JPH0829976A - Positive type photoresist composition - Google Patents

Abstract

PURPOSE:To form a resist pattern, which has high resolution, high sensitivity, excellent storage stability, excellent pattern forming property and the excellent heat resistance, by including at least one kind of alkali soluble resin, quinonediazide group contained compound and the specified polyphenol compound. CONSTITUTION:This positive type photo resist composition contains at least one kind of alkali soluble resin (A), quinonediazide group included compound (B) and polyphenol compound (C) expressed with the formula. In the formula, R<1>, R<2> and R<3> respectively mean hydrogen atom or low level alkyl group, Ar<1>, Ar<2> and Ar<3> respectively mean substitutional or non-substitutional benzyl group having 1-3 hydroxyl group, and (x), (y) and (z) respectively mean the integer at 1-3, (l), (m) and (n) mean the integer at 1 or 2. As the alkali soluble resin (A), for example, condensation product of the aromatic hydroxy compound and aldehyde group or ketone group, namely, novolack resin and polyhydroxystylene or the derivative thereof is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photoresist composition having excellent sensitivity, resolution and storage stability, heat resistance and a pattern having a good pattern shape.

[0002]

2. Description of the Related Art Recently, as a photoresist used in the manufacturing process of semiconductor devices such as IC and LSI and liquid crystal devices such as LCD, an alkali-soluble resin as a film forming component and a quinonediazide group as a photosensitive component are contained. A positive photoresist composition in combination with a compound has been put to practical use.

With respect to the alkali-soluble resin used as the above-mentioned film-forming component, the exposed portion is easily dissolved and removed by the alkaline aqueous solution during development, and the unexposed portion does not swell in the alkaline aqueous solution. As the above, a novolac resin is preferable because it exhibits excellent resistance to plasma etching.

Further, the quinonediazide group-containing compound used as the photosensitive component has an action of suppressing the alkali solubility of the novolak resin by itself, but
It exhibits a specific action of changing to alkali-soluble by irradiation with electromagnetic waves such as ultraviolet rays (g-rays and i-rays), far-ultraviolet rays including excimer laser, and electron rays, and at the same time, promoting alkali solubility of the novolak resin. Utilizing such a specific property, a large number of positive photoresist compositions containing a combination of an alkali-soluble novolac resin and a quinonediazide group-containing compound have been proposed and put into practical use (for example, US Patent 437
7631, JP-A-62-35349, JP-A-1-142548, and JP-A-1-179147.
(Japanese Patent Publication No. 3-4897).

By the way, in recent years, the degree of integration of semiconductors and liquid crystal devices is becoming higher and higher, and in the manufacture of VLSI, submicron (1.0 μm) or less and half micron (0.5 μm) or less. The processing accuracy of fine patterns has been required. As a result, even positive photoresist compositions having high sensitivity, high resolution, and excellent pattern shape satisfying the required characteristics of forming a heat resistant pattern that can withstand heat treatment after dry etching, exposure, and development. Is desired.

Therefore, a positive photoresist composition containing trihydroxybenzophenone in the basic composition of the resist (JP-A-61-141441) and a positive photoresist composition containing various trisphenol compounds are added. (JP-A-2-275955, JP-A-3
-200252 and JP-A-3-200254) are proposed.

However, the one containing trihydroxybenzophenone has a drawback that the heat resistance is low although the improvement of the sensitivity and the developing property is recognized, and the one containing the trisphenol compound has the sensitivity and the heat resistance. Even if some improvement in the resolution and the resolution is recognized, it is still insufficient to meet the required characteristics of the current semiconductor devices and liquid crystal devices, and it is not possible to meet them.

On the other hand, when the solution of the positive photoresist composition is stored, foreign matter is deposited, which causes a decrease in yield and an obstacle to the production line of semiconductor devices and liquid crystal devices. It has also been an important theme in this field to obtain a positive photoresist composition which is excellent in storage stability and does not cause the precipitation of various foreign matters.

[0009]

The present invention relates to such a positive photoresist composition sensitive to radiation,
High resolution, high sensitivity, and excellent storage stability, and improved to form a resist pattern with good pattern shape and heat resistance, for manufacturing highly integrated semiconductor devices and liquid crystal devices. The purpose is to provide something that can be dealt with.

[0010]

Means for Solving the Problems The present inventors have conducted various studies on the performance improvement of a positive photoresist composition, and as a result, use an alkali-soluble resin as a film forming component and a quinonediazide group-containing compound as a photosensitive component. By adding a specific hydroxyaryl compound having at least 7 benzene rings to the basic composition of photoresist, the sensitivity, resolution and storage stability are improved, and the resist pattern has excellent pattern shape and heat resistance. Can be given,
It was found that a positive photoresist composition suitable for manufacturing highly integrated semiconductor devices and liquid crystal devices can be obtained,
The present invention has been completed based on this finding.

That is, the present invention provides (A) an alkali-soluble resin, (B) a quinonediazide group-containing compound and (C).
General formula (I)

Embedded image (In the formula, R ¹ , R ² and R ³ are each a hydrogen atom or a lower alkyl group, and Ar ¹ , Ar ² and Ar ³ are 1 to ³ respectively.
A nuclear-substituted or unsubstituted benzyl group having 4 hydroxyl groups, wherein x, y and z are each an integer of 1 to 3, l,
m and n are each an integer of 1 or 2), and a positive photoresist composition comprising at least one polyphenolic compound represented by the formula.

In the composition of the present invention, a basic composition comprising an alkali-soluble resin as a film-forming substance and a quinonediazide group-containing compound as a photosensitive substance is used, but there is no particular limitation on each component constituting the basic composition. Instead, it can be arbitrarily selected from those used in ordinary positive photoresist compositions.

That is, the alkali-soluble resin as the component (A) of the basic composition of the composition of the present invention is, for example, a condensation product of an aromatic hydroxy compound and an aldehyde or a ketone, a so-called novolac resin, polyhydroxystyrene or the like. Examples thereof include derivatives.

Examples of the aromatic hydroxy compound as a raw material of the above novolak resin include phenol, m-cresol, p-cresol, o-cresol, 2,3-xylenol, 2,5-xylenol, 3,5- Xylenols such as xylenol and 3,4-xylenol, m
-Ethylphenol, p-ethylphenol, o-ethylphenol, 2,3,5-trimethylphenol,
2,3,5-triethylphenol, 4-tert-butylphenol, 3-tert-butylphenol, 2
-Tert-butylphenol, 2-tert-butyl-4-methylphenol, 2-tert-butyl-5-
Alkylphenols such as methylphenol and 6-tert-butyl-3-methylphenol, alkoxy such as p-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, m-ethoxyphenol, p-propoxyphenol and m-propoxyphenol Phenols, o-isopropenylphenol, p-isopropenylphenol, 2-methyl-4-isopropenylphenol, isopropenylphenols such as 2-ethyl-4-isopropenylphenol, arylphenols such as phenylphenol, 4 , 4'-dihydroxybiphenyl, bisphenol A, resorcinol, hydroquinone, polyhydroxyphenols such as pyrogallol, and the like. These may be used alone or in combination of two or more. Among these aromatic hydroxy compounds, m-cresol, p-cresol, 2,5-xylenol, 3,5-xylenol and 2,3,5-trimethylphenol are particularly preferable.

Examples of aldehydes to be condensed with these aromatic hydroxy compounds include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, propionaldehyde, butyraldehyde, trimethylacetaldehyde, acrolein, crotonaldehyde, cyclohexanaldehyde, furfural,
Furylacrolein, benzaldehyde, terephthalaldehyde, phenylacetaldehyde, α-phenylpropylaldehyde, β-phenylpropylaldehyde,
o-hydroxybenzaldehyde, m-hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-
Examples thereof include methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde and cinnamic aldehyde.
These may be used alone or in combination of two or more. Among these aldehydes,
Formaldehyde is preferred from the viewpoint of easy availability, but it is preferred to use hydroxybenzaldehydes in combination with formaldehyde in order to improve heat resistance.

Further, examples of the ketones include acetone, methyl ethyl ketone, diethyl ketone, diphenyl ketone and the like. These may be used alone or in combination of two or more. In particular, it is preferable to use pyrogallol as the aromatic hydroxy compound and acetone as the ketones in combination.

The condensation reaction product of the aromatic hydroxy compound and the aldehyde or ketone can be produced by a known method in the presence of an acidic catalyst. As the acidic catalyst in that case, hydrochloric acid, sulfuric acid, formic acid, acetic acid, oxalic acid, paratoluenesulfonic acid, or the like can be used. The condensation product thus obtained is preferably one obtained by cutting the low-molecular region by subjecting it to a treatment such as fractionation, because it has excellent heat resistance. For the treatment such as fractionation, the resin obtained by the condensation reaction is dissolved in a good solvent, for example, alcohol such as methanol and ethanol, ketone such as acetone and methyl ethyl ketone, ethylene glycol monoethyl ether acetate, tetrahydrofuran, etc., and then poured into water for precipitation. And the like. A suitable weight average molecular weight of the condensation reaction product is 2000 to 250.
00, preferably 2500 to 20000. Here, the weight average molecular weight is a polystyrene conversion value by a gel permeation chromatography method.

Examples of the polyhydroxystyrenes and their derivatives include homopolymers of vinylphenol and copolymers of vinylphenol and a comonomer copolymerizable therewith. Examples of the comonomer include acrylic acid derivatives, acrylonitrile, methacrylic acid derivatives, methacrylonitrile, styrene, α-methylstyrene, p-methylstyrene, o-methylstyrene,
Examples thereof include styrene derivatives such as p-methoxystyrene and p-chlorostyrene.

Next, naphthoquinone-1,2 used as a photosensitive material of the component (B) of the basic composition of the present invention.
-The diazide sulfonic acid ester compound is not particularly limited and can be arbitrarily selected from those commonly used, but preferred examples include naphthoquinone-1,2-diazide-5-sulfonic acid and naphthoquinone-
1,2-diazide-4-sulfonic acid, naphthoquinone-
An esterification product of a naphthoquinone-1,2-diazide sulfonic acid such as 1,2-diazide-6-sulfonic acid and a polyhydroxy compound is used. The ester compound may be a complete esterified product or a partial esterified product.

Examples of the polyhydroxy compound include the compounds (a) to (c) shown below. (A) Polyhydroxybenzophenones; Examples of compounds belonging thereto are 2,3,4-trihydroxybenzophenone, 2,4,4'-trihydroxybenzophenone, 2,4,6-trihydroxybenzophenone,
2,3,4,4'-tetrahydroxybenzophenone,
2,2 ', 4,4'-tetrahydroxybenzophenone, 2,3', 4,4 ', 6-pentahydroxybenzophenone, 2,2', 3,4,4'-pentahydroxybenzophenone, 2,2 ' , 3,4,5'-pentahydroxybenzophenone, 2,3 ', 4,5,5'-pentahydroxybenzophenone, 2,3,3', 4
4 ', 5'-hexahydroxybenzophenone and the like.

(B) General formula (II)

Embedded image (In the formula, R ^{4 to} R ⁶ are a hydrogen atom or a lower alkyl group, R ⁷
To R ¹² are hydrogen atom, halogen atom, lower alkyl group, lower alkoxyl group, lower alkenyl group or cycloalkyl group, R ¹³ and R ¹⁴ are hydrogen atom, halogen atom or lower alkyl group, x ′, y ′ and z ′. Are each an integer of 1 to 3 and n ′ is 0 or 1); examples of compounds belonging to this are tris (4-hydroxyphenyl) methane, bis (4-hydroxy-3,3) 5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -2-
Hydroxyphenylmethane, bis (4-hydroxy-
2,5-dimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2- Hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, bis ( Four
-Hydroxy-3,5-dimethylphenyl) -2,4-
Dihydroxyphenylmethane, bis (4-hydroxy-
2,5-Dimethylphenyl) -2,4-dihydroxyphenylmethane, bis (4-hydroxyphenyl) -3-
Methoxy-4-hydroxyphenylmethane, bis (3-
Cyclohexyl-4-hydroxyphenyl) -3-hydroxyphenylmethane, bis (3-cyclohexyl-4)
-Hydroxyphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxyphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl)-
2-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -3-hydroxyphenylmethane, bis (3-cyclohexyl-
4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-6-hydroxyphenyl) ) -3-hydroxyphenylmethane,
Bis (3-cyclohexyl-6-hydroxyphenyl)
-4-hydroxyphenylmethane, bis (3-cyclohexyl-6-hydroxyphenyl) -2-hydroxyphenylmethane, bis (3-cyclohexyl-6-hydroxy-4-methylphenyl) -2-hydroxyphenylmethane, bis (3 -Cyclohexyl-6-hydroxy-
4-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl-6-hydroxy-4-
Methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl)
Ethyl] benzene, 1- [1- (3-methyl-4-hydroxyphenyl) isopropyl] -4- [1,1-bis (3-methyl-4-hydroxyphenyl) ethyl] benzene and the like.

(C) General formula (III)

[Chemical 4] (In the formula, R ¹⁵ and R ¹⁶ are a hydrogen atom or a lower alkyl group,
x ″ and y ″ are integers of 1 to 3), and bis (hydroxyphenyl) alkanes represented by the formula; 2- (2,3,4-trihydroxyphenyl) -2- (2 ', 3', 4'-Trihydroxyphenyl) propane, 2- (2,4-dihydroxyphenyl) -2- (2 ', 4'-dihydroxyphenyl) propane, 2- (4-hydroxyphenyl)- 2- (4'-
Examples include hydroxyphenyl) propane, bis (2,3,4-trihydroxyphenyl) methane, and bis (2,4-dihydroxyphenyl) methane.

(D) Hydroxyaromatic compounds; examples of compounds belonging thereto include phenol, p-methoxyphenol, dimethylphenol, hydroquinone, bisphenol A, naphthol, pyrocatechol, pyrogallol monomethyl ether, and pyrogallol-1,3. -Dimethyl ether, gallic acid, partially esterified or partially etherified gallic acid, etc.

The quinonediazide group-containing compound used as the photosensitive substance of the composition of the present invention is, for example, naphthoquinone-
It can be produced by subjecting 1,2-diazide-4 (or 5) -sulfonyl halide to the above-mentioned hydroxy compounds (a) to (d) for condensation reaction to complete esterification or partial esterification. This condensation reaction is usually carried out in an organic solvent such as dioxane, N-methylpyrrolidone, dimethylacetamide, triethanolamine,
It is advantageous to work in the presence of a basic condensing agent such as alkali carbonate or alkali hydrogen carbonate.

In this case, the naphthoquinone-1,2-diazide-4 (or 5) is used in an amount of 50% or more, preferably 60% or more, based on the total number of moles of hydroxyl groups of the hydroxy compound.
It is preferable to use an ester condensed with -sulfonyl halide, that is, an esterification degree of 50% or more, preferably 60% or more because high resolution can be obtained.

The basic composition of the composition of the present invention is (A)
A mixture of 1 to 100 parts by weight of the component (B), preferably 10 to 50 parts by weight with respect to 100 parts by weight of the component is used. When the amount of the photosensitive resin is smaller than this, the resolution is lowered, and when the amount of the photosensitive resin is larger than this, the sensitivity and the pattern shape are deteriorated.

In the composition of the present invention, it is necessary to add the polyphenolic compound represented by the general formula (I) as the component (C) to the above basic composition. This polyphenolic compound is known and is commercially available. This is, for example, represented by the general formula (IV)

Embedded image (R ^{1 to} R ³ , x, y and z in the formula have the same meanings as described above), at least one methylol compound of the compound, and a nucleus-substituted or unsubstituted group having 1 to 3 hydroxyl groups. It can be produced by condensing at least one kind of benzene under an acidic catalyst.

Examples of the compound represented by the general formula (IV) include JP-A-3-48249 and JP-A-4-2518.
The materials described in Japanese Patent Publication No. 49 and Japanese Patent Application Laid-Open No. 4-211254 can be used. Preferred among such compounds are 1- [1- (4-hydroxyphenyl) isopropyl] -4- [bis (4-hydroxyphenyl) methyl] benzene, 1- [1- (3,4- Dihydroxyphenyl) isopropyl-4- [bis (3,4-
Dihydroxyphenyl) methyl] benzene, 1- (4-
Hydroxyphenyl) isopropyl] -4- [1,1-
Bis (4-hydroxyphenyl) ethyl] benzene, 1
-[1- (3-Chloro-4-hydroxyphenyl) isopropyl] -4- [1,1-bis (3-chloro-4-hydroxyphenyl) ethyl] benzene, 1- [1-
(2,3,4-Trihydroxyphenyl) isopropyl] -4- [1,1-bis (2,3,4-trihydroxyphenyl) ethyl] benzene, 1- [1- (3-allyl-4-hydroxy Phenyl) isopropyl] -4-
[1,1-Bis (3-allyl-4-hydroxyphenyl) ethyl] benzene, 1- [1- (3-methyl-4-
Hydroxyphenyl) isopropyl] -4- [1,1-
Bis (3-methyl-4-hydroxyphenyl) ethyl]
Benzene, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) -n-propyl] benzene and the like, particularly preferably 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene.

Next, examples of the nucleus-substituted or unsubstituted benzene compound having 1 to 3 hydroxyl groups to be condensed with the above compound include phenol, m-cresol and p-
Cresol, o-cresol, 2,3-xylenol,
2,4-xylenol, 2,5-xylenol, 2,6
-Xylenol, 3,5-xylenol, 3,4-xylenol, m-ethylphenol, p-ethylphenol, o-ethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2,
3,5-triethylphenol, 3,4,5-triethylphenol, 3-methyl-6-cyclohexylphenol, 4-tert-butylphenol, 3-tert
-Butylphenol, 2-tert-butylphenol, 2-tert-butyl-4-methylphenol, 2
-Tert-butyl-5-methylphenol, 6-te
rt-butyl-3-methylphenol, p-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, m-ethoxyphenol, p-propoxyphenol, m-propoxyphenol, resorcinol,
Examples thereof include hydroquinone and pyrogallol. These phenolic compounds may be used alone or in combination of two or more. Among these compounds, especially phenol, o-cresol, m-cresol, p-cresol, 2,4-xylenol, 2,
6-xylenol, 2,3,5-trimethylphenol and 3-methyl-6-cyclohexylphenol are preferred.

The polyphenolic compound represented by the general formula (I) includes a methylol compound of the compound represented by the general formula (IV) and a nuclear-substituted or unsubstituted benzene having 1 to 3 hydroxyl groups. It can be produced by reacting a compound with an acidic catalyst such as hydrochloric acid, sulfuric acid, formic acid, acetic acid, or paratoluenesulfonic acid.

Further, this is, for example, TPPA-1.
000P, TPPA-1100-2C, TPPA-11
00-3C, TPPA-1100-4C, TPPA-1
200-24X, TPPA-1200-26X, TPP
A-1300-235T, TPPA-1600-3M6
C is commercially available from Honshu Chemical Industry Co., Ltd.

In the composition of the present invention, the component (C) is added to 100 parts by weight of the alkali-soluble resin as the component (A).
The amount is 0.5 to 200 parts by weight, preferably 5 to 50 parts by weight. If this amount is less than 0.5 parts by weight,
In addition to lowering heat resistance and storage stability, the pattern shape of the obtained resist pattern deteriorates, and when it exceeds 200 parts by weight, the shape of the obtained resist pattern deteriorates.

In use, the composition of the present invention may optionally contain various additives commonly used in general positive photoresists, such as other resin components, plasticizers, stabilizers, etc. for improving the performance of resist films. Coloring agents and the like can be added.

The composition of the present invention is preferably used by mixing the components (A), (B) and (C) with additives used as desired and dissolving them in a suitable solvent.

Examples of such a solvent include acetone,
Ketones such as methyl ethyl ketone, cyclohexanone, and methyl isoamyl ketone; ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol monoacetate, propylene glycol monoacetate, diethylene glycol monoacetate, or their monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether. Or polyhydric alcohols such as monophenyl ether and its derivatives; cyclic ethers such as dioxane; and ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethoxy. Esters such as ethyl propionate may be mentioned. These may be used alone,
You may use it in mixture of 2 or more types.

About the preferred method of using the composition of the present invention 1
As an example, first, on a support such as a silicon wafer, (A) component, (B) component, (C) component and optional additional components are dissolved in a suitable solvent as described above. Apply the solution with a spinner or the like, dry it to form a photosensitive layer, and then use a light source that emits ultraviolet light, such as a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, an arc lamp, or a xenon lamp, through a required mask pattern. Exposure, or irradiating while scanning the electron beam.
Next, when this is dipped in a developing solution, for example, a weak alkaline aqueous solution such as a 1-10 wt% tetramethylammonium hydroxide aqueous solution, the exposed portion is dissolved and removed, and an image faithful to the mask pattern can be obtained.

[0037]

The positive photoresist composition of the present invention comprises
Suitable for manufacturing highly integrated semiconductor devices and liquid crystal devices that require high precision because they can form resist patterns with high sensitivity, high resolution, excellent storage stability, and excellent heat resistance and pattern shape. Is.

[0038]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Various physical properties of the photoresist composition were determined as follows. (1) Sensitivity: A sample was applied onto a silicon wafer using a spinner, and this was applied on a hot plate at 90 ° C and 90 ° C.
After drying for 2 seconds, a resist film having a film thickness of 1.05 μm was obtained. A reduction projection exposure apparatus NSR-1505G7E (manufactured by Nikon Corporation, NA = 0.54) was used for this film from 0.1 second to 0.
After exposure at intervals of 01 seconds, the film is developed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution at 23 ° C. for 60 seconds, washed with water for 30 seconds and dried, and the film thickness of the exposed portion after development becomes 0. The minimum exposure time was measured as the sensitivity in milliseconds (ms). (2) Resolution: The resolution is shown as the limiting resolution in the exposure amount that reproduces the 0.8 μm mask pattern.

(3) Heat resistance: A resist pattern having a pattern line width of 5 μm formed on a silicon wafer was
The temperature at which the resist pattern was deformed when the temperature was raised from 25 ° C. by 5 ° C. and baked at each temperature for 5 minutes on a hot plate was shown.

(4) Pattern shape: SEM (scanning electron microscope) was used to determine the cross-sectional shape of a 0.8 μm wide resist pattern.
Observed by a photograph, a rectangular shape was designated as A, a slightly trapezoidal shape was designated as B, and a top having a rounded and tapered shape was designated as C.

(5) Storage stability A coating solution of the prepared positive photoresist composition was added to 0.2
After filtering through a membrane filter of μm, it was stored at 40 ° C. in a closed brown container, and the number of precipitates in the solution was measured every month from the time of preparation using a particle counter KL-20 (manufactured by Lion Corporation). The number of months elapsed from the time of preparation when the particle counter became NG (the number of precipitates was too large to measure) was shown.

Reference Example 1 1- [1- (4-hydroxyphenyl) isopropyl]
Methylol compound of 4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene 1- {1- [4-
Hydroxy-3,5-di (hydroxymethyl) phenyl] isopropyl} -4- {1,1-bis [4-hydroxy-3,5-di (hydroxymethyl) phenyl] ethyl} benzene 42.2 g (0.07 Mol) and 367.2 g (3.4 mol) of p-cresol, methanol 80
g, and add 1 g of concentrated hydrochloric acid as an acidic catalyst,
The condensation reaction was carried out by stirring at 4 ° C for 4 hours. After completion of the reaction, the mixture was neutralized, methanol was distilled off, and the residue was redissolved in toluene. The toluene solution was washed several times with water to remove the generated salt. Then, the solvent and unreacted raw materials are removed from this solution by distillation to obtain the formula

[Chemical 6] The yield of the polyphenolic compound (C ₁ ) represented by
Obtained at 8%.

Reference Example 2 The phenol compound shown in Table 1 was used in place of p-cresol in Reference Example 1, and a condensation reaction was carried out in the same manner as in Reference Example 1 to give a compound of the general formula

[Chemical 7] Polyphenolic compounds C _{2 to} C ₈ in which Ar in Table 1 corresponds to the groups shown in Table 1 were obtained.

[0045]

[Table 1]

Example 1 An alkali-soluble resin having a weight average molecular weight of 8000 was obtained by condensing a mixture of m-cresol and p-cresol in a molar ratio of 4: 6 with formalin using an oxalic acid catalyst in a conventional manner. Prepared. This alkali-soluble resin is 20
% Methanol solution, and 1000 g of this solution is added to 500 parts of water.
The precipitate obtained by pouring into g was dehydrated and dried to obtain an alkali-soluble resin from which a low molecular weight fraction having a weight average molecular weight of 10,000 was removed. The quinonediazide group-containing compound was added to 100 parts by weight of the alkali-soluble resin from which the low molecular weight fraction had been removed as 2, 3, 4,
30 parts by weight of an esterified product of 1 mol of 4'-tetrahydroxybenzophenone and 3 mol of naphthoquinone-1,2-diazide-5-sulfonyl chloride and 20 parts by weight of the polyphenolic compound (C ₁ ) obtained in Reference Example 1 were used as ethyl lactate. After dissolving in a mixed liquid of 360 parts by weight and 40 parts by weight of butyl acetate, this was filtered using a membrane filter having a pore size of 0.2 μm to prepare a positive photoresist composition. Table 2 shows the physical properties of this product such as sensitivity, resolution, heat resistance, pattern shape and storage stability.

Examples 2 to 8 Examples except that the polyphenolic compound (C ₁ ) used as the component (C) in Example 1 was replaced with the polyphenolic compound (C _{2 to} C ₈ ) shown in Table 1. Similar to 1,
A positive photoresist composition was prepared. Table 2 shows the physical properties of the product such as sensitivity, resolution, heat resistance, pattern shape and storage stability.

[0048]

[Table 2]

Comparative Example 1 Instead of the polyphenolic compound C ₁ in Example 1, bis (4-hydroxy-3,5-dimethylphenyl)-
A positive photoresist composition was prepared in the same manner as in Example 1 except that 2-hydroxyphenylmethane was used. Table 3 shows the physical properties of the product such as sensitivity, resolution, heat resistance, pattern shape and storage stability.

Comparative Example 2 1- [1- (4-hydroxyphenyl) isopropyl] was used in place of the polyphenolic compound C ₁ in Example 1.
In the same manner as in Example 1 except that -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene was used,
A positive photoresist composition was prepared. Table 3 shows the physical properties of the product such as sensitivity, resolution, heat resistance, pattern shape and storage stability.

[0051] Alternatively 4,6-bis polyphenolic compound C ₁ of Comparative Example 3 Example 1 [1- (4-hydroxyphenyl) isopropyl] - with resorcinol, except that the amount added to 10 parts by weight A positive photoresist composition was prepared in the same manner as in Example 1. Table 3 shows the physical properties of this product such as sensitivity, resolution, heat resistance, pattern shape and storage stability.
Shown in

[0052]

[Table 3]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Tokutake 150 Nakamaruko, Nakahara-ku, Kawasaki, Kanagawa Tokyo Ohka Kogyo Co., Ltd. (72) Hidekatsu Ohara 150 Nakamaruko, Nakahara-ku, Kawasaki, Kanagawa Tokyo Ohka Kogyo Co., Ltd. (72) Inventor Hisasa Nakayama 150 Nakamaruko, Nakahara-ku, Kawasaki-shi, Kanagawa Tokyo Ohka Kogyo Co., Ltd.

Claims (2)

[Claims] 1. An (A) alkali-soluble resin, (B) a quinonediazide group-containing compound, and (C) a general formula: (In the formula, R ¹ , R ² and R ³ are each a hydrogen atom or a lower alkyl group, and Ar ¹ , Ar ² and Ar ³ are 1 to ³ respectively.
A nuclear-substituted or unsubstituted benzyl group having 4 hydroxyl groups, wherein x, y and z are each an integer of 1 to 3, l,
A positive photoresist composition containing at least one polyphenolic compound represented by m and n each being an integer of 1 or 2. 2. A methylol in which the polyphenolic compound as the component (C) is (a) 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene. And (b) phenol, o-cresol, m-cresol, p-cresol, 2,4-xylenol, 2,6-xylenol,
2,3,5-trimethylphenol and 3-methyl-6
The positive photoresist composition according to claim 1, which is a condensation product with at least one phenol compound selected from -cyclohexylphenol.