JP2000194136A - Pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pattern forming method excellent in the coarse/fine dependency of a resist pattern formed using far ultraviolet ray, particularly ArF excimer laser beam and suitable for the light source of the short wave by using a specific acid degradable resin as a composition and a specific one as a developer. SOLUTION: A photoresist composition containing a resin containing a compound generating an acid by the irradiation with active light or radiation and the resin containing a repeating unit expressed by formula I or a repeating unit expressed by formula II and degraded by the action of the acid to increase the solubility in an alkali is applied on the substrate. The pattern forming method further contains a process for exposing the photoresist composition film with active light or radiation and developing with an organic alkali aq. solution. In the formula, each of R1-R8, R1'-R8' represents hydrogen atom, a (substituted) alkyl group, a group degraded by the acid or the like. The ratio of m/n is 1/9-9/1, each of m+n and m'+n' is 10-100 and each of (m') and (n') is 0-100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern forming method relating to an ultra microlithography process such as the production of an ultra LSI and a high capacity micro chip, and other photofabrication processes. More specifically, the present invention relates to a pattern forming method which has excellent dependency on density and can form a high definition pattern.

[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 ultra LSIs, processing of ultrafine patterns having a line width of less than half a micron is required. It has become In order to meet this need, the wavelength of an exposure apparatus used for photolithography is becoming shorter and shorter, and now excimer laser light (XeCl, KrF, ArF, etc.) having a short wavelength among far ultraviolet rays is used.
The use of is being considered. 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-4-219775, JP-A-5-281745 and the like are examples thereof. 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, JP-A-3-206458, JP-A-2-19847, and the like. Proposed. These are suitable when using KrF excimer laser light of 248 nm,
When an ArF excimer laser is used as the light source, the sensitivity is low because the absorbance is still essentially too high. Further, 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
Nos. 99467 and 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. Hei 7-234511 discloses an acid-decomposable resin having an acrylate ester or a fumarate ester as a repeating unit. The fact is that performance has not been 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, there are 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. In response to such hydrophobicity of the resist, many approaches have been taken to improve various kinds of hydrophobic alicyclic hydrocarbon sites by introducing a hydrophilic group in the approach of improving the resist.

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,
Furthermore, there are many problems such as a significant decrease in resist film thickness, and the above-mentioned problems have not been solved. Further, JP-A-7-234511 discloses copolymerizing a monomer having a hydroxyl group or a cyano group in a molecule instead of a carboxylic acid group such as HEMA or acrylonitrile with a monomer having an alicyclic hydrocarbon group. By doing so, the aim was to solve the developability, 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.

As described above, 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 insufficient points, and improvements are desired.

On the other hand, in the approach of improving the process for making the resist hydrophobic, an approach such as mixing an organic solvent such as isopropyl alcohol in a developing solution has been studied. Although some results have been obtained, there are concerns about swelling of the resist film. The problem has not always been solved, for example, the process becomes complicated. Also, JP-A-9-244261 discloses that
It is described that an organic alkali aqueous solution is used as a developer in the presence of a surfactant having a higher alkyl group. However, there was a problem in the following sparse / dense dependency.

Since various patterns are included as a tendency of recent devices, resists are required to have various performances, and one of them has sparse / dense dependency. That is, the device has a dense portion of lines, a pattern having a wider space than the lines, and an isolated line. Therefore, it is important to resolve various lines with high reproducibility. However, it is not always easy to reproduce various lines due to optical factors.
At present, the solution by the resist or the process is not clear. In particular, in the above-described resist system containing an alicyclic group, the performance difference between the isolated pattern and the dense pattern is remarkable, and improvement is desired.

[0014]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a short-wavelength light source in which a resist pattern formed using far-ultraviolet light, particularly ArF excimer laser light, has good density dependence. Another object of the present invention is to provide a suitable pattern forming method.

[0015]

Means for Solving the Problems The present inventors have made intensive studies on the constituent materials of the resist composition and the pattern forming process in a positive-type chemical amplification system, and have found that a specific acid-decomposable resin is used in the composition, and Knowing that the purpose of the present invention is achieved by using a specific developer,
The present invention has been reached. That is, the above object is achieved by the following constitutions. (1) including (a) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (b) a repeating unit represented by the following general formula [I] or a repeating unit represented by the following general formula [II] A step of applying a positive photoresist composition for deep ultraviolet light exposure containing a resin which is decomposed by the action of an acid and has increased solubility in alkalis onto a substrate, and the obtained photoresist composition film is irradiated with actinic rays or radiation. A pattern forming method comprising the steps of: exposing in a pattern, and developing the exposed photoresist composition film with an organic alkali aqueous solution in the presence of a surfactant.

[0016]

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[0017]

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In the formula, R _{1 to} R ₈ , R ₁ ′ to R ₈ ′ may be the same or different, and may have a hydrogen atom, an alkyl group which may have a substituent, or a substituent. It represents a good cyclic hydrocarbon group, a halogen atom, a cyano group, and a group that decomposes under the action of an acid, —C (ＸO) —XA—R ₉ . However, at least one of R _{1 to} R ₈ or R ₁ ′ to R ₈ ′
One represents a group that is decomposed by the action of an acid. m / n; 1 / 9~9 / 1 m + n, m '+ n'; 10~100 m '; 0~100 n'; 0~100 X; oxygen atom, a sulfur _{atom, -NH -, - NHSO 2 -} ,
-NHSO ₂ NH- 2 divalent linking group selected _{from, R 9; -COOH, -COOR 10} '(R 10' represents one or the following lactone structure having the same meaning as R _10), - CN, hydroxyl, a substituted group An optionally substituted alkoxy group, -CO-
_{NH-R 10, -CO-NH} -SO 2 -R 10 or

[0019]

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R ₁₀ ; an alkyl group which may have a substituent, a cyclic alkyl group which may have a substituent, R _{11 to} R ₁₈ each independently have a hydrogen atom or a substituent. An alkyl group which may be selected from the group consisting of: A; 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, or a urea group. A or b; 1 or 2 alone or in combination of two or more groups.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The pattern forming method of the present invention will be described below in detail. First, the compound used in the positive photoresist composition used in the present invention will be described in detail. First, a resin which is decomposed by the action of an acid and has increased solubility in an alkaline developer, that is, a monomer represented by the general formula [I] or a monomer represented by the general formula [II] The resin containing a polymer containing a repeating unit will be described. In the general formula [I] or the general formula [II], a group (also referred to as an acid-decomposable group) decomposed by the action of an acid in R _{1 to} R ₈ and R ₁ ′ to R ₈ ′ includes
And a group represented by (ＯO) —X ₁ —R ₀ . Here, as R ₀ , 3 such as t-butyl group, t-amyl group, etc.
Primary alkyl group, isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group, 1-alkoxyethyl group such as 1-cyclohexyloxyethyl group, 1-methoxymethyl group, 1-ethoxymethyl Examples include an alkoxymethyl group such as a group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a trialkylsilyl ester group, and a 3-oxocyclohexyl ester group. Here, X ₁ has the same meaning as X described above.

The alkyl group for R _{1 to} R ₈ , R ₁ ′ to R ₈ ′, and R ₁₀ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably 1 to 10 carbon atoms. 6 linear or branched alkyl groups,
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 and a t-butyl group.

Examples of the cyclic hydrocarbon group for R _{1 to} R ₈ and R ₁ ′ to R ₈ ′ include a cyclic alkyl group and a bridged hydrocarbon group, such as a cyclopropyl group, a cyclopentyl group,
Cyclohexyl group, adamantyl group, 2-methyl-2-
An adamantyl group, a norbornyl group, a boronyl group, an isobornyl group, a tricyclodecanyl group, a dicyclopentenyl group, a nobornane epoxy group, a menthyl group, an isomenthyl group, a neomenthyl group, a tetracyclododecanyl group, and the like can be given.

Examples of the alkoxy group for R ₉ include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group.

The cyclic alkyl group for R ₁₀ includes cyclopropyl, cyclopentyl, cyclohexyl, adamantyl, 2-methyl-2-adamantyl, norbornyl, boronyl, isobornyl, tricyclodecanyl, dicyclodecanyl, Examples thereof include a cyclopentenyl group, a nobornane epoxy group, a menthyl group, an isomenthyl group, a neomenthyl group, and a tetracyclododecanyl group.

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.

Examples of the alkylene group and substituted alkylene group in A include the following groups. -[C (R _a ) (R _b )] _r-wherein R _a and R _b each represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, or an alkoxy 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 selected from the group consisting of a methyl group, an ethyl group, a propyl group and an isopropyl group. Represents a substituent. 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. r represents an integer of 1 to 10. In the above general formula [I] or general formula [II], examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom and an iodine atom.

In the general formula (I) or the general formula (II), at least one of R _{1 to} R ₈ in the general formula (I)
Or at least one of R ₁ ′ to R ₈ ′ in the general formula [II] represents an acid-decomposable group. In the general formula [I] or the general formula [II], the acid-decomposable group and -C (=
O) -XA-R ₉ may be contained both in the same repeating unit or may be contained in separate repeating units.

The resin of the present invention, which is decomposed by the action of an acid and has increased solubility in alkali, can be obtained by polymerizing a monomer having a norbornene skeleton and, if necessary, conducting a polymer reaction. The polymerization reaction can be obtained by radical polymerization using a general radical initiator such as an azo initiator, but more preferably, non-ring-opening polymerization using a Pd catalyst or the like or coordination polymerization such as a transition metal complex. It is synthesized by ring-opening polymerization using a catalyst. The resin obtained by the ring-opening polymerization is preferably reduced and used from the viewpoint of stability and optical absorption.

A resin having a repeating unit represented by the general formula [I] is obtained by ring-opening polymerization, and a resin having a repeating unit represented by [II] is obtained by non-ring-opening polymerization.

The above resin in the present invention is represented by the general formula [I] or
In addition to one or more monomer repeat units of [II], dry etching resistance, suitability for standard developer, substrate adhesion, resist profile, and resolution, heat resistance, and sensitivity, which are the general requirements for resists It can be used as a copolymer with various monomer repeating units for the purpose of adjusting the properties and the like. Preferred copolymerization components include repeating units represented by the following general formulas [V] to [VI] (ring-opening polymerization type) and [V '] to [VI'] (non-ring-opening polymerization type). .

[0032]

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[0033]

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Here, Z is an oxygen atom, -NH-, -N
(—R ₃ ) — and —N (—OSO ₂ R ₃ ) —, wherein R ₃ has the same meaning as the above (substituted) alkyl group and (substituted) cyclic alkyl group. Preferred combinations of the repeating units of the resin which decomposes under the action of the acid of the present invention to increase the solubility in alkali include the following ring-opening polymerization type and the following non-ring-opening polymerization type. However, it is not limited to this.

[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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[0041]

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[0042]

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[0043]

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In the present invention, the group decomposed by the action of an acid is contained in either the general formula [I] or [II] or in the copolymer component.

In the above resin in the present invention, the molar ratio of each repeating unit is determined by 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 and heat resistance, which are the general requirements of a resist. It is set as appropriate to adjust properties, sensitivity, and the like.

However, in the resin of the present invention, the content of the repeating unit represented by the general formula [I] or the general formula [II] is at least 10 mol% in all monomer repeating units.
Preferably 20 mol% or more, more preferably 30 mol%
That is all. In the resin of the present invention, the content of the repeating unit containing an acid-decomposable group is from 10 to 90 mol%, preferably from 15 to 85 mol%, of all monomer repeating units.
Mol%, more preferably 20 to 80 mol%. The content of the carboxyl group for providing adhesion is 0.0% in the resin.
5 to 2.0 meq / g, preferably 0.1 to
It is 1.8 meq / g, more preferably 0.3-1.5 meq / g.

The formula [I] or [II] constituting a resin which is obtained by ring-opening polymerization + reduction or further polymer reaction and which is decomposed by the action of an acid of the present invention and has increased solubility in alkali. A preferred copolymer component formula [II
Examples of repeating units represented by [I] to [VI] [I-1] to [I-4]
0], [II-1] to [II-40], [III-1] to [III-32], [IV-1] to
[IV-34], [V-1] to [V-8], and [VI-1] to [VI-8] are shown below, but the content of the present invention is by no means limited to these. The formula [I '] or [II'], which constitutes a resin which is obtained by non-ring-opening ordinary olefin polymerization and further polymer reaction and which is decomposed by the action of the acid of the present invention and has increased solubility in alkali. ], Preferred copolymer component formula
Examples of repeating units represented by [III '] to [VI'] [I'-41] to
[I'-80], [II'-41]-[II'-80], [III'-33]-[III'-6]
4], [IV'-35]-[IV'-68], [V'-9]-[V'-16], [VI'-9]
To [VI'-16] are shown below, but the content of the present invention is by no means limited to these.

[0048]

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[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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[0055]

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[0056]

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[0057]

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[0058]

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[0059]

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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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[0073]

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[0074]

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[0075]

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[0076]

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[0077]

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Such a resin can be further copolymerized as a repeating unit with the following monomers as long as the effects of the present invention can be effectively obtained, 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)
Fine adjustment of film loss (hydrophilic / hydrophobic, alkali-soluble group selection), (5) adhesiveness of the unexposed portion to the substrate, and (6) dry etching resistance can be performed. Examples of such a comonomer include acrylates, methacrylates, acrylamides, methacrylamides,
Examples thereof include compounds having one addition-polymerizable unsaturated bond selected from allyl compounds, vinyl ethers, vinyl esters, and the like.

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 (preferably having 1 to 10 carbon atoms in the alkyl group) 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 (the 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 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 repeating unit represented by the general formula [I] or [II] may be used. The content of the repeating unit based on the further monomer as described above in the resin is represented by the general formula [I]
Alternatively, it is preferably at most 99 mol%, more preferably at most 90 mol%, even more preferably at most 80 mol%, based on the total number of moles of the repeating structural units represented by the general formula [II]. If it exceeds 99 mol%, the effect of the present invention is not sufficiently exhibited, so that it is not preferable.

The weight average molecular weight of the resin according to the present invention is preferably from 2,000 to 200,000. When the weight average molecular weight is less than 2,000, heat resistance and dry etching resistance are deteriorated.
If it exceeds 000, a very unfavorable result such as deterioration of the developability and an extremely high viscosity will result in deterioration of the film-forming property.

The positive photoresist composition of the present invention mainly contains the above resin and a photoacid generator.
The addition amount of the above resin in the entire composition is preferably from 40 to 99% by weight, more preferably from 50 to 97% by weight, based on the total resist solids.

Next, the photoacid generator in the positive photoresist composition will be described. The photoacid generator needs to satisfy two properties. That is, (1) transparency to exposure light (however, when there is no light bleaching property);
(2) Sufficient photodegradability to ensure 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-
JP-A-25846, JP-A-7-28237, JP-A-7-92675, and JP-A-8-27102, aliphatic alkulfonium salts having a 2-oxocyclohexyl group, and N-hydroxy Succinimide sulfonates and the like can be mentioned. Furthermore, J. Photopolym. Sci. Technol., Vol 7,
No. 3, p 423 (1994) etc., and the following general formula (VI)
A sulfonium salt represented by the following general formula (VI
Disulfones represented by the formula (I), represented by the following general formula (VI
And the compounds represented by II).

[0091]

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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.

[0093]

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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 straight-chain C 1-20 group such as a methyl group, an ethyl group and 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 added to the composition is 0.1 to 0.1% of the total solid content of the positive photoresist composition.
To 20% by weight, more preferably 0.5 to 15% by weight.
%, More preferably 1 to 10% 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, Japanese Patent Application No. 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 No. 104,143, U.S. Patent No. 339,049, No. 410,201.
No., JP-A-2-150,848, iodonium salts described in JP-A-2-296,514, etc., JVCrivello et al., Polymer J. 17,7
3 (1985), JVCrivello et al. J. Org.Chem., 43, 3055 (19
78), WRWatt et al, J. Polymer Sci., Polymer Chem. E
d., 22, 1789 (1984), JVCrivello etal, Polymer Bul
l., 14,279 (1985), JVCrivello etal, Macromorecules,
14 (5), 1141 (1981), JVCrivelloetal, J. PolymerSci.,
Polymer Chem.Ed., 17,2877 (1979), EP 370,693
No. 3,902,114, No. 233,567, No. 297,443, No.
Nos. 297,442; U.S. Pat.Nos. 4,933,377; 161,811;
No. 410,201, No. 339,049, No. 4,760,013, No. 4,73
No. 4,444, No. 2,833,827, Dokoku Patent No. 2,904,626,
The sulfonium salts described in JP-A-3,604,580 and JP-A-3,604,581, etc., JVCrivello et al., Macromorecules, 10 (6), 1307
(1977), JVCrivello et al., J. PolymerSci., Polymer C
hem.Ed., 17,1047 (1979) and the like,
CSWen etal, Teh, Proc.Conf.Rad.Curing ASIA, p478 To
kyo, Oct (1988) and the like, onium salts such as arsonium salts, U.S. Pat.No. 3,905,815, JP-B-46-4605, JP-A-48-36281, JP-A-55-32070, JP-A-60-160 -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), TPGillet
al, Inorg.Chem., 19, 3007 (1980), D. Astruc, Acc.
s., 19 (12), 377 (1896), and organometallic / organic halides described in JP-A-2-14145, S. Hayase et al., J. Polymer
Sci., 25, 753 (1987), E. Reichmanis et al., J. Pholimer S
ci., PolymerChem. Ed., 23, 1 (1985), QQZhu et al., J. Pho
tochem., 36, 85, 39, 317 (1987), B. Amit etal, Tetrahedro
n Lett., (24) 2205 (1973), DHR Barton et al., J. Chem So
c., 3571 (1965), PMCollins et al., J. Chem.SoC., Perkin
I, 1695 (1975), M. Rudinsteinetal, Tetrahedron Lett.,
(17), 1445 (1975), JWWalker etal J. Am. Chem. Soc., 11
0,7170 (1988), SCBusman et al., J. Imaging Technol., 1
1 (4), 191 (1985), HMHoulihan et al, Macormolecules, 2
1,2001 (1988), PMCollins et al., J. Chem. Soc., Chem. Com
mun., 532 (1972), S. Hayase et al, Macromolecules, 18, 179.
9 (1985), E. Reichmanis et al., J. Electrochem. Soc., Soli
d State Sci.Technol., 130 (6), FMHoulihan et al, Mac
romolcules, 21, 2001 (1988), European Patent No. 0290,750, ibid.
46,083, 156,535, 271,851, 0,388,343
No. 3,901,710, U.S. Pat.No. 4,181,531, JP-A-60-198538, JP-A-53-133022, etc.
etal, Polymer Preprints 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
Preprints, Japan, 37 (3), European Patent Nos. 0199,672 and 8451
No. 5, 199,672, 044,115, 0101, 122, U.S. Patent Nos. 618,564, 4,371,605, 4,431,774
No., JP-A-64-18143, JP-A-2-245756, Japanese Patent Application No. 3-14
Compounds that generate sulfonic acid upon photolysis, such as iminosulfonates described in JP-A-61-166.
And the disulfone compound described in JP-A-544.

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 above compounds which can be used together and which generate an acid by being decomposed by irradiation with actinic rays or radiation, those which are particularly effectively used are 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).

[0103]

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

[0105]

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[0106]

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[0107]

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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).

[0109]

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In the formula, Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. Here, 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,
And mercapto groups and halogen atoms.

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, and an alkyl group is an alkoxy group having 1 to 8 carbon atoms, a carboxyl group and an alkoxycarbonyl group. .

[0112] Z ^- represents a counter anion, CF ₃ SO ₃ ^-
And the like, such as perfluoroalkanesulfonic acid anions and pentafluorobenzenesulfonic acid anions. Also R
Two of ²⁰³ , R ²⁰⁴ and R ²⁰⁵ and Ar ¹ and Ar
² may be bonded via each single bond or a substituent. Specific examples include the following compounds, but are not limited thereto.

[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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The above onium salts represented by the general formulas (PAG3) and (PAG4) are known, for example, JWKnapcz
yk etal, J. Am. Chem. Soc., 91, 145 (1969), ALMaycoke
tal, J. Org.Chem., 35, 2532, (1970), E. Goethas et al, Bu
ll.Soc.Chem.Belg., 73,546, (1964), HM Leicester,
J. Ame. Chem. Soc., 51, 3587 (1929), JVCrivello etal,
J. Polym. Chem. Ed., 18,2677 (1980), U.S. Pat.
It can be synthesized by the methods described in JP-A Nos. 8 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).

[0122]

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In the formula, Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group. R ²⁰⁶ represents a substituted or unsubstituted alkyl group or aryl group. A represents a substituted or unsubstituted alkylene group, alkenylene group, or arylene group. Specific examples include the following compounds, but are not limited thereto.

[0124]

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[0125]

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[0126]

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[0127]

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[0128]

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The positive photoresist composition is suitable for the purpose of improving the alkali solubility of the system, or adjusting the glass transition temperature of the system to prevent the film from becoming brittle or 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 photoresist composition for deep ultraviolet exposure used in the present invention may further contain, if necessary, an acid-decomposable dissolution inhibiting compound, a dye, a plasticizer, a surfactant, a photosensitizer, and an organic basic compound. And a compound that promotes solubility in a developing solution.

The composition of the present invention is dissolved in a solvent in which each of the above components is dissolved, 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 solvents. 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 resulting chemically amplified resist composition solution is applied on a substrate. The substrate used here may be any substrate that is commonly used in semiconductor devices and other devices. Specifically, silicon,
Examples include an oxide film, polysilicon, a nitride film, and aluminum. These substrates may have circuits already created. These substrates may, in some cases,
In order to improve the adhesion with the resist composition, it is preferable to pre-treat with an adhesion promoter such as hexamethyldisilazane (HMDS). Alternatively, a substrate coated with an organic antireflection film as necessary may be used. Examples of the antireflection film include a DUV series manufactured by Brewer Science, but are not limited thereto.

The application of the resist composition solution can be performed by using a conventional coating apparatus such as a spin coater, a dip coater, a roller coater and the like. The thickness of the formed resist film can be appropriately set according to the use of the resist composition film and the like.
The range is 0 μm. Next, before the formed resist composition film is selectively exposed to actinic rays or radiation in a pattern, the temperature is about 80 to 165 ° C, preferably about 90 to 15 ° C.
Prebaking at a temperature of 5 ° C. for about 60 to 180 seconds is preferred. For this pre-bake, for example, a heating means such as a hot plate can be used.

A top coat film (protective film) may be further provided on the resist composition film. In this case,
For example, a top coat film can be formed by applying a solution of an olefin resin onto a resist film by spin coating and performing baking at a temperature of about 100 ° C. After pre-baking the resist composition film, the resist film is exposed to actinic rays or radiation in a pattern using a conventional exposure apparatus. Suitable exposure apparatuses are commercially available ultraviolet (far ultraviolet / vacuum ultraviolet) exposure apparatuses, X-ray exposure apparatuses, electron beam exposure apparatuses, excimer steppers, and the like. As the exposure condition, an appropriate condition can be selected each time.

Next, the exposed resist composition film was subjected to a post-exposure bake (PEB: Post) prior to the developing step.
Exposure Bake) is preferable. By the post-exposure bake, an acid-catalyzed elimination reaction of the protecting group can be caused. This post-exposure bake
This can be performed in the same manner as in the previous pre-bake. For example, the baking temperature is about 60 to 150 ° C, preferably about 10 ° C.
0-150 ° C. When a top coat film is used in combination, after the post-exposure bake and before the development, it is removed by, for example, an organic solvent.

After completion of the post-exposure bake, the exposed resist composition film is developed with an organic alkali aqueous solution in the presence of a surfactant. The surfactant may be contained in the developer in advance, or may be added to the developer before or during the development. In the present invention, as the surfactant, a surfactant having an alkyl group having 3 or more carbon atoms is preferable. Here, the alkyl group having 3 or more carbon atoms is preferably an alkyl group having 3 to 20 carbon atoms, for example, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a nonyl group. , Decyl, pentadecyl, octadecyl, eicosyl and the like. The alkyl group preferably has 3 to 16 carbon atoms, and more preferably 3 to 16 carbon atoms.
The alkyl group may be substituted with an optional substituent, if necessary.

In the present invention, the surfactant is a cation
Surfactant, anionic surfactant, zwitterionic field
Either a surfactant or a nonionic surfactant
You may. Two or more fields as required
A surfactant may be used in combination. The present invention is described below.
Examples of surfactants that can be suitably used in
Show. In the following general formula, R_a1Each
And represents an optional substituent, provided that at least
Also have at least three carbon atoms as described above.
A higher alkyl group;_a2Is three or more as described above.
Is a higher alkyl group having the above carbon atoms, and M is
X is a chlorine atom,
Iodine atom, fluorine atom, BF_Four , BF₆ , PF₆ , As
F₆ , SbF₆ , CF _Three SO_Three , ClO_Four Etc.
You. Cationic surfactant Pyridinium salt:

[0140]

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Alkylamine salt:

[0142]

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Quaternary ammonium salt:

[0144]

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Anionic Surfactant Alkylbenzene Sulfonate:

[0146]

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Higher alkyl sulfonates:

[0148]

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Higher fatty acid salts:

[0150]

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Alkyl phosphate:

[0152]

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Alkyl sulfate:

[0154]

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Alkyl naphthalene sulfonate:

[0156]

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Polyoxyethylene alkyl ether sulfate:

[0158]

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Zwitterionic surfactant Alkyl betaine:

[0160]

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Amino acid type:

[0162]

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Alkyl imidazoline derivative:

[0164]

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Nonionic surfactant Polyoxyethylene alkyl ether:

[0166]

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Fatty acid sorbitan:

[0168]

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Fatty acid glycerin:

[0170]

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Polyoxyethylene alkyl phenyl ether:

[0172]

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Fatty acid alkanolamides:

[0174]

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Fatty acid polyethylene glycol:

[0176]

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Other acetylene alcohols:

[0178]

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Polyoxyethylene polyoxypropylene alkyl ether:

[0180]

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In the present invention, the above formulas WXX and WX
The surfactant represented by XI is preferable in that the effect of the present invention becomes remarkable. In the above formulas WXX and WXXI,
m and n each represent a number of 1 or more, and their molecular weight is 50
A number such as 0 to 10000, preferably 1000 to 8000, more preferably 1500
~ 5000. As the organic alkali aqueous solution used as the developer, an alkali aqueous solution commonly used in this technical field can be used. For example, an ammonium compound of the following formula as a developer:

[0182]

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(In the above formula, R ₁ , R ₂ , R ₃ and R
₄ represents a hydrocarbon group which may have a substituent, and at least one of R _{1 to} R ₄ has 2 to 2 carbon atoms.
Represents six alkyl groups. ) A morpholine compound of the formula:

[0184]

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(In the above formula, R ¹ represents a hydrogen atom or an optional substituent such as an alkyl group such as an ethyl group) or a developer containing an aqueous solution or an alcohol solution of a mixture thereof is advantageously used. be able to. Preferred examples of the ammonium compound as a developer include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrabutylammonium hydroxide (TBAH),
Tetrapropylammonium hydroxide (TPA
H), and the like. Further, the morpholine compound includes ethyl morpholine represented by the following formula.

[0186]

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These developers are dissolved in water together with the above-mentioned surfactant, or dissolved in an alcohol such as methanol, ethanol, isopropyl alcohol or the like to form a developer. The order of adding the developer and the surfactant can be arbitrarily changed. The concentration of the dissolving developer is generally in the range of about 0.1 to 15% by weight, preferably about 0.
It is in the range of 1 to 10% by weight. The concentration of the surfactant is preferably about 0.01 to 1 molar equivalent, more preferably about 0.01 to 0.5 molar equivalent, with respect to the concentration of the organic alkali in the organic alkali aqueous solution. The development time is
Generally, it will be in the range of about 1-5 minutes, preferably in the range of about 1-3 minutes. As a result of development, the exposed area of the resist film is dissolved and removed, and a desired resist pattern can be obtained. Finally, the obtained resist pattern is also rinsed with pure water according to a conventional method, and dried.

By using the above-mentioned ammonium compound or morpholine compound as a developer for the chemically amplified resist, the compatibility with the resist resin and the solubility are controlled, and as a result of the relaxation of the stress generated during the development, Reduce peeling and cracking of resist film,
Stable patterning characteristics can be obtained.

[0189]

EXAMPLES Next, 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 Resin A A resin having the following structure was synthesized according to Synthesis Example 2 of European Patent Publication No. 0789278. GPC measurement of the obtained resin A showed that the weight average molecular weight in terms of standard polyhydroxystyrene was 33,000. Resin A

[0191]

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(2) Synthesis of Resin B Resin B having the following structure was synthesized according to Synthesis Example 5 of European Patent Publication No. 0789278. GPC of the obtained resin B
Upon measurement, the weight average molecular weight in terms of standard polyhydroxystyrene was 30,000. Resin B

[0193]

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Examples and Comparative Examples 1.4 g of each of the resins shown in Table 1 synthesized in the above synthesis examples were added to a photoacid generator (4-
(Hydroxynaphthyldimethylsulfonium triflate) 0.18 g, 1,5-diazabicyclo [4.3.
0] -5-Nonene (DBN) 10 mg, and each was dissolved in propylene glycol monoethyl ether acetate at a solid content of 14% by weight, and then filtered through a 0.1 μm microfilter to obtain a positive type for deep ultraviolet light exposure. A photoresist composition solution was prepared.

Comparative Example 1 A positive photoresist composition solution was prepared in the same manner as in Example 1 except that the following resin A-1 was used instead of the resin of Example 1 described above.

[0196]

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(Evaluation Test) The obtained positive photoresist composition solution was applied on a silicon wafer by using a spin coater, dried at 120 ° C. for 90 seconds, and dried at about 0.5 μm.
Was formed and exposed to an ArF excimer laser (stepper having a wavelength of 193 nm and NA = 0.55). Heat treatment after exposure at 130 ° C 9
This was carried out for 0 second, developed with a 2.38% aqueous solution of tetramethylammonium hydroxide containing each of the surfactants and the amounts thereof shown in Table 1 below, and rinsed with distilled water to obtain a resist pattern profile.

[Coarse / Dense Dependence]: 0.25 μm each in a line and space pattern (dense pattern) and an isolated line pattern (sparse pattern) having a line width of 0.25 μm.
The overlap range of the focus margin allowing m ± 10% was determined. The greater this range, the better the density dependency.

Table 1 shows the evaluation results.

[0200]

[Table 1]

W-1: Tetra n-butylammonium chloride W-2: Ammonium 1-butanesulfonate W-3: Lauryl betaine W-4: Polyoxyethylene lauryl ether W-5: Tetra n-propylammonium chloride

[0202]

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As is evident from the results shown in Table 1, all the comparative examples are inferior in the density dependence. On the other hand, when the method of the present invention was used, the density dependency was at a satisfactory level.
That is, it is suitable for lithography using far ultraviolet rays such as ArF excimer laser exposure.

[0204]

According to the pattern forming method of the present invention, it is particularly suitable for light in the wavelength region of 170 nm to 220 nm, has good dependency on density, has excellent sensitivity, and has few development defects. And a good resist pattern profile can be obtained.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yasumasa Kawabe 4000F, Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd. FA17 FA41 2H096 AA25 BA11 EA03 EA05 GA09 GA11 HA23

Claims (1)

[Claims] (1) a compound capable of generating an acid upon irradiation with actinic rays or radiation; and (b) a repeating unit represented by the following general formula [I] or a repeating unit represented by the following general formula [II] A step of applying a positive photoresist composition for deep ultraviolet exposure containing a resin that is decomposed by the action of an acid and has increased solubility in alkalis on a substrate,
Patterning the obtained photoresist composition film by actinic rays or radiation in a pattern, and developing the exposed photoresist composition film with an organic alkali aqueous solution in the presence of a surfactant. Forming method. Embedded image Embedded image In the formula, R _{1 to} R ₈ , R ₁ ′ to R ₈ ′ may be the same or different, a hydrogen atom, an alkyl group which may have a substituent,
A cyclic hydrocarbon group which may have a substituent, a halogen atom, a cyano group, and a group which decomposes under the action of an acid;
It represents a C (= O) -X-A -R 9. However, at least one of R _{1 to} R ₈ or R ₁ ′ to R ₈ ′ represents a group decomposed by the action of an acid. m / n; 1 / 9~9 / 1 m + n, m '+ n'; 10~100 m '; 0~100 n'; 0~100 X; oxygen atom, a sulfur _{atom, -NH -, - NHSO 2 -} ,
-NHSO ₂ NH- 2 divalent linking group selected _{from, R 9; -COOH, -COOR 10} '(R 10' represents one or the following lactone structure having the same meaning as R _10), - CN, hydroxyl, a substituted group An optionally substituted alkoxy group, -CO-
_{NH-R 10, -CO-NH} -SO 2 -R 10 or ## STR3 ## R ₁₀ ; an alkyl group which may have a substituent, a cyclic alkyl group which may have a substituent, R _{11 to} R ₁₈ ; each independently may have a hydrogen atom or a substituent An alkyl group, A; 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, or a urea group; Represents a combination of one or more groups, a, b;