JPH09160232A - Positive type photoresist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoresist compsn. having high sensitivity and excellent in resolving power, developability, heat resistance and resist shape, especially resolving power by incorporating an alkali-soluble resin, a quinonediazido compd. and a specified compd. SOLUTION: This photoresist compsn. contains an alkali-soluble resin, a quinonediazide compd. and a compd. represented by the formula, wherein R1 is H or alkyl, R2 is H, alkyl or -COOR3 (where R3 is H, optionally substd. alkyl or cycloalkyl), R1 and R2 are not simultaneously H, Z is a group of atoms required to form 5 or 6-membered cycloalkane or an alicyclic condensed ring having 5- or 6-membered cycloalkane and (n) is an integer of 1-3.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention contains an alkali-soluble resin, a 1,2-quinonediazide compound and a specific carboxylic acid, and emits ultraviolet rays, far ultraviolet rays, X-rays, electron beams, molecular beams, γ-rays and synchrotron radiation. The present invention relates to a positive photoresist composition which is sensitive to radiation such as, and more specifically, a positive photoresist for microfabrication having high sensitivity, high resolution, excellent developability, heat resistance, and resist shape. It is about.

[0002]

2. Description of the Related Art A positive photoresist is applied on a substrate such as a semiconductor wafer, glass, ceramics or metal to a thickness of 0.5 to 2 .mu.m by a spin coating method or a roller coating method. Thereafter, the film is heated and dried, and a circuit pattern or the like is baked by ultraviolet irradiation or the like through an exposure mask. If necessary, the film is baked after exposure and then developed to form a positive image. Further, by etching using this positive image as a mask, pattern-shaped processing can be performed on the substrate. Typical application fields include semiconductor manufacturing processes such as ICs, manufacturing of circuit boards such as liquid crystals and thermal heads, and other photofabrication processes.

As a positive photoresist composition, a composition containing an alkali-soluble resin binder such as novolak and a naphthoquinonediazide compound as a photosensitive material is generally used. Novolak resins as binders are particularly useful in this application because they can be dissolved in aqueous alkaline solutions without swelling and give high resistance to plasma etching, especially when the resulting image is used as an etching mask It is. Further, the naphthoquinonediazide compound used in the photosensitive material itself acts as a dissolution inhibitor that reduces the alkali solubility of the novolak resin, but when decomposed by irradiation with light, generates an alkali-soluble substance and rather increases the alkali solubility of the novolak resin. It is unique in that it acts to enhance it, and is particularly useful as a photosensitive material for a positive photoresist because of its large property change to light. From this point of view, many positive type photoresists containing a novolac resin and a naphthoquinonediazide type photosensitive material have been developed and put into practical use. In particular, the progress of resist materials toward high resolution is remarkable, and sufficient results have been achieved in line width processing down to submicrons.

Conventionally, in order to enhance the resolution and obtain an image having a good pattern shape, it is advantageous to use a resist having a high contrast (γ value), and from the viewpoint of high productivity, a photoresist having a high sensitivity is used. Is required.
Technical development of resist compositions that meet such purposes has been carried out. There are numerous publications disclosing such techniques. In particular, with respect to the novolak resin, which is the main part of the positive photoresist, many patent applications have been made regarding the monomer composition, molecular weight distribution, synthetic method, etc., and some results have been achieved. Also, as for the photosensitive material, which is another main component, compounds having many structures which are effective for increasing the contrast have been disclosed. By designing a positive photoresist using these techniques, it has become possible to develop an ultrahigh resolution resist capable of resolving a pattern having a size comparable to the wavelength of light.

However, integrated circuits are becoming more and more integrated, and it is necessary to process an ultrafine pattern having a line width of 0.5 μm or less in the production of a semiconductor substrate such as a VLSI. Is becoming. In such applications, particularly stable and high resolution is obtained,
There is a demand for a photoresist having a wide development latitude in order to always secure a constant processing line width. The development latitude is usually the development time dependency of the resist line width obtained by development, the temperature dependency of the developing solution, or the development system dependency. Further, it is required that no resist residue is generated in the resist pattern after development in order to prevent circuit processing defects. Especially 0.5 μm
In the formation of the following ultra-fine pattern, there is a tendency for thinning, and the coating film thickness may be 0.80 μm or less. For example, at a film thickness of 1.0 μm or more, even if no resist residue is generated, 0.80 μm
In the following film thickness, there are cases in which resist residue is extremely generated, which is one obstacle. In addition, the etching method has been changed from the conventional wet etching method to the dry etching method in order to increase the integration degree of the integrated circuit. However, since the resist temperature rises during the dry etching, thermal deformation or the like occurs. To avoid this, the resist is required to have high heat resistance.

In order to improve the heat resistance of the resist, a resin containing no component having a weight average molecular weight of 2000 or less is used (JP-A-60-97347), and the total content of monomers to trimers is 10% by weight or less. A technique using a resin (JP-A-60-189739) has been disclosed.
However, when the above-mentioned resin from which the low molecular weight component is removed or reduced is used, there is a problem that the sensitivity is usually lowered and the throughput in device manufacturing is lowered.
Attempts have also been made to improve the sensitivity and developability of the resist by incorporating a specific compound into the resist composition. For example, JP-A-61-141441 discloses a positive photoresist composition containing trihydroxybenzophenone. The positive photoresist containing trihydroxybenzophenone has improved sensitivity and developability, but the addition of trihydroxybenzophenone has a problem that heat resistance and profile are deteriorated.

Further, Japanese Patent Application Laid-Open Nos.
-177032, 1-2780748, 2-1035
0, JP-A-3-200251, JP-A-3-19135
1, JP-A-3-200255, JP-A-4-29934
8. Japanese Patent Application Laid-Open No. 5-204144 discloses a technique for increasing the sensitivity without deteriorating heat resistance by adding an aromatic polyhydroxy compound other than trihydroxybenzophenone. Not always enough.

[0008]

SUMMARY OF THE INVENTION Therefore, the object of the present invention is to provide a positive photoresist which is highly sensitive and has excellent resolution, developability, heat resistance, resist shape, especially resolution, especially in the production of semiconductor devices and the like. To provide a composition.

[0009]

As a result of careful consideration of the above-mentioned various characteristics, the present inventors have found that the above-mentioned object can be achieved by the following constitution. That is, the present invention is a positive photoresist composition containing an alkali-soluble resin, a quinonediazide compound, and a compound represented by the general formula (I).

[0010]

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In the formula (I), R ₁ represents a hydrogen atom or an alkyl group, R ₂ represents a hydrogen atom, an alkyl group or --COOR ₃
(Wherein R ₃ represents a hydrogen atom, an optionally substituted alkyl group or a cycloalkyl group). However,
R ₁ and R ₂ do not represent hydrogen atoms at the same time. Z is 5
Member or 6-membered cycloalkane, or 5 member or 6
Represents a group of atoms necessary for forming an alicyclic condensed ring having a member cycloalkane. n represents an integer of 1 to 3. Also,
In the compound represented by the general formula (I), _two of R ₂ may combine with each other to form a dimer.

When the carboxylic acid represented by the general formula (I) of the present invention is used together with an alkali-soluble resin and a quinonediazide compound, the specific resolution is high, the resist shape is excellent, the development latitude is wide, and the development residue is unlikely to occur. It was found that a composition having excellent heat resistance was obtained. Further, the technique disclosed in JP-A-4-122938, that is, the combination of the above-mentioned carboxylic acids of the present invention with an alkali-soluble novolac resin having a small ratio of the weight average molecular weight to the number average molecular weight, is further found to have an excellent balance of resist performance. Obtained.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In R _{1 to} R ₃ of the general formula (I), the alkyl group which may be substituted is a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, 1 -Methylethyl group or t
An alkyl group having 1 to 4 carbon atoms such as a -butyl group is preferable, and a methyl group is particularly preferable. The cycloalkyl group for R ₃ is preferably a cyclopentyl group or a cyclohexyl group. Further, this cycloalkyl group may have a substituent, and as the substituent, an alkyl group,-
COOH and halogen atoms (for example, chlorine atom, bromine atom, iodine atom, etc.). Here, preferable examples of the alkyl group are the same as those shown above. A 5- or 6-membered cycloalkane, which Z forms with a carbon atom,
Alternatively, as the alicyclic condensed ring having a 5- or 6-membered cycloalkane,

[0014]

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Is preferred. Preferred examples of the compound represented by the general formula (I) include the following general formulas (IA) to
(IC).

[0016]

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In the formula (IA), R ₅ represents a monovalent (when m = 1) or divalent (when m = 2) group, a hydrogen atom,
-COOH, -COO- or _{-C (CH 3) (CH 3} )
Represents-. X is a single bond, -COO- or

[0018]

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## EQU1 ## n represents 1 or 2. Formula (I-
In B), R ₆ represents a hydrogen atom or an alkyl group, and q is 1
Represents an integer of 3; Here, preferable examples of the alkyl group are the same as above. In formula (IC), R ₇ and R ₈
Represents a hydrogen atom or an alkyl group, r and s may be the same or different, and represent an integer of 1 to 3. Here, preferable examples of the alkyl group are the same as above.

Specific examples of the compound represented by the general formula (I) include the compounds represented by the following [Ia] to [If], and the compounds usable in the present invention are It is not limited. These carboxylic acids may be used alone or in admixture of two or more.

[0021]

[Chemical 6]

The compound represented by the above general formula (I) can be a commercially available product or can be synthesized by a known technique. The compounding amount of the compound represented by the general formula (I) is 100% by weight of the alkali-soluble resin 100.
3 to 100 parts by weight, preferably 5 to 7 parts by weight
The amount is 0 parts by weight, more preferably 10 to 60 parts by weight. If the use ratio is less than 3 parts by weight, the effect of the present invention cannot be sufficiently obtained, and if it exceeds 100 parts by weight, the residual film rate and heat resistance decrease, which is not preferable.

Examples of the alkali-soluble resin used in the present invention include novolac resin, acetone-pyrogallol resin, polyhydroxystyrene and derivatives thereof. Of these, novolak resins are particularly preferable, and the resins are obtained by addition-condensing aldehydes in the presence of an acidic catalyst with a predetermined monomer as a main component. Examples of the predetermined monomer include cresols such as phenol, m-cresol, p-cresol and o-cresol, xylenols such as 2,5-xylenol, 3,5-xylenol, 3,4-xylenol and 2,3-xylenol. , Alkylphenols such as m-ethylphenol, p-ethylphenol, o-ethylphenol and pt-butylphenol, trialkylphenols such as 2,3,5-trimethylphenol and 2,3,4-trimethylphenol, p-methoxyphenol, m-methoxyphenol, 3,5-dimethoxyphenol, 2-methoxy-4-methylphenol, m-ethoxyphenol, p-ethoxyphenol, m-propoxyphenol, p-propoxyphenol, m-butoxyphenol , P-butoki Alkoxy phenols such as phenol, 2-methyl-4-isopropyl phenol, thymol, bis alkylphenols such as Isochimoru, m- chlorophenol, p- chlorophenol, o- chlorophenol, dihydroxybiphenyl,
Hydroxy aromatic compounds such as bisphenol A, phenylphenol, resorcinol, and naphthol can be used alone or in combination of two or more, but are not limited thereto.

Examples of aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde. , O-chlorobenzaldehyde,
m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde, p-nitrobenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-
Methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde, furfural,
Chloroacetaldehyde and its acetal form, such as chloroacetaldehyde diethyl acetal, can be used, and among these, formaldehyde is preferably used. These aldehydes are
They are used alone or in combination of two or more. As the acidic catalyst, hydrochloric acid, sulfuric acid, formic acid, acetic acid, oxalic acid and the like can be used.

Further, JP-A-60-45238 and 60-
97347, 60-14235, 60-1897
39, 64-14229, JP-A-1-276131,
2-60915, 2-275555, 2-282
745, 4-101147, 4-122938, etc., that is, it is preferable to use a technique in which low-molecular components of novolac resin are removed or reduced.

The novolak resin thus obtained preferably has a weight average molecular weight of 2000 to 20000. If it is less than 2000, the film loss of the unexposed area after development is large, and if it exceeds 20000, the developing speed becomes small. The range of 3000 to 15000 is particularly preferable. Here, the weight average molecular weight is defined as a value in terms of polystyrene by gel permeation chromatography. The degree of dispersion of these resins (the ratio of the weight average molecular weight Mw to the number average molecular weight Mn, that is, Mw / Mn) is preferably 1.5 to 7.0, and more preferably 1.
It is 5 to 4.0. If it exceeds 7, the effect of the present invention is not sufficiently obtained, while if it is less than 1.5, a high-level purification step is required for synthesizing the novolac resin, which is unpractical and unsuitable.

The sensitizer used in the present invention is a quinonediazide compound, and an esterified product of the following polyhydroxy compound and 1,2-naphthoquinonediazide-5- (and / or -4-) sulfonyl chloride is used. You can

Examples of polyhydroxy compounds include 2,
3,4-trihydroxybenzophenone, 2,4,4 '
-Trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone, 2,3,4-trihydroxy-2'-methylbenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,2 ', 4 4'-
Tetrahydroxybenzophenone, 2,4,6,3 ',
4'-pentahydroxybenzophenone, 2,3,4
2 ', 4'-pentahydroxybenzophenone, 2,
3,4,2 ', 5'-pentahydroxybenzophenone, 2,4,6,3', 4 ', 5'-hexahydroxybenzophenone, 2,3,4,3', 4 ', 5'-hexahydroxy Polyhydroxybenzophenones such as benzophenone,

Polyhydroxyphenyl alkyl ketones such as 2,3,4-trihydroxyacetophenone, 2,3,4-trihydroxyphenyl pentyl ketone and 2,3,4-trihydroxyphenylhexyl ketone,

Bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) propane-1, bis (2,3,4-tri) Hydroxyphenyl) propane-1, nordihydroguaiaretic acid, 1,1-
Bis ((poly) hydroxyphenyl) alkanes such as bis (4-hydroxyphenyl) cyclohexane,

Propyl 3,4,5-trihydroxybenzoate, phenyl 2,3,4-trihydroxybenzoate,
Polyhydroxybenzoic acid esters such as phenyl 3,4,5-trihydroxybenzoate,

Bis (2,3,4-trihydroxybenzoyl) methane, bis (3-acetyl-4,5,6-trihydroxyphenyl) -methane, bis (2,3,4-trihydroxybenzoyl) benzene, Screw (2,4,6
-Bis (polyhydroxybenzoyl) alkanes such as trihydroxybenzoyl) benzene or bis (polyhydroxybenzoyl) aryls,

Ethylene glycol-di (3,5-dihydroxybenzoate), ethylene glycol-di (3,3
Alkylene-di (polyhydroxybenzoates) such as 4,5-trihydroxybenzoates),

2,3,4-biphenyltriol, 3,
4,5-biphenyltriol, 3,5,3 ', 5'-
Biphenyl tetrol, 2,4,2 ', 4'-biphenyl tetrol, 2,4,6,3', 5'-biphenyl pentol, 2,4,6,2 ', 4', 6'-biphenyl Polyhydroxybiphenyls such as hexol, 2,3,4,2 ', 3', 4'-biphenylhexol,

Bis (polyhydroxy) sulfides such as 4,4'-thiobis (1,3-dihydroxy) benzene,

Bis (polyhydroxyphenyl) such as 2,2 ', 4,4'-tetrahydroxydiphenyl ether
Ethers,

Bis (polyhydroxyphenyl) sulfoxides such as 2,2 ', 4,4'-tetrahydroxydiphenyl sulfoxide,

Bis (polyhydroxyphenyl) sulfones such as 2,2 ', 4,4'-diphenyl sulfone,

Tris (4-hydroxyphenyl) methane, 4,4 ', 4 "-trihydroxy-3,5,3',
5'-tetramethyltriphenylmethane, 4,4 ',
3 ", 4" -tetrahydroxy-3,5,3 ', 5'-
Tetramethyltriphenylmethane, 4- [bis (3,5
-Dimethyl-4-hydroxyphenyl) methyl] -2-
Methoxy-phenol, 4,4 '-(3,4-diol-benzylidene) bis [2,6-dimethylphenol], 4,4'-[(2-hydroxy-phenyl) methylene] bis [2-cyclohexyl-5] -Methylphenol, 4,4 ', 2 ", 3", 4 "-pentahydroxy-
3,5,3 ', 5'-tetramethyltriphenylmethane, 2,3,4,2', 3 ', 4'-hexahydroxy-5,5'-diacetyltriphenylmethane, 2,3,3
4,2 ', 3', 4 ', 3 ", 4"-octahydroxy-5,5'-diacetyltriphenylmethane, 2,4
6,2 ', 4', 6'-Hexahydroxy-5,5'-
Polyhydroxytriphenylmethanes such as dipropionyltriphenylmethane, 4,4 '-(phenylmethylene) bisphenol, 4,4'-(1-phenyl-ethylidene) bis [2-methylphenol], 4,4 ',
Polyhydroxytriphenylethanes such as 4 ″ -ethylidene-trisphenol,

3,3,3 ', 3'-tetramethyl-1,
1'-spirobi-indane-5,6,5 ', 6'-tetrol, 3,3,3', 3'-tetramethyl-1,1 '
-Spirobi-indan-5,6,7,5 ', 6', 7 '
-Hexool, 3,3,3 ', 3'-tetramethyl-
1,1'-spirobi-indane-4,5,6,4 ',
5 ', 6'-hexol, 3,3,3', 3'-tetramethyl-1,1'-spirobi-indane-4,5
Polyhydroxyspirobiindanes such as 6,5 ′, 6 ′, 7′-hexool, 2,4,4-trimethyl-
Polyhydroxyflavans such as 2 ', 4', 7'-trihydroxyflavan,

3,3-bis (3,4-dihydroxyphenyl) phthalide, 3,3-bis (2,3,4-trihydroxyphenyl) phthalide, 3 ', 4', 5 ', 6'-
Polyhydroxyphthalides such as tetrahydroxyspiro [phthalide-3,9′-xanthene],

Flavono dyes such as morin, quercetin, rutin,

Α, α ', α "-tris (4-hydroxyphenyl) 1,3,5-triisopropylbenzene,
α, α ′, α ″ -tris (3,5-dimethyl-4-hydroxyphenyl) 1,3,5-triisopropylbenzene, α, α ′, α ″ -tris (3,5-diethyl-4-
Hydroxyphenyl) 1,3,5-triisopropylbenzene, α, α ′, α ″ -tris (3,5-di-n-propyl-4-hydroxyphenyl) 1,3,5-triisopropylbenzene, α, α ′, Α ″ -Tris (3,5-
Diisopropyl-4-hydroxyphenyl) 1,3,5
-Triisopropylbenzene, α, α ', α "-tris (3,5-di-n-butyl-4-hydroxyphenyl)
1,3,5-triisopropylbenzene, α, α ′,
α ″ -tris (3-methyl-4-hydroxyphenyl)
1,3,5-triisopropylbenzene, α, α ′,
α ″ -tris (3-methoxy-4-hydroxyphenyl) 1,3,5-triisopropylbenzene, α,
α ′, α ″ -tris (2,4-dihydroxyphenyl)
1,3,5-triisopropylbenzene, 1,3,5-
Tris (3,5-dimethyl-4-hydroxyphenyl)
Benzene, 1,3,5-tris (5-methyl-2-hydroxyphenyl) benzene, 2,4,6-tris (3,3
5-dimethyl-4-hydroxyphenylthiomethyl) mesitylene, 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl] -4- [α, α′-bis (4 ″ -hydroxyphenyl) ethyl] Benzene, 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl] -3-
[Α, α′-bis (4 ″ -hydroxyphenyl) ethyl] benzene, 1- [α-methyl-α- (3 ′, 5′-
Dimethyl-4'-hydroxyphenyl) ethyl] -4-
[Α, α'-bis (3 ", 5" -dimethyl-4 "-hydroxyphenyl) ethyl] benzene, 1- [α-methyl-α- (3'-methyl-4'-hydroxyphenyl) ethyl]- 4- [α ', α'-bis (3 "-methyl-4"
-Hydroxyphenyl) ethyl] benzene, 1- [α-
Methyl-α- (3′-methoxy-4′-hydroxyphenyl) ethyl] -4- [α ′, α′-bis (3 ″ -methoxy-4 ″ -hydroxyphenyl) ethyl] benzene,
1- [α-methyl-α- (2 ′, 4′-dihydroxyphenyl) ethyl] -4- [α ′, α′-bis (4 ″ -hydroxyphenyl) ethyl] benzene, 1- [α-methyl- α- (2 ′, 4′-dihydroxyphenyl) ethyl] -3- [α ′, α′-bis (4 ″ -hydroxyphenyl) ethyl] benzene and other polyhydroxy compounds described in JP-A-4-253058, α , Α, α ', α',
α ″, α ″ -hexakis- (4-hydroxyphenyl)
Japanese Patent Application Laid-Open No. 5-22 such as -1,3,5-triethylbenzene
Polyhydroxy compounds described in No. 4410, 1, 2,
2,3-tetra (p-hydroxyphenyl) propane,
1,3,3,5-tetra (p-hydroxyphenyl) pentane and the like, JP-A-5-303200, EP-5301
48. Poly (hydroxyphenyl) alkane according to 48.

P-bis (2,3,4-trihydroxybenzoyl) benzene, p-bis (2,4,6-trihydroxybenzoyl) benzene, m-bis (2,3,4-)
Trihydroxybenzoyl) benzene, m-bis (2,2
4,6-trihydroxybenzoyl) benzene, p-bis (2,5-dihydroxy-3-bromobenzoyl) benzene, p-bis (2,3,4-trihydroxy-5-)
Methylbenzoyl) benzene, p-bis (2,3,4-
Trihydroxy-5-methoxybenzoyl) benzene,
p-bis (2,3,4-trihydroxy-5-nitrobenzoyl) benzene, p-bis (2,3,4-trihydroxy-5-cyanobenzoyl) benzene, 1,3,5
-Tris (2,5-dihydroxybenzoyl) benzene, 1,3,5-tris (2,3,4-trihydroxybenzoyl) benzene, 1,2,3-tris (2,3,3)
4-trihydroxybenzoyl) benzene, 1,2,4
-Tris (2,3,4-trihydroxybenzoyl) benzene, 1,2,4,5-tetrakis (2,3,4-trihydroxybenzoyl) benzene, α, α'-bis (2,3,4-) Trihydroxybenzoyl) p-xylene, α, α ′, α′-tris (2,3,4-trihydroxybenzoyl) mesitylene,

2,6-bis- (2-hydroxy-3,5
-Dimethyl-benzyl) -p-cresol, 2,6-bis- (2-hydroxy-5'-methyl-benzyl) -p
-Cresol, 2,6-bis- (2,4,6-trihydroxy-benzyl) -p-cresol, 2,6-bis-
(2,3,4-trihydroxy-benzyl) -p-cresol, 2,6-bis (2,3,4-trihydroxy-
Benzyl) -3,5-dimethyl-phenol, 4,6-
Bis- (4-hydroxy-3,5-dimethylbenzyl)
-Pyrogallol, 2,6-bis- (4-hydroxy-
3,5-Dimethylbenzyl) -1,3,4-trihydroxy-phenol, 4,6-bis- (2,4,6-trihydroxybenzyl) -2,4-dimethyl-phenol, 4,6-bis -(2,3,4-trihydroxybenzyl) -2,5-dimethyl-phenol, 2,6-bis- (4-hydroxybenzyl) -p-cresol, 2,
6-bis (4-hydroxybenzyl) -4-cyclohexylphenol, 2,6-bis (4-hydroxy-3-)
Methylbenzyl) -p-cresol, 2,6-bis (4
-Hydroxy-3,5-dimethylbenzyl) -p-cresol, 2,6-bis (4-hydroxy-2,5-dimethylbenzyl) -p-cresol, 2,6-bis (4-
Hydroxy-3-methylbenzyl) -4-phenyl-phenol, 2,2 ', 6,6'-tetrakis [(4-hydroxyphenyl) methyl] -4,4'-methylenediphenol, 2,2', 6 , 6'-Tetrakis [(4-hydroxy-3,5-dimethylphenyl) methyl] -4,
4'-methylenediphenol, 2,2 ', 6,6'-tetrakis [(4-hydroxy-3-methylphenyl) methyl] -4,4'-methylenediphenol, 2,2'-
Bis [(4-hydroxy-3,5-dimethylphenyl)
Methyl] 6,6'-dimethyl-4,4'-methylenediphenol and the like can be mentioned.

It is also possible to use a low-nuclear substance of phenol resin such as novolac resin.

The esterification reaction for obtaining the photosensitive material is carried out by mixing a predetermined amount of the above polyhydroxy compound and 1,2-naphthoquinonediazide-5- (and / or -4-) sulfonyl chloride with dioxane, acetone or tetrahydrofuran. , Methyl ethyl ketone, N-methyl pyrrolidone,
It is dissolved in a solvent such as chloroform, trichloroethane, trichloroethylene or dichloroethane, and a basic catalyst such as sodium hydroxide, sodium carbonate, sodium hydrogen carbonate, triethylamine, N-methylmorpholine, N-methylpiperazine, 4-dimethylaminopyridine, etc. is added dropwise. The resulting product is washed with water, purified, and dried.

In the usual esterification reaction, a mixture having different esterification numbers and esterification positions is obtained. However, by selecting the synthesis conditions or the structure of the polyhydroxy compound, only a specific isomer can be selectively selected. Can also be esterified. The esterification rate of the present invention is
It means the average value of this mixture.

The esterification rate is such that the raw material polyhydroxy compound and 1,2-naphthoquinonediazide
It can be controlled by the mixing ratio with 5- (and / or -4-) sulfonyl chloride. That is, the added 1,2-naphthoquinonediazide-5- (and / or -4-) sulfonyl chloride undergoes an esterification reaction, so that
In order to obtain a mixture having a desired esterification ratio, the molar ratio of the raw materials may be adjusted. If necessary, 1,2-naphthoquinonediazide-5-sulfonyl chloride and 1,2-naphthoquinonediazide-4-sulfonyl chloride can be used in combination. The reaction temperature in the above method is
It is usually -20 to 60 ° C, preferably 0 to 40 ° C.

The photosensitive material synthesized by the above method is
When used in the composition of the present invention alone or 2
It is used by mixing it with at least one kind and blending it with an alkali-soluble resin, and the blending amount thereof is 5 to 100 parts by weight, preferably 20 to 60 parts by weight with respect to 100 parts by weight of the alkali-soluble resin.
Parts by weight. If the usage ratio is less than 5 parts by weight, the residual film rate is remarkably lowered, and if it exceeds 100 parts by weight, the sensitivity and the solubility in a solvent are lowered.

In addition to the compound represented by the general formula (I) of the present invention, the composition of the present invention can further contain other alkali dissolution accelerators. Examples of preferred alkaline dissolution accelerators include polyhydroxy compounds, for example, phenols, resorcin, phloroglucin, 2,
3,4-trihydroxybenzophenone, 2,3,4
4'-tetrahydroxybenzophenone, 2,3,4
3 ', 4', 5'-hexahydroxybenzophenone,
Acetone-pyrogallol condensation resin, phloroglucide,
2,4,2 ', 4'-biphenyl tetrol, 4,4'
-Thiobis (1,3-dihydroxy) benzene, 2,
2 ', 4,4'-tetrahydroxydiphenyl ether, 2,2', 4,4'-tetrahydroxydiphenyl sulfoxide, 2,2 ', 4,4'-tetrahydroxydiphenyl sulfone, tris (4-hydroxyphenyl) ) Methane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4 '-(α-methylbenzylidene) bisphenol, α, α', α "-tris (4-
Hydroxyphenyl) -1,3,5-triisopropylbenzene, α, α ′, α ″ -tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene,
1,2,2-tris (hydroxyphenyl) propane,
1,1,2-Tris (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2,5,5-tetrakis (4-hydroxyphenyl) hexane, 1,2-tetrakis (4-hydroxyphenyl) ethane , 1,1,3-
Tris (hydroxyphenyl) butane, para [α, α,
α ', α'-tetrakis (4-hydroxyphenyl)]
-Xylene and the like. These polyhydroxy compounds can be added in an amount of usually 50 parts by weight or less, preferably 30 parts by weight or less, relative to 100 parts by weight of the compound represented by the general formula (I) of the present invention.

As the solvent for dissolving the photosensitive material and the alkali-soluble resin of the present invention, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,
Methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol methyl ether acetate, propylene glycol propyl ether acetate, propylene glycol monomethyl ether propionate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2 -Ethyl hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy-3
-Methyl methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl β-methoxyisobutyrate, methyl α-hydroxyisobutyrate, methyl pyruvate, Ethyl pyruvate, ethyl acetate, butyl acetate and the like can be used. These organic solvents may be used alone or in combination of two or more.

Furthermore, N-methylformamide, N, N-
Dimethylformamide, N-methylacetamide, N,
High-boiling solvents such as N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, and benzylethyl ether can be mixed and used.

The positive photoresist composition of the present invention may contain a surfactant in order to further improve the coating properties such as striation. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether, and other polyoxyethylene alkyl ethers, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether. Polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, etc. Sorbitan fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sol Monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, nonionic surfactants of polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan tristearate, Eftop EF
301, EF303, EF352 (Shin-Akita Kasei Co., Ltd.)
Manufactured by) Megafac F171, F173 (manufactured by Dainippon Ink Co., Ltd.), Florard FC430, FC431 (manufactured by Sumitomo 3M Ltd.), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC10.
3, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.) and the like, organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), acrylic acid-based or methacrylic acid-based (co) polymerization polyflow No. 75, no. 95 (Kyoeisha Yushi Kagaku Kogyo Co., Ltd.)
Manufactured). Among these surfactants, fluorine surfactants and silicon surfactants are particularly preferred. The content 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 alkali-soluble resin and the quinonediazide compound in the composition. These surfactants may be added alone or in some combination.

The developer for the positive photoresist composition of the present invention includes sodium hydroxide, potassium hydroxide,
Inorganic alkalis such as 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; triethylamine and methyldiethylamine Tertiary amines such as
Use aqueous solutions of alkali amines such as alcoholamines such as dimethylethanolamine and triethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide and choline, and cyclic amines such as pyrrole and piperidine. can do. Further, an appropriate amount of an alcohol such as isopropyl alcohol or a surfactant such as a nonionic surfactant may be added to an aqueous solution of the above alkalis. Of these developers, quaternary ammonium salts are preferred, and tetramethylammonium hydroxide and choline are more preferred.

The positive photoresist composition of the present invention may contain a light absorber, a cross-linking agent, an adhesion aid and the like, if necessary. The light absorbing agent is added as needed for the purpose of preventing halation from the substrate or for enhancing the visibility when applied to a transparent substrate. For example, commercially available light absorbers described in "Technology and Market of Industrial Dyes" (CMC Publishing) and Handbook of Dyes (edited by the Society of Synthetic Organic Chemistry), such as CIDi
sperse Yellow 1, 3,4, 5, 7, 8, 13, 23, 31, 49, 50,
51, 54, 56, 60, 64, 66, 68, 79, 82, 88, 90, 93, 10
2, 114 and 124, CI Disperse Orange 1, 5, 13, 25, 2
9, 30, 31, 44, 57, 72 and 73, CIDisperse Red 1,
5, 7, 13, 17, 19, 43, 50, 54, 58,65, 72, 73, 88, 1
17, 137, 143, 199 and 210, CIDisperse Violet 43,
CIDisperse Blue 96, CI Fluorescent Brightening
Agents 112, 135 and 163, CI Solvent Yellow 14, 16,
33 and 56, CISolvent Orange 2 and 45, CISolventR
ed 1, 3, 8, 23, 24, 25, 27 and 49, CI Pigment Gree
n 10, CI Pigment Brown 2 and the like can be preferably used. The light absorbing agent is usually added in an amount of 100 parts by weight or less, preferably 50 parts by weight or less, and more preferably 30 parts by weight or less with respect to 100 parts by weight of the alkali-soluble resin.

The cross-linking agent is added within a range that does not affect the formation of a positive image. The purpose of adding the crosslinking agent is mainly
These include sensitivity adjustment, improvement of heat resistance, improvement of dry etching resistance, and the like. Examples of the cross-linking agent include melamine, benzoguanamine, glycoluryl, etc., which are reacted with formaldehyde, or alkyl modified products thereof, epoxy compounds, aldehydes, azide compounds, organic peroxides, hexamethylenetetramine, etc. You can These crosslinking agents can be blended in a proportion of less than 10 parts by weight, preferably less than 5 parts by weight, based on 100 parts by weight of the photosensitive agent. If the amount of the crosslinking agent exceeds 10 parts by weight, the sensitivity is lowered, and scum (resist residue) is undesirably generated.

The adhesion aid is mainly added for the purpose of improving the adhesion between the substrate and the resist and preventing the resist from being peeled off particularly in the etching step. Specific examples include trimethylchlorosilane, dimethylvinylchlorosilane, methyldiphenylchlorosilane, chlorosilanes such as chloromethyldimethylchlorosilane, trimethylmethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, dimethylvinylethoxysilane,
Alkoxysilanes such as diphenyldimethoxysilane and phenyltriethoxysilane, hexamethyldisilazane, N, N′-bis (trimethylsilyl) urea, dimethyltrimethylsilylamine, silazanes such as trimethylsilylimidazole, vinyltrichlorosilane, γ-
Silanes such as chloropropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, benzotriazole, benzimidazole, indazole, imidazole, 2-
Heterocyclic compounds such as mercaptobenzimidazole, 2-mercaptobenzthiazole, 2-mercaptobenzoxazole, urazole, thiouracil, mercaptoimidazole, mercaptopyrimidine, and urea such as 1,1-dimethylurea and 1,3-dimethylurea, or Thiourea compounds may be mentioned. These adhesion aids are usually added in an amount of 10 parts by weight per 100 parts by weight of the alkali-soluble resin.
It is blended in a proportion of less than 5 parts by weight, preferably less than 5 parts by weight.

A spinner or coater is provided on a substrate (eg, a silicon / silicon dioxide coating, a glass substrate, a transparent substrate such as an ITO substrate, etc.) on which the above positive photoresist composition is used for the production of precision integrated circuit devices. After applying a suitable coating method such as pre-baking, exposing through a specified mask, and post-baking (PEB: Post Exposure Bak)
Performing e), developing, rinsing, and drying can provide a good resist.

[0060]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited to these examples. Unless otherwise specified,% means% by weight. Synthesis Example (1) Synthesis of Photosensitive Material (A) α, α ′, α ″ -Tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene 35.3 g, 1,2-naphthoquinonediazide-5-sulfonyl Chloride (53.7 g) and acetone (800 ml) were charged into a three-necked flask and uniformly dissolved.
21.2 g of triethylamine was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 3 liters of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried to obtain 75.0 g of a photosensitive material (A).

Synthesis Example (2) Synthesis of Photosensitive Material (B) 2,6-bis (4-hydroxy-3,5-dimethylbenzyl) -p-cresol 37.6 g, 1,2-naphthoquinonediazide-5-sulfonyl Chloride (53.7 g) and acetone (750 ml) were charged into a three-necked flask and uniformly dissolved. Then
21.2 g of triethylamine was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture is a 1% aqueous hydrochloric acid solution 250
The mixture was poured into 0 ml and the precipitate formed was filtered off, washed with water and dried (4
0 ° C.) to obtain 1,2-naphthoquinonediazide-5-sulfonic acid ester of the following compound, photosensitive material (B) 72.1
g was obtained.

Synthesis Example (3) Synthesis of Photosensitive Material (C) 4,4 ′, 4 ″ -Trihydroxy-3,5,3 ′, 5′-tetramethylphenylmethane 39.3 g, 1,2-naphthoquinonediazide 53.7 g of -5-sulfonyl chloride and 750 ml of chloroform were charged into a three-necked flask and uniformly dissolved.
21.2 g of triethylamine was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was concentrated and redissolved in acetone. The obtained mixed solution was poured into 2.5 liters of a 1% hydrochloric acid aqueous solution, and the resulting precipitate was filtered off, washed with water and dried (40
C.), 1,2-naphthoquinonediazide-5-sulfonic acid ester of the following compound, photosensitive material (C) 72.1 g
I got

Synthesis Example (4) Synthesis of Novolac Resin A 43 g of m-cresol, 57 g of p-cresol, 49 g of 37% aqueous formalin solution and 0.13 g of oxalic acid were placed in a three-neck flask and heated to 100 ° C. with stirring. Then, it was reacted for 15 hours. Thereafter, the temperature was raised to 200 ° C. and the pressure was gradually reduced to 5 mmHg to remove water, unreacted monomers, formaldehyde, oxalic acid and the like. Then, the molten alkali-soluble novolac resin was returned to room temperature and recovered. The obtained novolak resin A had a weight average molecular weight of 8200 (in terms of polystyrene) and a dispersity of 6.3.
It was 0.

Synthesis Example (5) Synthesis of novolac resin B 60 g of m-cresol, 15 g of p-cresol, 28 g of 2,5-xylenol, 53 g of 37% aqueous formalin solution and 0.15 g of oxalic acid were placed in a three-necked flask and stirred. Meanwhile, the temperature was raised to 100 ° C. and the reaction was performed for 12 hours. Thereafter, the temperature was raised to 200 ° C. and the pressure was gradually reduced to 1 mmHg to remove water, unreacted monomers, formaldehyde, oxalic acid and the like. Next, the molten novolak resin was returned to room temperature and collected. The resulting novolak resin had a weight average molecular weight of 4,800 (in terms of polystyrene). Next, this novolac resin 20
g was completely dissolved in 60 g of methanol, and water 3
0 g was gradually added with stirring to precipitate the resin component. The upper layer was removed by decantation, the precipitated resin component was recovered, heated to 40 ° C., and dried under reduced pressure for 24 hours to obtain an alkali-soluble novolak resin B. The obtained novolak resin had a weight average molecular weight of 10700 (in terms of polystyrene) and a dispersity of 3.50. Further, the content of each of the monomer, dimer and trimer is 0.
%, 2.3% and 3.5%, and 51% of low molecular weight components were removed by the fractional reprecipitation operation.

Synthesis Example (6) Synthesis of Novolac Resin C m-cresol 65 g, p-cresol 15 g, 2,3,5-trimethylphenol 25 g, 37% formalin aqueous solution 56 g and oxalic acid 0.16 g were placed in a three-necked flask. After charging, the temperature was raised to 100 ° C. with stirring and the reaction was performed for 16 hours. Thereafter, the temperature was raised to 200 ° C. and the pressure was gradually reduced to 1 mmHg to remove water, unreacted monomers, formaldehyde, oxalic acid and the like. Next, the molten novolak resin was returned to room temperature and collected. The obtained novolak resin had a weight average molecular weight of 3800 (in terms of polystyrene). Next, this novolac resin 20
g was completely dissolved in 60 g of acetone, 60 g of hexane was gradually added thereto while stirring, and the mixture was allowed to stand for 2 hours.
The upper layer was removed by decantation, the precipitated resin component was recovered, heated to 40 ° C., and dried under reduced pressure for 24 hours to obtain an alkali-soluble novolak resin C. The obtained novolak resin had a weight average molecular weight of 8700 (in terms of polystyrene) and a dispersity of 3.40. The contents of monomer, dimer and trimer are 0% and 2.1, respectively.
% And 3.0%, and 56% of low molecular weight components were removed by the fractional reprecipitation operation.

Synthesis Example (7) Synthesis of Novolac Resin D p-cresol 25 g, o-cresol 19 g, 2,3-dimethylphenol 50 g, 2,3,5-trimethylphenol 20 g, 2,6-dimethylphenol 4.9 g Was mixed with 50 g of diethylene glycol monomethyl ether and charged into a three-necked flask equipped with a stirrer, a reflux condenser and a thermometer. Then, 85 g of a 37% aqueous formolin solution was added, and the mixture was stirred while being heated in an oil bath at 110 ° C. When the internal temperature reached 90 ° C, 6.3 g of oxalic acid dihydrate was added. Then, the temperature of the oil bath is 130 ° C for 18 hours
To continue the reaction, then remove the reflux condenser and
The unreacted monomer was removed by distillation under reduced pressure at 00 ° C. The obtained novolac resin has an Mw of 3620 and a dispersity of 2.
79.

Preparation and Evaluation of Positive Photoresist Composition Photosensitive Materials A to C obtained in the above Synthesis Examples (1) to (3) and novolak resin A obtained in the Synthesis Examples (4) to (7). ~
D, a solvent, and a compound of general formula (I) or a polyhydroxy compound for comparison were mixed at a ratio (weight) shown in Table 1 below to form a uniform solution, and a Teflon microfilter having a pore size of 0.10 μm was used. And filtered to prepare a photoresist composition. Using a spinner, this photoresist composition was coated on a silicon wafer while changing the rotation speed, and dried on a vacuum adsorption hot plate at 90 ° C. for 60 seconds,
A resist film having a film thickness of 0.76 μm was obtained.

[0068]

[Table 1]

[0069]

[Table 2]

The compounds used as additives in Table 1 are as shown in Table 2 below.

[0071]

[Table 3]

This film was exposed using a reduction projection exposure apparatus (reduction projection exposure apparatus NSR-2005i9C manufactured by Nikon Corporation), then PEB was performed at 110 ° C. for 60 seconds, and the film was exposed to 1% with a 2.38% tetramethylammonium hydroxide aqueous solution. It was developed for 1 minute, washed with water for 30 seconds and dried. The resist pattern of the thus obtained silicon wafer was observed with a scanning electron microscope to evaluate the resist. Table 3 shows the results.
Shown in

[0073]

[Table 4]

In Table 3, the sensitivity was defined as the reciprocal of the exposure dose for reproducing a mask pattern of 0.50 μm, and shown as a relative value to the sensitivity of the resist of Comparative Example 1.
The resolving power represents a limiting resolving power at an exposure amount for reproducing a mask pattern of 0.50 μm. The heat resistance was a temperature at which a silicon wafer having a resist pattern formed thereon was baked on a vacuum adsorption hot plate for 4 minutes and the pattern was not deformed. The resist shape is 0.50
The angle (θ) between the resist wall surface and the plane of the silicone wafer in the cross section of the resist pattern of μm. The development latitude represents a change in the line width of a resist pattern of 0.5 μm at the same exposure amount when the development method is changed from the paddle method to the shower method. The line width was almost unchanged, and the slightly observed line was marked with Δ, and the large one was marked with x. Development residue (scum) is 0.50 μm
The degree of development residue remaining in the resist pattern of No. 2 is shown. The case in which no residue is observed is indicated by ◯, the case in which some residue is observed is indicated by Δ, and the one which is considerably left is indicated by x. As can be seen from the results in Table 3, the resist containing the carboxylic acid of the present invention has excellent sensitivity, resolution, resist shape, heat resistance, and developability (a good balance of resist characteristics), and particularly Was excellent.

[0075]

According to the present invention, it is possible to provide a positive photoresist composition having high sensitivity and excellent in resolution, resist shape, developability, heat resistance, and particularly resolution.

Claims (2)

[Claims] 1. A positive photoresist composition comprising an alkali-soluble resin, a quinonediazide compound, and a compound represented by formula (I). Embedded image In formula (I), R ₁ represents a hydrogen atom or an alkyl group, and R _1
2 is a hydrogen atom, an alkyl group, -COOR ₃ (where R ₃
Represents a hydrogen atom or an optionally substituted alkyl group or cycloalkyl group. ). However, R ₁ and R ₂ do not represent hydrogen atoms at the same time. Z is 5 or 6
Represents a group of atoms necessary for forming an alicyclic condensed ring having a 5-membered cycloalkane or a 6-membered cycloalkane. n represents an integer of 1 to 3. The general formula (I)
In the compound represented by, _two of R ₂ may combine with each other to form a dimer. 2. The dispersity of the alkali-soluble resin (ratio of weight average molecular weight (Mw) to number average molecular weight (Mn), Mw
/ Mn) is 1.5 to 4.0, The positive photoresist composition according to claim 1, wherein