide, N-alkylacrylamide, wherein the alkyl group has 1 to 10 carbon atoms, for example, methyl, ethyl, propyl, butyl, t-butyl, heptyl, octyl Group, cyclohexyl group, hydroxyethyl group, etc.), N, N-dialkylacrylamide (alkyl group having 1 to 10 carbon atoms, for example, methyl group, ethyl group, butyl group, isobutyl group, ethylhexyl group, Cyclohexyl group, etc.), N-
Hydroxyethyl-N-methylacrylamide, N-2
-Acetamidoethyl-N-acetylacrylamide and the like;

Methacrylamides, for example, methacrylamide, N-alkyl methacrylamide (an alkyl group having 1 to 10 carbon atoms, for example, methyl, ethyl, t-butyl, ethylhexyl, hydroxyethyl, cyclohexyl) Groups, etc.), N, N-dialkylmethacrylamide (an alkyl group includes an ethyl group, a propyl group, a butyl group, etc.), N-hydroxyethyl-N-methylmethacrylamide and the like;

Allyl compounds such as allyl esters (eg, allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, allyl lactate), allyloxy Ethanol, etc .;

Vinyl ethers such as 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, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethyl Butyl vinyl ether, hydroxyethyl vinyl ether, diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether, etc.);

Vinyl esters such as vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl valate, vinyl caproate, vinyl chloroacetate, vinyl dichlor acetate, vinyl methoxy acetate, vinyl butoxy acetate, Vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinylcyclohexylcarboxylate and the like;

Dialkyl itaconates (eg, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, etc.); dialkyl esters of fumaric acid (eg, dibutyl fumarate, etc.) or monoalkyl esters;
Acrylic acid, methacrylic acid, crotonic acid, itaconic acid,
Examples include maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleilenitrile, and the like. In addition, any addition-polymerizable unsaturated compound copolymerizable with the above various repeating units may be used.

In the acid-decomposable resin, the molar ratio of each repeating unit depends on the dry etching resistance of the resist, the suitability for a standard developer, the substrate adhesion, the resist profile, and the resolution, heat resistance, which are the general requirements for a resist. ,
It is set as appropriate to adjust sensitivity and the like.

The content of the repeating unit containing the group represented by formula (I) in the acid-decomposable resin is preferably 0.1 to 50 mol%, more preferably 0.1 to 50 mol%, based on all the monomer repeating units. It is 5 to 45 mol%, more preferably 1 to 40 mol%. When the content of the repeating unit containing the group represented by the general formula (I) is less than 0.1 mol%, the effect of the present invention is hardly obtained. If it is more than 50 mol%, the stability over time of the resist is insufficient, so that it is not preferable.

In the case of the resin for KrF exposure, the content of the repeating unit containing an acid-decomposable group in the acid-decomposable resin is 3 to 65 mol% in all the monomer repeating units.
Is more preferable, more preferably 5 to 60 mol%, and still more preferably 7 to 55 mol%. In the case of a resin for ArF exposure, the content of a repeating unit containing an acid-decomposable group in the acid-decomposable resin is, for example, in the case of the resin of the above-described embodiment, 20 to 100% in all monomer repeating units. 70 mol%
And more preferably 25 to 65 mol%, and still more preferably 30 to 60 mol%. In the case of the resin of the above-mentioned embodiment (Ra portion is decomposed by acid, but this is excluded), 10-70 mol% is preferable in a unit, More preferably, it is 15-65 mol%, More preferably, it is 20-70 mol%.
It is 60 mol%, and in the case of the resin of the above-mentioned embodiment, it is preferably at least 20 mol%, more preferably at least 25 mol%, further more preferably at least 30 mol% in all monomer repeating units.

In the case of the resin for ArF exposure, the content of the repeating unit containing an alicyclic structure in the acid-decomposable resin may be, for example, 30 to 30 in the total monomer repeating unit in the case of the resin of the above embodiment. 70 mol% is preferred, more preferably 35 to 65 mol%, and still more preferably 40 to 60 mol%.
In the case of the resin of the above-mentioned embodiment, the content is preferably 30 to 70 mol%, more preferably 3 to 70 mol%, of all the monomer repeating units.
It is 5 to 65 mol%, more preferably 40 to 60 mol%, and in the case of the resin of the above embodiment, it is preferably at least 40 mol%, more preferably at least 45 mol%, even more preferably in all monomer repeating units. It is 50 mol% or more.

The acid-decomposable resin for ArF exposure according to the present invention may contain a carboxyl group, a hydroxyl group, a cyano group, a lactone group, etc. for the purpose of imparting adhesion. The acid value of the acid-decomposable resin is 1.5 meq / g
Or less, more preferably 1.2 meq / g or less, even more preferably 1.0 meq / g or less.

The content of the repeating unit based on the monomer of the additional copolymer component in the resin can be appropriately set according to the desired resist properties. To the total number of moles
It is preferably at most 90 mol%, more preferably at most 90 mol%, even more preferably at most 80 mol%.

The molecular weight of the acid-decomposable resin as described above is preferably 1,0 in terms of weight average (Mw: polystyrene standard).
00 to 1,000,000, more preferably 1,500
~ 500,000, more preferably 2,000 ~ 20
000, more preferably 2,500-100,
000, and the larger the value, the better the heat resistance and the like, but the lower the developability and the like. The acid-decomposable resin used in the present invention can be synthesized according to a conventional method (for example, radical polymerization).

In the positive photoresist composition of the present invention, the amount of the acid-decomposable resin added to the whole resist composition is 40 to 99.99% by weight based on the total solid content of the resist composition.
Is more preferable, and more preferably 50 to 99.97% by weight.

[2] Compound that generates an acid upon irradiation with actinic rays or radiation (photoacid generator) The photoacid generator used in the present invention is a compound that generates an acid upon irradiation with actinic rays or radiation. As the compound used in the present invention, which decomposes upon irradiation with actinic rays or radiation to generate an acid, a photoinitiator for photocationic polymerization,
Known light (400 to 200 nm ultraviolet light, far ultraviolet light, particularly preferably g-line, h-ray) used in photoinitiators of photoradical polymerization, photodecolorants of dyes, photochromic agents, micro resists and the like. Ray, i-ray, KrF excimer laser light), ArF excimer laser light, an electron beam, an X-ray, a compound generating an acid by a molecular beam or an ion beam, and a mixture thereof can be appropriately selected and used.

Other compounds that generate an acid upon irradiation with actinic rays or radiation used in the present invention include, for example, SI Schlesinger, Photogr. Sci. Eng., 18, 3
87 (1974), TSBetal, Polymer, 21,423 (1980) and the like diazonium salts, U.S. Pat.Nos. 4,069,055 and 4,06
No. 9,056, Re 27,992, ammonium salts described in JP-A-3-140140, DC Necker et al., Macromolecules, 1,
7,2468 (1984), CSwen et al, Teh, Proc.Conf.Rad.Curin
g ASIA, p478 Tokyo, Oct (1988), U.S. Pat.No. 4,069,055
No. 4,069,056, etc.
vello etal, Macromorecules, 10 (6), 1307 (1977), Chem.
& Eng.News, Nov. 28, p31 (1988), EP 104,143,
U.S. Patent Nos. 339,049 and 410,201, JP-A-2-150,84
No. 8, iodonium salts described in JP-A-2-296,514 etc.,
JVCrivello etal, Polymer J. 17, 73 (1985), JVCriv
ello etal. J. Org. Chem., 43, 3055 (1978), WRWatt eta
l, J. Polymer Sci., Polymer Chem. Ed., 22, 1789 (1984),
JVCrivello etal, Polymer Bull., 14,279 (1985), JV
Crivello etal, Macromorecules, 14 (5), 1141 (1981), J.
V. Crivello etal, J. PolymerSci., Polymer Chem. Ed., 17,
2877 (1979); European Patent Nos. 370,693 and 161,811;
No. 410,201, No. 339,049, No. 233,567, No. 297,443,
No. 297,442, U.S. Pat.No. 3,902,114 No. 4,933,377,
No. 4,760,013, No. 4,734,444, No. 2,833,827, Dokoku Patent No. 2,904,626, No. 3,604,580, No. 3,604,581,
Sulfonium salts described in JP-A-7-28237 and JP-A-8-27102, JVCrivello et al., Macromorecule
s, 10 (6), 1307 (1977), JVCrivello etal, J. PolymerSc
Selenonium salts described in i., Polymer Chem.Ed., 17, 1047 (1979), etc., CSWen et al., Teh, Proc. Conf. Rad. Curing AS
Onium salts such as arsonium salts described in IA, p478 Tokyo, Oct (1988), etc., U.S. Patent No. 3,905,815, JP-B-46-4605.
No., JP-A-48-36281, JP-A-55-32070, JP-A-60-2
39736, JP-A-61-169835, JP-A-61-169837, JP-A-62-58241, JP-A-62-212401, JP-A-63-70243
Nos., Organohalogen compounds described in JP-A-63-298339, K. Meier et al, J. Rad. Curing, 13 (4), 26 (1986), T.
P. Gill et al, Inorg.Chem., 19, 3007 (1980), D. Astruc, A
Chem. Res., 19 (12), 377 (1896), organometallic / organic halides described in JP-A-2-14145, etc., S. Hayase eta
l, J. Polymer Sci., 25, 753 (1987), E. Reichmanis et al., J.
Pholymer Sci., Polymer Chem. Ed., 23, 1 (1985), QQZhu
etal, J. Photochem., 36, 85, 39, 317 (1987), B. Amit etal,
Tetrahedron Lett., (24) 2205 (1973), DHR Barton eta
l, J. Chem Soc., 3571 (1965), PM Collins et al., J. Chem.
SoC., PerkinI, 1695 (1975), M. Rudinstein et al, Tetrahed
ron Lett., (17), 1445 (1975), JWWalker etal J. Am. Che
m.Soc., 110, 7170 (1988), SCBusman et al., J. Imaging Te
chnol., 11 (4), 191 (1985), HMHoulihan et al, Macormole
cules, 21, 2001 (1988), PM Collins et al., J. Chem. Soc.,
Chem. Commun., 532 (1972), S. Hayase et al, Macromolecule
s, 18, 1799 (1985), E. Reichman et al., J. Electrochem. So
c., Solid State Sci. Technol., 130 (6), FMHoulihan et.
al, Macromolcules, 21, 2001 (1988), EP 0290,750
Nos. 046,083, 156,535, 271,851, 0,38
No. 3,343, U.S. Pat.Nos. 3,901,710, 4,181,531, JP-A-60-198538, and photoacid generators having a 0-nitrobenzyl-type protecting group described in JP-A-53-133022, M. TUNOOKA
etal, PolymerPreprints Japan, 35 (8), G. Berner etal,
J.Rad.Curing, 13 (4), WJMijs etal, Coating Techno
l., 55 (697), 45 (1983), Akzo, H. Adachi et al, Polymer Pr
eprints, Japan, 37 (3), European Patent Nos. 0199,672 and 84515
Nos. 044,115, 618,564, 0101,122, U.S. Pat.Nos. 4,371,605, 4,431,774, and JP-A-64-18143.
Compounds which generate sulfonic acid upon photolysis, such as iminosulfonate described in JP-A-2-245756, JP-A-3-140109, etc .;
Disulfone compounds described in JP-A-71270 and the like;
No. 103854, No. 3-103856, No. 4-210
No. 960 and the like, and diazoketosulfone and diazodisulfone compounds.

Further, a group that generates an acid by these lights,
Alternatively, a compound having a compound introduced into the main chain or side chain of a polymer, for example, MEWoodhouse et al., J. Am. Chem.
Soc., 104, 5586 (1982), SPPappas etal, J. Imaging Sc
i., 30 (5), 218 (1986), S. Kondoetal, Makromol.Chem., Rap
id Commun., 9,625 (1988), Y.Yamadaetal, Makromol.Che
m., 152, 153, 163 (1972), JVCrivello etal, J. PolymerS
ci., Polymer Chem. Ed., 17, 3845 (1979), U.S. Pat.
49,137, Dokoku Patent 3914407, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038
JP-A-63-163452, JP-A-62-153853, JP-A-63-163452
Compounds described in JP-A-146029 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, those particularly effectively used 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 (PA)
An S-triazine derivative represented by G2).

[0097]

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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.

[0099]

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[0100]

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[0101]

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

[0103]

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Here, the formulas Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. Preferred substituents include an alkyl group, a haloalkyl group, a cycloalkyl group, an aryl group, an alkoxy group, a nitro group, a carboxyl group, an alkoxycarbonyl group, a hydroxy group, a mercapto group, and a halogen atom.

R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ each independently represent a substituted or unsubstituted alkyl group or aryl group. Preferably, an aryl group having 6 to 14 carbon atoms, 1 to 8 carbon atoms
And substituted derivatives thereof. Preferred substituents are those having 1 to 8 carbon atoms for the aryl group.
And an alkyl group having 1 to 8 carbon atoms, a nitro group, a carboxyl group, a hydroxy group and a halogen atom. The alkyl group is an alkoxy group having 1 to 8 carbon atoms, a carboxyl group or an alkoxycarbonyl group. is there.

[0106] Z ^- represents a counter anion, for example BF ₄ ^{-,
_{AsF 6 -, PF 6 -,}} SbF 6 -, SiF 6 2-, ClO 4 -,
CF ₃ SO ₃ ^-, etc. perfluoroalkane sulfonate anion, pentafluorobenzenesulfonic acid anion, condensed polynuclear aromatic sulfonic acid anion such as naphthalene-1-sulfonic acid anion, anthraquinone sulfonic acid anion, a sulfonic acid group-containing dyes Examples include, but are not limited to:

Further, 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.

[0109]

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[0110]

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[0111]

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[0112]

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[0113]

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[0114]

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[0115]

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[0116]

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[0117]

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[0118]

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[0119]

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[0120]

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[0121]

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The above-mentioned onium salts represented by the general formulas (PAG3) and (PAG4) are known, for example, JWKnapczyk
etal, J. Am. Chem. Soc., 91, 145 (1969), ALMaycok eta
l, J. Org. Chem., 35, 2532, (1970), E. Goethas et al., Bul
l.Soc.Chem.Belg., 73,546, (1964), HM Leicester, JA
me.Chem.Soc., 51,3587 (1929), JVCrivello etal, J.Po
Chem. Ed., 18,2677 (1980), U.S. Pat. Nos. 2,807,648 and 4,247,473, and JP-A-53-101,331.

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

[0124]

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In the formula, Ar^Three, Ar^FourAre each independently substituted
Or an unsubstituted aryl group. R ²⁰⁶ Is replaced or
It represents an unsubstituted alkyl group or aryl group. A is a substitution
Or unsubstituted alkylene, alkenylene, arylene
Shows a substituent group. Specific examples include the compounds shown below.
However, the present invention is not limited to these.

[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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The amount of the compound which decomposes upon irradiation with actinic rays or radiation to generate an acid is usually 0.000 based on the total weight of the resist composition (excluding the solvent).
It is used in the range of 1 to 20% by weight, preferably 0.01 to 20% by weight.
It is used in the range of 10 to 10% by weight, more preferably 0.1 to 5% by weight. 0.001% by weight of a compound capable of decomposing upon irradiation with actinic rays or radiation to generate an acid.
If the amount is smaller, the sensitivity is lowered, and the addition amount is 40% by weight.
If it is larger, the light absorption of the resist becomes too high, and the profile is deteriorated and the process (especially, baking) margin is undesirably reduced.

The positive resist composition of the present invention may further contain, if necessary, an acid-decomposable dissolution inhibiting compound, a dye, a plasticizer,
A surfactant, a photosensitizer, an organic basic compound, and a compound that promotes solubility in a developer can be contained.

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 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, methyl lactate, ethyl lactate, methyl methoxypropionate, ethyl ethoxypropionate , N-methylpyrrolidone and tetrahydrofuran.

A surfactant may be added to the above solvent. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether, polyoxyethylene octyl phenol ether,
Polyoxyethylene alkyl allyl ethers such as polyoxyethylene nonylphenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, Sorbitan fatty acid esters such as sorbitan tristearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Surfactants such as polyoxyethylene sorbitan fatty acid esters such as acrylates and the like, F-top EF301, E 303, EF352 (manufactured by Shin Akita Kasei Co., Ltd.), Megafac F171, F173 (manufactured by Dainippon Ink Co., Ltd.), Flora - de FC430, FC43
1 (manufactured by Sumitomo 3M Limited), Asahi Guard AG71
0, Surflon S-382, SC101, SC102,
Fluorinated surfactants such as SC103, SC104, SC105 and SC106 (manufactured by Asahi Glass Co., Ltd.), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), and acrylic or methacrylic (co) polymerized polyflow No. 75, no. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and the like. The content of these surfactants is 10% solids in the resist composition of the present invention.
It is usually at most 2 parts by weight, preferably at most 1 part by weight, per 0 parts by weight. These surfactants may be added alone or in some combination.

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 0.4 to 1.5 μm. Spinning the resist composition on a substrate (eg, silicon / silicon dioxide coating) such as used in the manufacture of precision integrated circuit devices;
After coating by an appropriate coating method such as a coater or the like, exposure is performed through a predetermined mask, baking and development are performed, whereby a good resist pattern can be obtained. Here, the exposure light is preferably light having a wavelength of 150 nm to 250 nm. Specifically, a KrF excimer laser (2
48 nm), ArF excimer laser (193 nm),
F ₂ excimer laser (157 nm), X-ray, electron beam and the like can be mentioned. The baking temperature after the above exposure is preferably 80 to 180 ° C, more preferably 85 to 180 ° C.
The temperature is 160 ° C, more preferably 90 to 150 ° C.

Examples of the developing solution 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.

[0139]

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 Resin-1) (1) Synthesis of Resin (i) t-Butoxystyrene and trimethylammonium methylstyrene heptadecafluorooctane sulfonate were charged at a ratio of 92/8, and N, N- It was dissolved in a mixed solvent of dimethylacetamide / tetrahydrofuran 2/8 to prepare 100 mL of a solution having a solid content of 22%. 1 mol% of V-65 manufactured by Wako Pure Chemical was added to this solution, and this was added dropwise to 10 mL of tetrahydrofuran heated to 60 ° C. over 2 hours under a nitrogen atmosphere. After completion of the dropwise addition, the reaction solution was heated and stirred for 6 hours. After completion of the reaction, the reaction solution is cooled to room temperature,
White powder crystallized and precipitated in 3 L of distilled water was recovered. Next, the obtained white powder was hydrolyzed under acidic conditions, and the t-butoxy group was partially deprotected to obtain the target resin (i). The polymer composition ratio determined from C ¹³ NMR was 23/70/7. The weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 8,
900.

(2) Synthesis of Resins (ii) to (xx) By the same operation as in the synthesis of Resin (i), Resins (ii) to Resin having the composition ratio and weight average molecular weight shown in Table 1 below (Xx)
Was synthesized. In addition, in the following table, the repeating units 1 to 3 are obtained by adding the repeating units in the structural formula of the specific example of the resin from the left except for the repeating unit represented by the general formula (I).

[0142]

[Table 1]

(Synthesis of Resin-2) (1) Synthesis of Resin (I) 1-Adamantyl methacrylate, mevalonic lactone methacrylate, and a triflate salt of dimethylethylammoniumethyl methacrylate were charged at a ratio of 42/48/10. , N-dimethylacetamide / tetrahydrofuran 3/7 and a solid content of 20
A 100 mL solution was prepared. 2 mol% of V-65 manufactured by Wako Pure Chemical Industries, Ltd. was added to this solution, and this was added dropwise to 10 mL of tetrahydrofuran heated to 60 ° C over 2 hours under a nitrogen atmosphere. After completion of the dropwise addition, the reaction solution was heated and stirred for 2 hours, and 1 mol% of V-65 was further added, and the mixture was further heated and stirred for 2 hours. After completion of the reaction, the reaction solution was cooled to room temperature, and white powder precipitated and crystallized in methanol / distilled water = 1/2 L was recovered. The polymer composition ratio determined from C ¹³ NMR was 43/4.
It was 7/10. The weight average molecular weight in terms of standard polystyrene determined by GPC measurement was 14,300.

(2) Synthesis of Resins (II) to (XVI) Resin (II) having the following structure and the composition ratio and weight average molecular weight shown in Table 2 below was obtained by the same operation as in the synthesis of resin (I). ) To Resin (XVI) were synthesized. In the table below,
The repeating units 1 and 2 are obtained by adding the repeating units in the structural formula of the resin below from the left except for the repeating unit represented by the general formula (I).

[0145]

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[0146]

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[0147]

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[0148]

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[0149]

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[0150]

[Table 2]

Examples 1 to 20 and Comparative Example 1 [Preparation and Evaluation of Photosensitive Composition] 2 g of the resin shown in Table 3 and 0.04 g of the above-mentioned (PAG4-36) as a photoacid generator, 4
0.02 g of dimethylaminopyridine and 2 mg of Megafac F171 as a surfactant were added, dissolved in 9.5 g of propylene glycol monomethyl ether acetate, and filtered through a 0.2 μm filter to prepare a positive resist composition solution. .

[0152]

[Table 3]

(Evaluation Test) These resist composition liquids were applied on a silicon wafer using a spin coater, and dried on a vacuum adsorption type hot plate at 90 ° C. for 90 seconds to obtain a 0.83 μm thick film. A resist film was obtained. This resist film was exposed using a 248 nm KrF excimer laser stepper (NA = 0.42). Immediately after the exposure, each was heated for 60 seconds on a vacuum adsorption type hot plate at 110 ° C., immediately immersed in a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 seconds, rinsed with water for 30 seconds, and dried. The profile of the pattern on the silicon wafer thus obtained was observed. With respect to these, development defects and edge roughness were evaluated as described below.

[Number of development defects]: Bare S of 6 inches
Each resist film was applied to a thickness of 0.83 μm on the i-substrate and dried at 90 ° C. for 60 seconds on a vacuum suction hot plate. Next, a 0.35 μm contact hole pattern (Hole)
Nik through a test mask with a duty ratio = 1: 3)
After exposure with an on-stepper NSR-1505EX, post-exposure heating was performed at 110 ° C. for 90 seconds. Subsequently, after paddle development with 2.38% TMAH (aqueous solution of tetramethylammonium hydroxide) for 60 seconds, 30% with pure water.
Washed with water for 2 seconds and spin-dried. The sample thus obtained was used as KLA-2112 manufactured by KLA-Tencor Corporation.
The number of development defects was measured by a machine, and the obtained primary data value was defined as the number of development defects.

[Edge Roughness] The edge roughness was measured by using a length-measuring scanning electron microscope (SEM) at the edge roughness of an isolated pattern, and a line pattern edge was detected at a plurality of positions in a measurement monitor. The variance (3σ) of the variation in the detection position is used as an index of the edge roughness, and the smaller the value, the more preferable.

Comparative Example 1 is different from Example 1 in that
As the resin, a resin R1 containing no repeating unit having a group represented by the general formula (I) in the resin (i),
It was synthesized in the same manner as in the synthesis of the resin (i). Resin R1
Has a copolymerization ratio of 21:79 and a weight average molecular weight of 8,800. Except for this, a positive resist composition was prepared and evaluated in the same manner as in Example 1.

As is evident from the results in Table 3, the comparative example has problems in both development defects and edge roughness. On the other hand, all of the positive resist compositions of the present invention are at a satisfactory level. That is, it is suitable for lithography using far ultraviolet rays such as KrF excimer laser exposure.

Examples 21 to 36 and Comparative Example 2 1.4 g of each of the resins shown in Table 4 synthesized in the above synthesis examples was used.
0.30 g of the (PAG4-36) as a photoacid generator,
10 mg of 1,5-diazabicyclo [4.3.0] -5-nonene (DBN) and 1 mg of Florad FC430 as a surfactant were added, each having a solid content of 14% by weight.
And dissolved in propylene glycol monoethyl ether acetate at a ratio of 0.1%, and then filtered through a 0.1 μm microfilter to prepare positive resist composition solutions of Examples 21 to 36. Further, as Comparative Example 2, a positive resist solution was prepared in the same manner as in Examples 21 to 36 except that the following resin R2 and a photoacid generator were used. (Resin R2) Resin R2 was synthesized by the synthesis method described in Example 13 of page (18) of JP-A-9-90637. That is, a methacrylic acid (±) -mevalonic lactone ester / 2-methyl-2-adamantyl methacrylate copolymer was synthesized. 4.96 g (25 mmol) of methacrylic acid (±) -mevalonic lactone ester, 5.87 g, were placed in a well-dried 100 ml eggplant-shaped flask containing Teflon ^™ -coated star rubber.
(25 mmol) 2-methyl-2-adamantyl methacrylate, 16.7 ml dioxane and 1.23 g (9
Mmol) of azobisisobutyronitrile (AIBN)
Was added and stirred at 80 ° C. for 8 hours under a nitrogen atmosphere. After diluting the reaction solution with tetrahydrofuran (THF),
The solution was added dropwise to 1 liter of methanol containing a small amount of hydroquinone. The generated precipitate is filtered off with a glass filter,
Dried at 0.1 mm Hg and 45 ° C. for 16 hours. The obtained white powder was dissolved again in THF, and the same precipitation to drying operation as described above was repeated twice to obtain a target white copolymer powder. Yield = 7.44 g (68.7%).
The copolymerization ratio of the obtained copolymer was lactone: adamantyl = 46.5: 53.5, and the weight average single molecular weight was 14
000 (in terms of standard polystyrene), and the degree of dispersion was 2.0.

[0159]

[Table 4]

(Evaluation Test) The obtained positive photoresist composition solution was applied on a silicon wafer using a spin coater and dried at 140 ° C. for 90 seconds to form a positive photoresist film of about 0.4 μm. And an ArF excimer laser (exposed with a stepper having a wavelength of 193 nm and NA = 0.55). 12 heat treatments after exposure
Perform at 90C for 90 seconds, develop with 2.38% aqueous solution of tetramethylammonium hydroxide, rinse with distilled water,
A resist pattern profile was obtained. With respect to these, development defects and edge roughness were evaluated as follows. Table 4 shows the results of these evaluations.

[Number of development defects]: Bare S of 6 inches
Each resist film was applied to a thickness of 0.4 μm on the i-substrate and dried at 140 ° C. for 60 seconds on a vacuum suction hot plate. Next, a 0.35 μm contact hole pattern (Hole)
Nik through a test mask with a duty ratio = 1: 3)
After exposure with an on-stepper NSR-1505EX, post-exposure heating was performed at 120 ° C. for 90 seconds. Subsequently, after paddle development with 2.38% TMAH (aqueous solution of tetramethylammonium hydroxide) for 60 seconds, 30% with pure water.
Washed with water for 2 seconds and spin-dried. The sample thus obtained was used as KLA-2112 manufactured by KLA-Tencor Corporation.
The number of development defects was measured by a machine, and the obtained primary data value was defined as the number of development defects.

[Edge Roughness] The edge roughness was measured by using a length-measuring scanning electron microscope (SEM) at the edge roughness of an isolated pattern, and a line pattern edge was detected at a plurality of positions in a measurement monitor. The variance (3σ) of the variation in the detection position is used as an index of the edge roughness, and the smaller the value, the more preferable.

As is clear from the results shown in Table 4, the comparative example has problems in both the number of development defects and the edge roughness. On the other hand, all of the positive resist compositions of the present invention are at a satisfactory level. That is, ArF
It is suitable for lithography using far ultraviolet rays such as excimer laser exposure.

[0164]

As described above, the positive photoresist composition for exposure to far ultraviolet rays according to the present invention has few development defects, provides a good resist pattern profile, and has excellent edge roughness.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] October 1, 1999 (1999.10.
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Name of invention

[Correction method] Change

[Correction contents]

[Title of the Invention] Positive photoresist composition for deep ultraviolet exposure

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshiaki Aoi 4,000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd.

Claims (2)

[Claims] 1. A compound which generates an acid upon irradiation with actinic rays or radiation and a repeating unit containing a group represented by the following general formula (I), and the action of an acid increases the dissolution rate in an alkali developing solution. A positive photoresist composition for deep ultraviolet exposure. Embedded image In the formula (I), R ₁ represents an organic group linked to the repeating unit, and R _{2 to} R ₄ each independently represent a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group, an aryl group, Represents an aralkyl group or a cyclic alkyl group. However, R _{2 to} R ₄ may combine with each other to form a non-aromatic ring or an aromatic ring. X: R—SO ₃ , R: an aliphatic hydrocarbon group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. 2. The positive photoresist composition for deep ultraviolet exposure according to claim 1, wherein the resin contains a repeating unit represented by the following general formula (II). Embedded image In the formula (II), R _{2 to} R ₄ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, or a cyclic alkyl group which may have a substituent. Where R ₂
To R ₄ may combine with each other to form a non-aromatic ring or an aromatic ring. R ₅ to R ₇ each independently represents a hydrogen atom, a halogen atom, a cyano group, an alkyl group. R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, an aralkyl group, or a cyclic alkyl group which may have a substituent. However, R ₁₁ and R ₁₂ may combine with each other to form a cyclic alkyl ring. m: an integer of 0 to 10 A: represents a single bond or a divalent organic group.