JP3501427B2 - Positive photoresist composition - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention contains an alkali-soluble resin and a specific 1,2-quinonediazide compound, and
The present invention relates to a positive photoresist composition sensitive to radiation such as deep ultraviolet rays, X-rays, electron beams, molecular beams, γ-rays, and synchrotron radiation. The present invention also relates to a positive photoresist for microfabrication, which provides high sensitivity and has a good development latitude.

[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. After that, it is heated and dried, and a circuit pattern or the like is baked through an exposure mask by irradiation of ultraviolet rays or the like, and if necessary, post-exposure baking is performed and then development is performed 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 film thickness, it can be obtained by slightly changing the coating film 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 P
Its existence was pointed out in roceedings 1925, p. 626 (1993), 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 when the contrast of the resist is increased so as to obtain a pattern having a high resolution and a rectangular cross section, the film thickness dependency is often increased. 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.

To date, a large number of 1,2-naphthoquinonediazide compounds, which are polyhydroxy compounds having a specific structure, have been proposed in order to increase the resolution. For example,
JP-A-57-63526, 60-163043, and 6
2-10645, 62-2, 10646, 62-150.
245, 63-220139, 64-76047,
JP-A-1-189644, 2-285351, 2-
296248, 2-296249, 3-4824
9, Same 3-48250, Same 3-158856, Same 3-2
28057, Japanese Patent Publication No. 4-502519, US Patent 495.
7846, 4992356, 5151340, 5
178986, European Patent 530148, etc. However, even if these photosensitive materials are used, they are insufficient from the viewpoint of reducing the film thickness dependency.

On the other hand, by using a photosensitive material having a hydroxyl group in the molecule, a resist having high contrast and high resolution can be obtained, for example, as described in JP-B-37-18.
015, JP-A-58-150948, JP-A-2-198.
46, ibid. 2-103543, ibid. 3-228057, ibid. 5
-323597, 6-148878, 6-2023.
21, the same 6-167805, U.S. Pat.
Same 3130047, same 3130048, same 313004
9, 3102809, 3184310, 3188
210, same 3180733, West German patent 938233, SP
IE Proceedings Vol. 631, page 210, Vol. 1672, page 231 (1992
, 1672, 262 (1992) and 1925, 227 (19).
1993) etc.

[0010]

However, even if these photosensitive materials are used, satisfactory resolution and film thickness dependence cannot be obtained. Thus, it has never been known how to design the composition of the resist material in order to obtain high resolution and excellent film thickness dependence.

Therefore, an object of the present invention is to provide a positive photoresist composition for ultrafine processing, which has a high resolution and an excellent film thickness dependency. In the present invention, “thickness dependency” means that the film thickness of the resist before exposure is λ
It refers to the fluctuation of the resolution of a resist obtained by exposure and (if necessary, baking) when it changes in the range of / 4n.

[0012]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies with attention to the above-mentioned characteristics, and as a result, have identified a specific quinonediazide sulfonic acid ester of an alkali-soluble resin and a polyhydroxy compound having a specific mother nucleus structure. The use of a positive photoresist containing a diester compound in a proportion, and using a positive photoresist in a specific region in which the proportion of all quinonediazide sulfonates containing the quinonediazide sulfonic acid ester in the resist solid content is certain. The inventors have found that the points 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, a low molecular weight compound having a phenolic hydroxyl group, and 1,2 of a polyhydroxy compound represented by the following general formula [I].
-A quinonediazide-5- (and / or -4-) sulfonic acid diester is contained, and the pattern area ratio of the quinonediazidosulfonic acid diester measured by high performance liquid chromatography with a measurement wavelength of 254 nm is 50% or more of the total pattern area. And the ratio of the weight of all the quinonediazide-based photosensitive materials to the weight of the solid content in the resist composition is 23% or more and 45% or less, which is achieved by the positive photoresist composition.

[0014]

[Chemical 3]

Here, R ₁ and R ₂ may be the same or different and each represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group or a cycloalkyl group, and R ₃ to R ₆ are They may be the same or different and represent an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group, R ₇ and R ₈ may be the same or different and represent a hydrogen atom or an alkyl group, R, R ′,
R ″ and R ′ ″ may be the same or different and each represents a hydrogen atom or an alkyl group, a and b represent 0, 1, 2, and 3, and A represents

[0016]

[Chemical 4]

R _{9 to} R ₁₄ and R _{18 to} R ₂₁ may be the same or different and each represents a hydrogen atom or an alkyl group (R ₉ and R ₁₀ may form a ring),
R ₁₅ , R ₁₇ and R _{23, which} may be the same or different, each represents a hydrogen atom, an alkyl group or an alkoxy group, and R ₁₆ ,
R ₂₂ and R ₂₄ may be the same or different and each represents an alkyl group, a cycloalkyl group or an aryl group.

The present invention will be described in detail below. In the above general formula [I], R _{1 to} R ₂₄ , R, R ′, R ″, R ′ ″
Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, s
An alkyl group having 1 to 4 carbon atoms such as an ec-butyl group and a tert-butyl group is preferable, and a methyl group, an ethyl group, a propyl group, an isopropyl group is more preferable,
A methyl group and an ethyl group are particularly preferable. As the halogen atom of R ₁ and R ₂ , chlorine atom, bromine atom and iodine atom are preferable, and chlorine atom is particularly preferable. The alkenyl group represented by R _{1 to} R ₆ is preferably a vinyl group, a propenyl group or an allyl group, more preferably an allyl group. R _{1 to} R ₆ ,
The aryl group of R ₁₆ , R ₂₂ , and R ₂₄ is a phenyl group,
A toluyl group, a xylyl group, a cumenyl group and a mesityl group are preferable. As the alkoxy group for R ₁ , R ₂ , R ₁₅ , R ₁₇ , and R ₂₃ , a lower alkoxy group such as a methoxy group and an ethoxy group is preferable, and a methoxy group and an ethoxy group are more preferable. The cycloalkyl group of R _{1 to} R ₆ , R ₁₆ , R ₂₂ and R ₂₄ is preferably a cyclopentyl group or a cyclohexyl group.

In the general formula [I], R₁, R₂age
Are hydrogen atom, methyl group, ethyl group, chlorine atom, ant
Group, methoxy group and cyclohexyl group are preferred.
R₃, R _FourOf these, a methyl group and an ethyl group are preferable.
R_Five, R₆Examples include methyl group, ethyl group, cyclohexyl group
Syl group and allyl group are preferred. R₇, R₈As the water
Elemental atoms and methyl groups are preferred. R, R ', R ", R'"
Of these, a hydrogen atom and a methyl group are preferable. R₉~
R₁₄, R₁₈~ R_{twenty one}As for, a hydrogen atom and a methyl group are preferred.
Good R₁₅, R₁₇, R_{twenty three}As a hydrogen atom, methyl
A methoxy group is preferred. R₁₆, R_{twenty two}, R_{twenty four}As
Is a methyl group, ethyl group, cyclohexyl group, phenyl
Groups are preferred. R₉And R_TenWhen form a ring, they
Is preferably a 5-membered ring or a 6-membered ring, and
A 6-membered ring is preferred.

With respect to the position of the substituent, the terminal hydroxyl group is preferably in the para position or meta position with respect to the connecting chain, and particularly preferably in the para position. As for the substitution positions of R ₁ and R ₂ , it is not preferable to substitute both ortho positions of the hydroxyl group at the same time. In other words, at least one of both ortho positions of the hydroxyl group is preferably a hydrogen atom. More preferably, meta-substituted, 2,5-substituted and unsubstituted with respect to the hydroxyl group.

It is not clear why the object of the present invention, that is, the high resolution and the good film thickness dependence thereof are specifically achieved by using the photosensitive material of the present invention.
Structural characteristics of the polyhydroxy compound represented by, that is, 1) the molecule is linear, 2) has 4 or 5 aromatic rings, and 3) has one hydroxyl group on each aromatic ring, 4) It is considered that the problem of the present invention has been solved by the fact that a substituent such as an alkyl group is introduced at the positions of R ₃ and R ₄ on the aromatic ring one inward from the end. As a result of diligent studies on compounds having a similar structure, we found that 4) is particularly effective for further improving the resolution. This was unexpected from the conventional knowledge. Further, in the present invention, it is important that the ratio of the weight of all the quinonediazide photosensitive materials including the photosensitive material of the present invention to the weight of the solid content in the resist composition is within the above specific range, and outside this range. Then, it turned out that the subject which should be achieved by this invention is not achieved. That is, the film thickness dependence of the resolution and especially the performance deteriorates in a region where the addition amount of all quinonediazide-based photosensitive materials is small, and conversely, a development residue occurs in a region where the addition amount is higher, resulting in deterioration of the resolution. .

Specific examples of the compound represented by the general formula [I] in the present invention are shown below. However, the contents of the present invention are not limited to these. These may be used alone or in combination of two or more.

Specific examples of the compound represented by the general formula [I] in the present invention are shown below. However, the contents of the present invention are not limited to these. These may be used alone or in combination of two or more.

[0024]

[Chemical 5]

[0025]

[Chemical 6]

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, a mixture having different esterification numbers and esterification positions is obtained. However, using the polyhydroxy compound of the present invention,
It is easy to selectively obtain the diester form. However, the content of the diester is required to be 50% or more of the area of high performance liquid chromatography. When the diester content is less than 50%, the effect of the present invention is not exerted due to the large film thickness dependency. The diester form is preferably 55% or more, more preferably 60% or more.

When the photosensitive material of the present invention is used as a resin composition, it may be used alone or as a mixture of two or more kinds thereof by blending an alkali-soluble resin and a phenolic low molecular weight compound. The proportion of the total weight of the quinonediazide-based photosensitive material including the above relative to the weight of the solid content in the resist composition is preferably 23% to 45%, more preferably 25% to 40%. If the usage ratio is less than 23%, the resolution and especially the film thickness dependence thereof deteriorate, and if it exceeds 45%, the sensitivity and the solubility in a solvent decrease and a development residue occurs, resulting in the deterioration of the resolution.

In the present invention, the above-mentioned photosensitive material should be used, but if necessary, the following polyhydroxy compound 1,2-naphthoquinonediazide-5- (and / or-
4-) Sulfonic acid ester can be used in combination.
At this time, the ratio of the quinonediazide ester photosensitive material of these polyhydroxy compounds to the photosensitive material of the present invention is 5 by weight.
/ 95 to 50/50. More preferably from 5/95
40/60. That is, if the photosensitive material of the present invention is less than 50% of the total quinonediazide 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'-biphenylbentol, 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" -diallyldiphenyl ether, 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 an 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 at least one aromatic hydroxyl group 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. 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-cresol, o-cresol and other cresols, 2,5-xylenol, 3,5-xylenol, 3,4-xylenol, 2,3-xylenol and other xylenols, m-ethylphenol, p- Alkylphenols such as ethylphenol, o-ethylphenol, pt-butylphenol, trialkylphenols such as 2,3,5-trimethylphenol, 2,3,4-trimethylphenol, p-methoxyphenol, m-methoxyphenol , 3,5-dimethoxyphenol, 2-methoxy-4-methylphenol, m-ethoxyphenol, p-ethoxyphenol, m-propoxyphenol, p-propoxyphenol, m-butoxyphenol, p-butoxyphenol, and other alkoxyphenols. Kind Bisalkylphenols such as 2-methyl-4-isopropylphenol, m-chlorophenol, p-chlorophenol, o-chlorophenol, dihydroxybiphenyl, bisphenol A, phenylphenol, resorcinol, naphthol and other hydroxyaromatic compounds alone or Two or more kinds can be mixed and used, but 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 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 60-
97347, 60-140235, 60-1897.
39, 64-14229, JP-A-1-276131,
2-60915, 2-275955, 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 weight average molecular weight of the novolak resin thus obtained is preferably in the range of 1500 to 25000. 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 becomes small. Here, the weight average molecular weight is defined by the polystyrene conversion value of gel permeation chromatography.

The degree of dispersion of the novolak resin (the ratio of the weight average molecular weight Mw to the number average molecular weight Mn, that is, Mw / Mn)
Is preferably 1.5 to 7.0, and more preferably 1.5 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 above novolak resin can be appropriately set depending on the kind of the novolak resin.

The alkali-soluble resin is a novolak resin synthesized by a condensation reaction of a mixture containing two or more kinds of phenol, cresol, xylenol and trimethylphenol (provided that m-cresol is essential) and an aldehyde compound. In this case, the weight average molecular weight is 5500.
It is preferably ˜25,000, more preferably 6
000 to 25,000. Furthermore, the above novolak resin has a ratio of the weight average molecular weight to the number average molecular weight of 1.5 to 5.
It is preferably 0.

The alkali-soluble resin is p-cresol, o-cresol, 2,3-xylenol, 2,6-
In the case of at least one type of novolak resin synthesized by a condensation reaction of a mixture containing at least four types of xylenol and trimethylphenol (o-cresol is essential) and an aldehyde compound, a weight average molecular weight and a number average molecular weight. Is preferably 1.5 to 5.0 and the weight average molecular weight is 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) 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 molecule 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 etc. can be mentioned.

Among these, the water-insoluble alkali-soluble low-molecular compound is a water-insoluble alkali-soluble low-molecular compound having a total carbon number of 60 or less in one molecule and having 2 to 8 phenolic hydroxyl groups in one molecule. Compounds are preferred. Furthermore, the water-insoluble alkali-soluble low molecular weight compound has a ratio of phenolic hydroxyl groups to aromatic rings of 0.5 to 1.
4 and the total number of carbon atoms in one molecule is 12 to 60, and at least one water-insoluble alkali-soluble low-molecular compound having 2 to 10 phenolic hydroxyl groups in one molecule is preferable. . Among such compounds, compounds that increase the rate of alkali dissolution 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. On the other hand, if it is less than 12, a new defect such as a decrease in heat resistance occurs.
In order to exert the effect 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. Also, the ratio of phenolic hydroxyl group to aromatic ring is 0.5.
If it is less than 1, there is a large dependency on the film thickness, and the development latitude tends to be narrowed. If this ratio exceeds 1.4, the stability of the composition deteriorates, and it becomes difficult to obtain high resolution and good film thickness dependency, 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. If the amount added exceeds 100% by weight, the development residue deteriorates and a new defect that the pattern is deformed during development is not preferable. The water-insoluble alkali-soluble low molecular weight compound having an aromatic hydroxyl group used in the present invention is described in, for example, JP-A-4-1-1.
22938, 2-28531, 2-242973,
2-275995, 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 by referring to the methods described in JP-A-5318875 and European Patent No. 219294.

As the solvent for dissolving the photosensitive material and the alkali-soluble novolac resin used in the present invention, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate,
Ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol methyl ether acetate, propylene glycol propyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclopentanone, cyclohexanone, 4-methoxy-4-methyl-2-pentanone, 2 -Ethyl hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, 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.

Further, 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 coating properties such as striation. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether and other polyoxyethylene alkyl ethers, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether. Polyoxyethylene alkyl allyl ethers, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, etc. Sorbitan fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sol Monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, nonionic surfactants of polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan tristearate, Eftop EF
301, EF303, EF352 (Shin-Akita Kasei Co., Ltd.)
Manufactured by) Megafac F171, F173 (manufactured by Dainippon Ink Co., Ltd.), Florard FC430, 431 (manufactured by 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 Oil and Fat Chemical Co., Ltd.) 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 combinations.

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
Uses an aqueous solution of alcohol amines such as dimethylethanolamine and triethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide and choline, and cyclic amines such as pyrrole and piperidine, etc. 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 absorber is added as necessary for the purpose of preventing halation from the substrate and for improving the visibility when applied to the transparent substrate. For example, commercially available light absorbers described in "Technology and Market of Industrial Dyes" (CMC Publishing) and Dye Handbook (edited by the Society of Synthetic Organic Chemistry), such as 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 preferably used. The light absorbing agent is usually added in an amount of 100 parts by weight or less, preferably 50 parts by weight or less, and more preferably 30 parts by weight or less with respect to 100 parts by weight of the alkali-soluble resin.

The cross-linking agent is added within a range that does not affect the formation of a positive image. The purpose of adding the crosslinking agent is mainly
These include sensitivity adjustment, improvement of heat resistance, and improvement of dry etching resistance. 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 cross-linking agents can be 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 photosensitizer. If the amount of the cross-linking agent is more than 10 parts by weight, the sensitivity is lowered and scum (resist residue) is generated, which is not preferable.

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 and 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 mixed 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, etc.) used for the production of precision integrated circuit devices. , Roll coating method,
Pre-bake after coating by an appropriate coating method such as a flow coating method, a dip coating method, a spray coating method, a doctor coating method, exposing through a predetermined mask, and if necessary, post-heating (PEB: Post Exposure Bake). ,
A good resist can be obtained by developing, rinsing and drying.

[0063]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. Unless otherwise specified,% means% by weight.

Synthesis Example (1) 46.9 g of the synthetic compound [I-1] of the photosensitive material a, 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 2.5 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
88.2 g of 2-naphthoquinonediazide-5-sulfonic acid ester (photosensitive material a) was obtained.

In high performance liquid chromatography measured with a detector using 254 nm ultraviolet light, the diester form of the photosensitive material a was 65% of the total pattern area. Incidentally, the measurement of the high performance liquid chromatography,
Using a LC-6A chromatograph manufactured by Shimadzu Corporation, a Nova-Pak C18 (4 manufactured by Waters) is used.
μm) 8 mmφ × 100 mm column is used, and as a carrier solvent, distilled water 68.6%, acetonitrile 30.
A solution of 0%, 0.7% triethylamine and 0.7% phosphoric acid was applied at a flow rate of 2.0 ml / min.

Synthesis Example (2) 49.7 g of the compound [I-3] of the photosensitive material b, 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 2.5 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-3] 1
91.2 g of 2-naphthoquinonediazide-5-sulfonic acid ester (photosensitive material b) was obtained.

In high performance liquid chromatography measured with a detector using 254 nm ultraviolet light, the diester form of the photosensitive material b was 55% of the total pattern area.

Synthesis Example (3) 60.3 g of the synthetic compound [I-9] of the photosensitive material c, 53.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 900 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 3.2 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-9] of 1,
100.5 g of 2-naphthoquinonediazide-5-sulfonic acid ester (photosensitive material c) was obtained.

In high performance liquid chromatography measured with a detector using 254 nm ultraviolet light, the diester form of the photosensitive material c was 54% of the total pattern area.

Synthesis Example (4) Synthesis of Photosensitive Material d of Comparative Example 46.9 g of the following compound [II], 53.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 800 mL of 1,4-dioxane were used. It was charged into a necked flask and uniformly dissolved. Then triethylamine 21.
2 g was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2.8 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 ester of compound [II] ( 88.5 g of a photosensitive material d) was obtained.

In high performance liquid chromatography measured with a detector using 254 nm ultraviolet light, the diester form of the photosensitive material d was 57% of the total pattern area.

[0072]

[Chemical 7]

Synthesis Example (5) Synthesis of Photosensitive Material e of Comparative Example 44.1 g of the following compound [III], 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, N-methylpiperidine 20.8 g
Was gradually added dropwise and reacted at 25 ° C. for 3 hours. The reaction mixture was poured into 2.5 L of a 1% hydrochloric acid aqueous solution, and the resulting precipitate was filtered off, washed with water and dried (40 ° C.) to obtain 1,2-naphthoquinonediazide-5-sulfonic acid ester of compound [III] ( 83.1 g of a photosensitive material e) was obtained.

In high performance liquid chromatography measured with a detector using 254 nm ultraviolet light, the diester form of the photosensitive material e was 52% of the total pattern area.

[0075]

[Chemical 8]

Synthesis Example (6) Synthesis of Photosensitive Material e ′ of Comparative Example 44.1 g of the following compound [III], 53.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 800 mL of 1,4-dioxane were mixed with 3 g. It was charged in a single-necked flask and uniformly dissolved. Then triethylamine 21.
2 g was gradually added dropwise and 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 separated by filtration, washed with water and dried (40 ° C.) to give compound [III].
82.2 g of 1,2-naphthoquinonediazide-5-sulfonic acid ester (photosensitive material e ′) was obtained.

In high performance liquid chromatography measured with a detector using 254 nm ultraviolet light, the diester form of the photosensitive material e'was 69% of the total pattern area.

Synthesis Example (7) Synthesis of Photosensitive Material f of Comparative Example 57.5 g of the following compound [IV], 53.7 g of 1,2-naphthoquinonediazide-5-sulfonyl chloride, and 900 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. The reaction mixture was poured into 3.2 L of a 1% hydrochloric acid aqueous solution, and the generated precipitate was filtered off,
After washing with water and drying (40 ° C), 1,2-
95.8 g of naphthoquinone diazide-5-sulfonic acid ester (photosensitive material f) was obtained.

In high performance liquid chromatography measured using a detector using ultraviolet rays of 254 nm, the diester form of the photosensitive material f was 60% of the total pattern area.

[0080]

[Chemical 9]

Synthesis Example (8) Synthesis of Novolac Resin A 50 g of m-cresol, 25 g of p-cresol, 2,5
-Prepare 28 g of dimethylphenol, 53 g of 37% formalin aqueous solution and 0.15 g of oxalic acid in a three-necked flask,
The temperature was raised to 100 ° C. with stirring and the reaction was performed for 14 hours.
After that, the temperature was raised to 200 ° C. and the pressure was gradually reduced to 1 mmHg, and water, unreacted monomer, formaldehyde,
Oxalic acid was distilled off. Next, the molten novolac resin was returned to room temperature and collected. The obtained novolak resin had a weight average molecular weight of 4,800 (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 A. The obtained novolak resin had a weight average molecular weight of 9960 (in terms of polystyrene) and a dispersity of 3.50. The contents of the monomer, dimer and trimer are 0%, 2.3% and 3.5%, respectively.
43% of low molecular weight components were removed by the fractional reprecipitation operation.

Synthesis Example (9) Synthesis of Novolac Resin B 259.5 g of m-cresol and 9.7 of p-cresol
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 Litchig condenser, and the bath temperature was raised to 200 ° C. over about 1 hour to remove unreacted formalin, water and the like. 1 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. It took 2 hours to evaporate under reduced pressure.

Next, the molten novolak resin was returned to room temperature and recovered. 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.

Synthesis Example (10) Synthesis of Novolac Resin C 30 g of p-cresol, 14 g of o-cresol, 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.
I put it 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
The hydrate was added. Then, the temperature of the oil bath is adjusted to 13 for 18 hours.
The reaction was continued at 0 ° C, the reflux condenser was removed, and the mixture was distilled at 200 ° C under reduced pressure to remove unreacted monomers. The obtained novolak resin has a weight average molecular weight of 328.
The degree of dispersion was 0 (in terms of polystyrene) and the degree of dispersion was 2.75.

Preparation and Evaluation of Positive Photoresist Compositions [Examples 1 to 8] Photosensitive Materials a to c Obtained in Synthesis Examples (1) to (3) and Synthesis Examples (8) to (10) Novolak resins A to C obtained in 1., a solvent, and a polyhydroxy compound (P) [a low molecular compound having a phenolic hydroxyl group]: 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. Then, a photoresist composition was prepared. Using a spinner, this photoresist composition was coated on a silicon wafer while changing the rotation speed,
It was dried at 90 ° C. for 60 seconds on a vacuum contact type hot plate to obtain resist films having film thicknesses of 0.97 μm and 1.02 μm, respectively.

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

The resolving power indicates the limiting resolving power in the exposure amount for reproducing the mask pattern of 0.60 μm. [Comparative Examples 1 to 7] Of the compounds used in the examples, the photosensitive materials a, d, and d obtained in the synthesis examples (1) and (4) to (7).
Using e, e ′, and f, a resist composition was prepared and evaluated in the same manner as in the examples.

[0088]

[Table 1]

[0089]

INDUSTRIAL APPLICABILITY As described above, the positive photoresist composition according to the present invention has characteristics such as high resolution and excellent film thickness dependency.

Continuation of the front page (56) Reference JP-A-6-167805 (JP, A) JP-A-6-148878 (JP, A) JP-A-6-202321 (JP, A) JP-A-7-104465 (JP , A) JP-A-5-323597 (JP, A) JP-A-2-103543 (JP, A) JP-A-2-19846 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) Name) G03F 7/004-7/18

Claims (2)

(57) [Claims] 1. An alkali-soluble resin, a low molecular weight compound having a phenolic hydroxyl group, and a 1,2-quinonediazide-5 of a polyhydroxy compound represented by the following general formula [I].
The pattern area ratio of the quinonediazide sulfonic acid diester containing-(and / or -4-) sulfonic acid diester measured by high performance liquid chromatography having a measurement wavelength of 254 nm is 50 of the total pattern area.
% Or more and the ratio of the weight of all the quinonediazide photosensitive materials to the weight of the solid content in the resist composition is 23%.
The positive photoresist composition is not less than 45%. [Chemical 1] Here, R ₁ and R ₂ may be the same or different, and a hydrogen atom,
Represents a halogen atom, an alkyl group, an alkenyl group, an aryl group, an alkoxy group or a cycloalkyl group, R ₃ to R ₆ may be the same or different, and represent an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group, R ₇ and R ₈ may be the same or different and represent a hydrogen atom or an alkyl group, and R, R ′, R ″ and R ″ ′ may be the same or different and each represent a hydrogen atom or an alkyl group. Represents, a, b represents 0, 1, 2, 3 and A represents R _{9 to} R ₁₄ and R _{18 to} R ₂₁ may be the same or different, and represent a hydrogen atom or an alkyl group (R ₉ and R ₁₀ may form a ring), R ₁₅ , R ₁₇ and R ₂₃ may be the same or different and represent a hydrogen atom, an alkyl group or an alkoxy group, and R ₁₆ , R ₂₂ and R ₂₄ may be the same or different and are an alkyl group, a cycloalkyl group or an aryl group. Represents a group. 2. A register of the weight of all quinonediazide type photosensitive materials.
The proportion of the solid content in the strike composition is 28% or less.
It is above 45%, The claim 1 characterized by the above-mentioned.
Positive photoresist composition.