JP3505679B2 - Copolymer for producing chemically amplified photoresist and chemically amplified positive photoresist composition containing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemically amplified photoresist-producing copolymer and a chemically amplified positive photoresist composition containing the same, and more specifically, it forms an excellent pattern regardless of the substrate. Yes, the alkali dissolution contrast before and after exposure is extremely high, it has a wide exposure margin, high sensitivity, high resolution, high heat resistance, and excellent stability after exposure. The present invention relates to a chemically amplified positive photoresist composition which is sensitive to radiation such as ultraviolet rays, far ultraviolet rays, excimer lasers, X-rays, and electron beams as a material for forming fine patterns for LSI manufacturing.

[0002]

2. Description of the Related Art Recently, in semiconductor technology, high integration of semiconductor devices has been rapidly advanced, and accordingly, super LS has been responded to.
Even in photolithographic patterning for manufacturing I or the like, an ultrafine pattern in a region of a quarter micron or less is being demanded. Therefore, the exposure wavelength is also g
Far-ultraviolet rays, Kr due to wavelength shortening in the region of − line and i line
Attention has been paid to researches on lithography using F excimer laser, X-ray and electron beam.

The conventional photoresists used for g-line and i-line use a novolac-quinonediazide compound, and the absorption of light is appropriate when they are suitable for the wavelength of deep ultraviolet ray and KrF excimer laser. Therefore, there are many studies on a chemically amplified photoresist using a polyhydroxystyrene derivative as a basic resin, which has relatively less light absorption than the novolac-quinonediazide compound.

In such a chemically amplified photoresist composition, the resist layer has chemical radiation.
The acid generator contained in the photoresist composition releases an acid when it is pattern-exposed to y), and the released acid causes a catalytic activity deprotection reaction with a resin component to change the solubility in a developer. Use the principle of letting.

Particularly, in the case of the chemically amplified photoresist composition, since the resin component is exhibited even with a small amount of acid generated from the acid generator, the pattern resolution is high and the photosensitivity to actinic radiation is excellent. It is useful in terms.

As such a chemically amplified photoresist material, a resist material using poly (pt-butoxycarbonyloxystyrene / p-hydroxystyrene) (US Pat. No. 4,491,628), poly ( pt
A resist material using butoxystyrene / p-hydroxystyrene (US Pat. No. 5,350,660),
And a resist material using poly (p-1-ethoxystyrene / p-hydroxystyrene) (Japanese Patent No. A-5
No. 249682) is known.

[0007]

However, among the basic resins of such photoresist materials, the protective group is ter.
In the case of a t-butyl group or a tert-butoxycarbonyl group, these protecting groups have the property of being decomposed by a strong acid and, as a result, are inactivated by reacting with a basic compound in the air. There is a problem that the T-top shape is likely to occur and the pattern varies depending on the type of substrate. On the other hand, in the case of a basic resin having a protective group that is decomposed into a weak acid such as an acetal group or a ketal group, the influence of a basic compound in the air is small, but the shape of the pattern depends on the time delay from exposure to heat treatment (PEB). Cannot be adapted to high resolution, with the drawback of being significantly narrowed.

An object of the present invention is to solve the problems of the basic resin which can be used in the conventional chemically amplified photoresist composition, and has a wide range of exposure latitude,
Provided is a novel chemically amplified copolymer for producing a photoresist, which has high sensitivity, high resolution, excellent heat resistance and pattern stability and can obtain an excellent resist pattern regardless of the type of substrate. Especially.

Another object of the present invention is to provide a chemically amplified positive photoresist composition containing a copolymer having the above-mentioned characteristics.

[0010]

In order to achieve such an object, the chemically amplified copolymer for producing a photoresist according to the present invention is represented by the following chemical formula 1 (Formula 5).

[0011]

[Chemical 5] In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or a lower alkyl group,
R ₅ , R ₆ , R ₇ and R ₈ are each a hydrogen atom or a carbon atom number 1 to
8 is an alkyl group, an alkoxy group, an alkoxycarbonyl group or a halogen atom, h and i are constants of 0 to 8 and k,
Each of l, m and n is a repeating unit, and 0.3 <k /
(K + l + m + n) <0.9, 0 ≦ l / (k + l + m
+ N) <0.6, 0 ≦ m / (k + 1 + m + n) <0.
6, and 0.01 <n / (k + 1 + m + n) <0.3
Satisfy the condition of. Then, k + l + m + n = 1 is satisfied, l and m cannot be 0 at the same time, and 0 at the same time.
It can be not.

R ₉ is a compound represented by the following chemical formula 2

[Chemical 6] In the above formula, R ₁₀ and R ₁₁ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ₁₂ is linear chain having 1 to 10 carbon atoms. A branched or cyclic alkyl group, and specific examples of the linear, branched or cyclic alkyl group are methyl, ethyl, propyl, isopropyl and n-butyl. Base,
The isobutyl group and t-butyl group, and the cyclic alkyl group is a cyclohexyl group.

Specific examples of the acid labile group represented by the chemical formula 2 are methoxyethyl group, ethoxyethyl group and n-
It is a butoxyethyl group, a cyclohexyl group or a methoxypropyl group.

Am is -NR ₁₃ R ₁₄ (wherein R ₁₃
And R ₁₄ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group or a phenyl group), a cyclic 2 is an amine and oxygen, or a cyclic 2 containing a sulfur atom is These are amines.

The chemically amplified positive photoresist composition according to the present invention is a copolymer represented by the above chemical formula 1,
It is characterized by being manufactured by dissolving an acid generator and an additive in a solvent.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.

Preferred examples of the basic resin represented by the chemical formula 1 used in the present invention are as follows.

(A) A quaternary copolymer of poly (hydroxystyrene / alkoxyalkoxystyrene / t-butylcarbonylalkoxystyrene / morpholinylcarbonylalkoxystyrene), in which k, l, m and n are each 0.3 < k / (k + 1 + m + n) <0.9, 0 ≦ l /
(K + l + m + n) <0.6, 0 ≦ m / (k + l + m
+ N) <0.6, and 0.01 <n / (k + l + m +
n) a resin satisfying the condition of <0.3, (B) a terpolymer of poly (hydroxystyrene / alkoxyalkoxystyrene / morpholinylcarbonylalkoxystyrene), in which k, l, m and n are each 0 .3 <k / (k +
l + m + n) <0.9, 0 ≦ l / (k + l + m + n)
<0.6, m = 0, and 0.01 <n / (k + l +
m + n) a resin satisfying the condition of <0.3, a terpolymer of (C) poly (hydroxystyrene / t-butylcarbonylalkoxystyrene / morpholinylcarbonylalkoxystyrene), k, l, m and n Respectively 0.3 <k / (k + l + m + n) <0.9, l = 0,
0 ≦ m / (k + 1 + m + n) <0.6, and 0.0
A resin satisfying the condition of 1 <n / (k + l + m + n) <0.3, and only one of the resins (A), (B) and (C) is used as a basic resin for photoresist. If necessary, two or more kinds of the resins (A), (B) and (C) may be mixed and used.

In the copolymer represented by the chemical formula 1, the hydroxy group has a role of improving the adhesive strength, heat resistance and sensitivity, and the t-butoxycarbonylmethoxy group is deprotected by the action of an acid upon exposure. The reaction occurs and is converted into a carboxylic acid or a hydroxy group, and the ethoxyethoxy group is converted into a hydroxy group by the action of an acid during exposure and converted into a hydroxy group to enhance the dissolution rate, thereby improving the resolution. Play a role to give. Ethoxy ethoxy groups can be exposed to a baking temperature (PE
B) has a feature that a deprotection reaction often occurs even in the process of 110 ° C., so that a pattern can be easily formed by a difference in solubility. The t-butoxycarbonylmethoxy group has a good pattern shape and resolution. With the advantage of being excellent, when these two substituents are properly blended, it is possible to form a photoresist having high resolution even in a low baking temperature process and being advantageous in forming a fine pattern. And the amide group maintains the affinity with the acid generated at the time of exposure to prevent the basic component in the atmosphere from coming into contact with the acid, and also prevents the acid from diffusing into the adjacent distance, A pattern narrowing phenomenon due to a time delay after exposure is prevented. The amide group serves to stabilize the acid without being changed by the action of the acid.

In the copolymer represented by the chemical formula 1, it is appropriate that the substitution amount of t-butoxycarbonylmethoxy group and ethoxyethoxy group is 10 to 50%, and the substitution amount of amide group is 1 to 30. % Is appropriate. If the amount of substitution with the t-butoxycarbonylmethoxy group and the ethoxyethoxy group is too large, the sensitivity becomes low, and if the amount of substitution is too small, the difference in dissolution rate between the exposed portion and the non-exposed portion becomes small. In view of such a point, the preferable substitution amount of t-butoxycarbonylmethoxy group and ethoxyethoxy group is 20 to 40%, and the substitution amount of amide group is preferably about 5 to 10%.

The method of introducing the t-butoxycarbonylmethoxy group and the amide group is carried out through a substitution reaction of polyhydroxystyrene and an alkylhalogen compound. At this time, tetramethylammonium hydroxide is always added as a basic compound. Must.

At this time, examples of the alkyl halogen compound include morpholinyl bromacetate and t-butyl bromacetate.

The molecular weight of the produced base resin is 1,000 to 1,000,000 as a polystyrene standard conversion molecular weight.
0, preferably 5,000 to 50,000 is preferable.

When a photoresist composition is prepared using such a copolymer, the acid generator and an appropriate amount of the additive are added in the present invention, but the acid generator is exposed to actinic radiation. If it is possible to generate acid when it does not adversely affect the formation of the resist pattern,
Any substance can be used, but more preferably 248n
A substance that can maintain an appropriate light absorption and a transparency of the resist material at a wavelength near m is used.

A preferred example of the acid generator having such characteristics is a sulfonium compound represented by the following chemical formula 3 (Chemical formula 7). However, the acid generator in the photoresist composition according to the present invention is not limited to the following compounds.

[0026]

[Chemical 7] In the above formula, R ₁₅ is a hydrogen atom, an alkyl group or an alkoxy group, R ₁₆ is an alkyl group, an alkoxyalkyl group, a t-butoxycarbonylmethyl group, and X is O or S.
Alternatively, in CH ₂ , g is a constant of 0-20.

Examples of specific compounds of the acid generator represented by Chemical Formula 3 are as follows. Triphenylsulfonium triplet, diphenyl (4-methylphenyl) sulfonium triplet, diphenyl (4-t-
Examples include butylphenyl) sulfonium triplet, diphenyl (4-methoxyphenyl) sulfonium triplet, diphenyl (4-t-butoxycarbonylmethoxyphenyl) sulfonium triplet, and the like.

In addition to the acid generator represented by the chemical formula 3, triphenylsulfonium hexafluoroantimonate, diphenyliodonium triplet, diphenyliodonium methylbenzene sulfonate, phenyl (4-t-methoxyphenyl) iodonium camphor sulfonate Salt, phenyl (4-t-butoxycarbonylmethoxyphenyl) iodonium camphorsulfonate, bis (cyclohexylsulfonyl) diazomethane,
And bis (2,4-dimethylphenylsulfonyl) diazomethane are also preferable.

As the halogen compound used as the acid generator, 1,1-bis (4-chlorophenyl) -2,
2,2-trichloroethane, phenyl-bis (trichloromethyl) -s-triazine, naphthyl-bis (trichloromethyl) -s-triazine and the like. In addition to these, there are 1,3-diketo-2-diazo compounds, diazobenzoquinone compounds, and diazonaphthoquinone compounds of diazoketone compounds, and sulfone compounds, sulfonic acid compounds, and nitrobenzyl compounds. Among these acid generators, onium salt compounds and diazoketone compounds are particularly preferable compounds.

Such an acid generator is used in an amount of 0.1 to 100 parts by weight based on 100 parts by weight of total solid components in the entire photoresist composition.
It is preferably used in 30 parts by weight, more preferably 0.1 to 10 parts by weight.

On the other hand, the above-mentioned acid generator may be used alone or in combination of two or more kinds.

In the photoresist composition according to the present invention, a compound which is decomposed by an acid and promotes dissolution in a developing solution can be used if necessary.
As a compound which is decomposed by an acid and promotes dissolution in a developing solution, an aromatic polyhydroxy compound is t-
Examples thereof include compounds protected with a butoxycarboxy group and compounds protected with an acetal group or a ketal group.
When such a compound is added during the manufacture of a photoresist, its content is 5 based on 100 parts by weight of the total solid component.
-80 parts by weight, preferably 10-50 parts by weight.

The composition according to the present invention may contain additives if necessary. Examples of such additives include surfactants, azo compounds, halation (hala).
anti-ion agents, adhesives, storage stabilizers, and defoamers.

Examples of the surface active agent include polyoxylauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, polyoxyethylene nonylphenol ether and polyethylene glycol dilaurate. . The content of these surfactants is preferably 2 parts by weight or less based on 100 parts by weight of the total solid components in the photoresist composition.

Further, in the positive photoresist composition according to the present invention, a light absorber may be used in addition to the above-mentioned components in order to improve sensitivity and resolution. As such a light absorber, a benzophenone compound and a naphthoquinone compound are preferable. Its content is 0.2 to 30 parts by weight, preferably 0.5 to 10 parts by weight, based on the total solid components.

Then, a basic compound may be used to prevent the diffusion of the acid generated after the exposure. Examples of the basic compound include amine compounds and ammonium compounds. Specific examples are triphenylamine, tetramethylammonium hydroxide, tetramethylammonium acetate, triethylamine, triethanolamine, diphenylamine, pyridine, dipyridyl or N, N-dimethylacetamide.
The amount of basic compound added is 0.05 to 5 relative to the total solid components.
The parts by weight are preferable. If the addition amount is larger than this, the acid diffusion is reduced, but the sensitivity is deteriorated.

Although an acid compound can be selectively added to the photoresist composition according to the present invention, specifically, phthalic acid, succinic acid, malonic acid, benzoic acid, salicylic acid, and m-hydroxybenzoic acid. , P-hydroxybenzoic acid, o-acetylbenzoic acid, o-acetyloxybenzoic acid, o-nitrobenzoic acid, thiosalicylic acid and thionicotinic acid, salicylaldehyde, salicylhydroxysanoic acid, succinimide, phthalimide and ascorbic acid. Can be used and the following chemical formula 4 can be used.
The polymer represented by (Chemical Formula 8) can also be used.
The addition amount of the acid compound is appropriately 0.05 to 5 parts by weight based on the total solid components. If the added amount is too large, the phenomenon that the pattern shape is distorted appears.

[0038]

[Chemical 8] In the above formula, 0.01 <y / (x + y) ≦ 0.4, the polystyrene standard weight average molecular weight is 500 to 50,000,
It is preferably 5,000 to 20,000.

The photoresist composition according to the present invention is usually used by dissolving it in a suitable solvent, but in order to obtain a uniform and flat coating film, a solvent having an appropriate evaporation rate and viscosity should be used. Is. Specific examples of the solvent having such physical properties are as follows. Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether Acetate, propylene glycol monopropyl ether acetate, methyl ethyl ketone, cyclohexanone, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 2
-Heptanone, N-methylpyrrolidine, N, N-dimethylformamide, N, N-dimethylacetamide, ethylpyruvate, n-amylacetate, ethyl lactate, γ-butyrolactone and the like, and in some cases, alone or in combination of two kinds. The above mixed solvent is used. The amount of the solvent used is adjusted according to the physical properties of the solvent used, that is, volatility, clay, etc., so that the solvent is uniformly formed on the wafer.

The composition according to the present invention may be prepared in the form of a solution, coated on a wafer substrate and dried to form a photoresist coating film. At this time, as a coating method, after the resist solution is manufactured and filtered, the obtained solution can be coated on the substrate by a method such as spin coating, flow coating, or roll coating.

In order to form a fine pattern through the photoresist film coated by such a method, radiation should be partially irradiated. At this time, usable radiation is not particularly limited, and specifically, i-ray of ultraviolet rays can be used.
Rays, far-ultraviolet excimer laser, X-ray, electron beam of charged particle beam and the like, which can be used according to the type of acid generator. In order to improve the sensitivity after the irradiation with such radiation, a heat treatment may be performed depending on the case.

As the developing solution used in the final stage of development in the pattern formation, sodium hydroxide is used.
Potassium hydroxide, sodium carbonate, sodium silicate,
Sodium metasilicate, aqueous ammonia, ethylamine,
An aqueous solution containing n-propylamine, triethylamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, etc. is selected and used. Of these, tetramethylammonium hydroxide is particularly preferable. At this time, if necessary, a surfactant, a water-soluble alcohol or the like can be used as an additive.

[0043]

EXAMPLES The present invention will be described in detail below with reference to examples. The invention is not limited to the examples.

Synthesis Example 1: Poly (hydroxystyrene / molybdenum
After manufacturing polyhydroxystyrene 250g Le morpholinyl carbonyl methoxystyrene) was dissolved in 2 l of acetone and a mixed solvent of water, was added 25% aqueous solution of tetramethylammonium hydroxide 58 g, this morpholinylmethyl bromoacetate 22g is added and 10
Stir for a period of time. After adding 33 ml of hydrochloric acid to the reaction product for neutralization, it was added dropwise to 20 liters of distilled water to obtain a white solid. The obtained solid was filtered, washed with distilled water, dehydrated, and then dissolved again in acetone. Then, it is precipitated with distilled water, washed, dehydrated and dried to replace 5% of the hydroxyl groups of polyhydroxystyrene with morpholinylcarbonylmethoxy groups, and to give poly (hydroxystyrene / mol of polystyrene standard conversion weight average molecular weight of 12,500). 253 g of folinylcarbonylmethoxystyrene) was obtained.

Synthesis Example 2: Poly (hydroxystyrene / molybdenum
Manufacture of a copolymer by the same method as in Synthesis Example 1 except that 116 g of morpholinyl bromoacetate was added instead of 58 g of a 25% aqueous solution of tetramethylammonium hydroxide. Instead of adding 22 g, 44 g was added to synthesize 250 g of a resin substituted with 10% of morpholinylcarbonylmethoxy groups. The obtained resin was poly (hydroxystyrene / morpholinylcarbonylmethoxystyrene) having a polystyrene standard weight average molecular weight of 13,200.

Synthesis Example 3: Poly (hydroxystyrene / t)
-Butoxycarbonyl methoxystyrene / morpholinyl
Carbonylmethoxystyrene) 100 g of polyhydroxystyrene was dissolved in a mixed solvent of 1.5 liter of acetone and water, 90 g of an aqueous solution of 25% tetramethylammonium hydroxide was added, and 16 g of t-butyl bromoacetate was added. 9 g of morpholinyl bromoacetate was added and stirred for 10 hours. After adding 26 ml of hydrochloric acid to the reaction product for neutralization, it was added dropwise to 15 liters of distilled water to obtain a white solid.
The solid was filtered, washed with distilled water, dehydrated, and then dissolved again in acetone. After that, precipitation with distilled water, washing,
After dehydration and drying, 8.4% of hydroxyl groups of polyhydroxystyrene became 5% of t-butoxycarbonylmethoxy group.
Was substituted with a morpholinylcarbonylmethoxy group to obtain 11 g of poly (hydroxystyrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) having a polystyrene standard conversion weight average molecular weight of 13,500.

Synthesis Example 4: Poly (hydroxystyrene / t)
-Butoxycarbonyl methoxystyrene / morpholinyl
Carbonylmethoxystyrene) 100 g of polyhydroxystyrene was dissolved in 1.5 liter of a mixed solvent of acetone and water, 120 g of 25% aqueous solution of tetramethylammonium hydroxide was added, and 40 g of t-butyl bromoacetate and moles were added. 9 g of folinyl bromoacetate was added and stirred for 10 hours. After adding 35 ml of hydrochloric acid to the reaction product for neutralization, 15 liters of the reaction product was added dropwise to distilled water to obtain a white solid.
The solid was filtered, washed with distilled water, dehydrated, and then dissolved again in acetone. After that, precipitation with distilled water, washing,
After dehydration and drying, 23.5% of the hydroxyl groups of polyhydroxystyrene became t-butoxycarbonylmethoxy groups and 5
% Was substituted with a morpholinylcarbonylmethoxy group to obtain 117 g of poly (hydroxystyrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) having a polystyrene standard conversion weight average molecular weight of 15,200.

Synthesis Example 5: Poly (hydroxystyrene / t)
-Butoxycarbonyl methoxystyrene / morpholinyl
Manufacture of a copolymer by the same method as in Synthesis Example 4, except that 126 g of 25% aqueous solution of tetramethylammonium hydroxide and 49 g of t-butyl bromoacetate were added to form 28. 119 g of a resin, 5% of which was substituted with a t-butoxycarbonylmethoxy group and 5% of which was substituted with a morpholinylcarbonylmethoxy group, was synthesized. This resin was a poly (hydroxystyrene / t) having a polystyrene standard conversion weight average molecular weight of 15,700. Butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene).

Synthesis Example 6: Poly (hydroxystyrene / E)
Toxyethoxystyrene / morpholinyl carbonyl meth
Production of xystyrene) 50 g of poly (hydroxystyrene / morpholinylcarbonylmethoxystyrene) obtained by the above Synthesis Example 1 and having 5% substituted with morpholinylcarbonylmethoxy group was dissolved in 500 ml of dimethylformamide. Thereafter, a catalytic amount of p-toluenesulfonic acid was added thereto, and 17 g of ethyl vinyl ether was added with stirring at 20 ° C. 1
After reacting for a time, it was neutralized with pyridine, and the neutralization reaction solution was added dropwise to 5 liters of water to obtain a white solid. This solid was filtered, washed with distilled water, dehydrated, dissolved in acetone again, added dropwise to 5 liters of water, filtered, washed, dehydrated and dried to give 27% of the hydroxyl groups of polyhydroxystyrene.
Was substituted with an ethoxyethoxy group and 5% was substituted with a morpholinylcarbonylmethoxy group to obtain 51 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene) having a polystyrene standard conversion weight average molecular weight of 14,100. Obtained.

Synthesis Example 7: Poly (hydroxystyrene / E)
Toxyethoxystyrene / morpholinyl carbonyl meth
Production of xystyrene) A copolymer was produced in the same manner as in Synthesis Example 6 except that ethyl vinyl ether was added in an amount of 18.5 g so that 32% of hydroxyl groups in polyhydroxystyrene were replaced with ethoxyethoxy groups. Was substituted with a morpholinylcarbonylmethoxy group to obtain 50 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene) having a polystyrene standard conversion weight average molecular weight of 14,400.

Synthesis Example 8: Poly (hydroxystyrene / E)
Toxyethoxystyrene / morpholinyl carbonyl meth
Production of xystyrene) A copolymer was produced by the same method as in Synthesis Example 6, except that the amount of ethyl vinyl ether added was 20 g, and 37% of the hydroxyl groups of polyhydroxystyrene were substituted with ethoxyethoxy groups, and 5% was mol. 52 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene) having a polystyrene-reduced weight average molecular weight of 14,700 substituted with a folinylcarbonylmethoxy group was obtained.

Synthesis Example 9: Poly (hydroxystyrene / E)
Toxyethoxystyrene / morpholinyl carbonyl meth
Production of xystyrene) 50 g of poly (hydroxystyrene / morpholinylcarbonylmethoxystyrene) having 10% substitution in the morpholinylcarbonylmethoxy group obtained in Synthesis Example 2 was dissolved in 500 ml of dimethylformamide. Then, a catalytic amount of p-toluenesulfonic acid was added thereto, and the temperature was 20 ° C.
15.5 g of ethyl vinyl ether was added with stirring. After reacting only for 1 hour, it was neutralized with pyridine and the neutralization reaction solution was added dropwise to 5 liters of water to obtain a white solid. After the solid is filtered, washed with distilled water and dehydrated,
It is again dissolved in acetone, added dropwise to 5 liters of water, filtered, washed, dehydrated and dried to replace 22% of the hydroxyl groups of polyhydroxystyrene with ethoxyethoxy groups,
A polystyrene standard conversion weight average molecular weight in which 10% was substituted with a morpholinylcarbonylmethoxy group was 14,500.
51 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene)
Got

Synthesis Example 10: Poly (hydroxystyrene /
Ethoxyethoxystyrene / morpholinyl carbonyl ester
Manufacture of a copolymer by the same method as in Synthesis Example 9 except that the addition amount of ethyl vinyl ether was 16.9 g and 26% of the hydroxyl groups of polyhydroxystyrene were substituted with ethoxyethoxy groups, 50 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene) having a polystyrene standard conversion weight average molecular weight of 14,700 in which 10% was substituted with a morpholinylcarbonylmethoxy group was obtained.

Synthesis Example 11: Poly (hydroxystyrene /
Ethoxyethoxystyrene / morpholinyl carbonyl ester
Manufacture of a copolymer by the same method as in Synthesis Example 9 except that the amount of ethyl vinyl ether added was 18 g and 31% of the hydroxyl groups of polyhydroxystyrene were replaced with ethoxyethoxy groups. 50 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene) having a polystyrene standard reduced weight average molecular weight of 15,100 substituted with morpholinylcarbonylmethoxy groups was obtained.

Synthesis Example 12: Poly (hydroxystyrene /
Ethoxyethoxystyrene / t-butoxycarbonyl
Toxystyrene / morpholinyl carbonyl methoxy starch
Len)) 8.4% based on the t-butoxycarbonylmethoxy group obtained in Synthesis Example 3 and 5% based on the morpholinylcarbonylmethoxy group.
50 g of poly (hydroxystyrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) substituted with dimethylformamide 50
It was dissolved in 0 ml. After that, p-
Toluenesulfonic acid was added, and 14 g of ethyl vinyl ether was added with stirring at 20 ° C. After reacting for 1 hour, the mixture was neutralized with pyridine, and the neutralization reaction solution was added dropwise to 5 liters of water to obtain a white solid. This solid is filtered, washed with distilled water, dehydrated, then again dissolved in acetone, added dropwise to 5 liters of water, filtered, washed, dehydrated and dried, and 16% of the hydroxyl groups of polyhydroxystyrene are ethoxyethoxy groups. Poly (hydroxystyrene / ethoxyethoxy) having a polystyrene-reduced weight average molecular weight of 14,400 substituted with styrene, 8.4% with a t-butoxycarbonylmethoxy group, and 5% with a morpholinylcarbonylmethoxy group. 52 g of styrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) was obtained.

Synthesis Example 13: Poly (hydroxystyrene /
Ethoxyethoxystyrene / t-butoxycarbonyl
Toxystyrene / morpholinyl carbonyl methoxy starch
The production of a copolymer by the same method as in Synthesis Example 12 above,
However, when the addition amount of ethyl vinyl ether was 15.5 g, 21% of the hydroxyl groups of polyhydroxystyrene were substituted with ethoxyethoxy groups, 8.4% were substituted with t-butoxycarbonylmethoxy groups, and 5% were morpholinylcarbonyl. Poly (hydroxystyrene / polystyrene having a standard weight average molecular weight of 14,800 substituted by methoxy groups)
50 g of ethoxyethoxystyrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) was obtained.

Synthesis Example 14: Poly (hydroxystyrene /
Ethoxyethoxystyrene / t-butoxycarbonyl
Toxystyrene / morpholinyl carbonyl methoxy starch
The production of a copolymer by the same method as in Synthesis Example 12 above,
However, when the amount of ethyl vinyl ether added was 17 g, 25% of the hydroxyl groups of polyhydroxystyrene were replaced by ethoxyethoxy groups, 8.4% by t-butoxycarbonylmethoxy groups, and 5% by morpholinylcarbonylmethoxy groups. To obtain 54 g of poly (hydroxystyrene / ethoxyethoxystyrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) having a polystyrene standard conversion weight average molecular weight of 15,000.

Synthesis Example 15: Production of acid compound After dissolving 100 g of polyhydroxystyrene in 1 liter of a mixed solvent of acetone and water, 120 g of an aqueous solution of 25% tetramethylammonium hydroxide was added, and 40 g of bromoacetate was added. Then, the mixture was stirred for 10 hours. After 100 ml of acetic acid was added to the reaction product to neutralize it, the reaction product was added dropwise to 10 liters of distilled water to obtain a white solid. After the solid is filtered, washed with distilled water and dehydrated,
Acid compound 1 represented by the following formula (Formula 9) is prepared by dissolving in acetone again, then precipitating with distilled water, washing, dehydrating and drying.
Got

[Chemical 9] Weight average molecular weight (Mw): 5,000 (based on polystyrene) Molecular weight distribution (Mw / Mn): 1.8 y / (x + y) = 0.35 Co-weight represented by the above chemical formula 1 produced through the above Synthesis Example The specific composition ratio of the coalescence, the molecular weight distribution of polyhydroxystyrene and the weight average molecular weight of the copolymer are as shown in Table 1 below.

[0059]

[Table 1] Examples 1 to 18 The polymer compounds obtained through the synthesis examples shown in Table 1 above were used as a base resin, and a photoacid generator, a basic compound, a surfactant, and a surfactant as shown in Table 2 below were used. A resist material such as an aromatic carboxylic acid was dissolved in a solvent to prepare a resist solution having the composition shown in Tables 3 and 4.

[0060]

[Table 2]

[Table 3]

[Table 4] Each of these compositions was filtered through a 0.1 μ1 membrane filter to obtain a resist solution. Apply the resist using a spinner and 90 ℃
Baked for 90 seconds at 0.7 μm to obtain a 0.7 μ thick coating. The film was exposed through a patterned chrome mask using a 248 nm KrF excimer laser stepper, then baked at 110 ° C. for 90 seconds and washed with a 2.38 wt% tetramethylammonium hydroxide aqueous solution.
It was developed for 0 seconds and dried to form a positive resist pattern.

With this resist pattern, the top (to) of line and space (line and space) is
The exposure amount when the sizes of the p) surface and the bottom surface became similar to 1: 1 was set to the optimum exposure energy (sensitivity), and the minimum line width obtained with this sensitivity was evaluated as the resolution.

On the other hand, the evaluation of the resolution was carried out by changing the baking time (PED) after exposure to 30 minutes and 2 hours, respectively, as described above.

Then, the resist pattern was observed with a scanning electron microscope (SEM).

The evaluation results are shown in Table 5 below.

[0065]

[Table 5] As a result of forming the pattern using the photoresist according to the present invention based on the results of Tables 3 and 4, stability is obtained because not only the resolution is excellent but also the pattern size does not change regardless of the baking time. It can be seen that the pattern profile is also excellent, and the pattern profile is sometimes formed in a somewhat rhombic shape, but it can be seen that it is formed in an excellent shape in general.

[0066]

Industrial Applicability As described above, the chemically amplified positive resist composition of the present invention containing a specific copolymer has a wide range of radiation to far ultraviolet rays, KrF excimer lasers, electron beams and the like. Loan of exposure margin, high sensitivity, high resolution, excellent heat resistance, stability of pattern size does not change due to time delay after exposure, excellent resist pattern regardless of substrate type Since it can be obtained, and a fine pattern can be easily formed especially at the exposure wavelength of a KrF excimer laser, it is optimal as a material for forming a fine pattern for VLSI manufacturing.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI H01L 21/027 H01L 21/30 502R (72) Inventor Park Joo Huon South Korea 305-345 Daejeong-do-dong 101, Shinseong-dong, Yousung-gu, Daejeon 1007 (72) Inventor Lee Jung Bam 305-390 Daejeong-gu, Korea 305-390 Geojeong-dong, Jung Min-dong Chung Nareapart 110-103 (56) References JP-A-6-93045 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 8/00-8/50 C08F 12/00

Claims (7)

(57) [Claims] 1. A polystyrene-reduced weight average molecular weight represented by the following chemical formula 1 (Chemical formula 1) is 1,000 to 1.00.
50,000 copolymers for chemically amplified photoresists In the above formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or a lower alkyl group, and R ₅ , R 3
₆ , R ₇ and R ₈ are a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group, an alkoxycarbonyl group or a halogen atom, h and i are constants of 0 to 8 and k, l, m and n Is 0.3 <k /
(K + l + m + n) <0.9, 0 ≦ l / (k + l + m
+ N) <0.6, 0 ≦ m / (k + 1 + m + n) <0.
6, and 0.01 <n / (k + 1 + m + n) <0.3
Satisfy the condition of. Then, k + l + m + n = 1 is satisfied, l and m cannot be 0 at the same time, and 0 at the same time.
It can be not. R ₉ is a compound represented by the following Chemical Formula 2 (Chemical Formula 2): In the above formula, R ₁₀ and R ₁₁ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and R ₁₂ is a linear alkyl group having 1 to 10 carbon atoms. , A branched or cyclic alkyl group. Am is -NR ₁₃ R ₁₄
(Here, R ₁₃ and R ₁₄ are each independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group or a phenyl group), the cyclic 2 is an amine and oxygen, or a sulfur atom. The contained ring 2 is an amine. 2. The copolymer for producing a chemically amplified photoresist according to claim 1, wherein the copolymer represented by the chemical formula 1 is one or a mixture selected from the following groups. Polymer: (A) Quaternary copolymer of poly (hydroxystyrene / alkoxyalkoxystyrene / t-butylcarbonylalkoxystyrene / morpholinylcarbonylalkoxystyrene), where k, l, m and n are 0.3. <K
/(K+l+m+n)<0.9, 0 ≦ l / (k + l +
m + n) <0.6, 0 ≦ m / (k + l + m + n) <
0.6, and 0.01 <n / (k + 1 + m + n) <
A resin satisfying the condition of 0.3, (B) a terpolymer of poly (hydroxystyrene / alkoxyalkoxystyrene / morpholinylcarbonylalkoxystyrene), in which k, l, m and n each represent a repeating unit. As a number, 0.3 <k / (k + 1 + m +
n) <0.9, 0 ≦ l / (k + 1 + m + n) <0.6,
m = 0, and 0.01 <n / (k + 1 + m + n) <
A resin satisfying the condition of 0.3, (C) a terpolymer of poly (hydroxystyrene / t-butylcarbonylalkoxystyrene / morpholinylcarbonylalkoxystyrene), in which k, l, m and n are each repeated. As a number indicating a unit, 0.3 <k / (k +
l + m + n) <0.9, l = 0, 0 ≦ m / (k + l
+ M + n) <0.6, and 0.01 <n / (k + l +)
It is a resin that satisfies the condition of m + n) <0.3. 3. The t-butoxycarbonylmethoxy group and the amide group are introduced through a substitution reaction of polyhydroxystyrene and an alkylhalogen compound by adding tetramethylammonium hydroxide as a basic compound. The copolymer for producing a chemically amplified photoresist according to 1. 4. The chemically amplified positive photoresist composition according to claim 1, which is produced by dissolving a copolymer, an acid generator and an additive in a solvent. 5. The acid generator is triphenylsulfonium hexafluoroantimonate, diphenyliodonium triplet, diphenyliodonium methylbenzenesulfonate, phenyl (4-t-methoxyphenyl).
Iodonium camphorsulfonate, phenyl (4-
t-butylacetylphenyl) iodonium camphorsulfonate, bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, 1,1-bis (4-chlorophenyl) -2,2,2-trichloroethane, One or more selected from phenyl-bis (trichloromethyl) -s-triazine, naphthyl-bis (trichloromethyl) -s-triazine, and a sulfonium compound represented by the following chemical formula 3 The chemically amplified positive photoresist composition according to claim 4, wherein the positive photoresist composition is chemically amplified. [Chemical 3] In the above formula, R ₁₅ is a hydrogen atom, an alkyl group or an alkoxy group, R ₁₆ is an alkyl group, an alkoxyalkyl group,
t-butoxycarbonylmethyl group, X is O, S or C
In H ₂ , g is a constant of 0-20. 6. The chemically amplified positive photoresist composition according to claim 4, further comprising an acid compound represented by the following Chemical Formula 4 (Formula 4). [Chemical 4] In the above formula, 0.01 <y / (x + y) ≦ 0.4, and the polystyrene standard weight molecular weight is 500 to 50,000, preferably 5,000 to 20,000. 7. The chemically amplified positive photoresist according to claim 4, wherein the additive is a surfactant, an azo compound, an antihalation agent, an adhesion aid, a storage stabilizer and a defoaming agent. Composition.