JP2000194135A - 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 by 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 radiation or the like and the resin containing an alkali soluble group protected by at least one of groups containing alicyclic hydrocarbon structure expressed by formula I-III 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 exposure and development with an organic alkali aqueous solution. In the formula, R11 represents a methyl group, ethyl group or the like, Z represents an atomic group necessary for forming an alicyclic hydrocarbon group with carbon atom. Each of R12-R16 independently represents a 1-4C linear or branched alkyl group or an alicyclic hydrocarbon group.

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.

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

As described above, a resin containing an acid-decomposable group used for 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 hydrophobizing the resist, measures such as mixing an organic solvent such as isopropyl alcohol with the developing solution have been studied, and 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 is dependent on the density. 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.

[0015]

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.

[0016]

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.

(A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (b) a compound represented by the following general formula (pI):
Far-ultraviolet light containing a resin containing an alkali-soluble group protected by at least one of the groups containing an alicyclic hydrocarbon structure represented by (pVI), and decomposed by the action of an acid to increase the solubility in alkali. Applying a positive photoresist composition for exposure onto a substrate, exposing the resulting photoresist composition film in a pattern by actinic rays or radiation, and applying the exposed photoresist composition film to an interface. A method for forming a pattern, comprising a step of developing with an organic alkali aqueous solution in the presence of an activator.

[0018]

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In the general formulas (pI) to (pVI), R ₁₁ is
Represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group, and Z represents an atomic group necessary for forming an alicyclic hydrocarbon group together with a carbon atom. Represents 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 each independently represent a hydrogen atom, a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{17 to} R ₂₁ One represents an alicyclic hydrocarbon group. Also,
Either R ₁₉ or R ₂₁ represents a linear or branched alkyl group having 1 to 4 carbon atoms or an alicyclic hydrocarbon group. R ₂₂
To R ₂₅ each independently 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 alicyclic group; Represents a hydrocarbon group.

[0020]

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. (A) Compound that generates an acid upon irradiation with actinic rays or radiation (photoacid generator) The (A) photoacid generator used in the present invention is a compound that generates an acid upon irradiation with actinic rays or radiation. Examples of the compound used in the present invention, which decomposes upon irradiation with actinic rays or radiation to generate an acid, include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, and a photodiscoloration agent. Known light (ultraviolet light of 400 to 200 nm, far ultraviolet light, particularly preferably g-ray, h-ray, i-ray, KrF excimer laser light), ArF excimer laser light, electron beam , X-ray,
A compound that generates an acid by a molecular beam or an ion beam and a mixture thereof can be appropriately selected and used.

Other compounds that generate an acid upon irradiation with actinic rays or radiation used in the present invention include, for example, SI Schlesinger, Photogr. Sci. Eng., 18, 3
87 (1974), diazonium salts described in TSBal et al, Polymer, 21, 423 (1980), and the like, U.S. Pat.Nos. 4,069,055 and 4,069.
No. 69,056, Re 27,992, ammonium salts described in JP-A-3-140140, etc., DCNecker et al, Macromolecules,
17,2468 (1984), CSWen et al, Teh, Proc.Conf.Rad.Cu
ring ASIA, p478 Tokyo, Oct (1988), U.S. Pat.No.4,069,0
No. 55, No. 4,069,056, phosphonium salts described in JV
Crivello et al, Macromorecules, 10 (6), 1307 (1977), Ch
em. & Eng.News, Nov. 28, p31 (1988), EP 104,143.
No., U.S. Pat.No. 339,049, No. 410,201, JP-A 2-15
0,848, iodonium salts described in JP-A-2-296,514 and the like, JVCrivello et al, Polymer J. 17, 73 (1985), J.
V. Crivello et al. J. Org. Chem., 43, 3055 (1978), WRWa
tt et al, J. Polymer Sci., Polymer Chem. Ed., 22, 1789 (1
984), JVCrivello etal, Polymer Bull., 14,279 (198
5), JVCrivello et al, Macromorecules, 14 (5), 1141 (1
981), JVCrivello et al, J. PolymerSci., Polymer Ch
em.Ed., 17,2877 (1979), European Patent Nos. 370,693, 161,
811, 410,201, 339,049, 233,567, 29
No. 7,443, No. 297,442, U.S. Pat.No. 3,902,114 No. 4,93
3,377, 4,760,013, 4,734,444, 2,833,827
No. 2,904,626, 3,604,580, 3,604,
No. 581, JP-A-7-28237, JP-A-8-27102, etc., sulfonium salts described in JVCrivello et al, Macro
morecules, 10 (6), 1307 (1977), JVCrivello et al, J.
Selenonium salts described in PolymerSci., Polymer Chem.Ed., 17, 1047 (1979), etc., CSWen et al, Teh, Proc. Conf. Ra.
d.Curing ASIA, p478 Tokyo, Oct (1988) Onium salts such as arsonium salts described in U.S. Pat.No. 3,905,815,
JP-B-46-4605, JP-A-48-36281, JP-A-55-32070
No., JP-A-60-239736, JP-A-61-169835, JP-A-61-169835
-169837, JP-A-62-58241, JP-A-62-212401, JP-A-63-70243, and organic halogen compounds described in JP-A-63-298339, K. Meier et al, J .Rad.Curing, 13 (4), 26
(1986), TPGill et al, Inorg.Chem., 19, 3007 (198
0), D. Astruc, Acc.Chem.Res., 19 (12), 377 (1896), organometallics / organic halides described in JP-A-2-14145 and the like,
S. Hayase et al, J. Polymer Sci., 25, 753 (1987), E. Reich
manis et al, J.Pholymer Sci., Polymer Chem.Ed., 23,1
(1985), QQZhu et al, J. Photochem., 36, 85, 39, 317 (198
7), B. Amit et al, Tetrahedron Lett., (24) 2205 (1973),
DHR Barton et al, J. Chem Soc., 3571 (1965), PMColl
inset al, J. Chem.SoC., Perkin I, 1695 (1975), M. Rudins
tein etal, Tetrahedron Lett., (17), 1445 (1975), JWWa
lker etal J. Am. Chem. Soc., 110, 7170 (1988), SCBusman
et al, J. Imaging Technol., 11 (4), 191 (1985), HMHouli
han et al, Macormolecules, 21, 2001 (1988), PMCollin
s et al, J. Chem. Soc., Chem. Commun., 532 (1972), S. Hayas
e et al, Macromolecules, 18, 1799 (1985), E. Reichman et.
al, J.Electrochem.Soc., Solid State Sci.Technol., 13
0 (6), FMHoulihan et al, Macromolcules, 21, 2001 (198
8), European Patent Nos. 0290,750, 046,083, 156,535
No. 271,851, No. 0,388,343, U.S. Pat.No. 3,901,71
No. 0, 4,181,531, JP-A-60-198538, JP-A-53-13
No. 3022, etc., a photoacid generator having a 0-nitrobenzyl-type protecting group, M. TUNOOKA et al, Polymer Preprints Japa
n, 35 (8), G. Berner et al, J. Rad. Curing, 13 (4), WJMij
s et al, Coating Technol., 55 (697), 45 (1983), Akzo, H.
Adachi et al, Polymer Preprints, Japan, 37 (3), European Patent Nos. 0199,672, 84515, 044,115, 618,564
No. 0101122, U.S. Pat.Nos. 4,371,605, 4,431,7
No. 74, JP-A-64-18143, JP-A-2-245756, JP-A-3
Compounds which generate sulfonic acid upon photolysis, such as iminosulfonate described in JP-A-140109, etc.
And disulfone compounds described in JP-A-2-71270, JP-A-3-103854 and JP-A-3-103.
No. 856, No. 4-210960, and the like.

A group that generates an acid by the light;
Alternatively, a compound having a compound introduced into the main chain or side chain of a polymer, for example, MEWoodhouse et al, J. Am. Chem.
c., 104, 5586 (1982), SPPappas et al, J. Imaging Sc
i., 30 (5), 218 (1986), S. Kondo et al., Makromol.Chem., Ra.
pid Commun., 9,625 (1988), Y.Yamada et al, Makromol.
Chem., 152, 153, 163 (1972), JVCrivello et al, J. Poly
merSci., Polymer Chem. Ed., 17,3845 (1979), U.S. Pat.No. 3,849,137, German Patent 3914407, JP-A-63-26653
No., JP-A-55-164824, JP-A-62-69263, JP-A-63-69
Compounds described in JP-A No. 146038, JP-A-63-163452, JP-A-62-153853, 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),
Compounds that generate an acid by light described in DHR Barton et al, J. Chem. Soc., (C), 329 (1970), U.S. Pat. No. 3,779,778, and EP 126,712 can also be used.

Among the compounds capable of decomposing upon irradiation with actinic rays or radiation to generate an acid, those 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 (PAG)
An S-triazine derivative represented by 2).

[0025]

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

[0027]

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[0028]

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[0029]

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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).

[0031]

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

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

[0034] Z ^- represents a counter anion, for example BF ₄ ^{-,
_{AsF 6 -, PF 6 -,}} SbF 6 -, SiF 6 2-, ClO 4 -,
CF ₃ SO ₃ ^-, etc. perfluoroalkane sulfonate anion, pentafluorobenzenesulfonic acid anion, condensed polynuclear aromatic sulfonic acid anion such as naphthalene-1-sulfonic acid anion, anthraquinone sulfonic acid anion, a sulfonic acid group-containing dyes Examples include, but are not limited to:

Further, two of R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ and Ar ¹ and Ar ² may be bonded through a single bond or a substituent.

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

[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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[0044]

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[0045]

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[0046]

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[0047]

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[0048]

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[0049]

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

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

[0052]

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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.

[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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The amount of the compound (a) which decomposes upon irradiation with actinic rays or radiation to generate an acid is usually 0.02% based on the total weight of the composition (excluding the coating solvent).
It is used in the range of 0.01 to 40% by weight, preferably 0.0
It is used in an amount of 1 to 20% by weight, more preferably 0.1 to 5% by weight. (A) The amount of the compound that decomposes upon irradiation with actinic rays or radiation to generate an acid is 0.001.
If the amount is less than 10% by weight, the sensitivity is lowered, and the amount of
If the content is more than 10% by weight, the light absorption of the resist becomes too high, and the profile is deteriorated and the process (especially baking) margin is undesirably reduced.

Resin which decomposes under the action of (b) acid to increase solubility in alkali The resin used in the composition of the present invention which decomposes under the action of (b) acid to increase solubility in alkali (hereinafter simply referred to as " (Also called "(b) alkali-soluble resin")
Contains an alkali-soluble group protected by at least one of groups having an alicyclic hydrocarbon structure represented by the above general formulas (pI) to (pVI).

In the general formulas (pI) to (pVI), R
The alkyl group for _{12 to} R ₂₅ represents a substituted or unsubstituted linear 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, and an n-
Examples thereof include a butyl group, an isobutyl group, a sec-butyl group and a t-butyl group. Further, as a further substituent of the alkyl group, an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an acyl group, an acyloxy group, a cyano group, a hydroxyl group, Examples include a carboxy group, an alkoxycarbonyl group, and a nitro group.

The alicyclic hydrocarbon group for 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.

[0064]

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[0065]

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[0066]

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Preferred examples of the alicyclic moiety include:
Adamantyl group, noradamantyl group, decalin residue,
Tricyclodecanyl group, tetracyclododecanyl group, norbornyl group, cedrol group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecanyl group,
A cyclododecanyl group can be mentioned. 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. As the alkyl group, a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group is preferable, and a methyl group, an ethyl group, a propyl group, and an isopropyl group are more preferable. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group.

Examples of the alkali-soluble group protected by the structure represented by formulas (pI) to (pVI) in the above (ii) alkali-soluble resin include various groups known in this technical field. Specifically, a carboxylic acid group,
Examples thereof include a sulfonic acid group, a phenol group, and a thiol group, and preferred are a carboxylic acid group and a sulfonic acid group. As the alkali-soluble group protected by the structure represented by any of the general formulas (pI) to (pVI) in the above resin, preferably, groups represented by the following general formulas (pVII) to (pXI) are exemplified.

[0070]

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Here, R _{11 to} R ₂₅ and Z are the same as defined above.

(B) The alkali-soluble resin has an alkali-soluble group protected by the structure represented by any of the above formulas (pI) to (pVI), but contains a repeating unit structure represented by the following formula (pA) Is preferred.

[0073]

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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 'represents a single bond, an alkylene group, a substituted alkylene group, an ether group, a thioether group, a carbonyl group or an ester group, or a single or a combination of two or more groups.
Ra represents a group represented by any of the above formulas (pI) to (pVI). Hereinafter, specific examples of the monomer corresponding to the repeating unit represented by the general formula (pA) are shown.

[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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[0080]

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Further, (ii) the alkali-soluble resin preferably contains a group which is decomposed by the action of an acid represented by the following general formula (A). Formula (A): —C (＝ O) —O—R _{0 In the} formula (A), R ₀ is a tertiary alkyl group, a 1-alkoxyethyl group, an alkoxymethyl group, a tetrahydropyranyl group, or a tetrahydrofuranyl group. , A trialkylsilyl group,
Represents a 3-oxocyclohexyl group or a lactone group.

(B) The alkali-soluble resin may contain other repeating units in addition to the repeating unit having an alkali-soluble group protected by the structure represented by the above general formulas (pI) to (pVI). Such another repeating unit is preferably a repeating unit represented by the following general formula (AI).

[0083]

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In the general formula (AI), R represents the above-mentioned general formula (p
It is synonymous with case A). B is a halogen atom, a cyano group, a group decomposed by the action of an acid, -C (= O) -YA
Represents -R _C9 or -COOR _C11 . Here, Y represents an oxygen atom or a sulfur atom. R _C9 : —COOH, —COOR _C10 (R _C10 has the same _meaning as R _C11 and the following lactone structure), —C
N, a hydroxyl group, an alkoxy group which may have a substituent,
—CO—NH—R _C11 or the following lactone structure.

R _C11 represents an alkyl group which may have a substituent or a cyclic hydrocarbon group which may have a substituent. A: represents one or a combination of two or more groups 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 and an ester group.

[0086]

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R ^a , R ^b , and R ^c of the lactone structure are
Represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms which may have a substituent, and n is an integer of 2 to 4. The group decomposed by the action of an acid in B in the above general formula (AI) is preferably -C (= O)-
It is a group represented by X ₁ -R ₀ . Here, as R ₀ ,
Tertiary alkyl groups such as t-butyl group and t-amyl group, 1-alkoxyethyl groups such as isobornyl group, 1-ethoxyethyl group, 1-butoxyethyl group, 1-isobutoxyethyl group and 1-cyclohexyloxyethyl group Groups, an alkoxymethyl group such as a 1-methoxymethyl group and a 1-ethoxymethyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, a trialkylsilyl group, and a 3-oxocyclohexyl group. X ₁ represents an oxygen atom, a sulfur atom, or —NH—, and is preferably an oxygen atom.

As the alkyl group for R _C11 ,
A linear or branched alkyl group having 1 to 10 carbon atoms is preferable, a linear or branched alkyl group having 1 to 6 carbon atoms is more preferable, and a methyl group, an ethyl group, and a propyl group are more preferable. Isopropyl group, n-butyl group, isobutyl group, sec-butyl group and t-butyl group.

Examples of the cyclic hydrocarbon group for R _C11 include 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, and a tricyclodecanyl group. Group, dicyclopentenyl group, nobornane epoxy group, menthyl group, isomenthyl group, neomenthyl group, tetracyclododecanyl group and the like.

The alkoxy group for R _C9 includes:
Examples thereof include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy 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.

In the above formulas (AI) and (pA), examples of the alkylene group and the substituted alkylene group represented by A ′ include groups represented by the following formulas. -[C (Ra) (Rb)] r- wherein Ra and Rb represent a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, or an alkoxy group, and they may be the same or different; The 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 represents a substituent selected from the group consisting of a methyl group, an ethyl group, a propyl group and an isopropyl group. . Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. 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, examples of the halogen atom include a chlorine atom, a bromine atom, a fluorine atom, and an iodine atom. As B, an acid-decomposable group and a mevalonic lactone group are preferred.

The (b) alkali-soluble resin of the present invention is such that the copolymerization component such as the repeating unit represented by the general formula (AI) is protected by the structure represented by the general formulas (pI) to (pVI). It preferably contains an acid-decomposable group other than the 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.

(B) In addition to the above, the alkali-soluble resin adjusts dry etching resistance, suitability for a standard developer, substrate adhesion, resist profile, and resolution, heat resistance, sensitivity, etc., which are the general requirements of a resist. It can be used as a copolymer with various monomer repeating units for the purpose.

Examples of such a repeating unit 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. 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 such as alkyl (preferably having 1 to 10 carbon atoms in the alkyl group) methacrylate (eg, 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 such as 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; other acrylic acid, methacrylic acid, croton Acid, itaconic acid, maleic anhydride, maleimide, acrylonitrile,
Examples thereof include methacrylonitrile and maleilenitrile. In addition, any addition-polymerizable unsaturated compound copolymerizable with the above various repeating units may be used.

(B) In the alkali-soluble resin, the molar ratio of each repeating unit structure depends on the dry etching resistance of the resist, the suitability for the standard developer, the substrate adhesion, the resist profile, and the resolution generally required for the resist. It is set as appropriate to adjust heat resistance, sensitivity and the like.

(B) In the alkali-soluble resin, the compound represented by the general formula (p
The content of the repeating unit having an alkali-soluble group protected by the structure represented by I) to (pVI) is 30 to 70 mol% of all the repeating units, preferably 35 to 65 mol%.
Mol%, more preferably 40 to 60 mol%. In addition, in the (b) alkali-soluble resin, a compound represented by the general formula (pI):
The content of the repeating unit containing an acid-decomposable group other than the alkali-soluble group protected by the structure represented by (pVI) is 65 mol% or less in all monomer repeating units, and is preferably 3 to 60%. Mol%, more preferably 5 to 55 mol%. The acid value of the (b) alkali-soluble resin is
Expressing the amount of acid groups per 1 g of resin in milliequivalents / g,
It is preferably at most 1.5, more preferably at most 1.2, even more preferably at most 1.0, and the molar ratio of each repeating unit structure is preferably adjusted so that the acid value falls within this range. This acid value correlates with the content of an acid value such as a carboxy group that provides adhesion. The acid value was determined by adding about 1 g of the resin to tetrahydrofuran / ion-exchanged water (54 mL / 6 m
It is measured by dissolving in the mixed solvent of L) and titrating with an aqueous sodium hydroxide solution.

The content of the repeating unit based on the monomer of the further copolymerization component in the resin can be appropriately set according to the desired performance of the resist. It is preferably at most 99 mol%, more preferably at most 90 mol%, based on the total number of moles of the repeating unit containing an alkali-soluble group protected by a group having an alicyclic hydrocarbon structure represented by (pI) to (pVI). Mol% or less, more preferably 80 mol% or less.

(B) The weight average molecular weight Mw of the alkali-soluble resin is preferably in the range of 1,000 to 1,000 by gel permeation chromatography based on polystyrene standards.
1,000,000, more preferably 1,500 to 50
000, more preferably 2,000 to 200,00.
0, particularly preferably in the range of 2,500 to 100,000, and the larger the weight average molecular weight, the higher the heat resistance and the like, while the lower the developability and the like. .

The (b) alkali-soluble resin used in the present invention can be synthesized according to a conventional method, for example, by a radical polymerization method.

In the positive photoresist composition used in the present invention, the amount of the acid-decomposable resin added to the whole composition is as follows.
It is preferably from 40 to 99.99% by weight, more preferably from 50 to 99.97% by weight, based on the total resist solids.

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 that dissolves the above-mentioned components, and applied on a support. As the solvent used here, ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ-butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate , Propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, 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-mentioned 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 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 carried out 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 is 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. Here, 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 1 carbon atoms.
There are eight, more preferably three to sixteen. The alkyl group may be substituted with an optional substituent, if necessary.

In the present invention, the surfactant is a cationic
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:

[0120]

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Alkylamine salt:

[0122]

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Quaternary ammonium salt:

[0124]

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Anionic surfactant alkyl benzene sulfonate:

[0126]

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Higher alkyl sulfonates:

[0128]

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Higher fatty acid salts:

[0130]

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Alkyl phosphate:

[0132]

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Alkyl sulfate:

[0134]

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Alkyl naphthalene sulfonate:

[0136]

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Polyoxyethylene alkyl ether sulfate:

[0138]

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Zwitterionic surfactant Alkyl betaine:

[0140]

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Amino acid type:

[0142]

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Alkyl imidazoline derivative:

[0144]

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Nonionic surfactant Polyoxyethylene alkyl ether:

[0146]

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The fatty acid sorbitan:

[0148]

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Fatty acid glycerin:

[0150]

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Polyoxyethylene alkyl phenyl ether:

[0152]

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Fatty acid alkanolamides:

[0154]

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Fatty acid polyethylene glycol:

[0156]

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Other acetylene alcohols:

[0158]

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Polyoxyethylene polyoxypropylene alkyl ether:

[0160]

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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:

[0162]

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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:

[0164]

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(In the above formula, R ¹ represents a hydrogen atom or an optional substituent, for example, an alkyl group, for example, 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.

[0166]

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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 development, Reduce peeling and cracking of resist film,
Stable patterning characteristics can be obtained.

[0169]

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 (Photoacid generator (PAG4-35)
Synthesis of 50 g of diphenyl sulfoxide in 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 is collected by filtration and washed with water,
After washing with ethyl acetate and drying, sulfonium iodide 7
2 g were 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 filtering the reaction solution, salt exchange was performed with potassium heptadecafluorooctanesulfonate to recover 40 g of the desired product (PAG4-35).

Synthetic Examples of Resins (1) Synthesis of Resin (I) Having the Following Structure 2-methyl-2-adamantyl methacrylate and 3-oxocyclohexyl methacrylate were charged at a ratio of 47/53, and N, N-dimethylacetamide / tetrahydrofuran was used. Dissolved in 8/2 mixed solvent, solid content concentration 20%
A 100 mL solution was prepared. This solution was added to Wako Pure Chemical V-
65 ml was added thereto, and this was added dropwise to 10 mL of tetrahydrofuran heated to 60 ° C. over 3 hours under a nitrogen atmosphere. After completion of the dropwise addition, the reaction solution was heated and stirred for 6 hours. After completion of the reaction, the reaction solution was cooled to room temperature, and white powder precipitated and precipitated in 3 L of methanol was recovered. The polymer composition ratio determined from C ¹³ NMR was 46/54. Also, GPC
The weight average molecular weight in terms of standard polystyrene determined by the measurement was 7,300.

(2) Resins (II) to (IX) having the following structures
In the synthesis of the resin (I), the resins (II) to (II) to ( I
X) was synthesized. The weight average molecular weight is shown in Table 1.

[0173]

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[0174]

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[0175]

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[0176]

[Table 1]

Examples and Comparative Examples Each of the resins shown in Table 2 synthesized in the above synthesis examples was 1.4.
g, a photoacid generator 0.18 g, and 1,5-diazabicyclo [4.3.0] -5-nonene (DBN) 10 mg, each of which was mixed with propylene glycol monoethyl ether acetate at a solid content of 14% by weight. After dissolving,
The solution was filtered through a 0.1 μm microfilter to prepare a positive photoresist composition solution for deep ultraviolet exposure. In Table 2 below, PAG-1 represents triphenylsulfonium triflate, and PAG-2 was synthesized as described above (PA
G4-35).

Comparative Example 1 A positive photoresist composition solution was prepared in the same manner as in Example 1 except that the following resin r1 was used instead of the resin of Example 1 described above.

[0179]

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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 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 seconds, developed with a 2.38% aqueous solution of tetramethylammonium hydroxide containing each of the surfactants and the amounts thereof shown in Table 2 below, and rinsed with distilled water to obtain a resist pattern profile.

[Dependency on Coarse / Dense]: 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 2 shows the evaluation results.

[0183]

[Table 2]

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

[0185]

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As is evident from the results in Table 2, all of 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.

[0187]

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 on the front page (72) Inventor Yasumasa Kawabe 4000F Kawashimajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd. CB41 FA17 FA41 2H096 AA25 BA11 EA03 EA05 GA09 GA11 HA23

Claims (1)

[Claims] 1. A compound which generates an acid upon irradiation with an actinic ray or radiation, and (b) a compound represented by the following general formula (pI):
To (pVI), a resin containing an alkali-soluble group protected by at least one of the groups having an alicyclic hydrocarbon structure and containing a resin which is decomposed by the action of an acid to increase the solubility in alkali. A step of applying a positive photoresist composition for ultraviolet exposure on a substrate, a step of exposing the resulting photoresist composition film in a pattern by actinic rays or radiation, and the exposed photoresist composition film, A pattern forming method comprising a step of developing with an organic alkali aqueous solution in the presence of a surfactant. Embedded image In the general formulas (pI) to (pVI), R ₁₁ represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group;
It represents an atomic group necessary for forming an alicyclic hydrocarbon group together with a carbon atom. R _{12 to} R ₁₆ each independently have 1 carbon atom
Represents up to four linear or branched alkyl groups or alicyclic hydrocarbon groups, provided that at least one of R _{12 to} R ₁₄
Or one of R ₁₅ and R ₁₆ represents an alicyclic hydrocarbon group. R _{17 to} R ₂₁ each independently represent a hydrogen atom, a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms, provided that at least one of R _{17 to} R ₂₁ One 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.