JPH0934107A - Positive type photoresist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure high sensitivity, high resolving power and low dependency on film thickness by using quinonediazidosulfonic ester of a polyhydroxy compd. having a specified structure. SOLUTION: This photoresist compsn. contains an alkali-soluble resin and 1,2-naphthoquinonediazido-5-(and/or -4-)sulfonic ester of a polyhydroxy compd. represented by formula I or II. The average rate of esterification of the quinonediazidosulfonic ester is 25-75%. In the formulae I, II, each of R1 -R6 and R1 '-R4 ' is H, halogen, alkyl, alkenyl, aryl, alkoxy, acyl or cycloalkyl, each of A and A' is -S-, -O-, -C(=O)-, -C(=O)O-, -S(=O)-, -S(=O)2 - or -C(R5 R6 )(R5 and R6 may form a ring and may be of the same kind) and each of (a)-(h) is an integer of 0-3.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention contains an alkali-soluble resin and a specific 1,2-quinonediazide compound, and emits radiation such as ultraviolet rays, far ultraviolet rays, X-rays, electron beams, molecular beams, γ-rays and synchrotron radiation. Relates to a positive photoresist composition which is sensitive to, and more specifically, relates to a positive photoresist for microfabrication, which has high resolution and high sensitivity regardless of film thickness variation and has a good development latitude. It is a thing.

[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. 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.

The degree of integration of integrated circuits is increasing, and 0.5 is used in the manufacture of semiconductor substrates such as VLSI.
It is becoming necessary to process an ultrafine pattern composed of a line radiation of μm or less. In such applications, there is a demand for a photoresist that can obtain a particularly high resolution and that has a wide development latitude in order to always maintain a constant processing radiation. In addition, in order to prevent processing defects of the circuit, the resist pattern after development,
It is required that no resist residue is generated.

Further, particularly in the formation of an ultrafine pattern of 0.5 μm or less, for example, even if a certain resolution is obtained with a certain coating thickness, it can be obtained by slightly changing the coating thickness. Phenomenon that resolution deteriorates (hereinafter,
It is known that there is "film thickness dependency"). Surprisingly, the resolution changes greatly when the film thickness changes by only a few hundreds of μm, and more or less than any of the typical positive photoresists currently on the market. I also found that there was a tendency. Specifically, when the thickness of the resist film before exposure changes within a range of λ / 4n (λ is the exposure wavelength, n is the refractive index of the resist film at that wavelength) with respect to the predetermined film thickness, The resolution that is applied varies. The problem of this film thickness dependence is, for example, SPIE Proceedings Vol.
The existence thereof was pointed out, and it is stated that this is caused by the multiple reflection effect of light in the resist film.

In particular, it has been found that this film thickness dependence is often increased when an attempt is made to increase the contrast of the resist so as to obtain a pattern having a high resolution and a rectangular cross section. When actually processing a semiconductor substrate, a pattern is formed by using a resist film applied with a film thickness slightly different depending on the location due to the unevenness on the substrate surface or the unevenness of the coating film thickness. Therefore, this film thickness dependence has been one obstacle in performing fine processing close to the resolution limit using a positive photoresist.

A quinonediazide sulfonic acid ester of a polyhydroxy compound in which an aromatic ring is linked by an oxygen atom is described in the following patent publications. For example, Japanese Patent Publication No. 2-12
96, JP-A-2-285351, and JP-A-2-29624.
No. 8, No. 4-274431, No. 6-148878 and No. 7-159989. In addition, JP-A-4-
Japanese Patent No. 242257 discloses, for example, a quinonediazide sulfonic acid ester of a polyhydroxy compound represented by the following formula [III], but in this photosensitive material, the resolution and the film thickness dependency were insufficient.

[0007]

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Further, Japanese Patent Application Laid-Open No. 7-120916 discloses a quinonediazide sulfonic acid ester of a polyhydroxy compound represented by the following formula [IV], but this photosensitive material is still unsatisfactory in terms of resolution. Was enough.

[0009]

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Further, Japanese Patent Laid-Open No. 7-159990 discloses a quinonediazide sulfonic acid ester of a polyhydroxy compound represented by the following formula [V]. In this photosensitive material, the resolution and the film thickness dependence are Was still dissatisfied.

[0011]

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[0012]

As described above, how to design the composition of the resist material is completely known so far in order to obtain high sensitivity, high resolution and excellent film thickness dependence. There wasn't. Therefore, the object of the present invention is to
It is to provide a positive photoresist composition for ultrafine processing, which has high sensitivity, high resolution and excellent film thickness dependency. In the present invention, the term "thickness dependency" refers to a resist obtained by exposure and (baking as necessary) and development when the film thickness of the resist before exposure changes in the range of λ / 4n. This is a change in resolution.

[0013]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies, paying attention to the above-mentioned characteristics, and as a result, by using a quinonediazide sulfonic acid ester of a polyhydroxy compound having a specific structure as a photosensitive material, the above-mentioned problems can be solved. They have found that they can be solved, and have completed the present invention based on this finding. That is, an object of the present invention is to provide an alkali-soluble resin and a 1,2-naphthoquinonediazide-5- (and / or-4-) sulfonic acid ester of a polyhydroxy compound represented by the following general formula [I] or [II]. A positive photoresist composition containing the quinonediazidosulfonic acid ester having an average esterification rate of 25% or more and 75% or less.

[0014]

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R ₁ , R ₂ , R ₁ ', R ₂ ', which may be the same or different, are a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an acyl group or a cyclo group. Alkyl group, R ₃ , R ₄ , R ₃ ′, R ₄ ′; which may be the same or different, hydrogen atom, halogen atom, alkyl group, alkenyl group, alkoxy group, cycloalkyl group, A, A ′; S-, -O-, -C (= O)-, -C (=
O) O-, -S (= O)-, -S (= O) _2- , -C
(R ₅ R ₆ )-(provided that R ₅ and R ₆ may form a ring), R ₅ and R ₆ may be the same or different and each is a hydrogen atom,
Alkyl group, ah: representing an integer of 0-3.

Hereinafter, the present invention will be described in detail. General above
In the formulas [I] and [II], R₁~ R₆, R₁’~
R_FourAs the alkyl group of ', a methyl group, an ethyl group,
Pill group, isopropyl group, n-butyl group, isobutyl
Group, sec-butyl group, tert-butyl group, etc.
Alkyl groups of the numbers 1 to 4 are preferred, more preferably methyl
Group, ethyl group, propyl group, isopropyl group,
A methyl group and an ethyl group are particularly preferable. R₁~ R_Four,
R₁’～ R _FourAs the halogen atom of ', chlorine atom, bromine
Atom and iodine atom are preferable, and chlorine atom is particularly preferable.
Yes. Examples of alkenyl groups include vinyl, propenyl, and
Ryl groups are preferred. A methoxy group as an alkoxy group,
A lower alkoxy group such as an ethoxy group is preferred, and methoxy
A group and an ethoxy group are more preferable. As a cycloalkyl group
Of these, a cyclopentyl group and a cyclohexyl group are preferable.
R₁, R_TwoAnd R₁', R_TwoIs an aryl group of '
Phenyl group, toluyl group, xylyl group, cumenyl group, mesh
A tyl group is preferable, and as the acyl group, a formyl group or an acetyl group is used.
A toxy group and a benzoyl group are preferable. Also the general formula
In [I] and [II], R₁, R_Two, R₁', R_Two'When
Is a hydrogen atom, chlorine atom, methyl group, ethyl group, ant
Group, phenyl group, methoxy group, cyclohexyl group are preferred.
More preferably, hydrogen atom, chlorine atom, methyl group, ethyl group,
A ryl group and a methoxy group are particularly preferable. R_Three, R_Four,
R_Three', R_FourAre hydrogen atom, chlorine atom, methyl group,
Ethyl group and allyl group are preferred. As connecting chains A and A '
Is -S-, -O-, -C (R_FiveR₆)-Is more preferred
, Especially -C (R_FiveR₆)-Is preferred. R_Five, R₆When
However, a hydrogen atom and a methyl group are more preferable.

Regarding the substitution position of each substituent, the hydroxyl group on the internal aromatic ring is preferably in the para-position or ortho-position with respect to the central connecting chain -O-, and particularly preferably in the para-position. At least one of both ortho positions of the hydroxyl group on the terminal aromatic ring is preferably a hydrogen atom. In the general formula [I], the structure of the terminal aromatic ring is preferably a phenol structure, an o-substituted structure, an m-substituted structure or a 2,5-substituted structure, and particularly preferably a phenol structure or a 2,5-substituted structure. , The reason is not clear. Further, in the general formula [II], a phenol structure is preferable. JP-A-7-15999
As disclosed in Japanese Unexamined Patent Publication (Kokai) No. 0, those having a p-substituted structure at the end are not preferable. It is not preferable that both ortho positions of the hydroxyl group on the internal aromatic ring are hydrogen atoms at the same time. In other words, it is preferable to dispose substituents or connecting chains at both ortho positions of the hydroxyl group so as to electronically or sterically hinder the esterification of the hydroxyl group.

General formulas [I] and [II] in the present invention
Specific examples of the compound represented by are shown below. However, the content of the present invention is not limited to these. These may be used alone or in combination of two or more.

[0019]

[Chemical 6]

[0020]

[Chemical 7]

[0021]

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The photosensitive material of the present invention includes, for example, the above polyhydroxy compound and 1,2-naphthoquinonediazide-5.
(And / or -4-) sulfonyl chloride can be obtained by carrying out an esterification reaction in the presence of a base catalyst. That is, a predetermined amount of a polyhydroxy compound and 1,2-naphthoquinonediazide-5- (and / or -4-) sulfonyl chloride and acetone, methyl ethyl ketone, dioxane, dimethoxyethane, tetrahydrofuran, diglyme, ethyl acetate, dichloromethane, chloroform, A solvent such as γ-butyrolactone or N-methylpyrrolidone is charged into a flask, and a base catalyst such as sodium hydroxide, sodium carbonate, triethylamine, 4-
Dimethylaminopyridine, N-methylmorpholine, N-
Methylpiperazine, N-methylpyrrolidine and the like are added dropwise for condensation. The obtained product was crystallized in water and washed with water,
Further refine and dry.

In the usual esterification reaction, various mixtures having different esterification numbers and esterification positions can be obtained. However, by selecting the synthesis conditions or the structure of the polyhydroxy compound, only certain isomers can be selectively selected. It can also be synthesized. The average esterification rate referred to in the present invention is defined as the average value of the esterification rates of those mixtures having different esterification rates. The esterification rate thus defined can be controlled by the molar ratio of the quinonediazide sulfonyl chloride as a raw material and the polyhydroxy compound to be mixed. That is, since the added quinonediazide sulfonyl chloride undergoes an esterification reaction substantially all, in order to obtain a mixture having a desired average esterification rate, the charging ratio (molar ratio) of the quinonediazide sulfonyl chloride as a raw material and the polyhydroxy compound is obtained. [Mole number of quinonediazide sulfonyl chloride / mol number of polyhydroxy compound] may be adjusted.

The preferred molar ratio of 1,2-naphthoquinonediazide-5- (and / or -4-) sulfonyl chloride to the polyhydroxy compound (general formulas [I] and [II]) is 1.0 to 3 0.0, more preferably 1.2 to 2.8, and even more preferably 1.5 to 2.
5 That is, the preferable range of the average esterification rate is 25% to 75%, more preferably 30% to 70%.
%, And more preferably 37.5% to 62.5%.
If the average esterification rate is less than 25%, a remarkable film loss occurs, and if it exceeds 75%, the high sensitivity and the film thickness dependency, which are the effects of the present invention, deteriorate. Furthermore, as the photosensitive material of the present invention, a quinonediazide diester of the polyhydroxy compound represented by the above general formulas [I] and [II] is preferable, that is, the proportion of the diester in the mixture having different esterification numbers is 254 nm. It is preferable that the area ratio of high performance liquid chromatography at the measurement wavelength is 50% or more. It is more preferably 55% or more, and further preferably 60% or more.

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 1
It is 5 to 100 parts by weight, preferably 20 to 60 parts by weight, relative to 00 parts by weight. When the use ratio is less than 5 parts by weight, the residual film rate is remarkably lowered, and when it exceeds 100 parts by weight, the sensitivity and the solubility in a solvent are lowered.

In the present invention, the above-mentioned photosensitive material should be used, but if necessary, 1,2-naphthoquinonediazide-5- (and / or-) of the polyhydroxy compound shown below is used.
4-) An esterified product with sulfonyl chloride can be used in combination. At this time, the ratio of the naphthoquinone diazide ester photosensitive material of these polyhydroxy compounds to the photosensitive material in the present invention is 20/80 to 80/20 (weight ratio).
Is preferable. That is, if the photosensitive material of the present invention is less than 20% by weight of the total photosensitive material, the effect of the present invention cannot be sufficiently exhibited.

As the polyhydroxy aromatic compound,
For example, 2,3,4-trihydroxybenzophenone,
2,4,4'-trihydroxybenzophenone, 2,
4,6-trihydroxybenzophenone, 2,3,4
4'-tetrahydroxybenzophenone, 2,2 ',
4,4'-tetrahydroxybenzophenone, 2,4
Polyhydroxybenzophenones such as 6,3 ′, 4 ′, 5′-hexahydroxybenzophenone and 2,3,4,3 ′, 4 ′, 5′-hexahydroxybenzophenone
2,3,4-trihydroxyacetophenone, 2,3
Polyhydroxyphenyl alkyl ketones such as 4-trihydroxyphenylhexyl ketone, bis (2,4-dihydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, bis (2,4-dihydroxyphenyl) Bis ((poly) hydroxyphenyl) alkanes such as propane-1, polyhydroxybenzoic acid esters such as propyl 3,4,5-trihydroxybenzoate and phenyl 3,4,5-trihydroxybenzoate
Bis (polyhydroxybenzoyl) alkanes such as bis (2,3,4-trihydroxybenzoyl) methane, bis (2,3,4-trihydroxybenzoyl) benzene or bis (polyhydroxybenzoyl) aryls, ethylene glycol-di Alkylene-di (polyhydroxybenzoates) such as (3,5-dihydroxybenzoate), 3,5,3 ′, 5′-biphenyl tetrol,
2,4,2 ', 4'-biphenyl tetrol, 2,4
6,3 ', 5'-biphenylpentol, 2,4,6
Polyhydroxybiphenyls such as 2 ′, 4 ′, 6′-biphenylhexol,

4,4 ', 4 "-trihydroxy-3,
5,3 ', 5'-tetramethyltriphenylmethane,
4,4 ', 4 "-trihydroxy-3" -methoxy-
3,5,3 ', 5'-tetramethyltriphenylmethane, 4,4', 2 "-trihydroxy-3,5,3 ',
5'-tetramethyltriphenylmethane, 4,4 ',
2 "-trihydroxy-2,2'-dimethyl-5,5 '
-Dicyclohexyltriphenylmethane, 4,4 ',
2 "-trihydroxy-2,5,2 ', 5'-tetramethyltriphenylmethane, 4,4', 3", 4 "-tetrahydroxy-3,5,3 ', 5'-tetramethyltriphenyl Methane, 4,4 ', 2 ", 3", 4 "-pentahydroxy-3,5,3', 5'-tetramethyltriphenylmethane, 2,3,4,2 ', 3', 4 ', 3 ″,
Polyhydroxytriphenylmethanes such as 4 ″ -octahydroxy-5,5′-diacetyltriphenylmethane, 3,3,3 ′, 3′-tetramethyl-1,1′-spirobi-indane-5,6,6. 5 ', 6'-tetrol,
3,3,3 ', 3'-Tetramethyl-1,1'-spirobi-indan-5,6,7,5', 6 ', 7'-hexool, 3,3,3', 3'-tetra Methyl-1,1 '
-Spirobiindane-4,5,6,4 ', 5', 6'-
Hexool, 3,3,3 ', 3'-tetramethyl-
1,1'-spirobi-indane-4,5,6,5 ',
Polyhydroxyspirobi-indanes such as 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], 2- (3,4-
Dihydroxyphenyl) -3,5,7-trihydroxybenzopyran, 2- (3,4,5-trihydroxyphenyl) -3,5,7-trihydroxybenzopyran, 2
-(3,4-dihydroxyphenyl) -3- (3,4,
5-trihydroxybenzoyloxy) -5,7-dihydroxybenzopyran, 2- (3,4,5-trihydroxyphenyl) -3- (3,4,5-trihydroxybenzoyloxy) -5,7-dihydroxy Polyhydroxybenzopyrans such as benzopyran, 2,4,4-trimethyl-2- (2 ', 4'-dihydroxyphenyl)
-7-hydroxychroman, 2,4,4-trimethyl-
2- (2 ', 3', 4'-trihydroxyphenyl)-
Polyhydroxyphenyl chromanes such as 7,8-dihydroxychroman, 2,4,4-trimethyl-2- (2 ', 4', 6'-trihydroxyphenyl) -5,7-dihydroxychroman, 2,6- Screw (2,3,4-
Trihydroxybenzyl) -4-methylphenol,
2,6-bis (2,4-dihydroxybenzyl) -4-
Methylphenol, 2,6-bis (5-chloro-2,4
-Dihydroxybenzyl) -4-methylphenol,
2,6-bis (2,4,6-trihydroxybenzyl)
-4-Methylphenol, 2,6-bis (2-acetyl-3,4,5-trihydroxybenzyl) -4-methylphenol, 2,4,6-tris (2,3,4-trihydroxybenzyl) Phenol, 2,6-bis (3,5
-Dimethyl-4-hydroxybenzyl) -4-methylphenol, 2,6-bis (2,5-dimethyl-4-hydroxybenzyl) -4-methylphenol, 2,6-bis (2,5-dimethyl-4) -Hydroxybenzyl) -4
-Phenylphenol, 2,6-bis (2,5-dimethyl-4-hydroxybenzyl) -4-cyclohexylphenol, 2,6-bis (4-hydroxybenzyl)-
4-cyclohexylphenol, 2,6-bis {3'-
(4 "-hydroxybenzyl) -4'-hydroxy-
5'-methylbenzyl} -4-cyclohexylphenol, 2,6-bis {3 '-(3 "-methyl-4" -hydroxybenzyl) -4'-hydroxy-5'-methylbenzyl} -4-cyclohexylphenol , 2, 4, 6
-Tris (3,5-dimethyl-4-hydroxybenzyl) -phenol, 4,6-bis (3,5-dimethyl-
4-hydroxybenzyl) pyrogallol, 2,6-bis (3-methyl-4-hydroxybenzyl) -4-methylphenol, 2,6-bis (3,5-dimethyl-4-hydroxybenzyl) phloroglucinol, etc. Hydroxybenzylphenols,

2,2'-dihydroxy-5,5'-bis (4 "-hydroxybenzyl) biphenol, 2,2 '
-Dihydroxy-3,3'-dimethoxy-5,5'-bis (4 "-hydroxybenzyl) biphenol, 2,
2'-dihydroxy-3,3'-dimethoxy-5,5 '
-Bis (3 ", 5" -dimethyl-4 "-hydroxybenzyl) biphenol, 2,2'-dihydroxy-3,
3'-dimethoxy-5,5'-bis (3 "-methyl-
4 "-hydroxybenzyl) biphenol, 4,4'-
Dihydroxy-3,3'-dimethyl-5,5'-bis (3 ", 5" -dimethyl-4 "-hydroxybenzyl)
Biphenols such as biphenols, 1,3,3,5-
Tetrakis (4-hydroxyphenyl) pentane, 1,
1-bis {3 '-(4 "-hydroxybenzyl) -4'
-Hydroxy-5'-methylphenyl} cyclohexane, 1,1-bis {3 '-(3 "-methyl-4" -hydroxybenzyl) -4'-hydroxy-5'-methylphenyl} cyclohexane, 1, 1-bis {3'-
(3 ", 6" -dimethyl-4 "-hydroxybenzyl)
-4'-hydroxy-5'-methylphenyl} cyclohexane, 4,4'-methylenebis {2- (4 "-hydroxybenzyl) -3,6-dimethylphenol}, 4,
4'-methylenebis {2- (3 "-methyl-4" -hydroxybenzyl) -3,6-dimethylphenol},
4,4'-methylenebis {2- (3 "-methyl-4"-
(Hydroxybenzyl) -3-cyclohexyl-6-methylphenol}, 4,4'-methylenebis {2-
(2 ", 4" -dihydroxybenzyl) -6-methylphenol}, 1,8-bis {3 '-(4 "-hydroxybenzyl) -4'-hydroxy-5'-methylphenyl} menthane, 1,8 -Bis {3 '-(3 "-methyl-
4 "-hydroxybenzyl) -4'-hydroxy-5 '
Hydroxyphenylalkanes such as -methylphenyl} menthane,

3,3'-bis (4 "-hydroxybenzyl) -4,4'-dihydroxy-5,5" -diallyldiphenylether, 3,3'-bis (4 "-hydroxybenzyl) -4 , 4'-dihydroxy-5,5 "-dimethyldiphenyl thioether, 3,3'-bis (3"-
Methyl-4 ″ -hydroxybenzyl) -4,4′-dihydroxy-5,5 ″ -dimethyldiphenylthioether, 3,3′-bis (3 ″, 6 ″ -dimethyl-4 ″ -hydroxybenzyl) -4,4 ′ -Dihydroxy-5,
5 "-dimethyldiphenyl thioether, 3,3'-bis (3" -methyl-4 "-hydroxybenzyl) -4,
Diphenyl ethers such as 4'-dihydroxy-5,5 "-diallyl diphenyl ether, 2,6-bis (4 '
-Hydroxybenzyl) -4-benzenesulfonamide-phenol, 2,6-bis (3 ', 6'-dimethyl-4'-hydroxybenzyl) -4-benzenesulfonamide-phenol and other sulfonamide phenols or quercetin, Flavono pigments such as rutin,
Furthermore, a low nucleolar form of novolac, or an analogue thereof can be used.

Further, a polymer containing an aromatic hydroxyl group such as acetone pyrogallol condensation resin or polyvinylphenol can be used instead of these low molecular weight compounds. Further, it is possible to substitute the hydroxyl group of novolac itself with quinonediazide in an appropriate amount so that it also functions as a photosensitive material or as a binder.

Among these, in particular, a portion having one or more aromatic hydroxyl groups on the same aromatic ring is included, and a total of 3
Those having a structure having one or more hydroxyl groups are preferable.
In addition, 1,2-naphthoquinonediaside-5- (and / or-, which is a known aromatic or aliphatic polyhydroxy compound,
4-) Sulfonic acid ester compounds include, for example, JP-B-56-2333, JP-B-62-3411, JP-B-3-2293, JP-B-3-42656, JP-A-58-150948, and JP-A-58-150948. 60-154249
No. 60-134235, JP-A 62-10646, JP-A 62-
153950, JP60-146234A, JP62-178562A, JP63-113451A, JP64-76047A, JP1-147538A.
No. 1, JP-A 1-189644, JP-A 1-309052, JP-A 2-19
846, JP2-84650, JP2-72363, JP2-1
03543, JP-A-2-285351, JP-A-2-296248, JP-A-2-296249, JP-A-3-48251, JP-A-3-48249, JP-A-3-119358, JP-A-3-144454 No. 3-185447
No. 4-1652, No. 4-60548, No. 5-15823
No. 4, JP-A-5-224410, JP-A No. 5-303198, JP-A No. 5-2
97580, Japanese Unexamined Patent Publication No. 5-323597, Japanese Patent Application No. 5-251781, Japanese Patent Application No. 5-251780, Japanese Patent Application No. 5-233537, U.S. Pat.No. 4,797,34
No. 5, No. 4,957,846, No. 4,992,356, No. 5,151,340,
Examples thereof include compounds described in JP-A-5,178,986, European Patent Nos. 530,148 and 573,056.

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 preferred,
It is obtained by subjecting a given monomer as a main component to addition condensation with an aldehyde in the presence of an acidic catalyst. As the predetermined monomer, phenol, m-cresol, p
Cresols such as -cresol, 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 and 3,5 Alkoxyphenols such as -dimethoxyphenol, 2-methoxy-4-methylphenol, m-ethoxyphenol, p-ethoxyphenol, m-propoxyphenol, p-propoxyphenol, m-butoxyphenol and p-butoxyphenol; 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 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 in the range of 1,500 to 25,000. If it is less than 1500, the film loss of the unexposed portion after development is large, and if it exceeds 25,000, the developing speed is reduced. Here, the weight average molecular weight is defined as a value in terms of polystyrene by gel permeation chromatography. Also, the degree of dispersion of the novolak resin (ratio of weight average molecular weight Mw to number average molecular weight Mn, ie, Mw / Mn)
Is preferably 1.5 to 7.0, and more preferably 1.5 to 5.0. If the dispersity exceeds 7, the effect of the present invention cannot be obtained. When the dispersity is less than 1.5, a high-level purification step is required for synthesizing the novolac resin, which is unsuitable for practical use. The weight average molecular weight and dispersity of the novolak resin can be appropriately set depending on the type of the novolac resin.

The alkali-soluble resin is a novolak resin synthesized by a condensation reaction between a mixture containing two or more kinds of phenol, cresol, xylenol and trimethylphenol (however, m-cresol is essential) and an aldehyde compound. In this case, the weight average molecular weight is 5500.
~ 25,000, more preferably 6
2,000 to 25,000. Further, the novolak resin has a ratio of the weight average molecular weight to the number average molecular weight of 1.5 to 5.0.
It is preferably 0. The alkali-soluble resin is p
It was synthesized by a condensation reaction of a mixture containing at least four of o-cresol, o-cresol, 2,3-xylenol, 2,6-xylenol and trimethylphenol (o-cresol is essential) with an aldehyde compound. If at least one novolak resin,
The ratio between the weight average molecular weight and the number average molecular weight is 1.5 to 5.0, and the weight average molecular weight is preferably 1500 to 6000. As described above, the effect of the present invention becomes more remarkable by setting the weight average molecular weight and the polydispersity within predetermined ranges depending on the type of novolac resin used.

The low molecular compound having a phenolic hydroxyl group (water-insoluble alkali-soluble low molecule) that can be used in the present invention will be described.

The composition of the present invention preferably further contains a water-insoluble alkali-soluble low molecule in order to accelerate the dissolution in the developing solution. Thereby, the development latitude can be improved. Specific examples of the water-insoluble alkali-soluble low molecular weight include polyhydroxy compounds. Preferred polyhydroxy compounds include:
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.

Among these, as the water-insoluble alkali-soluble low-molecular compound, the total number of carbon atoms in one molecule is 60 or less, and the water-insoluble alkali-soluble low-molecular compound having 2 to 8 phenolic hydroxyl groups in one molecule is used. Compounds are preferred. Further, the water-insoluble alkali-soluble low molecular weight compound has a ratio of phenolic hydroxyl group to aromatic ring of 0.5 to 1.
4, and preferably at least one water-insoluble alkali-soluble low-molecular compound having 12 to 60 phenolic hydroxyl groups in one molecule, having a total carbon number of 12 to 60 in one molecule. . Among these compounds, compounds that increase the alkali dissolution rate of the alkali-soluble resin when added to the water-insoluble alkali-soluble resin are particularly preferable. As a result, the development latitude is further improved. If the compound has more than 60 carbon atoms, the effect of the present invention is reduced. If the number is smaller than 12, new drawbacks such as a decrease in heat resistance occur. In order to exert the effects of the present invention, it is necessary to have at least two hydroxyl groups in the molecule, but if it exceeds 10, the effect of improving the development latitude is lost. On the other hand, when the ratio of the phenolic hydroxyl group to the aromatic ring is less than 0.5, the film thickness dependency is large, and the development latitude tends to be narrow. If this ratio exceeds 1.4, the stability of the composition deteriorates, and it becomes difficult to obtain high resolution and good film thickness dependence, which is not preferable.

The amount of the low molecular weight compound added is preferably 1 to 100% by weight, more preferably 2 to 80% by weight, based on the alkali-soluble resin. An addition amount exceeding 100% by weight is not preferable because the development residue deteriorates and a new defect that a pattern is deformed during development occurs. The water-insoluble alkali-soluble low molecular weight compound having an aromatic hydroxyl group used in the present invention is described in, for example,
22938, 2-28531, 2-242973,
2-275959, 4-251849, 5-30
3199, 5-22440, 6-301204, U.S. Pat. Nos. 4,916,210 and 5,210,657,
It can be easily synthesized by those skilled in the art with reference to the methods described in US Pat. No. 5,318,875 and European Patent No. 219294.

Solvents for dissolving the photosensitive material and the alkali-soluble novolac resin used in 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, cyclopentanone, cyclohexanone, 4-methoxy-4-methyl-2-pentanone, ethyl 2-hydroxypropionate, 2-hydroxy-2-methyl Ethyl propionate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-
Methyl hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, etc. 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,
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.)
, MegaFac F171, F173 (Dainippon Ink Co., Ltd.), Florado FC430,431 (Sumitomo 3M Ltd.), Asahi Guard AG710, Surflon S-382, SC101, SC102, SC103,
SC104, SC105, SC106 (Asahi Glass Co., Ltd.)
Manufactured by Shin-Etsu Chemical Co., Ltd., an acrylic acid-based or methacrylic acid-based (co) polymerized polyflow No.
75, no. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK) 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.

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. Furthermore, alcohols such as isopropyl alcohol and surfactants such as nonionic surfactants may be added to the aqueous solution of the above alkalis in appropriate amounts.

A light absorber, a cross-linking agent, and an adhesion aid can be added to the positive photoresist composition of the present invention, 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-absorbing agents described in “Technologies and Markets of Industrial Dyes” (CMC Publishing) and Dye Handbook (edited by the Society of Synthetic Organic Chemistry), for example, CI Di
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,
29, 30, 31, 44, 57, 72 and 73, CI Disperse Red
1, 5, 7, 13, 17, 19, 43, 50, 54, 58, 65, 72, 73, 8
8, 117, 137, 143, 199 and 210, CI Disperse Viole
t 43, CI Disperse Blue 96, CI Fluorescent Br
ightening Agent 112, 135 and 163, CI Solvent Yel
low 14, 16, 33 and 56, CI Solvent Orange 2 and 4
5, CI Solvent Red 1, 3, 8, 23, 24, 25, 27 and 4
9, CI Pigment Green 10, CI Pigment Brown 2, and the like can be suitably 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 less than 10 parts by weight, preferably less than 5 parts by weight, based on 100 parts by weight of the alkali-soluble resin.

The positive photoresist composition is spin-coated on a substrate (eg, a silicon / silicon dioxide coating, a glass substrate, a transparent substrate such as an ITO substrate) which is used for the production of precision integrated circuit devices. , Roll coating method,
After applying by a suitable coating method such as a flow coating method, a dip coating method, a spray coating method, and a doctor coating method, pre-baking is performed, exposure is performed through a predetermined mask, and post-heating (PEB: Post Exposure Bake) is performed as necessary. ,
By developing, rinsing and drying, a good resist can be obtained.

[0053]

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 [I-1] 4 equipped with stirrer, reflux condenser, thermometer, dropping device
A one-necked flask was charged with 60.7 g of bis (4-hydroxyphenyl) ether, 76.2 g of allyl bromide, 91.2 g of potassium carbonate and 1.2 L of dimethylformamide, and stirred with heating at 70 ° C. for 8 hours. The obtained reaction mixture was put into 3 L of distilled water, and the white powder deposited was collected by filtration. The powder was recrystallized with water to obtain 58 g of a white crystal diallyl ether compound. 40 g of the diallyl ether compound obtained above and 120 mL of N, N-dimethylaniline were charged in the same reaction apparatus, and the mixture was heated and stirred at 195 ° C. for 7 hours. After the reaction, N, N-dimethylaniline was distilled off under reduced pressure,
The brown viscous material obtained was purified by column chromatography to obtain 18 g of an o-allylated product. Furthermore, into the same reactor, charged with 18 g of the o-allylated product obtained above, 35 g of 50% dimethylamine aqueous solution, and 100 mL of ethanol,
After homogenizing, 32 g of 37% formalin aqueous solution was dropped.
The mixture was stirred under reflux conditions for 3 hours. The reaction solution was poured into 1.2 L of saline and extracted with ethyl acetate to obtain 24 g of aminomethyl compound. 24 g of the aminomethyl derivative obtained above and 100 mL of acetic anhydride were charged into the same reaction apparatus, and the mixture was heated and stirred at 150 ° C. for 4 hours. After the reaction, acetic anhydride was distilled off under reduced pressure, diluted with acetone, crystallized in 1.2 L of distilled water, extracted with ethyl acetate, and purified by column chromatography. 27 g of acetoxy compound, a pale yellow viscous substance, was obtained. Finally, 27 g of the acetoxy compound obtained above, 150 g of phenol, 100 mL of methanol
Then, 1 g of concentrated sulfuric acid was charged in the same reaction apparatus, and the mixture was heated and stirred for 8 hours under reflux conditions. The reaction mixture was crystallized in 1 L of ice water, and the obtained solid was purified by column chromatography to obtain 20 g of the desired product [I-1].

Synthesis Example (2) Compounds [I-3], [I-
8], Synthesis of [II-1] Compound [I-3] was synthesized in the same manner as in Synthesis Example (1) except that 2,5-xylenol was used instead of phenol. [I-8] and [II-1] were also synthesized by the same operation.

Synthesis Example (3) Synthesis of Photosensitive Material a A compound (I-1) (49.5 g), 1,2-naphthoquinonediazide-5-sulfonyl chloride (53.7 g) and acetone (800 mL) were charged into a three-necked flask and homogenized. Dissolved in. Then, 20.8 g of N-methylpiperidine was gradually added dropwise, and the mixture was reacted at 25 ° C for 3 hours. The reaction mixture was poured into 2.8 L of a 1% hydrochloric acid aqueous solution, and the generated precipitate was filtered off,
After washing with water and drying (40 ° C.), the compound [I-1] 1,
91.0 g of 2-naphthoquinonediazide-5-sulfonic acid ester (photosensitive material a) was obtained. Average esterification rate is 5
It was 0%. In high performance liquid chromatography measured using a detector using 254 nm ultraviolet light,
The diester form of the photoconductor a was 60% of the entire pattern area. In addition, the measurement of the said high performance liquid chromatography uses the LC-6A chromatograph made by Shimadzu Corporation, and Nova-PakC18 made by Waters.
(4 μm) 8 mmφ × 100 mm column was used, and as a carrier solvent, distilled water 68.6%, acetonitrile 3
A solution of 0.0%, 0.7% triethylamine and 0.7% phosphoric acid was applied at a flow rate of 2.0 ml / min.

Synthetic Example (4) Synthesis of Photosensitive Material b Compound [I-1] 49.5 g, 1,2-naphthoquinonediazide-5-sulfonyl chloride 67.2 g, and acetone 1000 mL were charged into a three-necked flask and homogenized. Dissolved in. Then, 26.0 g of N-methylpiperidine was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 3.3 L of a 1% hydrochloric acid aqueous solution, the resulting precipitate was filtered off, washed with water and dried (40 ° C.) to obtain 1,2-naphthoquinonediazide-5-sulfonic acid of compound [I-1]. 102.0 g of ester (photosensitive material b) was obtained. The average esterification rate was 62.5%. In high performance liquid chromatography measured using a detector using 254 nm ultraviolet light, the diester form of the photoconductor b was 52% of the total pattern area.

Synthesis Example (5) Synthesis of Photosensitive Material c (for Comparison) By the same operation as in Synthesis Example (3), the average esterification rate is 80%.
1,2-naphthoquinonediazide of the compound [I-1] of
5-Sulfonic acid ester (photosensitive material c) was synthesized. Two
In high performance liquid chromatography measured with a detector using 54 nm ultraviolet light, the diester form of the photoconductor c was 3% of the total pattern area.

Synthesis Example (6) Synthesis of Photosensitive Material d 55.1 g of compound [I-3], 53.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 900 mL of acetone were charged in a three-necked flask and homogeneously charged. Dissolved in. Then, 20.8 g of N-methylpiperidine was gradually added dropwise, and the mixture was reacted at 25 ° C for 3 hours. The reaction mixture was poured into 3.0 L of 1% hydrochloric acid aqueous solution, and the generated precipitate was filtered off,
After washing with water and drying (40 ° C.), the compound [I-3] 1,
95.2 g of 2-naphthoquinonediazide-5-sulfonic acid ester (photosensitive material d) was obtained. Average esterification rate is 5
It was 0%. In high performance liquid chromatography measured using a detector using 254 nm ultraviolet light, the diester form of the photoconductor d was 55% of the entire pattern area.

Synthesis Example (7) Synthesis of Photosensitive Material e Compound [I-8] 47.1 g, 1,2-naphthoquinonediazide-5-sulfonyl chloride 53.7 g, and acetone 800 mL were charged into a three-necked flask and homogenized. Dissolved in. Then, 20.8 g of N-methylpiperidine was gradually added dropwise, and the mixture was reacted at 25 ° C for 3 hours. The reaction mixture was poured into 2.8 L of a 1% hydrochloric acid aqueous solution, and the generated precipitate was filtered off,
After washing with water and drying (40 ° C.), the compound [I-8] 1
2-8.8 g of 2-naphthoquinonediazide-5-sulfonic acid ester (photosensitive material e) was obtained. Average esterification rate is 5
It was 0%. In high performance liquid chromatography measured using a detector using 254 nm ultraviolet light, the diester form of the photoconductor e was 58% of the total pattern area.

Synthesis Example (8) Synthesis of Photosensitive Material f 47.1 g of compound [II-1], 53.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 800 mL of acetone were charged into a three-necked flask and homogeneously charged. Dissolved in. Then, 20.8 g of N-methylpiperidine was gradually added dropwise, and the mixture was reacted at 25 ° C for 3 hours. The reaction mixture was poured into 2.8 L of a 1% hydrochloric acid aqueous solution, and the generated precipitate was filtered off,
After washing with water and drying (40 ° C.), the compound [II-1] 1,
88.2 g of 2-naphthoquinonediazide-5-sulfonic acid ester (photosensitive material f) was obtained. Average esterification rate is 5
It was 0%. In high performance liquid chromatography measured using a detector using 254 nm ultraviolet light, the diester form of the photoconductor f was 70% of the entire pattern area.

Synthesis Example (9) Synthesis of Photosensitive Material g (for Comparison) 30.7 g of compound [III], 53.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 700 mL of acetone were charged in a three-necked flask. , Uniformly dissolved. Then, 21.2 g of triethylamine was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2.4 L of a 1% hydrochloric acid aqueous solution, and the generated precipitate was filtered off, washed with water,
After drying (40 ° C.), 73.3 g of 1,2-naphthoquinonediazide-5-sulfonic acid ester of Compound [III] (photosensitive material g) was obtained. The average esterification rate was 50%. In high performance liquid chromatography measured using a detector using 254 nm ultraviolet light, the diester form of the photosensitive material g was 45% of the total pattern area.

Synthesis Example (10) Synthesis of Photosensitive Material h (for Comparison) 43.4 g of Compound [IV], 53.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 800 mL of acetone were charged in a three-necked flask. , Uniformly dissolved. Then, 20.8 g of N-methylpiperidine was gradually added dropwise, and the mixture was reacted at 25 ° C for 3 hours. 1% reaction mixture
The mixture was poured into 2.8 L of hydrochloric acid aqueous solution, the resulting precipitate was filtered off, washed with water and dried (40 ° C.), and 1,2-naphthoquinonediazide-5-sulfonic acid ester of Compound [IV] (photosensitive material h) 73. 3 g was obtained. The average esterification rate was 50%. In high performance liquid chromatography measured using a detector using 254 nm ultraviolet light, the photosensitive material g
The diester product of was 40% of the total pattern area.

Synthesis Example (11) Synthesis of Photosensitive Material i (for Comparison) According to the method described in JP-A-7-15990, 1,2-naphthoquinonediazide-5-sulfonic acid ester of compound [V] (photosensitive) The product i) was synthesized. The average esterification rate was 70%. In high performance liquid chromatography measured with a detector using 254 nm ultraviolet light, the diester form of the photosensitive material g was 30% of the total pattern area.
%Met.

Synthesis Example (12) Synthesis of Photosensitive Material j (for Comparison) 47.1 g of Compound [V], 53.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 800 mL of acetone were charged in a three-necked flask. , Uniformly dissolved. Then, 20.8 g of N-methylpiperidine was gradually added dropwise, and the mixture was reacted at 25 ° C for 3 hours. 1% reaction mixture
It was poured into 2.8 L of an aqueous hydrochloric acid solution, the resulting precipitate was separated by filtration, washed with water and dried (40 ° C.), and 1,2-naphthoquinonediazide-5-sulfonic acid ester of Compound [V] (photosensitive material j) 89. 0 g was obtained. The average esterification rate was 50%. In the high performance liquid chromatography measured using a detector using ultraviolet rays of 254 nm, the photosensitive material j
The diester product of was 53% of the total pattern area.

Synthesis Example (13) Synthesis of Novolac Resin A p-cresol 30 g, o-cresol 14 g, 2,3
-Dimethylphenol 50g, 2,3,5-trimethylphenol 20g, 2,6-dimethylphenol 4.9
g was mixed with 50 g of diethylene glycol monomethyl ether and equipped with a stirrer, a reflux condenser and a thermometer.
The flask was charged in a one-necked flask. Next, 85 g of a 37% formalin aqueous solution was added, and the mixture was stirred while heating in an oil bath at 110 ° C. When the internal temperature reached 90 ° C, 6.3 g of oxalic acid 2
Hydrate was added. After that, the oil bath temperature is set to 130 for 18 hours.
The reaction was continued while maintaining the temperature at 0 ° C, then the reflux condenser was removed, and the mixture was distilled under reduced pressure at 200 ° C to remove the unreacted monomer.
The obtained novolak resin had a weight average molecular weight of 3280 (in terms of polystyrene) and a dispersity of 2.75.

Synthesis Example (14) Synthesis of Novolac Resin B m-cresol 259.5 g, p-cresol 9.7
g, 2,3-dimethylphenol 62.3 g, and 37% formalin aqueous solution 218.1 g were charged into a three-necked flask equipped with a stirrer, a reflux condenser and a thermometer, and oxalic acid dihydrate 1 was stirred at 90 ° C. 0.13 g was added. 30 minutes later,
The bath temperature was raised to 130 ° C., and the contents were refluxed by further stirring for 3 hours and 30 minutes. Then, the reflux condenser was replaced with a Liebig condenser, and the bath temperature was raised to 200 ° C. over about 1 hour to remove unreacted formalin, water and the like. One more
After performing normal pressure distillation for a period of time, the pressure was gradually reduced to 1 mmHg to distill off unreacted monomers and the like. Two hours were required for distillation under reduced pressure. Next, the molten novolak resin was returned to room temperature and collected. The obtained novolak resin had a weight average molecular weight of 2290 (in terms of polystyrene). Next, 100 g of this novolak resin was completely dissolved in 1000 g of acetone, 1000 g of n-hexane was added with stirring, and the mixture was further stirred at room temperature for 30 minutes, and then allowed to stand for 1 hour. The upper layer was removed by decantation, and the remaining lower layer was distilled off the solvent using a rotary evaporator to obtain a novolak resin B. The obtained novolak resin had a weight average molecular weight of 5430 (in terms of polystyrene) and a dispersity of 2.4.
Met.

Preparation and Evaluation of Positive Photoresist Compositions [Examples 1 to 7] Above Synthesis Examples (3) to (4) and (6) to
Photosensitive materials a, b, d to f obtained in (8), novolak resins A and B obtained in Synthesis Examples (13) and (14) above.
Solvent and polyhydroxy compound (P): α, α, α '
-Tris (4-hydroxyphenyl) -1-ethyl-4
-Isopropylbenzene was mixed at a ratio shown in Table 1 to form a uniform solution, which was then filtered using a Teflon microfilter having a pore size of 0.10 µm to prepare a photoresist composition. This photoresist composition using a spinner,
It was applied on a silicon wafer while changing the rotation speed, and dried at 90 ° C. for 60 seconds on a vacuum contact hot plate to obtain resist films having film thicknesses of 0.97 μm and 1.02 μm, respectively. After exposing this film using a reduction projection exposure apparatus (reduction projection exposure apparatus NSR-2005i9C manufactured by Nikon Corporation),
PEB was carried out at 110 ° C. for 60 seconds, followed by development with a 2.38% tetramethylammonium hydroxide aqueous solution for 1 minute, washing with water for 30 seconds and drying. The resist pattern on the silicon wafer thus obtained was observed with a scanning electron microscope to evaluate the resist. Table 2 shows the results. The sensitivity was defined by the reciprocal of the exposure dose for reproducing a mask pattern of 0.60 μm, and shown as a relative value to the sensitivity of Comparative Example 1 at a resist film thickness of 0.97 μm. The resolving power indicates a limiting resolving power at an exposure amount for reproducing a mask pattern of 0.60 μm. [Comparative Examples 1 to 5] Of the compounds used in the Examples, instead of the photosensitizers a, b and df, Synthesis Examples (5) and (9) to.
Other than using the photosensitive materials c and g to j obtained in (12),
A resist composition was prepared and evaluated in the same manner as in the examples.

[0069]

[Table 1]

[0070]

[Table 2]

[0071]

According to the present invention, it is possible to provide a positive photoresist composition having high sensitivity and excellent in resolution and film thickness dependence.

Claims (1)

[Claims] 1. An alkali-soluble resin and 1,2-naphthoquinonediazide-5- (and / or-) of a polyhydroxy compound represented by the following general formula [I] or [II].
4-) Sulfonic acid ester is contained, and the average esterification rate of the quinonediazide sulfonic acid ester is 2
5% or more and 75% or less, The positive photoresist composition characterized by the above-mentioned. Embedded image Here, R ₁ , R ₂ , R ₁ ′, R ₂ ′, which may be the same or different, are a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an acyl group, a cycloalkyl group, R ₃ , R ₄ , R ₃ ′, R ₄ ′; which may be the same or different, are a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, a cycloalkyl group, A, A ′; -O-, -C (= O)-, -C (=
O) O-, -S (= O)-, -S (= O) _2- , -C
(R ₅ R ₆ )-(provided that R ₅ and R ₆ may form a ring), R ₅ and R ₆ may be the same or different and each is a hydrogen atom,
Alkyl group, a to h: represents an integer of 0 to 3.