JP2000181054A - Positive photoresist composition for exposure to far-uv ray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photoresist having good compatibility with resin, satisfactory stability with time in a solution state and superior sensitivity with respect to far-UV rays by incorporating a specified compound and a specified resin having an alkali-soluble group protected, with at least one of partial structures containing specified alicyclic hydrocarbons. SOLUTION: This photoresist contains a compound expressed by formula I or formula II which produces sulfonic acid through exposure to irradiation of active rays or radiation, and a resin which contains an alkali-soluble group protected with at least one of partial structures containing alicyclic hydrocarbons expressed by formula III or the like and which is decomposed by the effect of acid to increase in the solubility with an alkali. In the formulae I and II, R1 to R5 are each a hydrogen atom or alkyl group or the like which may have substituents and X is R-SO3, where R is an aliphatic hydrocarbon or the like which may have substituents. In the formula III, R11 is a methyl group or the like and Z represents a group of atoms necessary to form an alicyclic hydrocarbon group with carbon atoms.

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. More specifically, the present invention relates to a positive photoresist composition capable of forming a high-definition pattern using a far ultraviolet region including excimer laser light.

[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
For example, Japanese Patent Application Laid-Open No. Hei. 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. These are 24 KrF excimer lasers.
Although suitable when using 8 nm light, sensitivity is low when using an ArF excimer laser as the light source, because the absorbance is still essentially too high. In addition, there are other disadvantages associated therewith, such as deterioration of resolution, deterioration of focus tolerance, deterioration of pattern profile, and the like, and many points still need improvement.

[0005] Accordingly, a photoresist composition for an ArF light source is a photoresist composition in which a (meth) acrylic resin having a lower absorption than a partially hydroxylated styrene resin is combined with a compound capable of generating an acid by light. Resist compositions have been proposed. For example, JP-A-7-1
No. 99467 and No. 7-252324. Among them, JP-A-6-289615 discloses a resin in which a tertiary carbon organic group is ester-bonded to oxygen of a carboxyl group of acrylic acid.

Further, Japanese Patent Application Laid-Open No. 7-234511 discloses an acid-decomposable resin having an acrylate ester or a fumarate ester as a repeating unit. It is the fact that is not obtained.

Further, a resin into which an alicyclic hydrocarbon moiety has been introduced for the purpose of imparting dry etching resistance has been proposed. However, the introduction of an alicyclic hydrocarbon moiety has a disadvantage that the system becomes extremely hydrophobic. In addition, phenomena such as difficulty in developing with an aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH), which has been widely used as a resist developing solution, and peeling of the resist from the substrate during the development are observed. 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. Although some results have been obtained, concerns about 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.

In general, a measure has been taken to copolymerize a monomer having a carboxylic acid moiety such as acrylic acid or methacrylic acid with a monomer having an alicyclic hydrocarbon group. At the same time, although there is a tendency to improve the substrate adhesion, the dry etching resistance is deteriorated,
Further, there are many problems such as a significant decrease in resist film thickness, and the above-mentioned problems have not been solved. Further, in JP-A-7-234511, a monomer having a hydroxyl group or a cyano group in the molecule instead of a carboxylic acid group such as HEMA or acrylonitrile is copolymerized with a monomer having an alicyclic hydrocarbon group. This was aimed at solving the developing property, but it was completely insufficient.

On the other hand, in addition to the method of introducing an alicyclic hydrocarbon moiety into the side chain of the acrylate monomer, a method of imparting dry etching resistance utilizing an alicyclic hydrocarbon moiety as a polymer main chain has also been studied. I have. However, this system also has the above problem, and improvement by a similar approach is being studied. For example, Journal of Photopoly
mer Science and Technology, Vol.10, 1997, p529-534
And Journal of Photopolymer Science and Technology,
In Vol. 10, 1997, p521-528, the introduction of hydroxyl groups into the norbornene polymer main chain is studied from the viewpoint of imparting substrate adhesion. However, satisfactory results have not been obtained in both the developability and the substrate adhesion. Also, SPIE, Vol. 3049, pp. 92-105 (1988) describes a polymer obtained by ring-opening polymerization of a norbornene ring or a polymer having a norbornene ring in its main chain and having a carboxyl group and a t-butyl ester group. Compositions containing coalescence are disclosed. However, this technique also has a disadvantage that neither the substrate adhesion nor the suitability for a standard developer is practically sufficient.

Further, EP-A-789278 A2 discloses a polymer obtained by ring-opening polymerization of a norbornene ring or a polymer having a norbornene ring in a main chain and containing a resin containing an acid-decomposable group and a carboxyl group. Compositions are disclosed. WO 97/33198 discloses a photoresist composition containing a resin obtained by polymerizing a monomer having a norbornene ring having an acid-decomposable group. Also, JP-A-9-274318 discloses that
Further, a photoresist composition using a carboxylic acid is disclosed.

Further, Japanese Patent Application Laid-Open No. 9-73173,
JP-A-90637 and JP-A-10-161313 contain an alkali-soluble group protected by a structure containing an alicyclic group, and a structural unit which is made to be alkali-soluble by the removal of the alkali-soluble group by an acid. A resist material using an acid-sensitive compound is described.

As described above, a resin containing an acid-decomposable group generally contains an aliphatic cyclic hydrocarbon group in the molecule at the same time. Therefore, it is also true that the resin becomes hydrophobic due to these trends. On the other hand, as for the photoacid generator to be used in accordance therewith, onium salt compounds have been widely used and have achieved certain results. However, although the causes of the conventionally used onium salt compounds are unknown, they are poorly compatible during resist preparation and cause turbidity, or insoluble substances are precipitated over time, and as a result, there is a problem with stability over time. Left. Further, there is room for improvement such as a decrease in sensitivity over time.

[0013]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problem of the performance improvement technology inherent in microphotofabrication using far ultraviolet light, particularly ArF excimer laser light. An object of the present invention is to provide a positive photoresist composition having good compatibility with a resin when dissolved in an organic solvent, excellent stability over time of the solution, and excellent sensitivity to a short-wavelength light source.

[0014]

Means for Solving the Problems As a result of intensive studies on the constituent materials of a resist composition in a positive-type chemical amplification system, the present inventors have found that a specific acid-decomposable resin and a specific photoacid generator are used. It was found that the object of the present invention was achieved, and the present invention was achieved. That is, the above object is achieved by the following constitutions.

(1) The following general formula (I) or (I) which generates a sulfonic acid upon irradiation with an actinic ray or radiation.
A compound represented by the formula (I), and the following general formulas (pI) to (p
VI) containing an alkali-soluble group protected by at least one of the partial structures containing an alicyclic hydrocarbon represented by the formula:
A positive photoresist composition for deep ultraviolet exposure, comprising a resin that decomposes under the action of an acid to increase solubility in alkali.

[0016]

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In the formulas (I) and (II), R _{1 to} R ₅ each represent a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, An alkoxy group which may have a substituent, an alkoxycarbonyl group which may have a substituent, an acyl group which may have a substituent, an acyloxy group which may have a substituent, a nitro group, Represents a halogen atom, a hydroxyl group, and a carboxyl group. a: 1 to 5, b: 1 to 5, l: 1 to 5, m: 0 to 5, n: 0 to 5. Provided that at least one of R ₁ and R ₂ is an alkyl group having 5 or more carbon atoms which may have a substituent, a cycloalkyl group which may have a substituent,
Represents an alkoxy group which may have a substituent, an alkoxycarbonyl group which may have a substituent, an acyl group which may have a substituent, and an acyloxy group which may have a substituent . When 1 + m + n = 1, R ₃ represents an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an optionally substituted alkoxycarbonyl group, an optionally substituted acyl group, and an optionally substituted acyloxy group. X represents R—SO ₃ , R represents an aliphatic hydrocarbon group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent.

[0018]

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In the formula, R ₁₁ is a methyl group, an ethyl group, n-
Represents a propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z represents an atomic group necessary for forming an alicyclic hydrocarbon group together with a carbon atom. R _{12 to} R ₁₆ each independently represent a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{12 to} R ₁₄ , or Either R ₁₅ or R ₁₆ represents an alicyclic hydrocarbon group. R ₁₇
To R ₂₁ are each independently a hydrogen atom, 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 _{17 to} R ₂₁ represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms. R _{22 to} R ₂₅ each independently represent a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{22 to} R ₂₅ is an aliphatic group; Represents a cyclic hydrocarbon group.

(2) The positive photo for deep ultraviolet exposure according to the above (1), wherein the resin contains a group represented by the following general formula (A), which is decomposed by the action of an acid. Resist composition. Formula (A) -C (= O) -OR _{0 In the} formula (A), R ₀ is a tertiary alkyl group, a 1-alkoxyethyl group, an alkoxymethyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, Trialkylsilyl group,
Represents a 3-oxocyclohexyl group or a lactone group.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the compounds used in the present invention will be described in detail. [1] Photoacid generator represented by general formula [I] or [II] In the general formula [I] or [II], the alkyl group of R _{1 to} R ₅ may have a substituent. Good, methyl, ethyl, propyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, heptyl, octyl, t-amyl, decanyl, dodecanyl And those having 1 to 25 carbon atoms such as a hexadecanyl group. As the cycloalkyl group, a cyclopropyl group which may have a substituent,
Those having 3 to 25 carbon atoms such as a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a cyclododecanyl group, a cyclohexadecanyl group and the like can be mentioned. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group or a t-butoxy group, a pentyloxy group, and a t -Amyloxy group, n-hexyloxy group, n-octyloxy group, n-
Those having 1 to 25 carbon atoms such as a dodecaneoxy group are exemplified.

Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, an isobutoxycarbonyl group and a sec-butoxycarbonyl which may have a substituent. A group having 2 to 25 carbon atoms such as a t-butoxycarbonyl group, a pentyloxycarbonyl group, a t-amyloxycarbonyl group, an n-hexyloxycarbonyl group, an n-octyloxycarbonyl group, an n-dodecaneoxycarbonyl group, etc. One. The acyl group may have a substituent and has 1 carbon atom such as a formyl group, an acetyl group, a butyryl group, a valeryl group, a hexanoyl group, an octanoyl group, a t-butylcarbonyl group, and a t-amylcarbonyl group. To 25. Examples of the acyloxy group include an acetoxy group, an ethylyloxy group, a butyryloxy group, a t-butyryloxy group, and a t which may have a substituent.
-Amylyloxy group, n-hexanecarbonyloxy group,
Examples thereof include those having 2 to 25 carbon atoms such as an n-octanecarbonyloxy group, an n-dodecanecarbonyloxy group, and an n-hexadecanecarbonyloxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

As a substituent for these groups, 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, Carboxy group,
Examples thereof include an alkoxycarbonyl group and a nitro group. As described above, at least one of R ₁ and R ₂ has 5 or more carbon atoms, and may have an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, Represents an alkoxy group which may have a substituent, an alkoxycarbonyl group which may have a substituent, an acyl group which may have a substituent, and an acyloxy group which may have a substituent . Examples of the substituent having 5 or more carbon atoms include those having 5 to 25 carbon atoms in the above specific examples. When l + m + n = 1,
R ₃ is an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkoxy group which may have a substituent, an alkoxy group which may have a substituent It represents a carbonyl group, an acyl group which may have a substituent, or an acyloxy group which may have a substituent. R ₃ preferably has 2 or more carbon atoms, more preferably 4 or more carbon atoms.

Among the above, alkyl groups which may have a substituent of R _{1 to} R ₅ include methyl, ethyl, propyl, isopropyl, butyl, t-butyl, n- A pentyl group, a t-amyl group, an n-hexyl group, an n-octyl group, and a decanyl group are preferable.As the cycloalkyl group, a cyclohexyl group, a cyclooctyl group, and a cyclododecanyl group which may have a substituent may be used. Preferably, the alkoxy group may have a substituent,
Methoxy, ethoxy, isopropoxy, n-butoxy, sec-butoxy, t-butoxy, pentyloxy, t-amyloxy, n-hexyloxy,
An n-octyloxy group and an n-dodecaneoxy group are preferable. As the alkoxycarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, and an sec- Butoxycarbonyl group, t-butoxycarbonyl group, pentyloxycarbonyl group, t-amyloxycarbonyl group, n-hexyloxycarbonyl group,
An n-octyloxycarbonyl group and an n-dodecaneoxycarbonyl group are preferable, and as the acyl group, a formyl group, an acetyl group, a butyryl group, which may have a substituent,
A valeryl group, a hexanoyl group, an octanoyl group, a t-butylcarbonyl group, and a t-amylcarbonyl group are preferred.As the acyloxy group, an acetoxy group, an ethylyloxy group, a butyryloxy group, which may have a substituent,
-Butyryloxy group, t-amylyloxy group, n-hexanecarbonyloxy group and n-octanecarbonyloxy group are preferred.

The alkyl group having 5 or more carbon atoms and which may have a substituent is an n-pentyl group, a t-
Amyl, n-hexyl, n-octyl and decanyl are preferred. A cycloalkyl group having 5 or more carbon atoms, which may have a substituent, is a cyclohexyl group,
A cyclooctyl group and a cyclododecanyl group are preferred. Examples of the alkoxy group having 5 or more carbon atoms, which may have a substituent, include a pentyloxy group, a t-amyloxy group,
Hexyloxy, n-octyloxy and dodecaneoxy are preferred. An alkoxycarbonyl group having 5 or more carbon atoms, which may have a substituent, includes a pentyloxycarbonyl group, a t-amyloxycarbonyl group,
Hexyloxycarbonyl, n-octyloxycarbonyl and dodecaneoxycarbonyl are preferred. As the acyl group having 5 or more carbon atoms and which may have a substituent, a paleryl group, a hexanoyl group, an octanoyl group, and a t-amylcarbonyl group are preferable. As the acyloxy group having 5 or more carbon atoms and which may have a substituent, a t-amylyloxy group, an n-hexanecarbonyloxy group, and an n-octanecarbonyloxy group are preferable. Substituents for these groups include methoxy, ethoxy, t-butoxy, chlorine, bromine, cyano,
A hydroxyl group, a methoxycarbonyl group, an ethoxycarbonyl group, a t-butoxycarbonyl group, and a t-amyloxycarbonyl group are preferred.

The general expressions used in the present invention [I] or sulfonium, iodonium compound represented by [II], the counter anion, X ^- as, using a sulfonic acid having a specific structure as described above. Examples of the aliphatic hydrocarbon group which may have a substituent of R in the counter anion include a linear or branched alkyl group having 1 to 20 carbon atoms, or a cyclic alkyl group. R may be an aromatic group which may have a substituent. As the alkyl group for R, a methyl group, an ethyl group, a propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, which may have a substituent,
Examples thereof include those having 1 to 20 carbon atoms such as an n-octyl group, a 2-ethylhexyl group, a decyl group and a dodecyl group. The cyclic alkyl group may have a substituent,
Examples thereof include a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a cyclododecyl group, an adamantyl group, a norbornyl group, a camphor group, a tricyclodecanyl group, and a menthyl group. Examples of the aromatic group include a phenyl group and a naphthyl group which may have a substituent.

Among the above, as the alkyl group which may have a substituent for R, methyl, trifluoromethyl, ethyl, pentafluoroethyl, 2,2,2
2-trifluoroethyl group, n-propyl group, n-butyl group, nonafluorobutyl group, n-pentyl group, n-hexyl group, n-octyl group, heptadecafluorooctyl group, 2-ethylhexyl group, decyl group , Dodecyl group,
Examples of the cyclic alkyl group include a cyclopentyl group, a cyclohexyl group, and a camphor group. As the aromatic group, a phenyl group, naphthyl group, pentafluorophenyl group, p-toluyl group, p-
Fluorophenyl group, p-chlorophenyl group, p-hydroxyphenyl group, p-methoxyphenyl group, dodecylphenyl group, mesityl group, triisopropylphenyl group,
4-hydroxy-1-naphthyl group, 6-hydroxy-2
-Naphthyl group.

Among the above substituents, more preferred R
Specific examples of the ₁ to R _5, a methyl group, an ethyl group, a propyl group, an isopropyl group, n- butyl group, t- butyl group, n- pentyl group, t-amyl group, n- hexyl group,
n-octyl group, cyclohexyl group, methoxy group, ethoxy group, isopropoxy group, n-butoxy group, t-butoxy group, pentyloxy group, t-amyloxy group, hexyloxy group, n-octyloxy group, methoxycarbonyl group , Ethoxycarbonyl group, n-butoxycarbonyl group, t-butoxycarbonyl group, t-amyloxycarbonyl group, hexyloxycarbonyl group, n-octyloxycarbonyl group, formyl group, acetyl group, butyryl group, hexanoyl group, octanoyl group , T-butylcarbonyl group, t-amylcarbonyl group, acetoxy group, ethylyloxy group, butyryloxy group, t-butyryloxy group, t-amylyloxy group, n-hexanecarbonyloxy group, n-octanecarbonyloxy group, hydroxyl group, Chlorine atom, bromine atom, Is the Toro group. Specific examples of the group having 5 or more carbon atoms are preferably an n-pentyl group and a t-
Amyl group, n-hexyl group, n-octyl group, decanyl group, cyclohexyl group, pentyloxy group, t-amyloxy group, hexyloxy group, n-octyloxy group, dodecaneoxy group, pentyloxycarbonyl group, t-ami Roxycarbonyl group, hexyloxycarbonyl group,
n-octyloxycarbonyl group, dodecaneoxycarbonyl group, pareryl group, hexanoyl group, octanoyl group, t-amylcarbonyl group, t-amylyloxy group,
an n-hexanecarbonyloxy group and an n-octanecarbonyloxy group.

More preferred specific examples of the sulfonic acid substituent R include a methyl group, a trifluoromethyl group, an ethyl group, a pentafluoroethyl group, a 2,2,2-trifluoroethyl group, an n-butyl group and a nonafluoro group. Butyl group, n
-Hexyl group, n-octyl group, heptadecafluorooctyl group, 2-ethylhexyl group, camphor group, phenyl group, naphthyl group, pentafluorophenyl group, p-toluyl group, p-fluorophenyl group, p-chlorophenyl group, p-methoxyphenyl group, dodecylphenyl group, mesityl group, triisopropylphenyl group, 4-hydroxy-1-naphthyl group and 6-hydroxy-2-naphthyl group.

The total number of carbon atoms of the generated acid is preferably from 1 to 30. The number is more preferably 1 to 28, and still more preferably 1 to 25. If the total number of carbon atoms is less than 1, the pattern formation may be hindered such as a t-top shape, and if it exceeds 30, the development residue may be undesirably generated. Hereinafter, specific examples of the compound represented by the general formula [I] or [II] as the acid generator of the present invention include the following [I-1] to [I-18] and [II-1] to [II-20] is shown, but the present invention is not limited to this. These compounds are used alone or in combination of two or more.

[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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The general formula [I] or a compound represented by [II], for example the corresponding Cl ^- salt (formula [I] or [II] with X ^- the Cl ^- compounds substituted with) and, X ^- Y ⁺
(X ⁻ has the same meaning as in formula [I] or [II], and Y ⁺ is H ⁺ , Na ⁺ , K ⁺ , NH ₄ ⁺ , N (C
H ₃ ) ₄ ^{+ and} other cations. ) Can be synthesized by salt exchange in an aqueous solution. In addition to the above chlorides, hydroxides or methanesulfonates can be subjected to similar salt exchange. The amount of the photoacid generator represented by the general formula [I] or [II] in the composition is as follows:
In the total solid content of the positive photoresist composition, 0.01 to
It is preferably 5% by weight, more preferably 0.03 to 4% by weight, and still more preferably 0.05 to 3% by weight. 0.0
If the amount is less than 1% by weight, the sensitivity is lowered. If the amount is more than 5% by weight, the optical absorption is excessively increased.

[2] Resin which decomposes under the action of acid to increase solubility in alkali (acid-decomposable resin) In formulas (pI) to (pVI), the alkyl group in R _{12 to} R ₂₅ is substituted or substituted. Represents an unsubstituted, straight-chain or branched alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group and a t-butyl group. 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, Carboxy group, alkoxycarbonyl group,
Examples thereof include a nitro group.

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

[0039]

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[0040]

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[0041]

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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, 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. 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 general formulas (pI) to (pV)
Examples of the alkali-soluble group protected by the structure represented by I) 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. The alkali-soluble group protected by the structure represented by the general formulas (pI) to (pVI) in the above resin is preferably the following general formula (pVI)
Groups represented by I) to (pXI).

[0045]

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Here, R _{11 to} R ₂₅ and Z are the same as defined above. In the above resin, as the repeating unit having an alkali-soluble group protected by the structure represented by any of formulas (pI) to (pVI), a repeating unit represented by the following formula (pA) is preferable.

[0047]

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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 singly or two or more selected from the group consisting of a single bond, an alkylene group, a substituted alkylene group, an ether group, a thioether group, a carbonyl group, an ester group, an amide group, a sulfonamide group, a urethane group, and a urea group. Represents a combination of groups. R _a represents any one group of formulas (pI) ~ (pVI). Hereinafter, specific examples of the monomer corresponding to the repeating unit represented by the general formula (pA) are shown.

[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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In the above resin, the compounds represented by the general formulas (pI) to (pI)
In addition to the repeating unit having an alkali-soluble group protected by the structure represented by (pVI), another repeating unit may be included. Such another repeating unit is preferably a repeating unit represented by the following general formula (AI).

[0056]

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R has the same meaning as described above. B is a halogen atom, a cyano group, a group decomposed by the action of an acid, -C (=
O) represents _{-YAR c9} or -COOR _c11 . Y: an oxygen atom, a sulfur _{atom, -NH -, - NHSO 2 -} ,
Divalent bonding group selected from _{-NHSO 2 NH-, R c9: -COOH} , -COOR c10 (. R c10 those having the same meaning as R _c11, and representing the following lactone structure), - C
N, a hydroxyl group, an alkoxy group which may have a substituent,
_{-CO-NH-R c11, -CO} -NH-SO 2 -R c11
Alternatively, it represents the following lactone structure.

R _c11 : an alkyl group which may have a substituent, a cyclic hydrocarbon group which may have a substituent, A: a single bond, an alkylene group, a substituted alkylene group, an ether group, a thioether group, 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.

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R ₂₉ represents a linear or branched alkyl group having 1 to 4 carbon atoms which may have a substituent. n
Represents an integer of 1 to 4. The group decomposed by the action of the acid is preferably a group represented by —C (＝ O) —X ₁ —R ₀ . Here, R ₀ is a t-butyl group,
tertiary alkyl groups such as t-amyl group, isobornyl group, 1
-An ethoxyethyl group, a 1-butoxyethyl group, a 1-isobutoxyethyl group, a 1-alkoxyethyl group such as a 1-cyclohexyloxyethyl group, a 1-methoxymethyl group,
An alkoxymethyl group such as -ethoxymethyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a trialkylsilyl group, and a 3-oxocyclohexyl group. X ₁ is an oxygen atom, a sulfur atom, —NH—,
-HNSO ₂ -, - NHSO represents a ₂ HN-, preferably oxygen atom.

The alkyl group has 1 to 10 carbon atoms.
Linear or branched alkyl groups are preferred, more preferably a linear or branched alkyl group having 1 to 6 carbon atoms, even more preferably methyl, ethyl, propyl, isopropyl, n -Butyl group, isobutyl group, sec-butyl group and t-butyl group.

The above-mentioned cyclic hydrocarbon group includes, for example, a cyclic alkyl group and a bridged hydrocarbon group, such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a boronyl group, an isobornyl group, a tricyclodecanyl group and a dicyclodecanyl group. Cyclopentenyl group, nobornane epoxy group,
Menthyl, isomenthyl, neomenthyl, tetracyclododecanyl and the like can be mentioned.

As the alkoxy group, a methoxy group,
C1-C1 such as ethoxy, propoxy and butoxy groups
Four things can be mentioned.

Further substituents in the above alkyl group, cyclic alkyl group and alkoxy group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group and an acyloxy 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 acyl group include a formyl group and an acetyl group. Examples thereof include an acetoxy group.

The alkylene group and the substituted alkylene group represented by A in the above formulas (AI) and (pA) include the following groups. -[C (R _a ) (R _b )] _r-wherein R _a and R _{b are a} hydrogen atom, an alkyl group, a substituted alkyl group,
Represents a halogen atom, a hydroxyl group, or an alkoxy group; they may be the same or different; and the alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, or a butyl group, and more preferably a methyl group. Represents a substituent selected from the group consisting of a 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 a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
Individuals can be mentioned. r represents an integer of 1 to 10. In the above, a chlorine atom as the halogen atom,
Examples thereof include a bromine atom, a fluorine atom, and an iodine atom. As B, an acid-decomposable group and a mevalonic lactone group are preferred.

The acid-decomposable resin of the present invention has a structure represented by the general formulas (pI) to (pVI) added to a copolymerization component such as the repeating unit represented by the general formula (AI). It preferably contains an acid-decomposable group other than the protected alkali-soluble group. As such an acid-decomposable group that can be used in combination, a group represented by the above-mentioned —C (＝ O) —O—R ₀ is preferable.

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 other general requirements for resists. Can be used as a copolymer with various monomer repeating units.

Examples of such repeating units include, but are not limited to, repeating units corresponding to the following monomers. 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, (where the alkyl group has 1 to 10 carbon atoms, for example, methyl group, ethyl group, propyl group, butyl group, t-butyl group, heptyl group, 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 (alkyl 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 dichloroacetate, 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 developing solution, the substrate adhesion, the resist profile, and the resolution, heat resistance, which is a general requirement of the resist. ,
It is set as appropriate to adjust sensitivity and the like.

In the acid-decomposable resin, the compounds represented by the general formulas (pI) to (pV)
The content of the repeating unit having an alkali-soluble group protected by the partial structure represented by I) is from 30 to 70 mol%, preferably from 35 to 65 mol%, more preferably from all monomer repeating units. 40 to 60 mol%. Also,
In the acid-decomposable resin, the content of the repeating unit containing an acid-decomposable group other than the alkali-soluble group protected by the partial structure represented by any of the general formulas (pI) to (pVI) is determined by the total monomer repeating unit 70 mol% or less, preferably 5-65
Mol%, more preferably 10 to 60 mol%. The content of the carboxyl group for providing adhesion is 2.0% in the resin.
Meq / g or less, preferably 1.8 meq / g
g or less, more preferably 1.5 meq / g or less.

The content of the repeating unit based on the monomer of the further 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 in the whole composition is preferably from 40 to 99.99% by weight, more preferably from 50 to 99.99% by weight, based on the whole resist solids. 97% by weight.

Next, in the positive photoresist composition of the present invention, a compound (photoacid generator) which generates an acid upon irradiation with an actinic ray or radiation represented by the general formula [I] or [II] is added. The photoacid generator that can be used in combination will be described.

The photoacid generator needs to satisfy two properties. That is, (1) transparency to exposure light (provided that there is no light bleaching property) and (2) sufficient photodegradability to secure resist sensitivity. However, at present, there is no clear guideline for molecular design that satisfies such contradictory requirements. For example, the following examples can be given. That is, JP-A-7-25846,
Aliphatic alksulfonium salts having a 2-oxocyclohexyl group and N-hydroxysuccinimide sulfonates described in JP-A-7-28237, JP-A-7-92675 and JP-A-8-27102 And the like. And J. Phot
Opolym. Sci. Technol., Vol 7, No3, p 423 (1994), etc., and sulfonium salts represented by the following general formula (VI), disulfones represented by the following general formula (VII) And compounds represented by the following general formula (VIII).

[0084]

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Here, R _{12 to} R ₁₅ each represent an alkyl group or a cyclic alkyl group. These may be the same or different from each other. Further, N-hydroxymaleimide sulphonates represented by the following general formula (IX) are also suitable.

[0086]

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Here, R ₁₆ and R ₁₇ may be the same or different and represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group. R ₁₆ and R ₁₇ may be bonded via an alkylene group to form a ring. R ₁₈ represents an alkyl group, a perfluoroalkyl group, a cycloalkyl group or a substituted camphor. Such N-hydroxymaleimide sulphonates are particularly preferred in terms of photosensitivity.

The alkyl group having 1 to 6 carbon atoms for R ₁₆ and R ₁₇ in the general formula (IX) includes a methyl group,
Ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, n-pentyl group,
An n-hexyl group can be mentioned. Among them, preferred are a methyl group, an ethyl group and a propyl group, and a methyl group and an ethyl group are more preferred. Examples of the cycloalkyl group having 6 or less carbon atoms include a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group. Preferably, they are a cyclopentyl group and a cyclohexyl group. R ₁₆ ,
Examples of the case where R ₁₇ forms a ring with each other by an alkylene chain include a case where a cyclohexyl group, a norbornyl group, and a tricyclodecanyl group are formed.

As the alkyl group for R _18, a linear C 1-20 group such as a methyl group, an ethyl group, or a propyl group may be used.
Alkyl groups, isopropyl groups, isobutyl groups, t
Examples thereof include a branched alkyl group having 1 to 20 carbon atoms such as an tert-butyl group and a neopentyl group. It is preferably a linear or branched alkyl group having 1 to 16 carbon atoms, and more preferably 4 to 15 carbon atoms.
Linear or branched alkyl groups. Examples of the perfluoroalkyl group include a trifluoromethyl group, a pentafluoroethyl group and other straight-chain carbon atoms having 1 to 20 carbon atoms.
And a branched perfluoroalkyl group having 1 to 20 carbon atoms such as a perfluoroalkyl group, a heptafluoroisopropyl group, and a nonafluoro tert-butyl group. Preferably, it is a linear or branched perfluoroalkyl group having 1 to 16 carbon atoms. As the cyclic alkyl group, a monocyclic cyclic alkyl group such as a cyclopentyl group and a cyclohexyl group, a decalyl group,
Examples thereof include a plurality of cyclic alkyl groups such as a norbornyl group and a tricyclodecanyl group.

The amount of such a photoacid generator that can be used in combination is preferably 0.01 to 5% by weight, more preferably 0.1 to 5% by weight, based on the total solid content of the positive photoresist composition. It is preferably from 3 to 3% by weight, more preferably from 0.05 to 2% by weight.

In the positive photoresist composition of the present invention, the following photoacid generator may be used in addition to the above photoacid generator.

The amount of the photoacid generator which can be used in combination as described below in the composition is 2% by weight or less, more preferably 1% by weight, in the solid content of the whole positive photoresist composition.
The following is good. For example, SISchlesinger, Photogr.Sci.E
ng., 18,387 (1974), TSBal etal, Polymer, 21,423 (198
0) etc., U.S. Pat.No.4,069,055
No. 4,069,056, Re 27,992, JP-A-3-140,14
Ammonium salts described in No. 0 etc., DCNecker etal, Macr
omolecules, 17, 2468 (1984), CSwen et al, Teh, Proc. Co.
nf.Rad.Curing ASIA, p478 Tokyo, Oct (1988), U.S. Pat.Nos. 4,069,055, 4,069,056, phosphonium salts described in JVCrivello et al.
(1977), Chem. & Eng. News, Nov. 28, p31 (1988), European Patent Nos. 104,143, 339,049, 410,201, JP-A-2-150,848, JP-A-2-296,514, etc. Described iodonium salts, JVCrivello etal, Polymer J. 17, 73 (198
5), JVCrivello et al. J. Org. Chem., 43, 3055 (1978)
, WRWatt et al., J. Polymer Sci., Polymer Chem. Ed., 2
2,1789 (1984), JVCrivello etal, Polymer Bull., 14,
279 (1985), JVCrivello etal, Macromorecules, 14 (5),
1141 (1981), JVCrivello et al, J. PolymerSci., Polym
er Chem. Ed., 17, 2877 (1979), EP 370,693,
No. 161,811, No. 410,201, No. 339,049, No. 233,56
No. 7, 297,443, 297,442, U.S. Pat.
No. 377, No. 3,902,114, No. 4,760,013, No. 4,734,44
No. 4, No. 2,833,827, Dokoku Patent No. 2,904,626, No. 3,
Nos. 604,580 and 3,604,581, and the sulfonium salts described in JVCrivello et al., Macromorecules, 10 (6), 1307 (19
77), JVCrivello etal, J. PolymerSci., Polymer Che
m.Ed., 17,1047 (1979), etc.
S.Wen etal, Teh, Proc.Conf.Rad.Curing ASIA, p478 Toky
o, Oct (1988), etc., onium salts such as arsonium salts, U.S. Patent No. 3,905,815, -239736
No., JP-A-61-169835, JP-A-61-169837, JP-A-61-169837
No. 62-58241, JP-A-62-212401, JP-A-63-70243,
Organic halogen compounds described in JP-A-63-298339, etc.
Meier et al., J. Rad. Curing, 13 (4), 26 (1986), TPGill
etal, Inorg.Chem., 19, 3007 (1980), D. Astruc, Acc.
Res., 19 (12), 377 (1896), and organic metal / organic halides described in JP-A-2-14145, S. Hayase et al., J. Polym
er Sci., 25, 753 (1987), E. Reichmanis et al., J. Pholimer
Sci., Polymer Chem. Ed., 23, 1 (1985), QQ Zhu et al., J.
Photochem., 36, 85, 39, 317 (1987), B. Amit etal, Tetrahe
dron Lett., (24) 2205 (1973), DHR Barton et al., J. Chem.
Soc., 3571 (1965), PMCollins et al., J. Chem.SoC., Per
kin I, 1695 (1975), M. Rudinstein et al, Tetrahedron Le
tt., (17), 1445 (1975), JWWalker etal J. Am. Chem. So
c., 110, 7170 (1988), SCBusman et al, J. Imaging Techn
ol., 11 (4), 191 (1985), HMHoulihan et al, Macormolecu
les, 21, 2001 (1988), PM Collins et al., J. Chem. Soc., Che
m.Commun., 532 (1972), S.Hayase etal, Macromolecules, 1
8,1799 (1985), E. Reichmanisetal, J. Electrochem. Soc.,
Solid State Sci.Technol., 130 (6), FMHoulihan eta
1, Macromolcules, 21, 2001 (1988), European Patent 0290,750
Nos. 046,083, 156,535, 271,851, 0,
U.S. Pat.Nos. 3,901,710 and 4,181,531
, A photoacid generator having an o-nitrobenzyl-type protecting group described in JP-A-60-198538, JP-A-53-133022, etc.
TUNOOKA etal, Polymer Preprints Japan, 35 (8), G. Bern
er etal, J.Rad.Curing, 13 (4), WJMijs etal, Coating
Technol., 55 (697), 45 (1983), Akzo, H. Adachi et al, Pol
ymer Preprints, Japan, 37 (3), European Patent No. 0199,672,
No. 84515, No. 044,115, No. 618,564, No. 0101,122
No. 4,371,605, U.S. Pat.
64-18143, JP-A-2-245756, compounds capable of generating sulfonic acid upon photodecomposition represented by iminosulfonate and the like described in JP-A-3-140109, and JP-A-61-166544. The disulfone compounds described above can be exemplified.

Further, a group that generates an acid by these lights,
Alternatively, a compound having a compound introduced into a main chain or a side chain of a polymer, for example, MEWoodhouse et al., J. Am. Chem.
c., 104, 5586 (1982), SPPappas et al, J. Imaging Sc
i., 30 (5), 218 (1986), S. Kondoetal, Makromol.Chem., Ra
pid Commun., 9,625 (1988), Y.Yamada et al., Makromol.C
hem., 152, 153, 163 (1972), JVCrivello etal, J. Polym
erSci., Polymer Chem. Ed., 17,3845 (1979), U.S. Patent No. 3,849,137, Dokoku Patent No. 3,914,407, JP-A-63-266.
No. 53, JP-A-55-164824, JP-A-62-69263, JP-A-Showa
63-146038, JP-A-63-163452, JP-A-62-153853
And the compounds described in JP-A-63-146029 and the like can be used.

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

Among the compounds which can be used in combination and which generate an acid by being decomposed by irradiation with actinic rays or radiation, those particularly effectively used are exemplified below.

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The positive photoresist composition is suitable for improving the alkali solubility of the system and adjusting the glass transition temperature of the system to prevent the film from becoming brittle and from deteriorating the heat resistance. An alkali-soluble low molecular weight compound may be added. Examples of the alkali-soluble low molecular weight compound include a dialkyl sulfonamide compound, a dialkyl sulfonyl imide (—SO ₂ —NH—CO—) compound, and a dialkyl disulfonyl imide (—SO ₂ —NH
Compounds containing an acidic group in the molecule, such as —SO ₂ —) compounds, may be mentioned. The content of the alkali-soluble low molecular compound is 4 to the binder resin.
The content is preferably 0% by weight or less, more preferably 30% by weight or less, and further preferably 25% by weight or less.

The positive photosensitive 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 developer. A compound or the like which promotes solubility can be contained.

The photosensitive composition of the present invention is dissolved in a solvent capable of dissolving each of the above components, and coated 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, ethyl lactate, 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, 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 amount of these 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. These surfactants may be added alone or in some combination.

The positive photoresist 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 photosensitive composition onto 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 far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specific examples include a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), an F ₂ excimer laser (157 nm), an X-ray, an electron beam, and the like, and an ArF excimer laser (193 nm) is particularly preferable.

As the developer of the photosensitive composition of the present invention,
Sodium hydroxide, potassium hydroxide, sodium carbonate,
Inorganic alkalis such as sodium silicate, sodium metasilicate and aqueous ammonia, primary amines such as ethylamine and n-propylamine, secondary amines such as diethylamine and di-n-butylamine, and triethylamine and methyldiethylamine Use alkaline aqueous solutions such as triamines, alcoholamines such as dimethylethanolamine and triethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide, and cyclic amines such as pyrrole and pichelidine. be able to. Further, an appropriate amount of an alcohol or a surfactant may be added to the above alkaline aqueous solution.

[0104]

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 Example 1 (Synthesis of photoacid generator [I-3]) t-amylbenzene 60 g, potassium iodate 39.5
g, 81 g of acetic anhydride and 170 ml of dichloromethane were mixed, and 66.8 g of concentrated sulfuric acid was added dropwise over 2 hours while cooling in an ice bath. The reaction solution was stirred as it was for 2 hours, and then stirred at room temperature overnight to complete the reaction. After completion of the reaction, 50 ml of distilled water was added dropwise to the reaction solution while cooling in an ice bath, extraction was performed, the organic layer was washed with water, aqueous sodium bicarbonate and water, and the obtained organic layer was concentrated to give di (t-amylphenyl). ) 40 g of iodonium sulfate was obtained. By subjecting the obtained sulfate and potassium heptadecafluorooctanesulfonate to a salt exchange reaction, the target product [I-3] was obtained.

Synthesis Example 2 (Synthesis of photoacid generator [I-6]) 90 g of n-octylphenyl ether, 39.5 g of potassium iodate, 81 g of acetic anhydride, 180 g of dichloromethane
66.8 g of concentrated sulfuric acid while cooling in an ice bath.
Was added dropwise over 2 hours. The reaction solution was stirred as it was for 2 hours, and then stirred at room temperature overnight to complete the reaction. After completion of the reaction, distilled water (50 mL) was added dropwise to the reaction solution while cooling in an ice bath, extraction was performed, and the organic layer was washed with water, aqueous sodium bicarbonate and water, and the obtained organic layer was concentrated. 45 g of phenyl) iodonium sulfate were obtained. By subjecting the obtained sulfate and potassium heptadecafluorooctanesulfonate to a salt exchange reaction, the target product [I-6] was obtained.

Synthesis Example 3 (Synthesis of Photoacid Generator [I-9]) Salt exchange of di (t-amylphenyl) iodonium sulfate obtained in Synthesis Example (1) with sodium pentafluorobenzenebenzenesulfonate. [I-9]
Was synthesized.

Synthesis Example 4 (Synthesis of photoacid generator [I-5]) To 40 g of iodobenzene, 91 g of peracetic acid was slowly dropped, and the reaction solution was stirred at 30 ° C for 2 hours. When the white powder came out, it was cooled with ice, the precipitate was collected by filtration, and 38 g of iodosobenzene diacetate was recovered. 50 g of iodosobenzene diacetate, 30 g of octylphenyl ether, 70 g of acetic anhydride, and 725 mL of glacial acetic acid thus obtained were mixed, and concentrated sulfuric acid 8 was cooled in an ice bath.
g was added dropwise over 1 hour. After 1 hour, an aqueous solution in which 31 g of NaBr was dissolved in 150 mL was added dropwise, and 42 g of a precipitated white powder, iodonium bromide salt, was recovered. The obtained iodonium bromide salt and trifluoromethanesulfonate are subjected to salt exchange to obtain the desired product [I-5].
I got

Synthesis Example 5 (Synthesis of photoacid generator [II-3]) 50 g of diphenyl sulfoxide was added to 800 m of mesitylene.
L, and 200 g of aluminum chloride was added thereto, followed by stirring at 80 ° C. for 24 hours. After the completion of the reaction, the reaction solution was slowly poured into 2 L of ice. 400 mL of concentrated hydrochloric acid was added thereto, and the mixture was heated at 70 ° C. for 10 minutes. The reaction solution was cooled to room temperature, washed with ethyl acetate, and filtered. A solution prepared by dissolving 200 g of ammonium iodide in 400 mL of distilled water was added to the filtrate. The precipitated powder was collected by filtration, washed with water, washed with ethyl acetate, dried, and treated with sulfonium iodide 72.
g was obtained. 50 g of the obtained sulfonium iodide was dissolved in 300 mL of methanol, and 31 g of silver oxide was added thereto, followed by stirring for 4 hours. After the reaction solution was filtered, salt exchange was performed with potassium heptadecafluorooctanesulfonate to recover 40 g of the desired product [II-3].

Synthesis Example 6 (Synthesis of Photoacid Generator [II-2]) Using octylbenzene instead of mesitylene in Synthesis Example (5), the corresponding sulfonium iodide was synthesized, and then synthesized. [II-2] was synthesized in the same manner as in Synthesis Example (5) by subjecting to salt exchange with potassium trifluoromethanesulfonate in the same manner as in Example (5).

Synthesis Example 7 (Photoacid generator [II-8]) The corresponding sulfonium iodide was synthesized using octyloxybenzene instead of mesitylene in Synthesis example (5), and then synthesized. Salt exchange was performed with potassium nonafluorobutanesulfonate in the same manner as in 5) to obtain the desired product [II-8].

Synthesis Example 8 (Synthesis of photoacid generator [II-14]) Methanesulfonic acid / diphosphorus pentoxide (10/50 g) was added to 50 g of diphenyl sulfoxide and 45 g of 2,6-xylenol.
1) 100 mL of the solution was added. After the fever subsides, 5
Heat at 0 ° C. for 4 hours. After the completion of the reaction, the reaction solution was poured on ice. After washing this aqueous solution with toluene and filtering, an aqueous solution in which 200 g of ammonium iodide was dissolved in 400 mL of distilled water was added, and the precipitated powder was collected by filtration. The obtained residue was washed with water and dried to obtain sulfonium iodide. 50 g of the obtained sulfonium iodide was added to methanol 300 m
L, and 31 g of silver oxide was added thereto, followed by stirring for 4 hours. After the reaction solution was filtered, salt exchange was performed with potassium heptadecafluorooctanesulfonate to recover 43 g of the desired product [II-14].

Synthesis Example 9 (Synthesis of Resin A) Resin A was synthesized by the synthesis method described in Example 7 of page (27) of JP-A-9-73173. That is, 2-methyladamantyl methacrylate monomer and 3-oxocyclohexyl methacrylate monomer were charged into a polymerization vessel at a ratio of 4: 6 to obtain a 2 mol / L toluene solution. To this toluene solution, a polymerization initiator, AIBN, was added in an amount of 5 mol%, and polymerization was carried out at 80 ° C. for about 8 hours. After completion of the polymerization, purification was performed using methanol as a precipitant. 2-methyladamantyl methacrylate represented by the following formula /
A 3-oxocyclohexyl methacrylate copolymer was obtained. The obtained copolymer had a composition ratio (m: n) of 4
9:51, the weight average molecular weight (Mw) was 15,000, and the dispersity (Mw / Mn) was 2.4. Resin A

[0113]

Embedded image

Synthesis Example 10 (Synthesis of Resin B) Resin B was synthesized by the synthesis method described in Example 13 on page (18) of JP-A-9-90637. That is, a methacrylic acid (±) -mevalonic lactone ester / 2-methyl-2-adamantyl methacrylate copolymer was synthesized. Eggplant-shaped flask of 100ml, which was sufficiently dried, which was placed in a Teflon ^TM coated star rubber, 4.96g
(25 mmol) methacrylic acid (±) -mevalonic lactone ester, 5.87 g (25 mmol) 2-methyl-2-adamantyl methacrylate, 16.7 ml dioxane and 1.23 g (9 mmol) azo Bisisobutyronitrile (AIBN) was added, and the mixture was stirred at 80 ° C. for 8 hours under a nitrogen atmosphere. After the reaction solution was diluted with tetrahydrofuran (THF), it was added dropwise to 1 liter of methanol containing a small amount of hydroquinone. The resulting precipitate was filtered off with a glass filter, and the precipitate was filtered at 0.1 mmHg and 45 ° C for 1 hour.
Dry for 6 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, the weight-average molecular weight was 14000 (in terms of standard polystyrene), and the dispersity was 2.0.

Synthesis Examples 11 to 14 (Synthesis of Resins C to F) Resins prepared by charging the following monomers in the following molar ratios were synthesized in the same manner as in Synthesis Example 9 or 10. Resin C: Copolymer of the above monomer specific example 5 and mevalonic lactone methacrylate (molar ratio 50/50) (weight average molecular weight: 13500) Resin D: The above monomer specific example 11 and 3-oxocyclohexyl methacrylate and acrylic acid Copolymer (molar ratio 50/40/10) (weight average molecular weight: 13000) Resin E: Copolymer of monomer specific example 15 and mevalonic lactone methacrylate (molar ratio 50/50) (weight average molecular weight: 14000) ) Resin F: Copolymer of the above-mentioned monomer specific example 33 and mevalonic lactone methacrylate (molar ratio 50/50) (weight average molecular weight: 14500)

[Examples] As shown in Table 1, 10 g of each resin synthesized in the above synthesis example and 0.3 g of each photoacid generator were mixed with 1 solid content.
After dissolving at a ratio of 4% by weight in 2-heptanone (mixing with 2-hydroxypropionic acid if necessary), 0.1
The solution was filtered through a micrometer micro filter to prepare a positive photoresist composition solution. [Comparative Examples 1 and 2] Instead of the photoacid generator of the above example,
A positive photoresist composition solution was prepared in the same manner as in the above example except that triphenylsulfonium hexafluoroantimonate (B1) or triphenylsulfonium trifluoromethanesulfonate (B2) was used.

(Evaluation Test) The obtained positive photoresist composition solution was applied on a silicon wafer by using a spin coater, dried at 130 ° C. for 60 seconds, and dried at about 0.5 μm.
Was prepared and exposed to an ArF excimer laser (193 nm). A heat treatment after the exposure was performed at 130 ° C. for 60 seconds, developed with a 2.38% aqueous solution of tetramethylammonium hydroxide, and rinsed with distilled water to obtain a resist pattern profile.

[Temperature stability of composition solution]: The prepared positive photoresist composition solution (coating solution) was allowed to stand at 4 ° C for one week, and then the number of particles was counted with a particle counter manufactured by Rion. [Sensitivity]: Defined as the minimum exposure (mJ / cm ² ) for reproducing a 0.35 μm mask pattern. Table 1 shows the evaluation results.

[0119]

[Table 1]

As is clear from the results shown in Table 1, the positive photoresist composition for deep ultraviolet exposure using the resin and the photoacid generator according to the present invention obtained satisfactory results, respectively. The positive photoresist composition was unsatisfactory in the stability over time and sensitivity of the composition solution.

[0121]

As described above, the positive photoresist composition of the present invention is sufficiently suitable especially for light in a wavelength region of 170 nm to 220 nm, and can provide high sensitivity and high resolution, and can be used in the composition. It is possible to improve the stability over time of the product solution, and it has extremely high practicality.

Claims (2)

[Claims] 1. Irradiation with actinic rays or radiation,
A compound represented by the following general formula (I) or (II) which generates sulfonic acid, and the following general formulas (pI) to (pV)
It contains an alkali-soluble group protected by at least one of the partial structures containing an alicyclic hydrocarbon represented by I), and contains a resin that decomposes under the action of an acid to increase the solubility in alkali. Positive photoresist composition for deep ultraviolet exposure. Embedded image In the formulas (I) and (II), R _{1 to} R ₅ are each a hydrogen atom,
An alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkoxy group which may have a substituent, an alkoxycarbonyl group which may have a substituent, It represents an acyl group which may have a substituent, an acyloxy group which may have a substituent, a nitro group, a halogen atom, a hydroxyl group, and a carboxyl group. a: 1 to 5, b: 1 to 5, l: 1 to 5, m: 0 to 5, n: 0 to 5. Provided that at least one of R ₁ and R ₂ is an alkyl group having 5 or more carbon atoms which may have a substituent, a cycloalkyl group which may have a substituent,
Represents an alkoxy group which may have a substituent, an alkoxycarbonyl group which may have a substituent, an acyl group which may have a substituent, and an acyloxy group which may have a substituent . When 1 + m + n = 1, R ₃ represents an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an alkoxy group which may have a substituent, or a substituent. Represents an optionally substituted alkoxycarbonyl group, an optionally substituted acyl group, and an optionally substituted acyloxy group. X represents R—SO ₃ , R represents an aliphatic hydrocarbon group which may have a substituent, or an aromatic hydrocarbon group which may have a substituent. Embedded image In the formula, R ₁₁ is a methyl group, an ethyl group, an n-propyl group,
Isopropyl group, n-butyl group, isobutyl group or se
represents a c-butyl group, and Z represents an atomic group necessary for forming an alicyclic hydrocarbon group together with a carbon atom. R ₁₂ ~R
₁₆ independently represents a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that R
At least one of ₁₂ to R _14, or any of R _15, R ₁₆ represents an alicyclic hydrocarbon group. 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;
At least one of R _{17 to} R ₂₁ represents an alicyclic hydrocarbon group. Further, either R ₁₉ or R ₂₁ represents a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms. R _{22 to} R ₂₅ each independently represent a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{22 to} R ₂₅ is an aliphatic group; Represents a cyclic hydrocarbon group. 2. The positive photoresist composition for deep UV exposure according to claim 1, wherein the resin contains a group represented by the following general formula (A) that decomposes under the action of an acid. object. Formula (A) -C (= O) -OR _{0 In the} formula (A), R ₀ is a tertiary alkyl group, a 1-alkoxyethyl group, an alkoxymethyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, Trialkylsilyl group,
Represents a 3-oxocyclohexyl group or a lactone group.