JP3499160B2 - Positive photoresist composition - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to the same exposure condition,
The present invention relates to a positive photoresist composition capable of forming various resist patterns such as a dense pattern, an isolated pattern, and a dot pattern in good shape.

[0002]

2. Description of the Related Art In recent years, attention has been focused on the manufacture of high value-added logic ICs. However, in the manufacture of highly integrated logic ICs, a dense pattern, an isolated pattern,
There is a demand for a photoresist composition that can form a resist pattern having various shapes such as a dot pattern in an ultrafine region of half micron or less with a good shape. Further, it is desired that each of these resist patterns can be formed in a good shape even under the same exposure conditions. But,
In the conventional photoresist composition, although it is excellent in forming a dense pattern, it is not excellent in forming an isolated pattern or a dot pattern, or even if it can be formed, there are large variations in the depth of focus characteristics in each pattern under the same exposure conditions. Therefore, it is necessary to change the exposure condition for each pattern shape or the mask pattern size.

JP-A-6-167805 (Prior Art 1) and JP-A-7-168355 (Prior Art 2) exemplify a quinonediazide ester compound having a specific structure as a photosensitive component. A high-resolution positive photoresist composition containing the same is described. But,
With the positive resist compositions specifically exemplified in Prior Art 1 and 2, it is difficult to form various resist patterns in good shape without changing the exposure conditions.

Further, JP-A-9-110751 (Prior Art 3) describes a phenol compound represented by a wide range of general formulas, and describes that a quinonediazide esterified product of the phenol compound is useful as a photosensitive component. There is. However, the esterified product in the present invention is not specifically described. Further, in Prior Art 3, although a method for synthesizing a pentanuclear phenol compound is described, a by-product is likely to be generated, and it is difficult to isolate a target product in high yield.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to form various resist patterns such as a dense pattern, an isolated pattern, and a dot pattern even under the same exposure condition in the field of forming an ultrafine resist pattern of half micron or less. Another object of the present invention is to provide a positive photoresist composition which can be formed into a good shape and has excellent depth of focus width characteristics .

[0006]

Means for Solving the Problems As a result of intensive studies by the present inventors, the present invention contains a quinonediazide esterified compound of a compound represented by the following general formula (III) , and the average esterification rate of the esterified compound is 40 %. The positive photoresist composition having a concentration of up to 60 % can form various resist patterns such as a dense pattern, an isolated pattern, and a dot pattern with good shape even under the same exposure conditions, and has excellent depth of focus characteristics. I found that.

That is, the present invention provides a positive photoresist composition containing (A) an alkali-soluble resin, (B) a photosensitive component, and (C) a sensitivity improver (sensitizer), wherein (A) an alkali Soluble resin is m-cresol
, P-cresol, 2,3,5-trimethylphenol
Al obtained by the condensation reaction of
A potassium-soluble novolac resin, wherein the photosensitive component (B) contains at least one selected from quinonediazide ester compounds of polyphenol compounds represented by the following general formula (III), and the average ester of the quinonediazide ester compound is The conversion rate is 40 to 60%, and (C) the sensitivity improver (sensitizer) is bis (4-hydroxy-2,3,5).
-Trimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, 2,4-
Bis (3,5-dimethyl-4-hydroxyphenylmethyl) -6-methylphenol, 4,6-bis [1- (4
-Hydroxyphenyl) isopropyl] resorcin, 1
-[1- (4-hydroxyphenyl) isopropyl]-
The present invention provides a positive photoresist composition containing at least one selected from 4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene.

[0008]

[Chemical 2]

In the present invention, the blending ratio of the component (B) is
10 to 60 weight based on the total amount of the (A) component and the (C) component
The positive photoresist composition is provided in an amount of% .

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION (A) Alkali-Soluble Resin The alkali-soluble resin as the component (A) is not particularly limited, and can be selected from those usually used as a film-forming substance in a positive photoresist composition. You can choose to. Preferably, a condensation reaction product of an aromatic hydroxy compound and an aldehyde or a ketone,
Examples thereof include polyhydroxystyrene and its derivatives.

Examples of the aromatic hydroxy compound include phenol, m-cresol, p-cresol and o.
-Xylenols such as cresol, 2,3-xylenol, 2,5-xylenol, 3,5-xylenol, 3,4-xylenol; m-ethylphenol, p-ethylphenol, o-ethylphenol, 2,3,3 5-trimethylphenol, 2,3,5-triethylphenol, 4-tert-butylphenol, 3-tert-
Butylphenol, 2-tert-butylphenol,
2-tert-butyl-4-methylphenol, 2-t
Alkylphenols such as ert-butyl-5-methylphenol; alkoxyphenols such as p-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, m-ethoxyphenol, p-propoxyphenol, m-propoxyphenol; o- Isopropenylphenol, p-isopropenylphenol, 2-
Methyl-4-isopropenylphenol, 2-ethyl-
Examples thereof include isopropenylphenols such as 4-isopropenylphenol; arylphenols such as phenylphenol; polyhydroxyphenols such as 4,4′-dihydroxybiphenyl, bisphenol A, resorcinol, hydroquinone, and pyrogallol. These may be used alone or in combination of two or more.

Examples of the aldehydes 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-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde , P-chlorobenzaldeh And cinnamic acid aldehyde. These may be used alone or in combination of two or more. Of these aldehydes, formaldehyde is preferable because it is easily available, but it is preferable to use hydroxybenzaldehyde and formaldehyde in combination in order to improve heat resistance.

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. Furthermore, aldehydes and ketones may be used in appropriate 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, oxalic acid, paratoluenesulfonic acid, or the like can be used.

Examples of the polyhydroxystyrene and derivatives thereof include homopolymers of vinylphenol,
Examples thereof include a copolymer 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.

Among them, the alkali-soluble resin as the component (A) suitable in the present invention has a weight average molecular weight (Mw).
2000 to 20000, especially 3000 to 12000
Alkali-soluble novolac resin of is preferable, among them,
Alkali-soluble novolak resin obtained by condensation reaction of m-cresol, p-cresol and formaldehyde, alkali-soluble novolak resin obtained by condensation reaction of m-cresol, p-cresol, 2,3,5-trimethylphenol and formaldehyde Is preferable because a positive photoresist composition having high sensitivity and wide exposure latitude can be prepared.

(B) Photosensitive Component In the present invention, as the (B) photosensitive component, the following general formula (I) is used.
It is characterized by using a quinonediazide esterified product of the compound represented by

[0032]

[Chemical 3]

The polyphenol compound represented by the general formula (I) is represented by the following general formula (IV) in the presence of an acid catalyst.

[0034]

[Chemical 4]

A phenol compound represented by the following formula or a solution prepared by dissolving the phenol compound in an organic solvent is added with the following general formula (V):

[0036]

[Chemical 5]

It is possible to synthesize a polyphenol compound represented by the general formula (I) in high yield by adding a solution prepared by dissolving the compound containing a methylol group represented by This is preferable because it is possible and the generation of by-products is small. When the phenol compound is solid at room temperature, it is preferably dissolved in an organic solvent and used in the form of a solution. The organic solvent that dissolves the phenol compound or the compound containing a methylol group is preferably a good solvent for the polyphenol compound represented by the general formula (I). As such a solvent, γ-butyrolactone or a mixed solvent of this and alcohol is preferable.

In order to reduce the amount of by-products and to synthesize the polyphenol compound in a high yield, it is desirable to add the methylol group-containing compound to a large amount of the phenol compound as little as possible. The use of a methylol group-containing compound that is solid at room temperature in the form of a solution is preferable because it facilitates control so that the methylol group-containing compound can be quantitatively added in minute amounts. Further, by using a good solvent for the polyphenol compound as the reaction solvent, the reaction is carried out in a homogeneous solution,
Generation of by-products and unreacted substances is suppressed, and a high yield of polyphenol compound can be synthesized. In addition,
The larger the amount of the phenol compound used with respect to the methylol group-containing compound, the less the generation of by-products, but if it is too much, it will be difficult to isolate the target polyphenol compound and the raw material phenol compound. It is preferable to use the phenol compound in an amount of 2 to 50 mol, particularly 6 to 16 mol, per 1 mol of the methylol group-containing compound. The reaction product (polyphenol compound) can be precipitated and taken out by adding the reaction solution to a large amount of a poor solvent (such as water). The precipitated reaction product is filtered, recrystallized using a solvent such as butyl acetate, and the obtained crystal is washed with toluene or the like and dried to obtain the target polyphenol compound.

Then, the obtained polyphenol compound and 1,2-naphthoquinonediazide-4-sulfonyl halide, 1,2-naphthoquinonediazide-5-sulfonyl halide and other 1,2-naphthoquinonediazide sulfonic acid halide are subjected to a condensation reaction. (Esterification reaction) to produce a quinonediazide esterified product. This esterification reaction can usually be carried out in an organic solvent such as dioxane, N-methylpyrrolidone or dimethylacetamide in the presence of a basic condensing agent such as triethylamine, alkali carbonate or alkali hydrogen carbonate.

The esterification reaction must be carried out so that the average esterification rate is 20 to 80%. For that purpose, 1,2-naphthoquinonediazide sulfonic acid halide is reacted with 1 mol of the compound represented by the general formula (I) in the range of 1 to 4 mol, particularly in the range of 2 to 3 mol. preferable. The average esterification rate is
It matches well with the amount of each ingredient charged. The average esterification rate can be easily calculated from the charged amount and unreacted amount of 1,2-naphthoquinonediazidesulfonic acid halide. The average esterification rate is 40 to 60%.
Is particularly preferable, and within this range, the effect of forming dense, isolated, and dot resist patterns in good shape under the same exposure conditions is more excellent. Average esterification rate is 20
If it is less than 80%, the residual film rate in the unexposed portion and the resolution are remarkably lowered, and if it exceeds 80%, the sensitivity is remarkably lowered, so that the object of the present invention cannot be sufficiently achieved. The quinonediazide compound includes, among others, the following general formula (II)

[0041]

[Chemical 6]

A quinonediazide ester compound of the compound represented by the following formula, and the following general formula (III)

[0043]

[Chemical 7]

A quinonediazide esterified product of the compound represented by The compound represented by the general formula (III) has x = y = 1, x = 0 and y = 1, and x = y = 0.
There are three isomers of

In the photosensitive component (B) of the present invention, other quinonediazide ester compounds may be used for the purpose of improving sensitivity and resolution. Examples of such quinonediazide ester compounds include those represented by the following general formula (VI)

[0046]

[Chemical 8]

[In the formula, R ^{8 to} R ¹⁵ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, or a cycloalkyl group; ^{16 to} R ¹⁸ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; Q is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or R ¹⁶ to form a carbon atom chain of 3 to 6; Or the following chemical formula (VI
Residue represented by I)

[0048]

[Chemical 9]

(In the formula, R ¹⁹ and R ²⁰ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxyl group having 1 to 6 carbon atoms, or a cycloalkyl group; c Represents an integer of 1 to 3);
a and b each represent an integer of 1 to 3; d represents an integer of 0 to 3; n represents an integer of 0 to 3], and a quinonediazide esterified product of the polyphenol compound.
Specifically, 2,4-bis (3,5-dimethyl-4-hydroxybenzyl) -5-hydroxyphenol, 2,6
-Bis (2,5-dimethyl-4-hydroxybenzyl)
Linear trinuclear compounds such as -4-methylphenol; bis [2,5-dimethyl-3- (4-hydroxy-5-methylbenzyl) -4-hydroxyphenyl] methane, bis [2,5-dimethyl- 3- (4-hydroxybenzyl) -4-hydroxyphenyl] methane, bis [3-
(3,5-Dimethyl-4-hydroxybenzyl) -4-
Hydroxy-5-methylphenyl] methane, bis [3-
(3,5-Dimethyl-4-hydroxybenzyl) -4-
Hydroxy-5-ethylphenyl] methane, bis [3-
(3,5-diethyl-4-hydroxybenzyl) -4-
Hydroxy-5-methylphenyl] methane, bis [3-
(3,5-diethyl-4-hydroxybenzyl) -4-
Hydroxy-5-ethylphenyl] methane, bis [2-
Hydroxy-3- (3,5-dimethyl-4-hydroxybenzyl) -5-methylphenyl] methane, bis [2-
Hydroxy-3- (2-hydroxy-5-methylbenzyl) -5-methylphenyl] methane, bis [4-hydroxy-3- (2-hydroxy-5-methylbenzyl)-
Linear tetranuclear compounds such as 5-methylphenyl] methane; 2,4-bis [2-hydroxy-3- (4-hydroxybenzyl) -5-methylbenzyl] -6-cyclohexylphenol, 2,4-bis [4-hydroxy-3
-(4-Hydroxybenzyl) -5-methylbenzyl]
Linear polyphenol compounds such as linear pentanuclear compounds such as -6-cyclohexylphenol, tris (4-
Hydroxyphenyl) methane, bis (4-hydroxy-)
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)- Three
4-dihydroxyphenylmethane, bis (4-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-methyl) Phenyl) -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, bis (4- Hydroxy-2,3,5-trimethylphenyl)
2-hydroxyphenylmethane, bis (4-hydroxy-2,3,5-trimethylphenyl) -3-hydroxyphenylmethane, bis (4-hydroxy-2,3,5)
-Trimethylphenyl) -4-hydroxyphenylmethane, bis (4-hydroxy-2,3,5-trimethylphenyl) -3,4-dihydroxyphenylmethane, bis (4-hydroxy-2,3,5-trimethylphenyl)
Preferred are quinonediazide ester compounds such as trisphenolic polyphenol compounds such as -4-hydroxy-3-methoxyphenylmethane. However, the content of the quinonediazide esterified compound of the compound represented by the general formula (I) is 10% by weight or more, preferably 50% by weight or more, based on the total amount of the component (B), and the above effects are desired. It is preferable above.

In the composition of the present invention, the blending amount of the component (B) is such that the alkali-soluble resin which is the component (A) and the sensitivity improver (sensitizer) of the following component (C) which is optionally added. It is preferably 10 to 60% by weight, and more preferably 20 to 50% by weight, based on the total amount of
If the blending amount of the component (B) is less than the above range, an image faithful to the pattern cannot be obtained, and the transferability also deteriorates. on the other hand,
If the blending amount of the component (B) exceeds the above range, the sensitivity is deteriorated and the homogeneity of the formed resist film is deteriorated, and the resolution is deteriorated.

(C) Sensitivity improver (sensitizer) The (C) sensitivity improver (sensitizer) is not particularly limited, and known ones can be used. For example, a polyphenol compound represented by the above general formula (VI) can be used, and for example, bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane,
1,4-bis [1- (3,5-dimethyl-4-hydroxyphenyl) isopropyl] benzene, 2,4-bis (3,5-dimethyl-4-hydroxyphenylmethyl)
-6-methylphenol, bis (4-hydroxy-3,
5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -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, 2,6-bis [1- (2,4
-Dihydroxyphenyl) isopropyl] -4-methylphenol, 4,6-bis [1- (4-hydroxyphenyl) isopropyl] resorcin, 4,6-bis (3,3)
5-dimethoxy-4-hydroxyphenylmethyl) pyrogallol, 4,6-bis (3,5-dimethyl-4-hydroxyphenylmethyl) pyrogallol, 2,6-bis (3-methyl-4,6-dihydroxyphenylmethyl)
-4-methylphenol, 2,6-bis (2,3,4-
Preferred examples include trihydroxyphenylmethyl) -4-methylphenol and 1,1-bis (4-hydroxyphenyl) cyclohexane. Among them, bis (4-hydroxy-2,3,5-trimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, 2,4- Bis (3,5-dimethyl-4-hydroxyphenylmethyl) -6-methylphenol, 4,6-bis [1- (4-hydroxyphenyl) isopropyl] resorcin, 1- [1- (4-hydroxyphenyl) isopropyl ] -4- [1,1-Bis (4-hydroxyphenyl) ethyl] benzene is particularly preferred.

When these components (C) are blended, the content is 5 to the alkali-soluble resin which is the component (A).
It can be selected in the range of 50% by weight, preferably 10 to 35% by weight. In the present invention, it is more preferable to use these (C) sensitivity improvers (sensitizers) in the above range, because the exposure latitude, resolution and depth of focus characteristics are further improved and the sensitivity is also excellent.

The composition of the present invention may further contain, if necessary, compatible additives and UV absorbers for preventing halation, such as 2,2 ', 4,4'-tetrahydroxybenzophenone and 4 -Dimethylamino-2 ', 4'
-Dihydroxybenzophenone, 5-amino-3-methyl-1-phenyl-4- (4-hydroxyphenylazo) pyrazole, 4-dimethylamino-4'-hydroxyazobenzene, 4-diethylamino-4'-ethoxyazobenzene, 4- Diethylaminoazobenzene, curcumin, etc., and a surfactant for preventing striation, for example, Florard FC-430, FC431 (trade name, manufactured by Sumitomo 3M Ltd.), F-top EF122A,
A fluorinated surfactant such as EF122B, EF122C, EF126 (trade name, manufactured by Tochem Products Co., Ltd.) and the like can be added and contained within a range that does not hinder the purpose of the present invention.

Further, the composition of the present invention is preferably used in the form of a solution by dissolving the components (A) to (C) and various additives in a suitable solvent. Examples of such a solvent include solvents used in conventional positive photoresist compositions, such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2
-Ketones such as heptanone; 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 monophenyl ether, etc. Polyhydric alcohols and their derivatives; cyclic ethers such as dioxane; and ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc. Esters can be mentioned. These may be used alone or in combination of two or more. Particularly, ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc. Esters are preferred.

An example of a suitable method of using the composition of the present invention will be described. First, the component (A), the component (B) and the component (C), and various components added as necessary are described above. Dissolve in a suitable solvent such as, spin coater or the like to apply it to a silicone wafer or a support having an antireflection film formed thereon, and dry it to form a photosensitive layer, and then a light source that emits ultraviolet rays, for example, low pressure. Mercury lamp,
Use a high-pressure mercury lamp, ultra-high-pressure mercury lamp, arc, xenon lamp, etc. to expose through a desired mask pattern, or
Alternatively, irradiation is performed while scanning the electron beam. Next, this is immersed in a developing solution, for example, an alkaline aqueous solution such as a 1 to 10 wt% tetramethylammonium hydroxide (TMAH) aqueous solution, whereby the exposed portion is dissolved and removed, and an image faithful to the mask pattern can be obtained.

[0056]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Various evaluations of the positive photoresist composition were obtained as follows and shown in Table 1.

(1) Sensitivity The sample was coated on a silicon wafer using a spinner and dried on a hot plate at 90 ° C. for 90 seconds to obtain a resist film with a thickness of 1.05 μm. A reduction projection exposure apparatus NSR-2005i10D (manufactured by Nikon Corporation, through a mask (reticle) corresponding to a 0.35 μm resist pattern with a line and space (L & S) of 1: 1 on this film
NA = 0.57) and exposed at intervals of 0.1 to 0.01 seconds, and then PEB (post-exposure heating) treatment is performed at 110 ° C. for 90 seconds to obtain 2.38 wt% tetramethylammonium hydroxide. When developed with an aqueous solution at 23 ° C. for 60 seconds, washed with water for 30 seconds, and dried, the exposure time (Eop) at which the L & S width of a 0.35 μm resist pattern is formed is 1: 1 as a unit of millisecond (ms). Expressed as

[0058](2-1) Depth of focus characteristics (isolated pattern
) Reduction projection exposure apparatus NSR-2005i10D (Nikon Corporation
Manufactured by NA = 0.57), and Eop [mask pattern
The set dimensions (line width 0.35 μm, L & S 1: 1)
Exposure required for faithful reproduction] as the reference exposure
However, in that exposure amount, the focus is shifted up and down as appropriate
An isolated resist pattern (width
The SEM photograph of 0.35 μm) was observed. That SE
A rectangular resist pattern of 0.35 μm was prepared from the M photograph.
Maximum value of focal shift obtained within ± 10% of fixed size
(Μm) was used as the depth of focus width characteristic (isolated pattern).

[0059](2-2) Depth of focus width characteristics (dense pattern)
) Reduction projection exposure apparatus NSR-2005i10D (Nikon Corporation
Manufactured by NA = 0.57), and Eop [mask pattern
The set dimensions (line width 0.35 μm, L & S 1: 1)
Exposure required for faithful reproduction] as the reference exposure
However, in that exposure amount, the focus is shifted up and down as appropriate
Dense resist pattern (line width obtained by light and development)
Observation of SEM photograph of 0.35 μm and L & S 1: 1)
went. From the SEM photograph, a rectangular register of 0.35 μm
The strike pattern can be obtained within ± 10% of the set dimension.
The maximum value (μm) of point deviation is the depth of focus characteristics (dense pattern).
I said).

(2-3) Depth of focus width characteristics (dot pattern
N) Reduction projection exposure apparatus NSR-2005i10D (manufactured by Nikon Corporation, NA = 0.57), vertical width 0.6 μm × 0.6 μ
Using a mask corresponding to the m dot pattern and having a duty ratio of 2: 1 (dot spacing of 1.20 μm), E
op [Set dimensions of mask pattern (line width 0.35 μm,
The exposure amount required to faithfully reproduce L & S 1: 1)] is used as a reference exposure amount, and at the exposure amount, the focus is appropriately shifted up and down, and the dot pattern (0. The SEM photograph of 6 μm × 0.6 μm) was observed. From the SEM photograph 0.6 μm × 0.6 μm
The maximum value (μm) of the focus shift obtained in the rectangular dot pattern of 10% of the set dimension is defined as the depth of focus width characteristic (dot pattern).

(3) Total Depth of Width Property In the evaluations of (2-1) to (2-3) above, 0.35 μm was obtained for any of the dense pattern, the isolated pattern, and the dot pattern. The maximum value (μm) of the focal shift obtained by the rectangular resist pattern within a range of ± 10% of the set dimension was defined as the total depth of focus characteristic.

(4) Resolution It was represented by the limiting resolution in the exposure amount for reproducing a mask pattern with a line width of 0.35 μm and L & S of 1: 1.

(Synthesis Example 1) 2.03 g of p-toluenesulfonic acid was added to 1 mol of 2,4-xylenol to give 50-
Solution 1 was prepared by stirring and stirring at 60 ° C. 2,6-bis (2,5-dimethyl-4-hydroxy-3-methylolbenzyl)-represented by the following general formula (VIII)
Mixed solvent 1 of 0.05 mol of 4-methylphenol and γ-butyrolactone / methanol = 125/25 (weight ratio)
Solution 2 was prepared by adding to 50 g, stirring at 25 ° C. and dissolving.

[0064]

[Chemical 10]

At a temperature of 60 ° C., the solution 2 was added dropwise to the above solution 1 over 30 to 60 minutes, and the temperature was maintained and stirred for 3 hours. Then, the reaction solution was poured into 8 liters of pure water and left standing for 3 hours, whereby a reaction product was deposited.
The reaction product was separated by filtration, recrystallized from butyl acetate, and the obtained crystallized product was washed with toluene and dried to obtain a solid. As a result of GPC analysis, the following general formula (I
The peak of the compound represented by I) was confirmed, and the peak considered to be a by-product was hardly confirmed. 2,6-bis (2,5-dimethyl-4-) determined from the peak area
The yield based on hydroxy-3-methylolbenzyl) -4-methylphenol was 89.6%.

[0066]

[Chemical 11]

(Synthesis Example 2) Instead of the solution 1 used in Synthesis Example 1, 50 g of γ-butyrolactone was added with 1 mol of 3,4-xylenol and 2.03 g of p-toluenesulfonic acid at 50 to 60 ° C. Synthesis was performed in the same manner as in Synthesis Example 1 except that Solution 3 obtained by stirring and dissolving was used to obtain a solid. As a result of GPC analysis, the following general formula (II
The peak of the compound represented by I) was confirmed, and the peak considered to be a by-product was hardly confirmed. In addition, 2,6-bis (2,5-dimethyl-4-hydroxy-3-methylolbenzyl) -4- determined from the peak area
The yield based on methylphenol was 92.9%.

[0068]

[Chemical 12]

(Comparative Synthesis Example) In the same manner as in Synthesis Example 2, γ
-To 50 g of butyrolactone, 1 mol of 3,4-xylenol and 2.03 g of p-toluenesulfonic acid were added, and 50
Solution 3 was prepared by stirring and dissolving at -60 ° C.
At a temperature of 60 ° C., 2,6-bis (2,6-bis (2,6)
5-dimethyl-4-hydroxy-3-methylolbenzyl) -4-methylphenol was added to 10 parts of a powder of 0.05 mol.
The mixture was divided, charged for 30 to 60 minutes, and the temperature was maintained while stirring for 3 hours. Then, the reaction solution was poured into 8 liters of pure water and left standing for 3 hours, whereby a reaction product was deposited. The reaction product was separated by filtration, recrystallized from butyl acetate, and the obtained crystallized product was washed with toluene and dried to obtain a solid. As a result of GPC analysis, in addition to the peak of the compound represented by the above general formula (III), many peaks considered to be by-products were confirmed. In addition, 2,6-bis (2,5-dimethyl-4-) calculated from the peak area
The yield based on hydroxy-3-methylolbenzyl) -4-methylphenol was 13.5%.

Example 1 (Reference Example) Component (A): 100 parts by weight of alkali-soluble novolac resin [m-cresol / p-cresol / 2,3,5-trimethylphenol = 35/40/25 (molar ratio), weight Novolak resin having an average molecular weight of 4,500] Component (B): 35 parts by weight of photosensitive component [1 mol of the phenol compound (II) synthesized in Synthesis Example 1 and 1,2-naphthoquinonediazide-5-sulfonic acid chloride (hereinafter referred to as "5- NQD ") reaction product with 2.5 mol. Average esterification rate 50%. ] Component (C): 20 parts by weight of sensitivity improver Sensitivity improver: 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene Above (A ) To (C) were dissolved in 2-heptanone and then filtered using a membrane filter having a pore size of 0.2 μm to prepare a positive photoresist composition.

Example 2 (Example) Except that the component (B) used in Example 1 was replaced by a reaction product of 1 mol of the phenol compound (III) synthesized in Synthesis Example 2 and 2.5 mol of 5-NQD. A positive photoresist composition was prepared in the same manner as in Example 1. The average esterification rate was 50%.

[0072] (Comparative Example 1) used in Example 1 (B) below phenolic compounds in place of component (IX) except using the reaction product of 1 mole of 5-NQD2 mole in the same manner as Example 1 Positive A type photoresist composition was prepared. The average esterification rate was 50%.

[0073]

[Chemical 13]

[0074] (Comparative Example 2) used in Example 1 (B) below phenolic compounds in place of the component (X) except using the reaction product of 1 mole of 5-NQD2 mole in the same manner as Example 1 Positive A type photoresist composition was prepared. The average esterification rate was 50%.

[0075]

[Chemical 14]

[0076] (Comparative Example 3) used in Example 1 (B) below phenolic compounds in place of component (XI) except using the reaction product of 1 mole of 5-NQD2.5 mol in the same manner as in Example 1 To prepare a positive photoresist composition. The average esterification rate was 50%.

[0077]

[Chemical 15]

[0078] (Comparative Example 4) instead of the component (B) used in Example 1, except for using the Synthesis Example 1 phenol compound synthesized in (II) the reaction product of 1 mole of 5-NQD0.5 mol A positive photoresist composition was prepared in the same manner as in Example 1. The average esterification rate was 10%.

[0079] except that instead of (Comparative Example 5) used in Example 1 (B) component was used in Synthesis Example 1 phenol compound synthesized in (II) the reaction product of 1 mole of 5-NQD4.5 mol A positive photoresist composition was prepared in the same manner as in Example 1. The average esterification rate was 90%.

[0080] (Comparative Example 6) instead of the component (B) used in Example 2, phenol compound synthesized in Synthesis Example 2 (III) 1 mol of 5-NQD0.5
A positive photoresist composition was prepared in the same manner as in Example 2 except that the reaction product with mol was used. The average esterification rate was 10%.

[0081] (Comparative Example 7) instead of the component (B) used in Example 2, phenol compound synthesized in Synthesis Example 2 (III) 1 mol of 5-NQD4.5
A positive photoresist composition was prepared in the same manner as in Example 2 except that the reaction product with mol was used. The average esterification rate was 90%.

[0082] Examples 1 and 2, above with respect to positive photoresist compositions prepared in Comparative Examples 1-7 (1), (2
1), (2-2), (2-3), (3), and (4)
Was evaluated and the results are shown in Table 1.

[0083]

[Table 1]

It can be seen from Table 1 that the composition of the present invention is excellent in the depth of focus width characteristic in any of the isolated pattern, the dense pattern and the dot pattern, and is also excellent in the sensitivity and the resolution.

[0085]

According to the present invention, various resist patterns such as a dense pattern, an isolated pattern, and a dot pattern can be formed in good shape even in the same exposure condition in the field of forming an ultrafine resist pattern of half micron or less. And a positive photoresist composition having excellent depth of focus characteristics.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidekatsu Ohara, 150 Nakamaruko, Nakahara-ku, Kawasaki-shi, Kanagawa Tokyo Ohka Kogyo Co., Ltd. (72) Hisashi Nakayama 150, Nakamaruko, Nakahara-ku, Kawasaki-shi, Kanagawa Tokyo Ohka Kogyo Within the corporation (56) Reference JP-A-9-114093 (JP, A) JP-A-9-110751 (JP, A) JP-A-7-159989 (JP, A) JP-A-6-167805 (JP, A) JP-A-8-95240 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03F ^7/ 00-7/42

Claims (2)

(57) [Claims] 1. A positive photoresist composition comprising (A) an alkali-soluble resin, (B) a photosensitive component, and (C) a sensitivity-enhancing agent (sensitizer ).
Re-soluble resins include m-cresol, p-cresol,
2,3,5-Trimethylphenol and formaldehyde
Alkali-soluble novolac obtained by condensation reaction with
(B) the photosensitive component is a resin represented by the following general formula (III)
Containing at least one member selected from the quinone diazide esterified product of the polyphenol compound represented by
Is 60%, and (C) the sensitivity improver (sensitizer) is bis (4-hydroxy-2,3,5-trimethylphenyl).
2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane, 2,4-bis (3,5-dimethyl-
4-hydroxyphenylmethyl) -6-methylphenol, 4,6-bis [1- (4-hydroxyphenyl) isopropyl] resorcin, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1 -Bis (4-
A positive photoresist composition comprising at least one selected from hydroxyphenyl) ethyl] benzene. [Chemical 1] 2. The positive photoresist composition according to claim 1, wherein the blending ratio of the component (B) is 10 to 60% by weight based on the total amount of the components (A) and (C).