JP2002258481A - Radiation sensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation sensitive composition which is exposed with light of a wavelength used for lithography, exhibits superior characteristics such as high sensitivity, high resolution, a high rate of a residual film, high heat resistance, a wide margin for focus and a wide margin for exposure and enables the production of an integrated semiconductor having a high degree of integration. SOLUTION: The radiation sensitive composition contains the following components (1)-(3) as essential components; (1) a resin of formula (I) (where R is an organic polymer, repeating units R may be the same or different; A is an organic group represented by -O- or the like; P is an organic group which can be released by the action of hydrogen or the like; A and P may be the same or different every constitutional unit R; (l) is 1-20,000; (m) is 1-3 and may be the same or different every constitutional unit R; and (n) is 1-3 and the same number as (m)) having alkali solubility promoted by the action of an acid, (2) a compound which generates the acid under the action of light and (3) an organic solvent which dissolves the components (1) and (2).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-sensitive composition used for lithography in the production of semiconductors and the like. It exhibits excellent features such as resolution, high residual film ratio, high heat resistance, wide focus margin, and wide exposure margin, and enables production of highly integrated semiconductors.

[0002]

2. Description of the Related Art In general, a positive photoresist is made of a photosensitive agent having a quinonediazide group such as a naphthoquinonediazide compound and an alkali-soluble resin (for example, a novolak phenol resin). Positive photoresists having such a composition exhibit high resolving power when developed with an alkaline solution, and are used for manufacturing semiconductors such as ICs and LSIs and LCDs.
It is used for the production of circuit substrates such as. In addition, novolak type phenolic resin also has high heat resistance to plasma dry etching after exposure due to the structure having many aromatic rings, so far novolak type phenolic resin and naphthoquinonediazide-based photosensitizer Numerous positive-type photoresists containing have been developed and put into practical use, and have achieved great results.

Generally, a phenol resin obtained by reacting meta-paracresol and formaldehyde in the presence of an acid catalyst is used as a phenol resin for a photoresist. In order to adjust or improve the characteristics of photoresist, the ratio and molecular weight of meta-paracresol have been studied.
Technology has been applied. In semiconductor photoresists,
Characteristics such as high heat resistance, high resolution and high sensitivity are required, and to improve heat resistance, monomers such as alkylphenols such as xylenol and trimethylphenol and aromatic aldehydes have been studied. There is an example in which hydroxybenzaldehyde and the like have been studied for higher sensitivity. In each of these cases, although a slight improvement effect can be obtained, a sufficient effect has not yet been obtained.

In recent years, as the demand for higher integration of semiconductors has been increasing year by year, there has been a demand for resolution of a region which cannot be theoretically drawn with a wavelength of light such as g-line and i-line. Thus, light having a shorter wavelength has been applied as a light source. However, the amount of light of shorter wavelength generated from the light source is smaller than the amount of light such as g-line and i-line generated from a high-pressure mercury lamp, etc. A chemically amplified photoresist, which is a system utilizing the technology, has come to be applied. In addition, since the resin used uses light having a shorter wavelength, the novolak resin used for g-line and i-line is inferior in transparency due to absorption of light by the aromatic ring of itself. In addition, polyhydroxystyrene, acrylic resin and cycloolefin resin have come to be used. However, the transparency of polyhydroxystyrene is not sufficient, and it is very expensive. Therefore, the transparency of a low-cost phenolic resin system is improved, and the resin which exhibits high resolution and high sensitivity photoresist characteristics is improved. Development requirements are very high.

[0005]

The present invention relates to a radiation-sensitive composition used in lithography when manufacturing semiconductors and the like, and has excellent transparency with respect to the wavelength of light used in lithography. High sensitivity, high resolution, high residual film ratio, high heat resistance, wide focus margin, wide exposure margin
It is an object of the present invention to provide a radiation-sensitive composition which exhibits excellent features such as gin and enables production of a highly integrated semiconductor.

[0006]

Means for Solving the Problems The present invention provides (1)
A radiation-sensitive composition containing (2) and (3) as essential components. (1) a resin whose alkali solubility is promoted by the action of an acid represented by the formula (I),

Embedded image (In the formula (I), R is an organic polymer, and the repeating units of R may be the same or different. A represents -O-,-
An organic group represented by COO—, P is an organic group that can be eliminated by the action of hydrogen or an acid. A and P may be the same or different for each structural unit of R. l is 1-2
0000 and m are 1 to 3 and may be the same or different for each structural unit of R. n is 1 to 3 and is the same number as m. (2) Compounds that generate an acid by the action of light, (3)
An organic solvent that dissolves (1) and (2).

First, the component (1) will be described in detail. Component (1) is a resin represented by the formula (I),
In which P is substituted by a group capable of leaving by the action of an acid. In the formula (I), R is an organic polymer, and any resin such as an addition polymerization resin such as vinyl polymerization and a polycondensation resin can be used. Particularly preferably,
Phenol resin, polyvinyl phenol resin, acrylic resin, cycloolefin resin and the like can be mentioned. The repeating units of R may be the same or different. A is an organic group represented by -O- or -COO-;
May be the same or different for each repeating unit.
P is an organic group which can be eliminated by the action of hydrogen or an acid;
May be the same or different for each structural unit. l is
It is particularly preferably from 1 to 20,000, more preferably from 10 to 10,000. If it is too small, the film formability will deteriorate, and if it is too large, the sensitivity will be low. m is 1 to 3 and may be the same or different for each structural unit of R. n is 1 to 3,
It is the same number as m.

In the case where R in the formula (I) is an organic group represented by the formula (II), a compound having particularly excellent characteristics of a photoresist can be obtained.

Embedded image In the formula (II), X is hydrogen, a hydroxyl group, an alkyl group having 1 to 8 carbon atoms, an alkenyl group and an alkoxy group, and halogen,
a = 0-3. Y is a divalent organic group, and is not particularly limited. Examples thereof include a methylene group and an ethylene group.

The method for obtaining the photoresist resin represented by the formula (I) is not particularly limited, but it is most effective to derive from a phenol resin from an economic point of view. Alternatively, a method of introducing an organic group which can be eliminated by the action of an acid can be used. First, the phenol resin used for obtaining the formula (I) will be described below. The phenol resin to be used can be obtained by reacting phenols and aldehydes in the presence of an acid and a base. First, the raw materials used will be described. Examples of phenols include phenol, meta-cresol, ortho-cresol, para-cresol, 2,
3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3 4-trimethylphenol, 2,3,5-trimethylphenol, 2,
3,6-trimethylphenol, 2,4,5-trimethylphenol, 3,4,5-trimethylphenol, ethylphenol, propylphenol, butylphenol
Octylphenol, nonylphenol, 1-naphthol, 2-naphthol, phenylphenol and the like can be used, but there is no particular limitation, and they may be used alone or as a mixture. From the viewpoint of high sensitivity,
, Orthocresol, 3,5-xylenol, 2,
3,5-Trimethylphenol is particularly preferred, and more preferably 90% or more of meta-cresol is used.

The aldehydes include formaldehyde,
Acetaldehyde, propylaldehyde, butyraldehyde and the like can be used without any particular limitation, and they may be used alone or in combination. Formaldehyde is particularly preferred from the viewpoint of high sensitivity. In the case of formaldehyde, formalin (aqueous solution), paraformaldehyde, alcohol
Any raw material can be used as long as it generates formaldehyde such as hemiformal and trioxane. Considering the price, it is preferable to use formalin and paraformaldehyde.

As the catalyst used for the reaction between phenols and aldehydes, an acid catalyst is generally used, and organic carboxylic acids such as oxalic acid and acetic acid, benzenesulfonic acid, paratoluenesulfonic acid, methanesulfonic acid and the like are used. Inorganic acid such as organic sulfonic acid, hydrochloric acid, sulfuric acid, etc. can be used, but there is no particular limitation, and it is also possible to use two or more kinds alone. In addition, a basic catalyst can also be used, and examples thereof include amines such as triethylamine and hydroxides such as sodium hydroxide and potassium hydroxide. The amount used is from 0.01% by weight to 10% by weight based on the phenols, but is preferably as small as possible in order to maintain the characteristics of the phenolic resin for photoresist. The reaction solvent can be used if necessary, but the type is not particularly limited. Any resin can be used as long as it dissolves the phenolic resin and lowers the viscosity of the resin obtained by the reaction. As an example,
Ketones such as acetone and methyl ethyl ketone, alcohols such as ethanol and butanol, esters such as ethyl acetate and butyl acetate, ether alcohols such as ethoxyethyl alcohol, and propylene glycol monomethyl ether And ether esters of teracetate.

Further, the reaction (production) procedure of the phenol resin will be described. The reaction method described below is an example, and is not particularly limited thereto. The reaction is
Phenol in a reaction vessel equipped with a stirrer, thermometer and heat exchanger
And a catalyst such as aldehydes, aldehydes, acids or bases. The reaction temperature and time can be appropriately set depending on the reactivity of the above-mentioned reaction raw materials, but the reaction time is 2 to 10 hours and the reaction temperature is 70 to 150 ° C.
Is particularly preferred. If necessary, a reaction solvent can be used. The type of the solvent is not particularly limited, but a solvent that dissolves the phenol resin obtained by the reaction is particularly preferable.

After the completion of the reaction, if necessary, a neutralizing agent may be added to remove the acid and base catalysts to form a neutralized salt, and water may be added and washing may be performed. Although the amount and the number of times of the washing water are not particularly limited, the number of times of the washing is 1 from the viewpoint of economically removing the neutralized salt from the resin to a level that does not substantially affect the washing.
About -5 times is preferable. The washing temperature is not particularly limited, but may be 40 from the viewpoint of the efficiency of removing neutralized salts and workability.
It is preferably carried out at -95 ° C. During the washing, if the separation of the washing water from the resin is poor, it is effective to add a solvent or raise the washing temperature to reduce the viscosity of the resin. The type of solvent is not particularly limited, but any solvent can be used as long as it dissolves the phenol resin obtained by the reaction and lowers the viscosity.

After the completion of the reaction or washing with water, dehydration and de-monomerization are performed under normal pressure and reduced pressure to obtain a phenol resin for photoresist. The temperature at which the phenol resin is removed from the reaction vessel after the dehydration and demonomerization can be appropriately set depending on the characteristics of the phenol resin and the viscosity of the resin. In the case of the novolak resin, from 150 to 250 ° C. from the viewpoint of stability. It is particularly preferable to carry out the process, and in the case of a resole resin, it is preferable to take it out at 100 ° C. or lower. Although the degree of pressure reduction can be set as appropriate, it is particularly preferable to perform the pressure reduction at about 0.1 to 200 torr.

The weight average molecular weight of the phenolic resin for a photoresist which can be produced by the present invention is not particularly limited, but is preferably from 1,000 to 50,000 in view of the performance of the photoresist and the handling property in production. , 20
00 to 40,000 is more preferable, and still more preferably,
2500-30000. The most suitable method for controlling the weight average molecular weight is to adjust the molar ratio of aldehydes to phenols, which can be appropriately set according to the target molecular weight.
From 1 to 2.5, more preferably 0.1 from the viewpoint of the weight average molecular weight, alkali solubility, heat resistance and the like of the obtained resin.
2-1.2. More preferably, 0.3-1.0
It is. In some cases, the molecular weight and molecular weight distribution of the phenolic resin obtained by a fractionation method utilizing the difference in solubility between various solvents and water are adjusted. The material of the equipment such as a reaction vessel for the production is not particularly limited, but from the viewpoint of contamination with impurities, glass lining, Teflon (registered trademark), tantalum, hafnium,
It is preferable to use a manufacturing apparatus which is made of a metal selected from zirconium, niobium, and titanium or an alloy thereof and which does not substantially contain other materials and is resistant to corrosion, as a material for the reaction equipment.

Next, a method for introducing a group decomposable by the action of an acid will be described with reference to a phenol resin. The group substituted by the hydroxyl group of phenols and decomposable by an acid is not particularly limited, but may be any group as long as it is stable in the absence of an acid and easily decomposed by the action of an acid. An acetyl group, a tetrahydropyranyl group, a tetrahydrofuranyl group, and organic groups represented by the formulas (III) and (IV) can be mentioned.

Embedded image

Embedded image In the formula (III), Za is hydrogen, a methyl group, and Zb is
A methyl group, an ethyl group, and Zc are an alkyl group or an alkenyl group having C = 1 to 8, and in the formula (IV), Zd is a group having C = 1 to 1.
The alkyl group and alkenyl group of No. 8 are not particularly limited and may be the same or different, and may be the same or different depending on the repeating unit of R. Specifically, a C1-6 alkyl group such as a methyl group and a butyl group,
Cycloalkyl group such as cyclohexyl group, aryl group such as dinitrophenyl group, aralkyl group such as benzyl group, alicyclic ether group such as tetrahydropyranyl group and tetrahydrofuranyl group, acetyl group, cyclohexylcarbonyl group, An acyl group such as a benzoyl group, t-
Alkoxycarbonyl groups such as butoxycarbonyl groups,
Examples thereof include an alkoxyalkyl group such as an ethoxyethyl group and an isopropyloxyethyl group, and a t-butoxycarbonyl group, an ethoxyethyl group, and a tetrahydropyranyl group are particularly preferable in terms of the sensitivity, resolution, and heat resistance of the photoresist. The substitution rate of phenolic hydroxyl groups in the phenolic resin is preferably from 10 to 100%,
Particularly preferably, it is 25 to 90%. If the substitution rate is too low, the transparency is deteriorated. If the substitution rate is high, the transmittance is good, but the sensitivity of the photoresist may be reduced. The method for substituting a hydroxyl group in the phenolic resin is not particularly limited because it differs depending on the group to be substituted.In the case of a t-butoxycarbonyl group, di-tert-butoxydicabonone is used in the presence of a basic compound. For example, in the case of an ethoxyethyl group and a tetrahydropyranyl group, a method using ethylvinyl ether and 3,4-dihydro-2H-pyran in the presence of an acidic catalyst can be mentioned.

Next, the component (2) will be described. The component (2) is not particularly limited as long as it generates an acid by the action of light. For example, diazonium salts, phosphonium salts, sulfonium salts, and iodonium salts CF ₃ S
Salts such as O ₃ ⁻ , p-CH ₃ PhSO ₃ ⁻ and p-NO ₂ PhSO ₃ ⁻ (where Ph is a phenyl group), organic halogen compounds, orthoquinonediazidosulfonyl chloride or diazomethane compounds such as sulfonate and bissulfonyldiazomethane , Nitrobenzyl compounds, naphthylimidyl sulfonates and the like. A specific compound is bis (pt-butylphenyl).
Iodonium trifluoromethanesulfonate, diphenyliodonium trifluoromethanesulfonate, benzointosylate, triphenylsulfonium trifluoromethanesulfonate, tri (t-butylphenyl) sulfonium trifluoromethanesulfonate G, benzenediazonium paratoluenesulfonate, 4-
(Di-n-propylamino) -benzonium tetrafluoroborate, 4-p-tolyl-mercapto-2,5-
Diethoxy-benzenediazonium hexaflucophosphate, diphenylamine-4-diazonium sulfate, 4-methyl-6-trichloromethyl-2-pyrone, 4- (3,4,5-trimethoxy-styryl) -6
-Trichloromethyl-2-pyrone, 4- (4-methoxy-styryl) -6- (3,3,3-trichloro-propenyl) -2-pyrone, 2-trichloromethyl-benzimidazole, 2-tribromo Methyl-quinoline, 2,4
-Dimethyl-1-tribromoacetyl-benzene, 4-
Dibromoacetyl-benzoic acid, 1,4-bis-dibromomethyl-benzene, tris-dibromomethyl-S-triazine, 2- (naphth-1-yl) -4,6-bis-
Trichloromethyl-S-triazine, 2- (4-ethoxyethyl-naphthyl-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (benzopyrani-
3-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-methoxy-anthrac-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (phenanthi- 9-yl) -4,6-bis-trichloromethyl-S-triazine, o-naphthoquinonediazide-4-sulfonic acid chloride, biscyclohexylsulfoniumdiazomethane, bis (p-toluenesulfonyl) diazomethane, methylsulfonyl-p-toluenesulfonyl Diazomethane, 1-cyclohexylsulfonyl-1- (1,1-dimethylethylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl)
Examples thereof include diazomethane, bis (1-methylethylsulfonyl) diazomethane, and 2-nitrobenzyl p-toluenesulfonate. From the viewpoints of transparency, sensitivity, resist properties, handling and economics, it is particularly effective to use triphenylsulfonium trifluoromethanesulfonate and / or biscyclohexylsulfoniumdiazomethane. The amount of addition is not particularly limited, and can be adjusted according to the required characteristics of the photoresist. Considering the sensitivity of the resist characteristics, heat resistance, and economy, 0.01% to the resin used
5% is preferable, and 0.02 to 4% is more preferable.

The component (3) will be described. Ingredient (3)
Can be used as long as it dissolves the components (1) and (2), and is not particularly limited, and ethyl lactate, ethyl acetate,
Esters such as butyl acetate, ethoxyethyl alcohol
Cellosolves, such as ethyl cellulose, ethyl cellosolve acetate
G, propylene glycol monomethyl ether acetate
And ether ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and methyl amyl ketone. Particularly preferred are ethyl lactate and propylene glycol monomethyl ether acetate from the viewpoints of coating film stability and economy.

The present invention will be described according to a method for producing a radiation-sensitive composition. First, a compound that generates an acid by the action of light of the resin of the component (1) and the component (2) is dissolved in an organic solvent. Surfactant for preventing repelling, sensitizer for improving sensitivity, additive for improving edge roughness,
Various materials for finely adjusting the properties of the photoresist, such as a low molecular compound additive for improving the adhesion, can be appropriately added. Before using the resin of the component (1) to finely adjust the properties, it is possible to perform fractionation utilizing the difference in solubility in various solvents, water, and the like. Further, at an appropriate stage during the production, in order to remove metal impurities, washing with pure water or the like or demetallization treatment with an ion exchange resin can be performed. Finally, the filter (0.2 μm
A foreign substance is removed by using a PTFE filter or the like described below), and the product is packaged.

Next, a method of measuring an analytical value described in the claims of the present invention will be described. First, the weight average molecular weight of the resin will be described. The weight average molecular weight is determined by gel
It is calculated based on a calibration curve prepared by using a polystyrene standard material by measurement chromatography (GPC). The GPC measurement was performed using tetrahydrofuran as an elution solvent under the conditions of a flow rate of 1.0 ml / min and a column temperature of 40 ° C. Body: H made by TOSOH
LC-8020, detector: UV-8011, manufactured by TOSOH, set at a wavelength of 280 nm, analytical column: one SHOdex KF-802, KF-8031, manufactured by Showa Denko
And one KF-805.

The optical density (OD) was measured using a UV spectrophotometer (U-2000, manufactured by Hitachi, Ltd.) and a specific wavelength (248).
(nm) from the measured absorbance. The sample for evaluation was prepared by applying a resin solution dissolved in a solvent on a quartz glass by a spin coater and treating at 90 ° C. for 100 seconds to form a resin film on the quartz glass to a thickness of about 0.5 μm. Adjusted. Regarding the substitution rate of the group capable of leaving by an acid, a thermogravimetric analyzer (TG-D manufactured by Seiko-Electronics Co., Ltd.) was used.
TA6300), the substitution rate was calculated from the weight loss corresponding to each substituent from the obtained results. TG-DT
A measurement was performed at a heating rate of 10 ° C./min.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments.
All “parts” and “%” described herein indicate “parts by weight” and “% by weight”, and the present invention is not limited by these examples.

<< Production Example 1 >> Metacresol 1800 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 3716% formalin 1216 parts (aldehydes / phenols (F / P) = 0.90) and 9 g of oxalic acid
After conducting the reaction at 98-102 ° C for 4 hours, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C, and further dehydrated under reduced pressure to 200 ° C at 80 torr.
The monomer was removed to obtain 1850 g of a phenol resin.
The weight average molecular weight of the obtained resin was 8,500, and the free monomer was 1.5%.

<< Production Example 2 >> Metacresol 1800 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 1284 parts of 37% formalin (aldehydes / phenols (F / P) = 0.95) and 9 g of oxalic acid,
After conducting the reaction at 98-102 ° C for 4 hours, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C, and further dehydrated under reduced pressure to 200 ° C at 80 torr.
The monomer was removed to obtain 1900 g of a phenol resin.
The weight average molecular weight of the obtained resin was 38,000, and the free monomer was 1.2%.

<< Production Example 3 >> Metacresol 1800 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 371% formalin (1081 parts) (aldehydes / phenols (F / P) = 0.80) and 9 g of oxalic acid
After conducting the reaction at 98-102 ° C for 4 hours, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C, and further dehydrated under reduced pressure to 200 ° C at 80 torr.
The monomer was removed to obtain 1800 g of a phenol resin.
The weight average molecular weight of the obtained resin was 3,500, and the free monomer was 1.7%.

<< Production Example 4 >> Metacresol 1800 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 1243 parts of 37% formalin (aldehydes / phenols (F / P) = 0.92) and 9 g of oxalic acid,
After conducting the reaction at 98-102 ° C for 4 hours, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C, and further dehydrated under reduced pressure to 200 ° C at 80 torr.
The monomer was removed to obtain 1850 g of a phenol resin.
The weight average molecular weight of the obtained resin was 13,500, and the free monomer was 1.6%.

<< Production Example 5 >> Metacresol 1600 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 3,5-xylenol 200 parts, 37% formalin 1201 parts (aldehydes / phenols (F / P) =
0.90) and 9 g of oxalic acid, and reacted at 98-102 ° C. for 4 hours. Then, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C., and further 80 torr.
Dehydration and demonomerization were performed at 200 ° C. under reduced pressure to 200 ° C. to obtain 1850 g of a phenol resin. The weight average molecular weight of the obtained resin was 9,000, and the free monomer was 1.4%.

<< Production Example 6 >> Metacresol 1600 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Part, 2,3,5-trimethylphenol 200 g 37%
1188 parts of formalin (aldehydes / phenols (F / P) = 0.90) and 9 g of oxalic acid were charged, and 98-1
After reacting at 02 ° C. for 4 hours, ethyl cellosolve 65 was added.
After adding 0 parts, dehydration was performed under normal pressure to an internal temperature of 170 ° C., and dehydration and demonomerization were performed under reduced pressure at 200 torr at 80 torr to obtain 1850 g of a phenol resin. The weight average molecular weight of the obtained resin is 9000, and the free monomer is 1.
9%.

<< Production Example 7 >> Metacresol 1000 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Part, Orthocresol 800g 37% Formalin 121
6 parts (aldehydes / phenols (F / P) = 0.9
0), 9 g of oxalic acid was charged, and the reaction was carried out at 98-102 ° C. for 4 hours. Then, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated at an internal temperature of 170 ° C. under normal pressure, and further dried at 80 torr.
Dehydrate and remove the monomer under reduced pressure to 00 ° C,
Thus, 1850 g of a resin was obtained. The weight average molecular weight of the obtained resin was 8,800, and the free monomer was 1.6%.

<< Production Example 8 >> Metacresol 600 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Parts, 3,5-xylenol 1200 g 37% formalin 1123 parts (aldehydes / phenols (F / P) =
0.90) and 9 g of oxalic acid, and reacted at 98-102 ° C. for 4 hours. Then, 650 parts of ethyl cellosolve was added, and the mixture was dehydrated under normal pressure to an internal temperature of 170 ° C., and further 80 torr.
Dehydration and demonomerization were performed at 200 ° C. under reduced pressure to 200 ° C. to obtain 1850 g of a phenol resin. The weight average molecular weight of the obtained resin was 8,200, and the free monomer was 1.9%.

<< Production Example 9 >> Metacresol 900 was placed in a 5 L four-necked flask equipped with a stirrer, thermometer and heat exchanger.
Part, 2,3,5-trimethylphenol 900 g 37%
1091 parts of formalin (aldehydes / phenols (F / P) = 0.90) and 9 g of oxalic acid were charged, and 98-1
After reacting at 02 ° C. for 4 hours, ethyl cellosolve 65 was added.
After adding 0 parts, dehydration was performed under normal pressure to an internal temperature of 170 ° C., and dehydration and demonomerization was performed at 80 torr under reduced pressure to 200 ° C. to obtain 1900 g of a phenol resin. The weight average molecular weight of the obtained resin was 8,600, and the free monomer was 1.
3%.

Production Examples 1 to 9 Table 1 summarizes the properties of the obtained resins.

[Table 1]

Next, a group capable of being eliminated by an acid was introduced into the phenol resin. << Production Examples 10 to 27 >> (1) In the case of tert-butoxycarbonyl group Di-tert-butyl-dica-bonate and triethylamine are added in appropriate amounts to the resins obtained in Production Examples 1 to 9 dissolved in tetrahydrofuran. After reaction at room temperature for 24 hours, diethyl ether was added. Further, ion-exchanged water was added thereto, and the resultant was washed with water three times, and the solvent was removed and dried to obtain a desired resin for a photoresist having a group removable by an acid. (2) In the case of ethoxyethyl group and tetrahydropyranyl group An appropriate amount of ethyl vinyl ether and / or 3,4-dihydro-2H-pyran was added to the resin obtained in Production Examples 1 to 9 dissolved in tetrahydrofuran, and the catalyst was added. An amount of paratoluenesulfonic acid was added and reacted at room temperature for 4 hours. Thereafter, diethyl ether is added, ion-exchanged water is further added, and the resultant is washed three times with water, and the solvent is removed and dried to obtain a desired resin for a photoresist having a group removable by an acid. Was.

The reaction conditions of Production Examples 10 to 27 and the characteristic values of the obtained photoresist resin are summarized in Table 2.

[Table 2]

<< Examples 1 to 18 >> Evaluation of Characteristics of Photoresist The resin for photoresist obtained in the production example was adjusted to a resin concentration of 15% with propylene glycol monomethyl ether.
Compound that dissolves in teracetate and generates acid by light (Midori Chemical DAM-301 and TPS-105)
Was added in an appropriate amount to prepare a resist characteristic evaluation sample. The prepared sample was applied on a 5-inch silicon wafer using a spin coater, and was prebaked on a hot plate at 90 ° C. for 60 seconds. The rotation speed of the spin coater was adjusted so that the thickness of the applied sample became about 0.5 μm. After pre-baking, exposure was carried out using UVES-2000 manufactured by Lithotech Japan while changing the exposure amount of light having a wavelength of 248 nm at several points, and post-baking was performed at 110 ° C. for 90 seconds on a hot plate. Thereafter, the film thickness of the exposed portion was measured with a film thickness measuring device, and development was performed using 2.38% tetramethylammonium hydroxide aqueous solution using RDA-790 manufactured by Lithotech Japan, and the amount of reduction in film thickness was measured. And the rate of decrease. Based on the measurement results, 0.18 μm, L & S = 1/1, using simulation software of LeapSet and Prolith / 2.
Under the conditions of 1, the tan θ of the photoresist characteristic value, the sensitivity (exposure amount) depth of focus, the limit resolution, and the pattern shape were evaluated.

Table 3 shows the compositions of the evaluation samples and the evaluation values of the resist characteristics.

[Table 3]

As is clear from these results, the radiation-sensitive compositions obtained in the examples have excellent photoresist properties.

[0038]

According to the present invention, a radiation-sensitive composition having high sensitivity and high resolution can be provided. Since the radiation-sensitive composition of the present invention enables finer lithography, it is expected to lead to an improvement in the semiconductor industry. In addition, since it can be manufactured at low cost, it is thought that it is also useful for cost reduction.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AA01 AA02 AA04 AA10 AB16 AC04 AC08 AD03 BE00 BE07 BE10 BG00 CB28 CB41 CB55 CC03 4J002 BC121 BG001 BK001 CC031 CC051 EB116 EQ016 EV296 FD206 GQ05

Claims (16)

[Claims] 1. A radiation-sensitive composition comprising (1), (2) and (3) as essential components. (1) a resin whose alkali solubility is promoted by the action of an acid represented by the formula (I): (In the formula (I), R is an organic polymer, and the repeating units of R may be the same or different. A represents -O-,-
An organic group represented by COO—, P is an organic group that can be eliminated by the action of hydrogen or an acid. A and P may be the same or different for each structural unit of R. l is 1-2
0000 and m are 1 to 3 and may be the same or different for each structural unit of R. n is 1 to 3 and is the same number as m. (2) a compound that generates an acid by the action of light, (3)
An organic solvent that dissolves (1) and (2). 2. The radiation-sensitive resin according to claim 1, wherein R in the formula (I) in the resin of the component (1) is an organic group represented by the formula (II). Embedded image (In the formula (II), X is hydrogen, a hydroxyl group, an alkyl group, an alkenyl group and an alkoxy group having C = 1 to 8, and halogen, and a = 0 to 3. Y is a divalent organic group. .) 3. The radiation-sensitive composition according to claim 1, wherein the resin (1) has an optical density (OD) of 1.0 or less. 4. The radiation-sensitive composition according to claim 1, wherein the resin of component (1) is derived from a phenol resin. 5. The radiation-sensitive composition according to claim 1, wherein the resin of the component (1) has a weight average molecular weight obtained by GPC measurement of 1,000 to 50,000. 6. The radiation-sensitive composition according to claim 1, wherein the phenol resin used for deriving the component (1) is synthesized by using meta-cresol as an essential component as phenols. object. 7. A phenol resin used for deriving the component (1) is a resin synthesized by using 90% or more of phenols with meta-cresol and using formaldehyde as aldehydes. The radiation-sensitive composition according to claim 1. 8. The phenolic resin used for deriving the component (1) is ortho-cresol or meta-cresol.
At least one phenol selected from the group consisting of 3,5-xylenol and 2,3,5-trimethylphenol
2. The radiation-sensitive composition according to claim 1, wherein the composition is 100% synthesized using formaldehyde as an aldehyde. 9. The phenol resin used for deriving the component (1) has a weight average molecular weight obtained by GPC of 1,000 to 50,000 and an optical density (OD) of 1.0.
The radiation-sensitive composition according to claim 1, which is: 10. P in the formula (I) of the component (1) is hydrogen, a tetrahydropyranyl group, a tetrahydrofuranyl group, an acetyl group or any one or more of the general formulas (III) and (IV). The photoresist resin according to claim 1. Embedded image Embedded image (In the formula (III), Za is hydrogen, a methyl group, Zb is
A methyl group, an ethyl group, and Zc are an alkyl group or an alkenyl group having C = 1 to 8, and in the formula (IV), Zd is a group having C = 1 to 1.
8 alkyl and alkenyl groups. ) 11. Among P in the formula (I) of the component (1),
The radiation-sensitive composition according to claim 1, wherein the proportion other than hydrogen is 10 to 100%. 12. P in the formula (I) of the component (1) is te
The tert-butoxycarbonyl group, the ethoxyethyl group, and the tetrahydropyranyl group are any one or more kinds.
The radiation-sensitive composition as described in the above. 13. The radiation-sensitive composition according to claim 1, which is sensitive to light having a wavelength of 150 nm to 500 nm. 14. The radiation-sensitive composition according to claim 1, wherein the compound that generates an acid by light as the component (2) is at least one selected from a sulfonium salt, an iodonium salt, and diazomethanes. . 15. The radiation-sensitive composition according to claim 1, wherein the compound which generates an acid by light as the component (2) contains at least one of triphenylsulfonium trifluoromethanesulfonate and / or biscyclohexylsulfonyldiazomethane. Composition. 16. The radiation-sensitive composition according to claim 1, wherein the solvent which dissolves (1) and (2) contains at least one of propylene glycol monomethyl ether acetate and ethyl lactate.