JP2001114822A - Copolymer for producing chemical amplification type photoresist and chemical amplification type positive photoresist composition comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a copolymer for producing a chemical amplification type photoresist and a positive photoresist composition comprising the copolymer. SOLUTION: This copolymer for producing the chemical amplification type photoresist comprises a recurring unit represented by chemical formula 1 [wherein R1, R2, R3 and R4 are each hydrogen atom or a lower alkyl group as an independent group; R5, R6, R7 and R8 are each hydrogen atom, a 1-8C alkyl group, a 1-8C alkoxy group, a 1-8C alkoxycarbonyl group or a halogen atom; R9 is a compound represented by chemical formula 2 (wherein R10 and R11 are each independently hydrogen atom or a 1-6C linear or branched chainlike alkyl group; R12 is a 1-10C linear or branched chainlike or cyclic alkyl group); Am is NR13R14 (R13 and R14 are each hydrogen atom or the like as an independent group). The chemical amplification type positive photoresist composition comprises the copolymer as a base resin and an acid generator and an additive added thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolymer for producing a chemically amplified photoresist and a chemically amplified positive photoresist composition including the same, and more particularly, to forming an excellent pattern regardless of a substrate. It has a very high alkali dissolution contrast before and after exposure, a wide range of exposure latitude, high sensitivity, high resolution, high heat resistance and excellent post-exposure stability. The present invention relates to a chemically amplified positive photoresist composition that is sensitive to radiation such as ultraviolet rays, far ultraviolet rays, excimer laser, X-rays, and electron beams as a material for forming a fine pattern for LSI production.

[0002]

2. Description of the Related Art Recently, in semiconductor technology, high integration of semiconductor devices has been rapidly progressing.
Even in photolithography patterning for manufacturing I and the like, an ultrafine pattern in a sub-quarter micron region is being demanded. Therefore, the exposure wavelength is also
-Wavelength and Kr which are shortened in the region of
Attention has been focused on lithography using F excimer lasers, X-rays and electron beams.

The photoresist used for the conventional g-line and i-line uses a novolak-quinonediazide-based compound. When the photoresist conforms to the far ultraviolet light and the KrF excimer laser wavelength, the light absorption is reduced. Because of the large number, research on a chemically amplified photoresist using a polyhydroxystyrene derivative having less light absorption than a novolak-quinonediazide-based compound as a base resin is in progress.

[0004] In such a chemically amplified photoresist composition, the resist layer is formed by chemical radiation.
The acid generator contained in the photoresist composition releases the acid when the pattern is exposed to y), and the released acid causes a catalytically active deprotection reaction with the resin component to change the solubility in the developer. Utilize the principle.

In particular, in the case of a chemically amplified photoresist composition, a small amount of acid generated from an acid generator exerts a resin component, so that the pattern resolution is high and the sensitivity to actinic radiation is excellent. Useful in that respect.

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

[0007]

However, in the basic resin of such a photoresist material, the protecting group is tertiary.
In the case of a t-butyl group or a tert-butoxycarbonyl group, these protecting groups have a property of being decomposed by a strong acid, and consequently react with a basic compound in the air to be deactivated. There is a problem that a T-top shape is easily formed and a pattern differs according to the type of a substrate. On the other hand, in the case of a base resin having a protecting group that can be decomposed into a weak acid, such as an acetal group or a ketal group, the effect 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 a high resolution because of the remarkable narrowing.

An object of the present invention is to solve the problems of the base resin which can be used in the conventional chemically amplified photoresist composition, and has a wide range of exposure latitude.
To provide a new chemically amplified photoresist production copolymer having high sensitivity, high resolution, excellent heat resistance and pattern stability, and capable of obtaining an excellent resist pattern regardless of the type of substrate. It is in.

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

[0010]

In order to achieve the above object, a copolymer for producing a chemically amplified photoresist according to the present invention is represented by the following chemical formula 1.

[0011]

Embedded image 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 each} represent a hydrogen atom, a carbon atom having 1 to 1;
An alkyl group, an alkoxy group, an alkoxycarbonyl group, or a halogen atom, wherein h and i are constants of 0 to 8;
l, m and n each represent 0.3 <k /
(K + 1 + m + n) <0.9, 0 ≦ l / (k + 1 + m)
+ N) <0.6, 0 ≦ m / (k + 1 + m + n) <0.
6, and 0.01 <n / (k + 1 + m + n) <0.3
Satisfies the condition. Then, k + l + m + n = 1 is satisfied, and l and m cannot be 0 at the same time, but are 0 at the same time.
You can also not.

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

Embedded image 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, wherein specific examples of the linear, branched or cyclic alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group and an n-butyl group. Group,
An isobutyl group and a t-butyl group, and a cyclic alkyl group is a cyclohexyl group.

Specific examples of the acid labile group represented by Formula 2 include a methoxyethyl group, an ethoxyethyl group, and an n-
Butoxyethyl, cyclohexyl or methoxypropyl.

Am is -NR ₁₃ R ₁₄ (where 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), and the ring 2 is an amine and a ring 2 containing an oxygen or sulfur atom. Amines.

Further, the chemically amplified positive photoresist composition according to the present invention comprises a copolymer represented by the above formula 1,
It is produced by dissolving an acid generator and an additive in a solvent.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

Preferred examples of the base resin represented by Formula 1 used in the present invention are as follows.

(A) A quaternary copolymer of poly (hydroxystyrene / alkoxyalkoxystyrene / t-butylcarbonylalkoxystyrene / morpholinylcarbonylalkoxystyrene), wherein k, l, m and n are each 0.3 < k / (k + 1 + m + n) <0.9, 0 ≦ l /
(K + 1 + m + n) <0.6, 0 ≦ m / (k + 1 + 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), wherein k, l, m and n are each 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 +
(C) a terpolymer of poly (hydroxystyrene / t-butylcarbonylalkoxystyrene / morpholinylcarbonylalkoxystyrene) which satisfies the condition of (m + n) <0.3, k, l, m and n Are respectively 0.3 <k / (k + 1 + m + n) <0.9, l = 0,
0 ≦ m / (k + 1 + m + n) <0.6, and 0.0
A resin which satisfies the condition of 1 <n / (k + 1 + m + n) <0.3, wherein only one of the resins (A), (B) and (C) is used as a basic resin for a photoresist It is possible to use two or more of the resins (A), (B) and (C) as needed.

In the copolymer represented by the above formula 1, the hydroxy group has a role of improving 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 increases the resolution by increasing the dissolution rate by causing a deprotection reaction to take place by exposure to the action of an acid upon exposure to increase the dissolution rate. Play a role. The ethoxyethoxy group is exposed to a baking temperature (PE
B) has a feature that a deprotection reaction often occurs even in a process at 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 high resolution. Having the advantage of being excellent, when these two substituents are appropriately blended, a photoresist having high resolution even in a low baking temperature process and capable of forming a fine pattern can be formed. And the amide group maintains the affinity with the acid generated at the time of exposure to prevent the basic component in the air from coming into contact with the acid, and to prevent the acid from being diffused to an adjacent distance, It prevents a pattern narrowing phenomenon due to a time delay after exposure. The amide group serves to stabilize the acid without being changed by the action of the acid.

In the copolymer represented by the above formula 1, the substitution amount of the t-butoxycarbonylmethoxy group and the ethoxyethoxy group is suitably from 10 to 50%, and the substitution amount of the amide group is from 1 to 30%. % Is appropriate. If the amount of substitution with the t-butoxycarbonylmethoxy group and the ethoxyethoxy group is too large, the sensitivity will be low, and if the amount of substitution is too small, the difference in dissolution rate between exposed and unexposed sites will be small. In view of such a point, a preferable substitution amount of the t-butoxycarbonylmethoxy group and the ethoxyethoxy group is 20 to 40%, and a substitution amount of the amide group is most preferably about 5 to 10%.

The method of introducing a t-butoxycarbonylmethoxy group and an amide group as described above is carried out through a substitution reaction between polyhydroxystyrene and an alkyl halogen compound. In this case, tetramethylammonium hydroxide is always added as a basic compound. Must.

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

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

When a photoresist composition is prepared using such a copolymer, an acid generator and an appropriate amount of an additive are added. If it does not adversely affect the formation of the resist pattern while being able to generate acid when
Any substance can be used, but more preferably 248n
A substance capable of maintaining appropriate light absorption and 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). However, the acid generator in the photoresist composition according to the present invention is not limited to the following compounds.

[0026]

Embedded image 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, S
Or CH _2, g is the constant of 0-20.

Specific examples of the acid generator represented by Formula 3 are as follows. Triphenylsulfonium triplet, diphenyl (4-methylphenyl) sulfonium triplet, diphenyl (4-t-
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 Chemical Formula 3, triphenylsulfonium hexafluoroantimonate, diphenyliodonium triplet, diphenyliodonium methylbenzenesulfonate, phenyl (4-t-methoxyphenyl) iodonium camphorsulfonic acid Salt, phenyl (4-t-butoxycarbonylmethoxyphenyl) iodonium camphorsulfonate, bis (cyclohexylsulfonyl) diazomethane,
And bis (2,4-dimethylphenylsulfonyl) diazomethane.

Examples of the halogen compound used as the acid generator include 1,1-bis (4-chlorophenyl) -2,
Examples include 2,2-trichloroethane, phenyl-bis (trichloromethyl) -s-triazine, and naphthyl-bis (trichloromethyl) -s-triazine. In addition, there are 1,3-diketo-2-diazo compounds, diazobenzoquinone compounds and diazonaphthoquinone compounds of diazoketone compounds, and there are sulfone compounds, sulfonic acid compounds and nitrobenzyl compounds. Particularly preferred compounds among these acid generators are onium salt compounds and diazoketone compounds.

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

On the other hand, the above-mentioned acid generators can be used alone or in combination of two or more.

In the photoresist composition according to the present invention, if necessary, a compound which is decomposed by an acid to promote dissolution in a developer can be used.
As a compound which is decomposed by an acid and promotes dissolution in a developer, an aromatic polyhydroxy compound is t-
Examples include compounds protected with a butoxycarboxy group, compounds protected with an acetal group or a ketal group.
When such a compound is added during the production of a photoresist, its content is 5 parts per 100 parts by weight of the total solid components.
The amount is from 80 to 80 parts by weight, preferably from 10 to 50 parts by weight.

[0033] The composition according to the present invention may optionally contain additives. Examples of such additives include surfactants, azo compounds, halation (hala).
tion) Inhibitors, adhesives, storage stabilizers, and defoamers.

Examples of the surfactant include polyoxylauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol 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.

In addition, the positive photoresist composition according to the present invention may use a light absorbing agent in order to improve sensitivity and resolution in addition to the above components. As such a light absorbing agent, a compound of benzophenones and a compound of naphthoquinones 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.

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

The 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, m-hydroxybenzoic acid Organic acids such as, p-hydroxybenzoic acid, o-acetylbenzoic acid, o-acetyloxybenzoic acid, o-nitrobenzoic acid, thiosalicylic acid and thionicotinic acid, salicylaldehyde, salicylhydroxysanic acid, succinimide, phthalimide and ascorbic acid Can be used, and the following chemical formula 4
The polymer represented by (Chem. 8) can also be used.
An appropriate amount of the acid compound to be added is 0.05 to 5 parts by weight based on the total solid components. If the addition amount is excessive, a phenomenon that the pattern shape is distorted appears.

[0038]

Embedded image In the above formula, 0.01 <y / (x + y) ≦ 0.4, and the polystyrene standard weight average molecular weight is 500 to 50,000.
Preferably it is 5,000-20,000.

The photoresist composition according to the present invention is usually used after being dissolved in an appropriate solvent, but a solvent having an appropriate evaporation rate and viscosity should be used in order to obtain a uniform and flat coating film. It 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, ethyllactate, γ-butyrolactone, etc., depending on the case, alone or in combination The above mixed solvent is used. The amount of the solvent used is adjusted in accordance with the physical properties of the solvent used, that is, volatility, clay, etc., using an appropriate amount so as to be 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. At this time, as a coating method, after a resist solution is manufactured and filtered, the obtained solution can be coated on a substrate by a method of spin coating, flow coating, or roll coating.

In order to form a fine pattern through a photoresist film applied by such a method, radiation must be partially applied. At this time, usable radiation is not particularly limited, and specifically, i-
X-ray, electron beam of charged particle beam, etc., which can be used according to the type of acid generator. In order to improve the sensitivity after irradiation with such radiation, heat treatment may be performed in some cases.

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

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on embodiments. The present invention is not limited to the embodiments.

Synthesis Example 1: Poly (hydroxystyrene / mo
Preparation of ruphorinylcarbonylmethoxystyrene) After dissolving 250 g of polyhydroxystyrene in 2 liters of a mixed solvent of acetone and water, 58 g of a 25% aqueous solution of tetramethylammonium hydroxide was added, and morpholinyl bromoacetate was added thereto. Add 22g and add 10
Stirred for hours. The reaction product was neutralized by adding 33 ml of hydrochloric acid and then dropped into 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. After that, it is precipitated with distilled water, washed, dehydrated and dried to replace polyhydroxystyrene with 5% of hydroxyl groups by morpholinylcarbonylmethoxy group, and poly (hydroxystyrene / mole having a weight average molecular weight in terms of polystyrene of 12,500). (Holinylcarbonylmethoxystyrene) 253 g.

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

Synthesis Example 3: Poly (hydroxystyrene / t
-Butoxycarbonylmethoxystyrene / morpholinyl
Preparation of carbonyl methoxy styrene) 100 g of polyhydroxystyrene was dissolved in 1.5 liter of a mixed solvent of acetone and water, 90 g of a 25% aqueous solution of 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. The reaction product was neutralized by adding 26 ml of hydrochloric acid and then dropped into 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 the hydroxyl groups of the polyhydroxystyrene were converted to t-butoxycarbonylmethoxy groups by 5%.
Was substituted with a morpholinylcarbonylmethoxy group to obtain 11 g of poly (hydroxystyrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) having a weight average molecular weight in terms of polystyrene of 13,500.

Synthesis Example 4: Poly (hydroxystyrene / t
-Butoxycarbonylmethoxystyrene / morpholinyl
Preparation of carbonyl methoxy styrene) After dissolving 100 g of polyhydroxystyrene in 1.5 liter of a mixed solvent of acetone and water, 120 g of a 25% aqueous solution of tetramethylammonium hydroxide was added, and 40 g of t-butyl bromoacetate and 9 g of holinyl bromoacetate was added and stirred for 10 hours. The reaction product was neutralized by adding 35 ml of hydrochloric acid, and 15 liters were dropped into distilled water to obtain a white solid.
This 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 the polyhydroxystyrene were converted to t-butoxycarbonylmethoxy groups.
% Was substituted with a morpholinylcarbonylmethoxy group to obtain 117 g of poly (hydroxystyrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) having a weight average molecular weight in terms of polystyrene of 15,200.

Synthesis Example 5: Poly (hydroxystyrene / t
-Butoxycarbonylmethoxystyrene / morpholinyl
Preparation of carbonyl methoxy styrene) A copolymer was prepared in the same manner as in Synthesis Example 4 above, except that 126 g of a 25% aqueous solution of tetramethylammonium hydroxide and 49 g of t-butylbromoacetate were added, and 28. 119 g of a resin having 5% substituted with t-butoxycarbonylmethoxy group and 5% substituted with morpholinylcarbonylmethoxy group was synthesized, and this resin was poly (hydroxystyrene / t) having a weight average molecular weight in terms of polystyrene of 15,700. -Butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene).

Synthesis Example 6: Poly (hydroxystyrene / d
Toxethoxyethoxystyrene / morpholinylcarbonyl meth
Preparation of Xylstyrene 50 g of poly (hydroxystyrene / morpholinylcarbonylmethoxystyrene) obtained in Synthesis Example 1 and substituted with 5% of 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 while stirring at 20 ° C. 1
After reacting for an hour, the mixture was neutralized with pyridine, and the neutralized reaction solution was added dropwise to 5 liters of water to obtain a white solid. This solid was filtered, washed and dehydrated with distilled water, dissolved again in acetone, dropped into 5 liters of water, filtered, washed, dehydrated and dried to obtain 27% of the hydroxyl group of polyhydroxystyrene.
Is substituted with an ethoxyethoxy group, and 5 g of a poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene) having a weight-average molecular weight in terms of polystyrene of 14,100 in which 5% is substituted with a morpholinylcarbonylmethoxy group. Obtained.

Synthesis Example 7: Poly (hydroxystyrene / d
Toxethoxyethoxystyrene / morpholinylcarbonyl meth
Preparation of Xystyrene) A copolymer was prepared in the same manner as in Synthesis Example 6 above, except that the amount of ethyl vinyl ether added was 18.5 g, and that 32% of the hydroxyl groups of the polyhydroxystyrene were replaced with ethoxyethoxy groups, and 5% Was substituted with a morpholinylcarbonylmethoxy group to obtain 50 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene) having a weight average molecular weight in terms of polystyrene of 14,400.

Synthesis Example 8: Poly (hydroxystyrene / d
Toxethoxyethoxystyrene / morpholinylcarbonyl meth
Preparation of Xyloxystyrene) A copolymer was prepared in the same manner as in Synthesis Example 6 above, except that the amount of ethyl vinyl ether added was 20 g and 37% of the hydroxyl groups of polyhydroxystyrene were replaced with ethoxyethoxy groups, and 5% 52 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene) substituted with a holinylcarbonylmethoxy group and having a weight average molecular weight in terms of polystyrene of 14,700 was obtained.

Synthesis Example 9: Poly (hydroxystyrene / d
Toxethoxyethoxystyrene / morpholinylcarbonyl meth
Preparation of Xystyrene) 50 g of poly (hydroxystyrene / morpholinylcarbonylmethoxystyrene) obtained in Synthesis Example 2 and substituted with 10% of morpholinylcarbonylmethoxy group was dissolved in 500 ml of dimethylformamide. Thereafter, a catalytic amount of p-toluenesulfonic acid was added thereto, and the mixture was added at 20 ° C.
While stirring with, 15.5 g of ethyl vinyl ether was added. After reacting for only 1 hour, the mixture was neutralized with pyridine, and the neutralized reaction solution was added dropwise to 5 liters of water to obtain a white solid. After filtering and washing the solid with distilled water and dehydrating,
After dissolving again in acetone, dropping into 5 liters of water and filtering, washing, dehydrating and drying, 22% of the hydroxyl groups of polyhydroxystyrene are replaced with ethoxyethoxy groups,
The polystyrene standard weight average molecular weight of which 10% is substituted by a morpholinylcarbonylmethoxy group is 14,500.
51 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene)
I got

Synthesis Example 10: Poly (hydroxystyrene /
Ethoxyethoxystyrene / morpholinylcarbonylmeth
Production of Toxic Styrene) A copolymer was produced in the same manner as in Synthesis Example 9 above, except that the amount of ethyl vinyl ether added was 16.9 g, and 26% of the hydroxyl groups of polyhydroxystyrene were replaced with ethoxy ethoxy groups. 50 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene) having a weight average molecular weight in terms of polystyrene of 14,700 in which 10% was substituted with a morpholinylcarbonylmethoxy group was obtained.

Synthesis Example 11: Poly (hydroxystyrene /
Ethoxyethoxystyrene / morpholinylcarbonylmeth
Preparation of Toxic Styrene) A copolymer was prepared in the same manner as in Synthesis Example 9 above, except that the amount of ethyl vinyl ether added was 18 g, and 31% of the hydroxyl groups of polyhydroxystyrene were replaced with ethoxy ethoxy groups, and 10% 50 g of poly (hydroxystyrene / ethoxyethoxystyrene / morpholinylcarbonylmethoxystyrene) having a weight average molecular weight in terms of polystyrene of 15,100 substituted with morpholinylcarbonylmethoxy group was obtained.

Synthesis Example 12: Poly (hydroxystyrene /
Ethoxyethoxystyrene / t-butoxycarbonylmeth
Toxylstyrene / morpholinylcarbonylmethoxysty
8.4% to t- butoxycarbonyl methoxy group obtained in Production Synthesis Example 3 Len), 5% morpholinylcarbonyl methoxy
Are substituted with 50 g of poly (hydroxystyrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene).
It was dissolved in 0 ml. After that, p-
Toluenesulfonic acid was added, and 14 g of ethyl vinyl ether was added while stirring at 20 ° C. After reacting for 1 hour, the mixture was neutralized with pyridine, and the neutralized reaction solution was added dropwise to 5 liters of water to obtain a white solid. This solid was filtered, washed and dehydrated with distilled water, dissolved again in acetone, dropped into 5 liters of water, filtered, washed, dehydrated and dried to make 16% of the hydroxyl groups of the polyhydroxystyrene an ethoxyethoxy group. Poly (hydroxystyrene / ethoxyethoxy) having a weight-average molecular weight in terms of polystyrene of 14,400, in which 8.4% is substituted with a t-butoxycarbonylmethoxy group and 5% is substituted with a morpholinylcarbonylmethoxy group. 52 g of styrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) were obtained.

Synthesis Example 13: Poly (hydroxystyrene /
Ethoxyethoxystyrene / t-butoxycarbonylmeth
Toxylstyrene / morpholinylcarbonylmethoxysty
Production of a copolymer) was produced in the same manner as in Synthesis Example 12 above.
However, when the amount of ethyl vinyl ether added was 15.5 g, 21% of the hydroxyl groups of polyhydroxystyrene were substituted by ethoxyethoxy groups, 8.4% were substituted by t-butoxycarbonylmethoxy groups, and 5% were morpholinylcarbonyl. A methoxy-substituted poly (hydroxystyrene / polystyrene having a weight-average molecular weight in terms of polystyrene of 14,800.
(Ethoxyethoxystyrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) 50 g was obtained.

Synthesis Example 14: Poly (hydroxystyrene /
Ethoxyethoxystyrene / t-butoxycarbonylmeth
Toxylstyrene / morpholinylcarbonylmethoxysty
Production of a copolymer) was produced in the same manner as in Synthesis Example 12 above.
However, with the addition amount of ethyl vinyl ether being 17 g, 25% of the hydroxyl groups of polyhydroxystyrene are substituted with ethoxyethoxy groups, 8.4% are substituted with t-butoxycarbonylmethoxy groups, and 5% are morpholinylcarbonylmethoxy groups. Was obtained, and 54 g of poly (hydroxystyrene / ethoxyethoxystyrene / t-butoxycarbonylmethoxystyrene / morpholinylcarbonylmethoxystyrene) having a weight average molecular weight in terms of polystyrene of 15,000 substituted with styrene was obtained.

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 a 25% aqueous solution of tetramethylammonium hydroxide was added, and 40 g of bromoacetoic acid was added. Thereafter, the mixture was stirred for 10 hours. The reaction product was neutralized by adding 100 ml of acetic acid, and then dropped into 10 liters of distilled water to obtain a white solid. After filtering and washing the solid with distilled water and dehydrating,
After re-dissolving in acetone, it is precipitated with distilled water, washed, dehydrated and dried to obtain an acid compound 1 represented by the following formula (Chem. 9)
I got

Embedded image Weight average molecular weight (Mw): 5,000 (based on polystyrene) Molecular weight distribution (Mw / Mn): 1.8 y / (x + y) = 0.35 Copolymer represented by the above chemical formula 1 manufactured through the above synthesis example. The specific composition ratio of the union, the molecular weight distribution of the polyhydroxystyrene, and the weight average molecular weight of the copolymer are as shown in Table 1 below.

[0059]

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

[0060]

[Table 2]

[Table 3]

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

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

On the other hand, the resolution was evaluated while changing the baking time (PED) to 30 minutes and 2 hours after exposure as described above.

The pattern shape of the resist pattern was observed using a scanning electron microscope (SEM).

The evaluation results are shown in Table 5 below.

[0065]

[Table 5] As a result of forming a pattern using the photoresist according to the present invention based on the results of Tables 3 and 4, not only the resolution was excellent, but also the stability of the pattern was not changed regardless of the baking time. It can be seen that the pattern profile was sometimes formed somewhat diamond-shaped, but was generally formed into an excellent shape.

[0066]

As described above, the chemically amplified positive resist composition containing the specific copolymer according to the present invention can be applied to a wide range of radiation such as far ultraviolet rays, KrF excimer laser, and electron beam. Financing the exposure margin, high sensitivity, high resolution, excellent heat resistance, excellent stability without changing the pattern size due to time delay after exposure, excellent resist pattern regardless of substrate type Since it is easy to form a fine pattern at an exposure wavelength of a KrF excimer laser, it is most suitable as a material for forming a fine pattern for VLSI manufacturing.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court ゛ (Reference) H01L 21/027 H01L 21/30 502R (72) Inventor Kim Seoju Sinseongdong Dalim, Yusong-gu 305-345 Daejeon, Korea Dole Apartment 101-702 (72) Inventor Park Joo Hyun 305-345 South Korea, Daeseon Metropolitan City, Seongsong-dong Dalim Dore Apartment 101-1007 (72) Inventor Lee Jung-Bam South Korea 305-390 Taejon Metropolitan City, Yuseon-gu Geomindong Changnarare Apartment 110- 103 F-term (Reference) 2H025 AA01 AA02 AA03 AA10 AA11 AB16 AC04 AC08 AD03 BE00 BE07 BE08 BE10 BG00 BJ10 CB17 CB41 CB43 CB45 CB55 CC02 CC04 CC06 CC20 4J002 BC101 CH022 EB126 EQ016 EU186 EV256 EV296 FD026 FD206 4J100 AB07P AB07Q AB07R AB07S BA02Q BA02R BA02S BA03P BA04Q BA05Q BA15Q BA15R BA15S BA16Q BC79Q BC79R BC79S CA05 CA06 DA01 JA38

Claims (7)

[Claims] 1. A compound represented by the following chemical formula 1 and having a weight average molecular weight in terms of polystyrene of 1,000 to 1,000.
000 Chemically Amplified Copolymer for Photoresist Production In the above _formula, as R _1, R 2, _{R 3} and those _{R 4} is a each independently, a hydrogen atom or a lower alkyl _{group, R} 5, R
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, and h and i are constants of 0 to 8, and k, l, m and n Is a number indicating a repeating unit, and 0.3 <k /
(K + 1 + m + n) <0.9, 0 ≦ l / (k + 1 + m)
+ N) <0.6, 0 ≦ m / (k + 1 + m + n) <0.
6, and 0.01 <n / (k + 1 + m + n) <0.3
Satisfies the condition. Then, k + l + m + n = 1 is satisfied, and l and m cannot be 0 at the same time, but are 0 at the same time.
You can also not. R ₉ is a compound represented by the following chemical formula 2 (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 >
(Where 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), and the ring 2 is an amine and an oxygen or sulfur atom. The contained cyclic 2 is an amine. 2. The copolymer for producing a chemically amplified photoresist according to claim 1, wherein the copolymer represented by Formula 1 is one or a mixture selected from the following group. (A) a quaternary copolymer of (A) poly (hydroxystyrene / alkoxyalkoxystyrene / t-butylcarbonylalkoxystyrene / morpholinylcarbonylalkoxystyrene), wherein k, l, m and n are 0.3 <K
/(K+1+m+n)<0.9, 0 ≦ l / (k + 1 +
m + n) <0.6, 0 ≦ m / (k + 1 + m + n) <
0.6, and 0.01 <n / (k + 1 + m + n) <
(B) a terpolymer of poly (hydroxystyrene / alkoxyalkoxystyrene / morpholinylcarbonylalkoxystyrene), wherein 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) <
(C) a terpolymer of poly (hydroxystyrene / t-butylcarbonylalkoxystyrene / morpholinylcarbonylalkoxystyrene), wherein k, l, m and n are each repeated 0.3 <k / (k +
l + m + n) <0.9, l = 0, 0 ≦ m / (k + 1)
+ M + n) <0.6, and 0.01 <n / (k + 1 +
The resin satisfies the condition of (m + n) <0.3. 3. The tert-butoxycarbonylmethoxy group and the amide group are introduced through a substitution reaction between polyhydroxystyrene and an alkyl halogen compound by adding tetramethylammonium hydroxide as a basic compound. 3. The copolymer for producing a chemically amplified photoresist according to claim 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. An acid generator comprising 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 Embedded image In the above formula, R ₁₅ is a hydrogen atom, an alkyl group or an alkoxy group, and R ₁₆ is an alkyl group, an alkoxyalkyl group,
X is O, S or C in a t-butoxycarbonylmethyl group
In H _2, g is the 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). Embedded image 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 additives are a surfactant, an azo compound, an antihalation agent, an adhesion aid, a storage stabilizer, and a defoaming agent. Composition.