JP2001188348A - Positive photoresist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive photoresist composition having high resolving power in the production of a semiconductor device, having evaluation with the same light exposure near the margin of resolution by which the size in which a nondense pattern vanishes and the marginal resolution size of a dense pattern show approximate values closer to each other and ensuring low surface roughness of a line pattern. SOLUTION: The positive photoresist composition contains a resin containing repeating units with a specified structure and having solubility to an alkali developing solution increased by the action of an acid, a compound which generates the acid when irradiated with active light or radiation and an organic solvent which dissolves the above components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photoresist composition used for manufacturing semiconductor integrated circuit elements, masks for manufacturing integrated circuits, printed wiring boards, liquid crystal panels, and the like.

[0002]

2. Description of the Related Art As a pattern forming method for manufacturing electronic components such as a semiconductor device, a magnetic bubble memory, and an integrated circuit, a method utilizing a photoresist which is sensitive to ultraviolet light or visible light has been widely used. Have been. There are two types of photoresist: a negative type, in which the irradiated part is insoluble in the developer by light irradiation, and a positive type, in which the exposed part is solubilized.The negative type has higher sensitivity than the positive type and is necessary for wet etching. Until recently, photoresists occupied the mainstream because of their excellent adhesion to substrates and chemical resistance.

However, with the increase in density and integration of semiconductor devices and the like, the line width and spacing of patterns have become extremely small.
In addition, since dry etching has been adopted for etching the substrate, photoresists have been desired to have high resolution and high dry etching resistance,
At present, positive photoresists occupy the majority. Further, in recent years, as electronic devices have become multifunctional and sophisticated, there has been a strong demand for finer patterns to achieve higher density and higher integration.

That is, since the vertical dimension of the integrated circuit is not much reduced as compared with the horizontal dimension of the integrated circuit, the ratio of the height to the width of the resist pattern has to be increased. For this reason, it has become more difficult to suppress the dimensional change of the resist pattern on a wafer having a complicated step structure as the pattern becomes finer. Further, in various types of exposure methods, there is a problem with the reduction of the minimum size. For example,
In light exposure, the interference effect of reflected light due to the step of the substrate has a great effect on dimensional accuracy, whereas in electron beam exposure, the proximity effect caused by backscattering of electrons causes the fine resist pattern The height to width ratio can no longer be increased.

It has been found that many of these problems are eliminated by using a multilayer resist system. For a description of multilayer resist systems, see Solid State Technology, 74 (1981) [Solid State Technolog
y, 74 (1981)], but many other studies on this system have been published. Generally, a multilayer resist method includes a three-layer resist method and a two-layer resist method. In the three-layer resist method, an organic flattening film is applied on a stepped substrate, an inorganic intermediate layer and a resist are stacked thereon, and the resist is patterned. Then, the inorganic intermediate layer is dry-etched using the resist as a mask. This is a method of patterning an organic flattening film by O2 RIE (reactive ion etching) using the inorganic intermediate layer as a mask. Basically, this method has been studied from an early stage because conventional techniques can be used, but the process is very complicated, or the organic film, the inorganic film, and the organic film have different three-layer physical properties. The problem is that cracks and pinholes are likely to occur in the intermediate layer due to the overlapping of the objects.

In contrast to the three-layer resist method, the two-layer resist method uses a resist having both properties of the resist and the inorganic intermediate layer in the three-layer resist method, that is, a resist having oxygen plasma resistance. In addition, the generation of cracks and pinholes is suppressed, and the process is simplified because the number of layers is reduced from three to two. However, in the three-layer resist method, a conventional resist can be used as the upper resist, whereas in the two-layer resist method, there is a problem that a new resist having oxygen plasma resistance has to be developed.

[0007] From the above background, it has excellent oxygen plasma resistance which can be used as an upper layer resist such as a two-layer resist method.
There has been a demand for the development of a high-sensitivity, high-resolution positive photoresist, in particular, an alkali developing type resist that can be used without changing the current process.

Further, in the manufacture of VLSI, which requires processing of an ultrafine pattern having a line width of half a micron or less, the wavelength used by an exposure apparatus used for lithography has been shortened, and now a KrF excimer laser beam is used. The use of ArF excimer laser light has been studied. In such short wavelength optical lithography, a resist generally called a chemically amplified type is used. In particular, when an ArF excimer laser beam is used, it is not appropriate to introduce a phenol structure into a binder resin, which is a main component of the resist, from the viewpoint of optical transparency of the film. In general, a resin polymer containing, as an image-forming portion, a structure capable of decomposing with an acid to generate a carboxylic acid, such as an ester, a 1-alkyladamantyl ester, or a THP-protected carboxylic acid, is used as a binder.

As an example of a Si-containing resist containing an image-forming portion transparent to ArF excimer laser light, maleic anhydride-unsaturated carboxylic acid t-butyl ester-
A terpolymer comprising allyltrimethylsilane is disclosed in JP-A-5-11450. Although this resist is excellent in resolution of a dense line / space pattern for processing an ultrafine pattern, there is a problem that a sparse pattern is easily lost around the resolution limit. Further, there is a problem that the surface roughness (surface roughness) of the line pattern is large.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor device having a high resolution and a size at which a sparse pattern disappears at the same exposure dose evaluation around the resolution limit. It is an object of the present invention to provide a positive photoresist composition in which the critical resolution dimension of a dense pattern shows a closer approximation. Another object of the present invention is to provide a positive photoresist composition having a small surface roughness of a line pattern.

[0011]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on a resist composition in a positive-type chemical amplification system and found that an acid-decomposable resin copolymerized with a specific repeating unit and a specific additive were used. Have achieved the object of the present invention. That is, the present invention is the following positive photoresist composition.

(1) A positive photoresist composition containing at least the following (A) to (C): (A) a repeating unit represented by the following general formula (I), a repeating unit represented by the following general formula (II), and a repeating unit represented by the following general formula (III), (B) a compound capable of generating an acid upon irradiation with actinic rays or radiation; (C) an organic solvent capable of dissolving the above (A) and (B);

[0013]

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In the formula (I), R ^{1 to} R ³ each independently represent an alkyl group, a haloalkyl group, a halogen atom, an alkoxy group, a trialkylsilyl group or a trialkylsilyloxy group. n represents 0 or 1. General formula (II)

[0015]

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In the formula (II), Y represents a hydrogen atom, a methyl group, a cyano group or a chlorine atom. L represents a single bond or a divalent linking group. Q represents a tertiary alkyl group having 5 to 20 carbon atoms, or an alkoxymethyl group, an alkoxyethyl group, or an isobornyl group. General formula (III)

[0017]

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In the formula (III), Z represents an oxygen atom or —N (R ³ )
Represents-. R ³ represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group, or —O—SO ₂ —R ⁴ . R ⁴
Represents an alkyl group or a trihalomethyl group.

(2) n in the general formula (I) is 1
The positive photoresist composition according to the above (1), wherein (3) The positive photoresist composition according to (1) or (2), wherein the component (B) is a compound that generates an organic sulfonic acid upon irradiation with actinic rays or radiation. (4) The positive photoresist composition according to the above (3), wherein the component (B) is a sulfonium salt or iodonium salt compound which generates an organic sulfonic acid upon irradiation with actinic rays or radiation.

In the present invention, the rectangularity and line edge roughness of the pattern are improved by using an organic basic compound and a specific surfactant together with a silicon-containing acid-decomposable resin having a specific repeating unit. . Although the mechanism is not clear, the organic basic compound and the specific surfactant cooperate to work, and the acid-decomposable group decomposition rate of the acid-decomposable resin in the area corresponding to the line side wall and the edge portion, and It is presumed that the resulting developer solubility was controlled.

[0021]

First, the resin (A) of the present invention will be described. In the repeating structural unit (I), R ^{1 to} R
³ represents a group independently selected from an alkyl group, a haloalkyl group, a halogen atom, an alkoxy group, a trialkylsilyl group, and a trialkylsilyloxy group. The alkyl group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms.
And more preferably a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, an s-butyl group, a t-
It is a butyl group. Examples of the haloalkyl group include a chloromethyl group, a bromomethyl group, and an iodomethyl group.

The alkoxy group is a linear or branched alkoxy group having 1 to 6 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propyloxy group, an i-propyloxy group, an n-butoxy group, i-butoxy group, s
-Butoxy group and t-butoxy group, particularly preferred are methoxy and ethoxy groups.

The alkyl group of the trialkylsilyl is a linear or branched alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an n-propyl group, or an i-alkyl group.
-Propyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, and most preferred is a methyl group. The alkyl group of the trialkylsilyloxy group is a linear or branched alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, i-butyl group, s
-Butyl group and t-butyl group, and among them, the most preferred is a methyl group. n represents 0 or 1, and is preferably 1. Thereby, the edge roughness is further improved.

The following are specific examples of the repeating unit represented by the above general formula (I), but the present invention is not limited to these specific examples.

[0025]

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In the repeating unit (II), Y represents a group selected from a hydrogen atom, a methyl group, a cyano group and a chlorine atom. L represents a single bond or a divalent linking group. Q represents a tertiary alkyl group having 5 to 20 carbon atoms, or an alkoxymethyl group, an alkoxyethyl group, or an isobornyl group. Specific examples of such a group include a tertiary alkyl group such as a t-amyl group, an isobornyl group, a 1-ethoxyethyl group, a 1-butoxyethyl group, a 1-isobutoxyethyl group, and a 1-cyclohexyloxyethyl group. And the like, an alkoxymethyl group such as a 1-alkoxyethyl group, a 1-methoxymethyl group and a 1-ethoxymethyl group, a 3-oxocyclohexyl group, and a 2-methyl-adamantyl group.

Further, as the tertiary alkyl group having 3 to 20 carbon atoms represented by Q, the following formula (pI) or (pI
The groups represented by I) are preferred.

[0028]

Embedded image (Wherein, 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, and Z represents an alicyclic hydrocarbon group together with a carbon atom. Represents an atomic group necessary for forming R ₁₂
To R ₁₄ each independently represent a linear or branched alkyl group or an alicyclic hydrocarbon group having 1 to 4 carbon atoms, and examples of the alkyl group include a methyl group, an ethyl group, and an n-
Examples include a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a t-butyl group. Further, as a further substituent of the alkyl group, an alkoxy group having 1 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an acyl group, an acyloxy group, a cyano group, a hydroxyl group, Examples include a carboxy group, an alkoxycarbonyl group, and a nitro group.

The alicyclic hydrocarbon group represented by R _{12 to} R _{14 or} the alicyclic hydrocarbon group formed by Z and a carbon atom may be monocyclic or polycyclic. Specific examples include groups having a monocyclo, bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms. 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.

[0030]

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[0031]

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[0032]

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In the present invention, preferred examples of the alicyclic moiety include an adamantyl group, a noradamantyl group, a decalin residue, a tricyclodecanyl group, a tetracyclododecanyl group, a norbornyl group, a cedrol group, and a cyclohexyl group. , Cycloheptyl group, cyclooctyl group,
Examples thereof include a cyclodecanyl group and a cyclododecanyl group. More preferred are an adamantyl group, a decalin residue, a norbornyl group, a cedrol group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, and a cyclododecanyl group.

Examples of the substituent of these alicyclic hydrocarbon groups include an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, a carboxyl group and an alkoxycarbonyl group. The alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group and a butyl group, and more preferably a methyl group, an ethyl group, a propyl group, and a substituent selected from the group consisting of an isopropyl group. Represent. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group.

Specific examples of the repeating unit represented by the general formula (IIa) include the following, but the present invention is not limited to these specific examples.

[0036]

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[0037]

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In the repeating unit (III), Z represents an oxygen atom, NR ³ . R ³ represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group, or —O—SO ₂ —R ⁴
Represents R ⁴ represents an alkyl group or a trihalomethyl group.
The alkyl group of R ³ and R ⁴ is preferably a straight-chain or branched alkyl group having 1 to 10 carbon atoms, more preferably a straight-chain or branched alkyl group having 1 to 6 carbon atoms, and further preferably methyl Group, ethyl group, n-propyl group, i-
Propyl group, n-butyl group, i-butyl group, s-butyl group and t-butyl group. Specific examples of the repeating unit represented by the general formula (III) include the following, but the present invention is not limited to these specific examples.

[0039]

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[0040]

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In the resin according to the present invention, the following monomers may be further copolymerized to give a repeating unit constituting the resin within a range where the effects of the present invention can be effectively obtained. However, it is not limited 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, and (4) film loss (hydrophobicity, alkali (Selection of a soluble group), (5) adhesion of the unexposed portion to the substrate, and (6) dry etching resistance can be finely adjusted. Examples of such a comonomer include acrylates, methacrylates,
Examples thereof include compounds having one addition-polymerizable unsaturated bond selected from acrylamides, methacrylamides, 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 (alkyl having preferably 1 to 10 carbon atoms) methacrylate (for example, methyl methacrylate,
Ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate,
Benzyl methacrylate, chlorobenzyl methacrylate, octyl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate,
5-hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, etc.);

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

Methacrylamides, for example, methacrylamide, N-alkyl methacrylamide (where the alkyl group has 1 to 10 carbon atoms, for example, methyl, ethyl, t-butyl, ethylhexyl, hydroxyethyl, cycloethyl) 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 and the like); acrylic acid, methacrylic acid, crotonic acid, itaconic acid, acrylonitrile, methacrylonitrile and the like.

In the resin (A) according to the present invention, the repeating unit represented by the general formula (I), one of the repeating units represented by the repeating unit (II), and the general formula (III)
The content of the repeating unit represented by is the desired resistance to oxygen plasma etching, the sensitivity, the prevention of pattern cracking, the substrate adhesion, the resist profile, and the resolution, heat resistance, which is a necessary requirement for general resists. , Etc., can be set as appropriate. Generally, in the resin (A) of the present invention, the content of the repeating unit represented by the general formula (I) is 10 to 90 mol%, preferably 15 to 70 mol%, based on all repeating units. %, More preferably 20 to 50 mol%. The content of the repeating unit represented by the repeating unit (II),
It is 5 to 50 mol%, preferably 10 to 40 mol%, based on all repeating units. The content of the repeating unit (III) is 10 to 90 mol% based on all the repeating units.
, Preferably 15 to 70 mol%, more preferably 20 to 60 mol%.

In the resin (A) of the present invention, a monomer corresponding to the repeating unit represented by the general formula (I), a monomer corresponding to the repeating unit represented by the general formula (II), It can be obtained by copolymerizing a monomer corresponding to the repeating unit represented by the formula (III) in the presence of a polymerization catalyst.

The weight average molecular weight of the resin according to the present invention is G
It is preferably from 1,000 to 200,000 in terms of polystyrene according to the PC method. When the weight average molecular weight is less than 1,000, heat resistance and dry etching resistance are deteriorated, so that it is not preferable. When the weight average molecular weight exceeds 200,000, the developability is deteriorated and the viscosity becomes extremely high, so that the film forming property is deteriorated. And so on, which produces very unfavorable results.

In the positive photoresist composition of the present invention, the compounding amount of the resin (A) according to the present invention in the whole composition is preferably 40 to 99.99% by weight, more preferably in the total solid content of the resist. 50-99.97% by weight.

Next, the compound (B) which generates an acid upon irradiation with actinic rays or radiation will be described. 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 photobleaching agent for dyes, and a photodiscoloration agent. Agents or known light used for micro resists (ultraviolet rays of 400 to 200 nm, far ultraviolet rays, particularly preferably g-rays, i-rays, KrF excimer laser light, A
A compound capable of generating an acid by rF excimer laser light, electron beam, X-ray, molecular beam or ion beam, and a mixture thereof can be appropriately selected and used. 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 photobleaching agent 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 ,
Compounds that generate an acid by X-rays, molecular beams or ion beams and mixtures 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, 38.
7 (1974), TSBetal, Polymer, 21,423 (1980) and the like diazonium salts, U.S. Pat.Nos. 4,069,055 and 4,069,0
No. 56, Re 27,992, ammonium salts described in JP-A-3-140140, etc., DCNecker et al., Macromolecules, 17, 24.
68 (1984), CSwen et al., Teh, Proc. Conf. Rad. Curing AS
IA, p478 Tokyo, Oct (1988), U.S. Pat.No. 4,069,055,
4,069,056, etc., phosphonium salts, JVCrivell
o etal, Macromorecules, 10 (6), 1307 (1977), Chem. & E
ng. News, Nov. 28, p31 (1988), EP 104,143.
No., U.S. Patent Nos. 339,049 and 410,201,
No. 0,848, JP-A-2-296,514 and the like, iodonium salts, JVCrivello et al., Polymer J. 17, 73 (1985), J.
V. Crivello et al. J. Org. Chem., 43, 3055 (1978), WRWa
tt etal, J. Polymer Sci., Polymer Chem. Ed., 22, 1789 (1
984), JVCrivello etal, Polymer Bull., 14,279 (198
5), JVCrivello etal, Macromorecules, 14 (5), 1141 (19
81), JVCrivello etal, J. PolymerSci., Polymer Che
m.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, JVCrivello et al., Macro
morecules, 10 (6), 1307 (1977), JVCrivello etal, JP
olymerSci., Polymer Chem.Ed., 17, 1047 (1979), etc., selenonium salts, CSWen et al., Teh, Proc. Conf. Rad.C
uring ASIA, p478 Tokyo, Oct (1988), etc., 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-60-239736, JP-A-61-169835, JP-A-61-169
No. 837, JP-A-62-58241, JP-A-62-212401, JP-A-62-212401
63-70243, organic halogen compounds described in JP-A-63-298339, etc., 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),
Organometallic / organic halides described in JP-A-2-14145, S. Hayase et al., J. Polymer Sci., 25, 753 (1987), E.
Reichmanis etal, J. Pholymer Sci., Polymer Chem. E
d., 23, 1 (1985), QQ Zhu et al., J. Photochem., 36, 85, 3
9, 317 (1987), B. Amit etal, Tetrahedron Lett., (24)
2205 (1973), DHR Barton et al., J. Chem Soc., 3571 (1
965), PM Collins et al., J. Chem. SoC., PerkinI, 1695 (19
75), M. Rudinstein et al., Tetrahedron Lett., (17), 14
45 (1975), JWWalker etal J. Am. Chem. Soc., 110, 7170
(1988), SCBusman et al., J. Imaging Technol., 11
(4), 191 (1985), HM Houlihan et al, Macormolecules,
21, 2001 (1988), PM Collins etal, J. Chem. Soc.,
Chem. Commun., 532 (1972), S. Hayase etal, Macromolec
ules, 18, 1799 (1985), E. Reichmanetal, J. Electrochem. So
c., SolidStateSci.Technol., 130 (6), FMHoulihan eta
l, Macromolcules, 21, 2001 (1988), EP 0290,750
Nos. 046,083, 156,535, 271,851, 0,38
No. 3,343, U.S. Pat.Nos. 3,901,710, 4,181,531, JP-A-60-198538, and photoacid generators having a 0-nitrobenzyl-type protecting group described in JP-A-53-133022, M. TUNOOKA
etal, Polymer Preprints Japan, 35 (8), G. Berner eta
l, J. Rad. Curing, 13 (4), WJMijs etal, CoatingTechn
ol., 55 (697), 45 (1983), Akzo, H. Adachi et al, Polyme
r Preprints, Japan, 37 (3), European Patent Nos. 0199,672, 84
No. 515, No. 044,115, No. 618,564, No. 0101,122, U.S. Pat.Nos. 4,371,605, 4,431,774, JP-A-64-1814
No. 3, JP-A-2-245756, JP-A-3-140109, etc., compounds which generate sulfonic acid by photodecomposition represented by iminosulfonate, etc .;
Disulfone compound described in JP-A-71270
-103854, 3-10856, 4-21
No. 0960 and the like.

Further, a group which generates an acid by these lights,
Alternatively, a compound having a compound introduced into the main chain or side chain of a polymer, for example, ME Woodhouse etal, J. Am. Che.
m. Soc., 104, 5586 (1982), SPPappas etal, J. Imagi
ng Sci., 30 (5), 218 (1986), S. Kondo et al., Makromol. C
hem., Rapid Commun., 9, 625 (1988), Y. Yamadaetal, Mak
romol. Chem., 152, 153, 163 (1972), JVCrivello eta
l, J. PolymerSci., Polymer Chem. Ed., 17, 3845 (197
9), U.S. Patent No. 3,849,137, Dokoku Patent No. 3914407, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263
No., JP-A-63-146038, JP-A-63-163452, JP-A-62-163452
Compounds described in JP-A-153853 and JP-A-63-146029 can be used.

Further, VNRPillai, Synthesis, (1), 1 (19
80), A. Abad et al, Tetrahedron Lett., (47) 4555 (197
1), DHR Barton et al, J. Chem. Soc., (C), 329 (197
0), compounds which generate an acid by light described in US Pat. No. 3,779,778 and European Patent No. 126,712 can also be used.

Among the compounds capable of decomposing upon irradiation with actinic rays or radiation to generate an acid, those particularly effectively used 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).

[0059]

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

[0061]

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[0062]

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[0063]

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

[0065]

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

R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ each independently represent a substituted or unsubstituted alkyl group or aryl group. Preferably, it is an aryl group having 6 to 14 carbon atoms, an alkyl group having 1 to 8 carbon atoms, or a substituted derivative thereof. Preferred substituents include an aryl group, an alkoxy group having 1 to 8 carbon atoms, 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.

[0068] 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.

[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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[0078]

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[0080]

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[0081]

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[0082]

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[0083]

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

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

[0086]

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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.

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[0089]

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[0090]

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[0091]

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[0092]

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[0093]

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

[0095]

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Here, R ²¹ and R ²² are each independently
It represents an alkyl group which may have a substituent, a cycloalkyl group, or an aryl group which may have a substituent. Here, the alkyl group is preferably a linear or branched alkyl group having 1 to 20 carbon atoms, and more preferably a linear or branched alkyl group having 1 to 12 carbon atoms. As the cycloalkyl group, a cyclopentyl group or a cyclohexyl group is preferable. As the aryl group, an aryl group which may have a substituent having 6 to 10 carbon atoms is preferable. Here, as a substituent, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, n
Alkyl such as -butyl group, i-butyl group, s-butyl group, t-butyl group, n-pentyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, nonyl group, decyl group and dodecyl group Groups, a methoxy group, an ethoxy group, a propoxy group, an alkoxy group such as a butoxy group, a halogen atom, a nitro group, and an acetyl group.

Specific examples of the diazodisulfone derivative compound include the following compounds. Bis (methylsulfonyl) diazomethane, bis (ethylsulfonyl) diazomethane, bis (propylsulfonyl) diazomethane,
Bis (1-methylpropylsulfonyl) diazomethane,
Bis (butylsulfonyl) diazomethane, bis (1-methylbutylsulfonyl) diazomethane, bis (heptylsulfonyl) diazomethane, bis (octylsulfonyl) diazomethane, bis (nonylsulfonyl) diazomethane, bis (decylsulfonyl) diazomethane, bis (dodecylsulfonyl) Diazomethane, bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (benzylsulfonyl) diazomethane, bis (2-chlorobenzylsulfonyl) diazomethane, bis (4-chlorobenzylsulfonyl) diazomethane, bis (phenylsulfonyl) Diazomethane, bis (4-methoxyphenylsulfonyl)
Diazomethane, bis (2-methylphenylsulfonyl)
Diazomethane, bis (3-methylphenylsulfonyl)
Diazomethane, bis (4-methylphenylsulfonyl)
Diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, bis (2,5-dimethylphenylsulfonyl) diazomethane, bis (3,4-dimethylphenylsulfonyl) diazomethane, bis (2,4,6-
Trimethylphenylsulfonyl) diazomethane, bis (4-fluorophenylsulfonyl) diazomethane, bis (2,4-difluorophenylsulfonyl) diazomethane, bis (2,4,6-trifluorophenylsulfonyl) diazomethane, bis (4-nitrophenylsulfonyl) ) Diazomethane

(5) A diazoketosulfone derivative compound represented by the following general formula (PAG8). (PAG8)

[0099]

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Here, R ²¹ and R ²² are each independently
It represents an alkyl group which may have a substituent, a cycloalkyl group, or an aryl group which may have a substituent. Specific examples of these substituents include the same as those described in the above (PAG-7). Specific examples of the diazoketosulfone derivative compound include the following compounds.

Methylsulfonyl-benzoyldiazomethane, ethylsulfonyl-benzoyldiazomethane,
Methylsulfonyl-4-bromobenzoyldiazomethane, ethylsulfonyl-4-bromobenzoyldiazomethane, phenylsulfonyl-benzoyldiazomethane, phenylsulfonyl-2-methylphenyldiazomethane, phenylsulfonyl-3-methylphenyldiazomethane, phenylsulfonyl- 4-methylphenyldiazomethane, phenylsulfonyl-3-methoxyphenyldiazomethane, phenylsulfonyl-4-methoxyphenyldiazomethane, phenylsulfonyl-3
-Chlorobenzoyldiazomethane, phenylsulfonyl-4-chlorophenyldiazomethane, tolylsulfonyl-3-chlorobenzoyldiazomethane, tolylsulfonyl-4-chlorophenyldiazomethane, phenylsulfonyl-4-fluorophenyldiazomethane,
Tolylsulfonyl-4-fluorophenyldiazomethane

Among the above, compounds which decompose upon irradiation with actinic rays or radiation to generate organic sulfonic acids can be suitably used. Here, the organic sulfonic acid is a sulfonic acid having an organic group, and the organic group is
Examples thereof include an alkyl group which may have a substituent, a phenyl group which may have a substituent, and a naphthyl group which may have a substituent. The substituent may have 1 carbon atom
To 12 linear or branched alkyl groups, 1 to 6 carbon atoms
And halogen atoms such as fluorine, chlorine, bromine and iodine. As the organic group, specifically,
Methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, n-
Amyl group, i-amyl group, t-amyl group, s-amyl group, n-hexyl group, n-pentyl group, n-octyl group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl group and other alkyl groups , A substituted alkyl group such as a chloromethyl group, a dichloromethyl group, a trichloromethyl group, a chloroethyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, a perfluorooctyl group, a phenyl group, a tosyl group, Substituted phenyl groups such as dimethylphenyl group, trimethylphenyl group, methoxyphenyl group, ethoxyphenyl group, chlorophenyl group, bromophenyl group, iodophenyl group, fluorophenyl group, pentafluorophenyl group, naphthyl group, methylnaphthyl group, methoxynaphthyl Group, chlorophenyl group, bromonaphthyl And a substituted naphthyl group such as Yodonafuchiru group. Among these organic groups, a group having a fluorine atom is particularly preferable.

The photoacid generator generates an organic sulfonic acid upon irradiation with actinic rays or radiation (B-3)
The compound (B-6) is preferable because the resolution of the resist pattern is improved, and the compounds (B-3) to (B-6) that generate a fluorinated organic sulfonic acid have high sensitivity and are particularly preferable.

The addition amount of the photoacid generator (B) is usually in the range of 0.001 to 40% by weight based on the total weight of the positive photoresist composition of the present invention (excluding the coating solvent). It is preferably used in the range of 0.01 to 20% by weight, more preferably 0.1 to 5% by weight. If the amount of the compound that decomposes upon irradiation with actinic rays or radiation to generate an acid is less than 0.001% by weight, the sensitivity becomes low. If the amount is more than 40% by weight, the light absorption of the resist becomes high. This is not preferable because the profile is deteriorated and the process (especially baking) margin is narrowed.

The positive photoresist composition of the present invention comprises
Further, it is preferable to contain an organic basic compound. Examples of the organic basic compound include compounds having the following structures.

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Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are the same or different and are a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aminoalkyl group having 1 to 6 carbon atoms, a hydroxyalkyl having 1 to 6 carbon atoms. Or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, wherein R ²⁵¹ and R ²⁵² may be bonded to each other to form a ring.

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

Preferred specific compounds are guanidine, 1,1-dimethylguanidine, 1,1,3,3,-
Tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (aminomethyl) pyridine,
-Amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethylpyridine, 4-aminoethylpyridine, 3-amino Pyrrolidine, piperazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 4-piperidinopiperidine, 2-imino Piperidine, 1- (2-
Aminoethyl) pyrrolidine, pyrazole, 3-amino-
5-methylpyrazole, 5-amino-3-methyl-1-
p-tolylpyrazole, pyrazine, 2- (aminomethyl) -5-methylpyrazine, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine,
-Pyrazoline, 3-pyrazoline, N-aminomorpholine, N- (2-aminoethyl) morpholine, 1,5-
Diazabicyclo [4,3,0] non-5-ene, 1,8
-Diazabicyclo [5,4,0] undec-7-ene,
3,4,5-triphenylimidazole, N-methylmorpholine, N-ethylmorpholine, N-hydroxyethylmorpholine, N-benzylmorpholine, cyclohexylmorpholinoethylthiourea (CHMETU), etc.
Grade morpholine derivatives, hindered amines described in JP-A-11-52575 (for example, [0005]
, Etc.) and the like, but is not limited thereto.

Particularly preferred specific examples are 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5.4.0] -7-undecene (DBU), 1,4- Tertiary morpholines such as diazabicyclo [2.2.2] octane, 4-dimethylaminopyridine, hexamethylenetetramine, 4,4-dimethylimidazoline, pyrroles, pyrazoles, imidazoles, pyridazines, pyrimidines, and CHMETU; Hindered amines such as bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebagate and the like can be mentioned.

Among them, 1,5-diazabicyclo [4,
3,0] non-5-ene, 1,8-diazabicyclo [5,4,0] undec-7-ene, 1,4-diazabicyclo [2,2,2] octane, 4-dimethylaminopyridine, hexamethylene Preferred are tetramine, CHMETU, and bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate.

These organic basic compounds are used alone or in combination of two or more. The amount of the organic basic compound used is usually 0.001 to 10% by weight, preferably 0.01 to 5% by weight, based on the total solid content of the resist composition.
% By weight. If the amount is less than 0.001% by weight, the effect of the addition of the organic basic compound cannot be obtained. On the other hand, 10% by weight
If it exceeds 300, the sensitivity tends to decrease and the developability of the unexposed portion tends to deteriorate.

It is preferable that the positive photoresist composition of the present invention also contains a surfactant. That is, it contains at least one surfactant of a fluorine-based surfactant, a silicon-based surfactant, a surfactant containing both a fluorine atom and a silicon atom, and a nonionic surfactant. Among them, a fluorine-based surfactant, a silicon-based surfactant, and a surfactant containing both a fluorine atom and a silicon atom are particularly preferable. As these surfactants, for example, JP-A-62
-36663, JP-A-61-226746, JP-A-61-226745, JP-A-62-170950, JP-A-63-34540, JP-A-7-230165
No., JP-A-8-62834, JP-A-9-54432, JP-A-9-5988
And the commercially available surfactants described below can be used as they are. Commercially available surfactants that can be used, for example, F-top EF301, EF30
3, (Shin-Akita Chemical Co., Ltd.), Florado FC430, 431 (Sumitomo 3M), MegaFac F171, F173, F176, F18
9, R08 (Dainippon Ink Co., Ltd.), Surflon S-382,
SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.) and other fluorine-based surfactants or silicon-based surfactants. In addition, polysiloxane polymer KP-341
(Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.

Specific examples of other surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether; Ethylene octyl phenol ether, polyoxyethylene alkyl allyl ethers such as polyoxyethylene nonyl phenol 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, Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; Can be mentioned. (E)
The amount of the surfactant is usually 0.001% to 2% by weight, preferably 0.01% to 1% by weight, based on the solid content in the composition of the present invention. These surfactants may be added alone or in some combination.

The positive photoresist composition of the present invention comprises
It contains a solvent that dissolves the above components (A) and (B). Examples of the solvent include propylene glycol monomethyl ether acetate, propylene glycol monoalkyl ether acetates such as propylene glycol monoethyl ether acetate, methyl lactate, alkyl lactates such as ethyl lactate, propylene glycol monomethyl ether, propylene glycol monoethyl ether and the like. Ethylene glycol monoalkyl ethers such as propylene glycol monoalkyl ethers, ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; -Heptanone, γ-butyrolactone, methoxyp Methyl acid, ethyl ethoxypropionate alkoxypropionic acid alkyls such as methyl pyruvate, pyruvate alkyl esters such as ethyl pyruvate, N- methylpyrrolidone, N, N
-Applied using at least one solvent selected from dimethylacetamide, dimethylsulfoxide and the like.

The positive photoresist composition of the present invention may further contain an acid-decomposable dissolution inhibiting compound, a dye,
A plasticizer, a surfactant other than the above, a photosensitizer, a compound that promotes solubility in a developer, and the like can be contained.

The positive photoresist composition of the present invention is applied on a substrate to form a thin film. The thickness of this coating film is preferably from 0.4 to 1.5 μm. The above composition is applied to a substrate (eg, such as used in the manufacture of precision integrated circuit devices).
A good resist pattern can be obtained by applying a suitable coating method such as a spinner, a coater or the like on a silicon / silicon dioxide coating), exposing through a predetermined mask, baking and developing. Here, the exposure light is preferably 250 nm or less, more preferably 22 nm or less.
It is far ultraviolet light having a wavelength of 0 nm or less. Specifically, Kr
F excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (157
nm), X-rays, electron beams and the like, and an ArF excimer laser (193 nm) is particularly preferable.

Examples of the developer for the positive photoresist composition for deep ultraviolet exposure according to the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia.
Primary amines such as ethylamine and n-propylamine;
Secondary amines such as diethylamine and di-n-butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide and the like An alkaline aqueous solution such as a quaternary ammonium salt, a cyclic amine such as pyrrole, or pyrhelidine can be used. Further, an appropriate amount of an alcohol or a surfactant may be added to the above alkaline aqueous solution.

When the resist of the positive photoresist composition of the present invention is used as the upper resist of a two-layer resist, the lower organic polymer film is etched by oxygen plasma using the upper resist pattern as a protective mask. The upper resist has sufficient resistance to oxygen plasma. Although the oxygen plasma resistance of the positive photoresist composition of the present invention depends on the silicon content of the upper resist, the etching apparatus, and the etching conditions, the etching selectivity (the etching rate ratio between the lower resist and the upper resist) is 10%. It can be taken as a sufficiently large value of ~ 100.

In the pattern forming method using the positive photoresist composition of the present invention, first, an organic polymer film is formed on a substrate to be processed. The organic polymer film may be various known photoresists, and examples thereof include FH series and FHi series manufactured by Fujifilm Olin Co., or OiR series manufactured by Olin Co., and PFI series manufactured by Sumitomo Chemical Co., Ltd. The formation of the organic polymer film is performed by dissolving these in an appropriate solvent and applying the resulting solution by a spin coating method, a spraying method or the like. Next, a film of the positive photoresist composition of the present invention is formed on the first layer of the organic polymer film. This is performed by dissolving the resist material in an appropriate solvent in the same manner as in the first layer, and applying the resulting solution by spin coating, spraying, or the like. The obtained two-layer resist is then subjected to a pattern forming step. As a first step, a pattern forming process is first performed on the second layer, that is, the film of the upper photoresist composition. Perform mask alignment as necessary, and irradiate high-energy radiation through this mask to make the irradiated portion of the photoresist composition soluble in an alkaline aqueous solution,
The pattern is formed by developing with an alkaline aqueous solution.

Next, the organic polymer film is etched as a second step. This operation is performed by oxygen plasma etching using the film pattern of the resist composition as a mask to form a fine pattern having a high aspect ratio. I do. The etching of the organic polymer film by the oxygen plasma etching is exactly the same technique as the plasma ashing used when the resist film is peeled off after the etching of the substrate is completed by the conventional photoetching operation. This operation can be performed by, for example, a cylindrical plasma etching apparatus or a parallel flat slope plasma etching apparatus using oxygen as a reactive gas, that is, an etching gas. Further, the substrate is processed using this resist pattern as a mask. As a processing method, a dry etching method such as sputter etching, gas plasma etching, or ion beam etching can be used.

The etching treatment by the two-layer film resist method including the resist film of the present invention is completed by the operation of removing the resist film. The removal of the resist layer can be carried out simply by dissolving the organic polymer material of the first layer. Since this organic polymer material is an arbitrary photoresist and has not been altered (hardened or the like) at all in the photoetching operation, an organic solvent of each known photoresist itself can be used. Or,
By a process such as plasma etching, separation can be performed without using a solvent.

[0124]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. Synthesis Example 1 (Synthesis of Resin (1)) 11.4 g of trimethylallylsilane, 9.8 g of maleic anhydride, and 7.1 g of t-amyl acrylate were dried in TH.
After adding to 34 g of F, the mixture was heated to 65 ° C. under a nitrogen stream. When the reaction temperature was stabilized, a polymerization initiator V-65 manufactured by Wako Pure Chemical Industries, Ltd. was added at 10 mol% of the total number of moles of the monomers to start the reaction. After reacting for 6 hours, the reaction mixture was diluted twice with THF, and then poured into a large amount of hexane to precipitate a white powder. Next, in order to reduce residual monomers and low molecular components, the precipitated powder was dissolved in acetone, and hexane was added little by little to precipitate a polymer. After the polymer precipitated in the lower layer was dissolved again in acetone, it was poured into a large amount of hexane to precipitate a white powder. After recovering the white polymer by filtration, drying under reduced pressure was performed to obtain a resin (1). As a result of GPC measurement, the molecular weight of the obtained resin (1) was 5600 in weight average using polystyrene as a standard sample, and the content of components having a molecular weight of 1000 or less was 4% by area ratio of GPC
Met.

Synthesis Examples 2 to 18 (Synthesis of Resins (2) to (18)) Resins (2) to (18) were synthesized by the same synthesis method as in Synthesis Example 1. The molar ratio and weight average molecular weight of each repeating unit of the resins (1) to (18) are shown in the following structural formula and Table 1.

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[0127]

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Synthesis of Comparative Example (Synthesis of Resin (C1)) 11.4 g of trimethylallylsilane, 9.8 g of maleic anhydride and 6.4 g of t-butyl acrylate were dried in TH.
After adding to 34 g of F, the mixture was heated to 65 ° C. under a nitrogen stream. When the reaction temperature was stabilized, a polymerization initiator V-65 manufactured by Wako Pure Chemical Industries, Ltd. was added at 10 mol% of the total number of moles of the monomers to start the reaction. After reacting for 6 hours, the reaction mixture was diluted twice with THF, and then poured into a large amount of hexane to precipitate a white powder. Next, in order to reduce residual monomers and low molecular components, the precipitated powder was dissolved in acetone, and hexane was added little by little to precipitate a polymer. After the polymer precipitated in the lower layer was dissolved again in acetone, it was poured into a large amount of hexane to precipitate a white powder. After recovering the white polymer by filtration, drying under reduced pressure was performed to obtain a resin (C1). As a result of GPC measurement, the molecular weight of the obtained resin (C1) was 9600 in weight average using polystyrene as a standard sample,
The content of the component having a molecular weight of 1,000 or less was 4% by GPC area ratio.

(Example 1) 2 g of resin (1) as an acid-decomposable resin (A) component, 0.12 g of triphenylsulfonium nonaflate and 0.012 g of DBU as a compound component generating an acid upon exposure, surface activity The agent (MegaFac F176) (0.003 g) was dissolved in propylene glycol monomethyl ether acetate (19.2 g), followed by microfiltration with a 0.1 μm membrane filter. FHi-028 on silicon wafer
D resist (a resist for i-line, manufactured by Fujifilm Ohlin Co.) was applied using a coater CDS-650 manufactured by Canon, and baked at 90 ° C. for 90 seconds to obtain a uniform film having a thickness of 0.83 μm. When this was further heated at 200 ° C. for 3 minutes, the film thickness became 0.71 μm. The silicon-containing resist composition prepared above was applied thereon, baked at 90 ° C. for 90 seconds, and applied to a thickness of 0.20 μm.

The wafer thus obtained was exposed to an ArF excimer laser stepper while loading a resolving power mask thereon while changing the exposure amount and focus. Then, after heating in a clean room at 120 ° C. for 90 seconds, tetramethylammonium hydroxide developer (2.38%) was used for 60 minutes.
After developing for 2 seconds, rinsing with distilled water and drying were performed to obtain a pattern. When observed with a scanning electron microscope, it was 0.15 μm
(A dense pattern of line / space (1/1)) was resolved. When the line width at which the line / space (1/10) sparse pattern disappeared was observed under the same exposure amount and depth of focus conditions, it was 0.17 μm. The surface roughness was A by visual evaluation. Here, the surface roughness is 0.17 μm line / space pattern (1/1).
The magnitude of the roughness of the line surface in 1) was observed with a SEM and evaluated visually.
The evaluation was made in three stages of A, B and C. A indicates little surface roughness, B indicates a slight surface roughness, and C indicates a clear one.

Examples 2 to 4 Positive photoresists were prepared in exactly the same manner as in Example 1 except that the resist compositions of Examples 1 to 4 were used instead of the resist compositions of Example 1. The composition was prepared, and exposed and developed in the same manner as in Example 1. Table 3 shows the obtained performance.

Comparative Example 1 In Example 1, as shown in Table 2, the following organic basic compound and / or fluorine-based compound
Except for removing silicon-based or nonionic surfactants,
A positive photoresist composition was prepared in exactly the same manner as in Example 1, and exposed and developed in the same manner as in Example 1. Table 4 shows the obtained performance. (Comparative Example 2
12) In the same manner as in Comparative Example 1, the compositions having the formulations shown in Table 2 were evaluated. Table 4 shows the results.

[0133]

[Table 1]

[0134]

[Table 2]

[0135]

[Table 3]

[0136]

[Table 4]

As can be seen from the above results, the composition of the present invention showed excellent performance in all evaluation items.

[0138]

According to the present invention, it is possible to provide a positive resist composition having a high resolution and a small loss of a sparse pattern around the resolution limit in the manufacture of a semiconductor device, and further having a low surface roughness. A small positive resist composition can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 33/04 C08L 33/04 35/00 35/00 43/04 43/04 G03F 7/004 501 G03F 7 / 004 501 7/075 511 7/075 511 H01L 21/027 H01L 21/30 502R F-term (reference) 2H025 AA02 AB16 AC04 AC08 AD03 BE00 BE07 BE10 BF02 BF11 BF30 BG00 CB10 CB43 CC03 FA17 4J002 BG041 BG051 BG051 BG051 BG051 EU186 EU226 EV226 EV296 FD206 4J100 AK32R AL03Q AL04Q AL08Q AM43R AM45R AM47R AP16P BA03R BA05Q BA06Q BA11R BA58R BA72P BA78P BA80P BA85P BB07R BC04Q BC07Q BC07R CA05 FA03

Claims (4)

[Claims] 1. A positive photoresist composition comprising at least the following (A) to (C). (A) a repeating unit represented by the following general formula (I), a repeating unit represented by the following general formula (II), and a repeating unit represented by the following general formula (III), (B) a compound that generates an acid upon irradiation with actinic rays or radiation (C) an organic solvent that dissolves the above (A) and (B) General formula (I) 1) In the formula (I), R ^{1 to} R ³ each independently represent an alkyl group,
Represents a haloalkyl group, a halogen atom, an alkoxy group, a trialkylsilyl group, or a trialkylsilyloxy group. n represents 0 or 1. General formula (II) In the formula (II), Y represents a hydrogen atom, a methyl group, a cyano group or a chlorine atom. L represents a single bond or a divalent linking group.
Q represents a tertiary alkyl group having 5 to 20 carbon atoms, or an alkoxymethyl group, an alkoxyethyl group, or an isobornyl group. General formula (III) Wherein (III), Z is an oxygen atom or -N (R ³⁾ - represents a. R
³ represents a hydrogen atom, a hydroxyl group, a linear or branched alkyl group, or —O—SO ₂ —R ⁴ . R ⁴ represents an alkyl group or a trihalomethyl group. 2. The positive photoresist composition according to claim 1, wherein n in the general formula (I) is 1. 3. The positive photoresist composition according to claim 1, wherein the component (B) is a compound that generates an organic sulfonic acid upon irradiation with actinic rays or radiation. 4. The positive photoresist composition according to claim 3, wherein said component (B) is a sulfonium salt or iodonium salt compound which generates an organic sulfonic acid upon irradiation with actinic rays or radiation.