JPH07159989A - Positive type photoresist composition - Google Patents

Abstract

PURPOSE:To obtain a photoresist compsn. for fine work ensuring high resolving power independently of a change in film thickness, hardly generating residue on development and excellent in development latitude. CONSTITUTION:This photoresist compsn. contains 1,2-naphthoquinonediazido-5 (and/or -4-)sulfonic ester of a polyhydroxy compd. represented by the general formula and an alkali-soluble resin. In the formula, each of R1-R17 is H, halogen, alkyl, aryl, alkoxy, acyloxy, acyl, alkenyl, aralkyl or hydroxyl and each of A, B is a combining group such as -CH2- or -S-.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an ultraviolet ray, a deep ultraviolet ray, an X-ray, an electron beam, a molecular beam, a γ-ray, which contains an alkali-soluble novolac resin and a specific 1,2-quinonediazide compound.
The present invention relates to a positive photoresist composition that is sensitive to radiation such as synchrotron radiation. More specifically, high resolution can be obtained regardless of the change in film thickness, less development residue occurs, and development latitude is also improved. The present invention relates to an excellent photoresist composition for microfabrication. The positive photoresist according to the present invention is applied on a substrate such as a semiconductor wafer by spin coating or another coating method to have a thickness of 0.5 to 2 μm.
It is applied to a thickness of about. After that, it is heated and dried, and a circuit pattern or the like is baked by irradiation of ultraviolet rays through an exposure mask, and if necessary, post-exposure baking is performed and then development is performed to obtain a positive image. Furthermore, the substrate can be processed in a pattern by etching using this positive image as a mask. Typical fields of application are semiconductor manufacturing processes such as ICs, circuit boards such as liquid crystal and thermal heads, and other photofabrication processes.

[0002]

2. Description of the Related Art As a positive photoresist composition,
Generally, a composition containing an alkali-soluble resin binder such as novolac and a naphthoquinonediazide compound as a photosensitive material is used. Novolac resin as a binder is
It is particularly useful for this application because it can be dissolved in an alkaline aqueous solution without swelling, and when it is used as a mask for etching, it gives a high resistance to plasma etching. Further, the naphthoquinonediazide compound used for the photosensitive material acts as a dissolution inhibitor which lowers the alkali solubility of the novolak resin by itself, but when it is decomposed by irradiation with light, an alkali-soluble substance is produced and the alkali solubility of the novolak resin is rather increased. 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 with respect 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 higher resolution has been remarkable, and sufficient results have been achieved in line width processing down to submicrons.

Conventionally, it has been considered advantageous to use a resist having a high contrast (γ value) in order to enhance the resolution and obtain an image having a good pattern shape, and technical development of a resist composition suitable for such purpose has been carried out. Came. There are a great number of patents and reports disclosing such technology, and many patent applications have been made regarding the technology of the novolac resin, which is the main component of the positive photoresist, regarding its monomer composition, molecular weight distribution, synthetic method, etc. , Has achieved certain results. With respect to the photosensitive material which is another main component, many structures that are effective for increasing the contrast have been disclosed. If a positive photoresist is designed by utilizing such knowledge, 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, the degree of integration of integrated circuits is increasing, and in the manufacture of semiconductor substrates such as VLSI,
It has become necessary to process an ultrafine pattern having a line width of 0.5 μm or less. In such applications, there is a demand for a photoresist having a wide development latitude in order to obtain a stable and high resolving power and to always maintain a constant processing line width. Further, in order to prevent processing defects in the circuit, it is required that no resist residue is generated in the resist pattern after development.

Further, particularly in the formation of an ultrafine pattern of 0.5 μm or less, even if a constant resolution can be obtained with a certain coating film thickness, it can be obtained by slightly changing the coating film thickness. It has been found that there is a phenomenon (hereinafter referred to as film thickness dependency) that the obtained resolution deteriorates. Surprisingly, the resolution changes greatly even if the film thickness changes by only a few hundredths of μ, and moreover, there is such a tendency in all of the typical positive photoresists currently on the market. There was found. Specifically, if the thickness of the resist film before exposure changes with respect to the predetermined film thickness within the range of λ / 4n (λ is the exposure wavelength, n is the refractive index of the resist film at that wavelength) Therefore, the resolution obtained is changed.

In particular, it has been found that when the contrast of the resist is increased so as to obtain a pattern having a high resolution and a rectangular cross-sectional shape, the film thickness dependency often becomes large. When actually processing a semiconductor substrate, a pattern is formed by using a resist film applied with a film thickness slightly different for each location due to unevenness on the substrate surface or unevenness of the application film thickness. Therefore, this film thickness dependence will be one obstacle in carrying out microfabrication near the limit of its resolution using a positive photoresist. The problem of the film thickness dependence is, for example, SPIE Proceedin
Its existence is pointed out in gs 1925, p. 626 (1993), and it is caused by the multiple reflection effect of light in the resist film, and it is said that it also correlates with the insolubilization phenomenon of the resist surface. Has been.

However, in order to reduce this film thickness dependency and obtain a high resolution regardless of the film thickness, it has not been known at all until now how to design the composition of the resist material. Since the film thickness dependence is caused by multiple reflection of light, the present inventors attempted to improve this by adding a dye into the resist, but the increased light absorption by the dye eventually reduced the resolution. However, the cross-sectional shape of the pattern became trapezoidal and could not be a resist suitable for fine processing.

[0008]

SUMMARY OF THE INVENTION Therefore, a first object of the present invention is to provide a positive photoresist for ultrafine processing which has a high resolution and a small "film thickness dependency". The term "thickness dependency" as used in the present invention means the magnitude of variation in resolution obtained when the resist film thickness before exposure changes in the range of λ / 4n. Another object of the present invention is to provide a positive photoresist which has a wide development latitude and is less likely to cause development residuals. Here, the development latitude can be expressed by the development time dependency or the temperature dependency of the resist line width obtained by development. The development residue refers to a trace amount of resist insoluble matter that remains between fine patterns after development, which can be observed with a scanning electron microscope or the like.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies with the above characteristics in mind, and as a result, can achieve the above object by using an alkali-soluble resin and a quinonediazide compound having a specific structural formula. Based on this finding, they have completed the present invention. That is, an object of the present invention is to provide a polyhydroxy compound represented by the following general formula (I) with 1,2-naphthoquinonediazide-5- (and /
Or -4-) Sulfonic acid ester and an alkali-soluble resin.

[0010]

[Chemical 3]

In the general formula (I), R _{1 to} R ₁₇ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group,
Aryl group, alkoxy group, acyloxy group, acyl group,
It represents an alkenyl group, an aralkyl group or a hydroxyl group. A,
B may be the same or different and represents a linking group represented by the following chemical formula 4.

[0012]

[Chemical 4]

In the chemical formula 4, R ₁₈ and R ₁₉ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group or an alkoxy group. However, R ₁₈ and R ₁₉ may combine to form a ring.

The present invention will be described in detail below. In R _{1 to} R ₁₉ of the above general formula (I), the halogen atom is a chlorine atom, a bromine atom or an iodine atom, and the alkyl group is a methyl group, an ethyl group, a propyl group, an n-butyl group, an isobutyl group, sec. An alkyl group having 1 to 4 carbon atoms such as -butyl group or t-butyl group as the alkoxy group, methoxy group, ethoxy group, hydroxyethoxy group, propoxy group, hydroxypropoxy group, isopropoxy group, n-butoxy group. , Isobutoxy group, sec-
1 to 4 carbon atoms such as butoxy group or t-butoxy group
Alkoxy groups are preferred. The alkenyl group is preferably a C2-C4 alkenyl group such as a vinyl group, a propenyl group, an allyl group or a butenyl group.

The aryl group is a phenyl group, a xylyl group, a tolyl group or a cumenyl group, the aralkyl group is a benzyl group, a phenethyl group or an α, α-dimethylbenzyl group, and the acyloxy group is a butyryloxy group or an acetoxy group. The acyl group is preferably a formyl group, acetyl group, butyryl group, benzoyl group, cinnamoyl group or valeryl group. Among these, particularly preferable are:
Examples thereof include a chlorine atom as a halogen atom, a methyl group and an ethyl group as an alkyl group, a methoxy group and an ethoxy group as an alkoxy group, a phenyl group and a tolyl group as an aryl group, and an acetoxy group as an acyloxy group.

R _{1 to} R ₁₇ are preferably hydrogen atoms,
A halogen atom, an alkyl group, an alkoxy group and a hydroxyl group are more preferable, and a hydrogen atom, an alkyl group and a hydroxyl group are more preferable. R _{18 to} R ₁₉ are preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The ring formed by combining R ₁₈ and R ₁₉ is preferably a 5- to 7-membered ring. A, a preferably B, -O -, - S - , - SO 2 -, - CR 18 R 19 - is.

Specific examples of the compound represented by the general formula (I) include, but are not limited to, the compounds represented by the following (1) to (35). These polyhydroxy compounds are used alone or in combination of two or more.

[0018]

[Chemical 5]

[0019]

[Chemical 6]

[0020]

[Chemical 7]

[0021]

[Chemical 8]

[0022]

[Chemical 9]

[0023]

[Chemical 10]

[0024]

[Chemical 11]

[0025]

[Chemical 12]

[0026]

[Chemical 13]

[0027]

[Chemical 14]

The compound of the present invention can be prepared by, for example, partially or entirely converting the hydroxyl groups of the above polyhydroxy compound into 1,2-naphthoquinonediazide-5- (and / or -4-) sulfonyl chloride in the presence of a basic catalyst. And can be obtained by carrying out a usual esterification reaction. That is, a predetermined amount of polyhydroxy compound and 1,2-naphthoquinonediazide-5-
(And / or -4-) sulfonyl chloride, and a solvent (for example, dioxane, acetone, methyl ethyl ketone,
A solvent such as N-methylpyrrolidone, a solvent such as chloroform or a mixed solvent is charged into a flask, and a basic catalyst (for example, sodium hydroxide, sodium carbonate, sodium hydrogen carbonate,
Triethylamine etc.) is added dropwise to condense. The obtained product is crystallized in water, washed with water, purified, and dried. In the usual esterification reaction, a mixture having different numbers of esterifications and esterification positions can be obtained. However, if a synthesis condition or a structure of a polyhydroxy compound is selected, only a specific isomer is selectively esterified. You can also The esterification rate in the present invention is defined as the average value of this mixture.

The esterification rate thus defined can be controlled by the mixing ratio of the raw material polyhydroxy compound and 1,2-naphthoquinonediazide-5- (and / or -4-) sulfonyl chloride. That is, the added 1,
2-naphthoquinonediazide-5- (and / or -4-)
Substantially all of the sulfonyl chloride undergoes an esterification reaction, so the molar ratio of the raw materials may be adjusted in order to obtain a mixture having a desired esterification rate. A preferable range of the molar ratio of the polyhydroxy compound and 1,2-naphthoquinonediazide-5- (and / or -4-) sulfonyl chloride is 1/1 to 1/5, more preferably 1 / 1.5.
˜1 / 4, particularly preferably 1 / 1.5 to ⅓. When the molar ratio is within this range, a certain amount of the hydroxy groups of the polyhydroxy compound remains, which shows a good effect for the purpose of the present invention. If necessary, 1,2-naphthoquinonediazide-5-sulfonic acid ester and 1,2-naphthoquinonediazide-4-sulfonic acid ester may be used in combination. The reaction temperature in the above method is usually -2.
It is 0 to 60 ° C, preferably 0 to 40 ° C.

When the photosensitive compound of the present invention synthesized by the above-mentioned method is used as a resin composition, it may be used alone or as a mixture of two or more kinds thereof in an alkali-soluble resin. The compounding amount is novolac resin 100.
5 to 100 parts by weight of the compound, preferably 1
It is 0 to 50 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.

Examples of the alkali-soluble resin used in the present invention include novolac resin, acetone-pyrogallol resin, polyhydroxystyrene and derivatives thereof. Among these, novolac resin is particularly preferable,
It can be obtained by addition-condensing an aldehyde with a predetermined monomer as a main component in the presence of an acidic catalyst. As the predetermined monomer, phenol, m-cresol, p
-Cresols, cresols such as o-cresol, 2,
Xylenols such as 5-xylenol, 3,5-xylenol, 3,4-xylenol, 2,3-xylenol, m-ethylphenol, p-ethylphenol, o
-Alkylphenols such as ethylphenol and pt-butylphenol, trialkylphenols such as 2,3,5-trimethylphenol and 2,3,4-trimethylphenol, p-methoxyphenol, m-methoxyphenol, 3,5 -Alkoxyphenols such as dimethoxyphenol, 2-methoxy-4-methylphenol, m-ethoxyphenol, p-ethoxyphenol, m-propoxyphenol, p-propoxyphenol, m-butoxyphenol and p-butoxyphenol, 2- Bisalkylphenols such as methyl-4-isopropylphenol, m-chlorophenol, p-chlorophenol, o-chlorophenol, dihydroxybiphenyl, bisphenol A, phenylphenol,
Hydroxy aromatic compounds such as resorcinol and naphthol may be used alone or in combination of two or more, but are not limited thereto.

Examples of the 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 acetals thereof such as chloroacetaldehyde diethyl acetal can be used, and of these, formaldehyde is preferably used. These aldehydes are
They may be used alone or in combination of two or more. As the acidic catalyst, hydrochloric acid, sulfuric acid, formic acid, acetic acid, oxalic acid or the like can be used.

Further, JP-A-60-45238 and JP-A-60-45238
-97347, 60-140235, 60-1
89739, 64-14229 and JP-A-1-27.
6131, 2-60915, and 2-275955.
No. 2,282,745, No. 4,101,147, No. 4,122,938 and the like, that is, a technique in which a low-molecular component of a novolak resin is removed or reduced may be used.

The weight average molecular weight of the novolak resin thus obtained is preferably in the range of 2000 to 30000. If it is less than 2,000, the film loss of the unexposed area after development is large, and if it exceeds 30,000, the developing speed becomes small. Particularly preferred is the range of 6000 to 20000. Here, the weight average molecular weight is defined by the polystyrene conversion value of gel permeation chromatography.

In the present invention, the photosensitive material should be mainly used, but if necessary, the following polyhydroxy compound 1,2-naphthoquinonediazide-5- (and / or -4-) sulfonyl chloride may be used. The esterification product of can be used together.

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, bis ((poly) hydroxyphenyl) alkanes such as nordihydroguaiaretic acid,

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'-tetrahydroxydiphenylsulfoxide,

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, 4,4 ', 2 ",
3 ", 4" -pentahydroxy-3,5,3 ', 5'-
Tetramethyltriphenylmethane, 2,3,4,2 ',
3 ', 4'-hexahydroxy-5,5'-diacetyltriphenylmethane, 2,3,4,2', 3 ', 4',
3 ", 4"-octahydroxy-5,5'-diacetyltriphenylmethane, 2,4,6,2 ', 4', 6'-
Hexahydroxy-5,5'-dipropionyltriphenylmethane and other polyhydroxytriphenylmethanes,

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'-hexool, 3,3,3', 3'-tetramethyl-1,1'-spirobi-indane-4,5,5
Polyhydroxyspirobi-indanes such as 6,5 ′, 6 ′, 7′-hexool,

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 and 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,

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'-hydroxy-3 ', 5'-di-t-butyl-benzyl) −
p-cresol, 2,6-bis- (2'-hydroxy-
5'-ethyl-benzyl) -p-cresol, 2,6-
Bis- (2 ', 4'-dihydroxy-benzyl) -p-
Cresol, 2,6-bis- (2'-hydroxy-3 '
-T-butyl-5'-methyl-benzyl) -p-cresol, 2,6-bis- (2 ', 3', 4'-trihydroxy-5'-acetyl-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'-dimethyl-benzyl) -pyrogallol, 4,6-bis-
(4'-Hydroxy-3 ', 5'-dimethoxy-benzyl) -pyrogallol, 2,6-bis- (4'-hydroxy-3', 5'-dimethyl-benzyl) -1,3,4-
Trihydroxy-phenol, 4,6-bis- (2 ',
4 ', 6'-trihydroxy-benzyl) -2,4-dimethyl-phenol, 4,6-bis- (2', 3 ',
4'-trihydroxy-benzyl) -2,5-dimethyl-phenol and the like can be mentioned.

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

The naphthoquinone diazide ester photosensitive materials of these polyhydroxy compounds are used alone or in combination of two or more kinds.

The composition of the present invention may further contain a polyhydroxy compound in order to accelerate the dissolution in the developing solution. Preferred polyhydroxy compounds are phenols, resorcin, phloroglucin, 2,3,4-
Trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, 2,3,4,3 ',
4 ', 5'-hexahydroxybenzophenone, acetone-pyrogallol condensation resin, phlorogluside, 2,4
2 ', 4'-biphenyl tetrol, 4,4'-thiobis (1,3-dihydroxyphenyl) 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-
Examples thereof include hydroxyphenyl) -1,3,5-triisopropylbenzene, α, α ′, α ″ -tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene, etc. These polyhydroxy compounds Can be added in an amount of usually 100 parts by weight or less, preferably 5 to 50 parts by weight or less, relative to 100 parts by weight of the quinonediazide compound.

Solvents for dissolving the photosensitive material and the alkali-soluble novolak resin of the present invention include 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, toluene,
Xylene, methyl ethyl ketone, cyclohexanone, 2
-Ethyl hydroxypropionate, 2-hydroxy-2
-Ethyl methylpropionate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, 3-ethoxypropionic acid Methyl, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate and the like can be used. These organic solvents are used alone or in combination of two or more.

Furthermore, N-methylformamide, N, N-
Dimethylformamide, N-methylacetamide, N,
A high-boiling solvent such as N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, benzyl ethyl 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 alkylaryl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate,
Sorbitan fatty acid esters such as sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, poly Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as oxyethylene sorbitan trioleate and polyoxyethylene sorbitan tristearate, F-top 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) and the like. 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 of the present invention. These surfactants may be added alone or in some combinations.

As a developer for the positive photoresist composition of the present invention, 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 an aqueous solution of alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide, cyclic amines such as pyrrole and piperidine, and alkalis such as You can Further, an appropriate amount of alcohols and surfactants may be added to the above aqueous solution of alkalis for use.

The positive type foot resist composition of the present invention may contain a dye, a plasticizer and an adhesion aid, if necessary. Specific examples thereof include dyes such as methyl violet, crystal violet and malachite green, plasticizers such as stearic acid, acetal resin, phenoxy resin and alkyd resin, and adhesion aids such as hexamethyldisilazane and chloromethylsilane.

The positive photoresist composition is applied onto a substrate (eg, silicon / silicon dioxide coating) used for the production of precision integrated circuit devices by a suitable coating method such as a spinner or coater, and then prebaked. Exposure through a specified mask and post-heating (PEB: Po
A good resist can be obtained by carrying out st Exposure Bake), developing, rinsing and drying.

[0063]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. In addition,% indicates weight% unless otherwise specified. Synthesis example 1: Synthesis of compound example (1) 2,6-bis (hydroxymethyl) -p-cresol 5
0.6 g of o-cresol 194.7 g of methanol 2
It was dissolved in 00 ml, and 9.1 g of 36% hydrochloric acid was added. Then, the mixture was reacted under heating under reflux for 7 hours. The reaction mixture was added to water 4
The mixture was poured into a liter, the precipitate was washed with water, and further stirred in hexane / CH ₂ Cl ₂ (2/1) to remove unreacted raw materials. By recrystallizing with ethanol / water, 54 g of a white solid was obtained. NMR confirmed that this was 2,6-bis (3'-methyl-4'-hydroxybenzyl) -p-cresol. The obtained 2,6-bis (3'-methyl-4'-hydroxybenzyl) -p-cresol 34.9 g and potassium hydroxide 5.7 g were dissolved in methanol / water (4/6) 300 ml to give 37%. 81 g of formalin was added. Then, the mixture was reacted at 40 ° C. for 24 hours. The reaction mixture was diluted with 500 ml of water and then neutralized with acetic acid. The precipitated pale yellow solid was filtered and washed with water,
2,6-bis (3'-methyl-4'-hydroxy-5 '
-Hydroxymethylbenzyl) -p-cresol 35 g
Got To 20.5 g of this 2,6-bis (3'-methyl-4'-hydroxy-5'-hydroxymethylbenzyl) -p-cresol, 56.5 g of phenol and 200 ml of methanol were added, and 3.0 g of 36% hydrochloric acid was further added. It was added and heated to reflux for 7 hours. Then, the mixture was poured into 3 liters of water, and the precipitated light brown solid was purified by column chromatography (filler: silica gel, eluent: hexane / ethyl acetate = 3/1). 12 g of white powder was obtained, and it was confirmed by NMR that this had the structure of Compound Example (1).

Synthesis Example 2: Synthesis of Compound Example (15) Instead of 50.5 g of 2,6-bis (hydroxymethyl) -p-cresol of Synthesis Example 1, 4,6-bis (hydroxymethyl) -2- Methylphenol (50.5 g) was used. Others were the same as in Synthesis Example 1 except that white powder (14 g) was used.
Got It was confirmed by NMR that this was the example compound (15).

Synthesis Example 3: Synthesis of Compound Example (6) 2,6-bis (hydroxymethyl) -p-cresol 1
6.8 g and 91.3 g of bis (3-methyl-4-hydroxyphenyl) methane (manufactured by Honshu Kagaku Kogyo) were dissolved in 200 ml of methanol, and 6.1 g of 36% hydrochloric acid was added.
Then, it heated and refluxed for 24 hours. The reaction mixture was poured into 3 liters of water, and the viscous solid precipitated was washed with water and then purified by column chromatography (filler: silica gel, eluent: hexane / ethyl acetate = 2/1). 28 g of white powder was obtained, and it was confirmed by NMR that this was the structure of Compound Example (6).

Synthesis Example 4: Synthesis of Photosensitive Material a (Invention) Compound Example (1) 11.2 g, 1,2-naphthoquinonediazide-5-sulfonyl chloride 10.7 g and acetone 2
It was dissolved in 00 ml. 4.2g of triethylamine
20 ml of acetone solution was added dropwise at room temperature over 30 minutes, and the reaction was continued for another 3 hours. After adding 2.5 g of acetic acid to the reaction mixture, it was poured into 3 liters of water. The deposited yellow precipitate was separated by filtration, washed with water and dried to obtain 19.5 g of 1,2-naphthoquinonediazide-5-sulfonic acid ester (photosensitive material a) of Compound Example (1).

Synthesis Example 5: Synthesis of Photosensitive Material b (Invention) 11.2 g of Compound Example (15), 13.4 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 200 ml of acetone were charged into a three-necked flask. , Uniformly dissolved. Then, triethylemine / acetone = 5.3 g
/ 20 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 3000 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain 1,2-naphthoquinonediazide-5-sulfonic acid ester of Compound Example (15) ( 21.5 g of photosensitive material b) was obtained.

Synthesis Example 6: Synthesis of Photosensitive Material c (Invention) Compound Example (6) 11.8 g, 1,2-naphthoquinonediazide-5-sulfonyl chloride 10.7 g, and acetone 200 ml were charged into a three-necked flask. , Uniformly dissolved. Then, triethylamine / acetone = 4.2 g /
20 ml was gradually added dropwise and reacted at 25 ° C. for 3 hours.
The reaction mixture was poured into 3000 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain 1,2-naphthoquinonediazide-5-sulfonic acid ester of Compound Example (6) ( 20.7 g of photosensitive material c) was obtained.

Synthesis Example 7: Synthesis of Photosensitive Material d (for Comparison) 12.3 g of 2,3,4,4'-tetrahydroxybenzophenone shown in Chemical Formula 15 below, 1,2-naphthoquinonediazide-5-sulfonyl chloride 40.3 g and 300 ml of acetone were charged into a three-necked flask and uniformly dissolved. Then, triethylamine / acetone = 15.2
g / 50 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 1500 ml of a 1% aqueous hydrochloric acid solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to give 1,2,2-naphtho of 2,3,4,4′-tetrahydroxybenzophenone. 39.7 g of quinonediazide-5-sulfonic acid ester (photosensitive material d) was obtained.

[0070]

[Chemical 15]

Synthesis Example 8: Synthesis of Photosensitive Material e (for Comparison) 42.5 g of α, α, α'-tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene shown in Chemical Formula 16 below, 1,2-naphthoquinonediazide-5-
61.8 g of sulfonyl chloride and 650 m of acetone
1 was charged into a three-necked flask and uniformly dissolved. Then
Triethylamine / acetone = 24.4 g / 80 ml was gradually added dropwise, and the mixture was reacted at 25 ° C. for 4 hours. The reaction mixture was poured into 2500 ml of a 1% hydrochloric acid aqueous solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to obtain α, α, α ′.
-Tris (4-hydroxyphenyl) -1-ethyl-4
83.1 g of 1,2-naphthoquinonediazide-5-sulfonic acid ester of isopropylbenzene (photosensitive material e) was obtained.

[0072]

[Chemical 16]

Synthesis Example 9: Synthesis of Photosensitive Material f (for Comparison) 2,2-bis [4-hydroxy-
30.8 g of 3,5-di (4-hydroxybenzyl) phenyl] propane, 1,2-naphthoquinonediazide-5
-Sulfonyl chloride 53.8 g, and acetone 600
ml was charged into a three-necked flask and uniformly dissolved. Then, triethylamine / acetone = 21.3 g / 50 m
1 was gradually added dropwise and reacted at 25 ° C. for 6 hours. The reaction mixture was poured into 2500 ml of a 1% hydrochloric acid aqueous solution, the precipitate formed was filtered off, washed with water and dried (40 ° C.) to give 2,2-
1,2-naphthoquinonediazide-5-sulfonic acid ester of bis [4-hydroxy-3,5-di (4-hydroxybenzyl) phenyl] propane (photosensitive material f) 67.2
g was obtained.

[0074]

[Chemical 17]

Synthesis Example 10: Synthesis of Photosensitive Material g (for Comparison) o-Cresol Novolac Oligomer shown in Chemical Formula 18 below, OCN-4400 (average molecular weight 830, binuclear body to 1)
01.5 mixture; manufactured by Nippon Kayaku), 41.5 g, 1,2-
Naphthoquinonediazide-5-sulfonyl chloride 37.
6 g and 500 ml of acetone were charged into a three-necked flask and uniformly dissolved. Then, triethylamine / acetone = 14.9 g / 50 ml was gradually added dropwise at 4 ° C at 25 ° C.
Reacted for hours. The reaction mixture was added with 1% hydrochloric acid aqueous solution 2500
The resulting precipitate was filtered off, washed with water and dried (4
0 ° C.) to give 1,2-naphthoquinonediazide-5-sulfonate of OCN-4400 (photosensitive material g).
71.5 g was obtained.

[0076]

[Chemical 18]

Synthesis Example 11: Synthesis of Novolac Resin A 40 g of m-cresol, 60 g of p-cresol, 37%
Formalin aqueous solution (49 g) and oxalic acid (0.13 g) were charged into a three-necked flask, heated to 100 ° C. with stirring, and reacted for 15 hours. Then raise the temperature to 200 ° C,
The pressure was gradually reduced to 5 mmHg to remove water, unreacted monomers, formaldehyde, oxalic acid and the like. Then, the molten alkali-soluble novolak resin was returned to room temperature and recovered. The obtained novolak resin A had a weight average molecular weight of 7100 (in terms of polystyrene).

Synthesis Example 12: Synthesis of novolak resin B m-cresol 50 g, p-cresol 25 g, 2,5
-Xylenol 28 g, 37% formalin aqueous solution 53 g
Then, 0.15 g of oxalic acid was charged into a three-necked flask, the temperature was raised to 100 ° C. with stirring, and the reaction was performed for 12 hours. Then, the temperature was raised to 200 ° C., and the pressure was gradually reduced to 1 mmHg, and water, unreacted monomers, formaldehyde, oxalic acid, etc. were distilled off. Then, the molten novolac resin was returned to room temperature and recovered. The obtained novolak resin had a weight average molecular weight of 4,300 (in terms of polystyrene). Next, 20 g of this novolak resin was completely dissolved in 60 g of methanol, and then 30 g of water was gradually added thereto 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 B had a weight average molecular weight of 8920 (in terms of polystyrene), and the contents of the monomer, dimer and trimer were 0% and 2.3, respectively.
% And 3.5%.

Examples 1 to 6 and Comparative Examples 1 to 4 Preparation and Evaluation of Positive Photoresist Compositions Photosensitive materials a to g obtained in Synthesis Examples 4 to 10 and synthesis examples 11 and 12 described above. A novolak resin, a solvent and, if necessary, a polyhydroxy compound were mixed in a ratio shown in Table 1 to form a uniform solution, which was then filtered using a microfilter having a pore size of 0.10 μm to prepare a photoresist composition. This photoresist composition was applied to a silicon wafer using a spinner, and a vacuum adsorption hot plate
After drying at 0 ° C for 60 seconds, the film thickness is 0.97μm and 1.02μ
m resist films were obtained. A reduction projection exposure device (reduction projection exposure device NSR-2005i manufactured by Nikon Corporation) is formed on this film.
After exposure with 9C), PEB was performed at 110 ° C. for 60 seconds, development was performed with a 2.38% tetramethylammonium hydroxide aqueous solution for 1 minute, followed by washing with water for 30 seconds and drying. The resist pattern of the silicon wafer thus obtained was observed with a scanning electron microscope to evaluate the resist. The results are shown in Table 2. Sensitivity is defined as the reciprocal of the exposure dose that reproduces a 0.60 μm mask pattern,
The value is shown as a relative value with respect to the sensitivity at a resist film thickness of 1.02 μm in Comparative Example 1. The residual film rate was expressed as a percentage of the ratio of the unexposed area before and after development. The resolving power represents a limiting resolving power at an exposure amount for reproducing a mask pattern of 0.60 μm.
The heat resistance was a temperature at which a resist-patterned silicon wafer was baked on a hot plate for 4 minutes and the deformation of the pattern did not occur. The shape of the resist is represented by the angle (θ) formed by the resist wall surface and the plane of the silicon wafer in the 0.50 μm resist pattern cross section. Regarding the storage stability, the solution of the positive photoresist composition was allowed to stand at room temperature, and the presence or absence of precipitates in the solution after 3 months was examined. The thing which precipitation was not observed was represented by (circle), and the thing observed was represented by x.

[0080]

[Table 1]

[0081]

[Table 2]

As can be seen from Table 2, in the system using the compound of the present invention, the variation in resolution and resist shape due to a slight difference in film thickness due to a slight difference in film thickness was smaller than that in the comparative example, and the film thickness dependence. It has excellent properties. In addition, the system using the compound of the present invention has excellent heat resistance and solvent solubility. (Comparison of Examples 1, 2, 3 and Comparative Examples 1, 2, 3 and Comparison of Examples 4, 5 with Comparative Examples 4, 5)

[0083]

According to the present invention, a photoresist composition for microfabrication having a high resolving power irrespective of the variation of the film thickness, a small amount of development residue and an excellent development latitude can be obtained.

Claims (1)

[Claims] 1. A 1,2-naphthoquinonediazide-5- (and / or -4-) sulfonic acid ester of a polyhydroxy compound represented by the following general formula (I) and an alkali-soluble resin. Positive photoresist composition. [Chemical 1] In formula (I), R _{1 to} R ₁₇ may be the same or different and represent a hydrogen atom, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an acyloxy group, an acyl group, an alkenyl group, an aralkyl group or a hydroxyl group. . A and B may be the same or different and represent a linking group represented by the following chemical formula 2. [Chemical 2] In Chemical formula 2, R ₁₈ and R ₁₉ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, an aryl group or an alkoxy group. However, R ₁₈ and R ₁₉ may combine to form a ring.