JP2003226689A - New ester compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new ester compound capable of giving a resist material which has excellent transparency and excellent adhesion to a substrate and therefore is useful for fine processing by using electron rays, far ultraviolet rays, or especially by using fluorine eximer laser, when the ester compound is polymerized to form a resin and the resin is used as the resist material. <P>SOLUTION: This ester compound is expressed by general formula (1) (R<SP>1</SP>is F or a 1-15C straight chain, branched chain or cyclic alkyl having one or more fluorine atoms; R<SP>2</SP>is H, F or a 1-15C straight chain, branched chain or cyclic alkyl or fluorinated alkyl; and R<SP>3</SP>and R<SP>4</SP>are each a single bond or a 1-20C alkylene). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ester compound useful as a monomer for a base polymer of a chemically amplified resist material suitable for microfabrication technology.

[0002]

2. Description of the Related Art In recent years,
Along with high integration and high speed of LSI, miniaturization of pattern rules is required. Background of the rapid progress in miniaturization is to increase the NA of the projection lens, improve the performance of the resist, and shorten the wavelength. With regard to higher resolution and higher sensitivity of the resist, the chemically amplified positive resist material using an acid generated by light irradiation as a catalyst has excellent performance and has become a mainstream resist material in deep ultraviolet lithography. (Japanese Patent Publication No. 27660/1990, Japanese Unexamined Patent Publication No. Sho 6)
3-27829, etc.). In addition, i-line (365
(nm) to KrF (248 nm) has brought about a great change, and the resist material for KrF excimer laser started with 0.30 micron process, went through 0.25 micron rule, and is now mass produced with 0.18 micron rule. It is being applied to Furthermore, studies on the 0.15 micron rule have begun, and the momentum for miniaturization is accelerating.

With ArF (193 nm), it is expected that the fineness of the design rule will be 0.13 μm or less, but the conventionally used resins such as novolac and polyvinylphenol are very strong in the vicinity of 193 nm. Therefore, it cannot be used as a base resin for resist. Therefore, in order to secure transparency and necessary dry etching resistance, acrylic resins and cycloolefin-based alicyclic resins have been investigated (Japanese Patent Laid-Open No. 9-7317).
3, JP-A-10-10739, JP-A-9-2305.
95, WO 97/33198).

For F ₂ (157 nm), 0.10 μ
Although miniaturization of m or less is expected, it becomes more and more difficult to ensure transparency, and acrylic resins, which are base polymers for ArF, do not transmit light at all, and cycloolefins with carbonyl groups are also available. It turned out to have a strong absorption. Further, it has been found that polyvinylphenol, which is the base polymer for KrF, has an absorption window near 160 nm and the transmittance is slightly improved, but it is far from a practical level.

The present invention has been made in view of the above circumstances, and is 300 nm or less, particularly F ₂ (157 nm) and Kr.
₂ (146 nm), KrAr (134 nm), Ar ₂ (1
It is an object of the present invention to provide an ester compound useful as a monomer that is a raw material of a base polymer of a chemically amplified resist material having excellent transmittance in vacuum ultraviolet light (26 nm).

[0006]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of extensive studies conducted by the present inventor to achieve the above object, the resin obtained from an acrylic acid derivative containing fluorine in the α-position has high transparency. In addition to the above, it was found that the introduction of a lactone ring into the ester side chain dramatically improves the adhesion of the resin synthesized from this monomer to the substrate, and has reached the present invention.

That is, the present invention provides the following ester compounds. Claim 1: An ester compound represented by the following general formula (1).

[Chemical 3] (In the formula, R ¹ is a fluorine atom or a linear, branched, or cyclic alkyl group having 1 to 15 carbon atoms and having at least one or more fluorine atoms. R ² is a hydrogen atom, a fluorine atom, or a carbon atom. A linear, branched or cyclic alkyl group or a fluorinated alkyl group having a number of 1 to 15. R ³ and R ⁴ each represent a single bond or an alkylene group having a carbon number of 1 to 20.) Claim 2: An ester compound represented by the following general formula (2).

[Chemical 4] (In the formula, R ¹ is a fluorine atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms and having at least one fluorine atom. R ⁵ is an alkylene group having 1 to 10 carbon atoms. Represents an oxygen atom or a sulfur atom.) Claim 3: In the above general formula (1) or (2), R ¹
Is a trifluoromethyl group, The ester compound according to claim 1 or 2, wherein

The present invention will be described in more detail below. According to the study of the present inventor, as a method for improving the transmittance of a resin near 157 nm, it is considered that reducing the number of carbonyl groups or carbon-carbon double bonds is also one method. It has been found that the introduction of fluorine atoms also contributes greatly to the improvement of the transmittance. In particular, the present inventors have found that a polymer obtained from an acrylic acid ester monomer containing fluorine at the α-position as represented by the structures of the following general formulas (1) and (2) can secure high transparency in the vicinity of 157 nm. I found it. Furthermore, since this monomer has a lactone ring in the ester side chain, the substrate adhesion of the obtained polymer is dramatically improved.

[0009]

[Chemical 5] (In the formula, R ¹ is a fluorine atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, particularly 1 to 10 carbon atoms, having at least one fluorine atom. R ² is a hydrogen atom, A fluorine atom, or a linear, branched or cyclic alkyl group or fluorinated alkyl group having 1 to 15 carbon atoms, particularly 1 to 10. R ³ and R ⁴ are each a single bond or 1 to 20 carbon atoms, Particularly, it represents an alkylene group of 1 to ^5. R ⁵
Represents an alkylene group having 1 to 10 carbon atoms, an oxygen atom or a sulfur atom. )

Here, the alkyl group is a methyl group,
Examples thereof include ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group, decyl group and dodecyl group. Examples of the alkyl group having a fluorine atom and the fluorinated alkyl group include groups in which some or all of the hydrogen atoms of the above alkyl group are substituted with fluorine atoms. Examples of the alkylene group include those obtained by removing one hydrogen atom from the above alkyl group.

Specific examples of the ester compound of the present invention are shown below, but the invention is not limited thereto.

[Chemical 6]

The production of the ester compound of the present invention can be carried out, for example, in the following steps, but is not limited thereto.

[Chemical 7]

Here, R ^{1 to} R ⁵ are the same as above. The reaction proceeds easily under known conditions, but preferably in a solvent such as toluene, an alcohol having a lactone ring as a raw material, an acrylic acid having fluorine at the α-position in an equimolar amount thereto, and a catalytic amount of toluenesulfonic acid. Acids such as the above are added sequentially or simultaneously and reacted under heating reflux, and the produced water is taken out of the system to move the equilibrium to the product side and complete the reaction.

[0014]

Resist material of the ester compound with a resin prepared as a monomer of the present invention according to the present invention is excellent in adhesion to substrates along with excellent transparency, electron beam or deep UV, fine in particular by F ₂ excimer laser Useful for processing.

[0015]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited to the following examples.

Synthesis Example 1 Synthesis of Monomer 1 below 33.0 g of α-hydroxy-γ-butyrolactone, 5
0.0 g α-trifluoromethylacrylic acid, 12.
3 g of p-toluenesulfonic acid monohydrate was dissolved in 200 g of toluene together with a polymerization stabilizer. Dea in a flask
An n-Stark tube was attached, the reaction mixture was allowed to react under heating reflux for 4 hours, and the water formed was removed. After cooling to room temperature, usual reaction post-treatment was carried out, and the obtained oily substance was purified by silica gel chromatography to obtain 60.1 g of the following monomer 1. Yield 8
It was 3.0%.

[0017]

[Chemical 8] ¹ H-NMR (CDCl ₃ , 270 MHz): δ 2.38
(M, 1H), 2.78 (m, 1H), 4.31-4.
52 (m, 2H), 5.57 (t, 1H), 6.56
(M, 1H), 6.83 (m, 1H) FT-IR (NaCl): 2997, 2927, 178.
6, 1743, 1401, 1377, 1244, 122
2,1176,1144,1107,1016cm ^-1

Synthesis Example 2 Synthesis of Monomer 2 36.7 g of starting alcohol 1, 50.0 g of α-trifluoromethylacrylic acid and 9.1 g of p-toluenesulfonic acid monohydrate were used as polymerization stabilizers. Together with 200 g of toluene. The Dean-Stark tube was attached to the flask, the reaction mixture was reacted under reflux for 24 hours, and the water formed was removed. After cooling to room temperature, usual reaction post-treatment was carried out, and the obtained oily substance was purified by silica gel chromatography to obtain 50.5 g of Monomer 2. The yield was 76.8%.

[0019]

[Chemical 9] ¹ H-NMR (CDCl ₃ , 270 MHz): δ 1.69
~ 1.80 (m, 2H), 1.98-2.08 (m, 2
H), 2.50 to 2.61 (m, 2H), 3.24
(M, 1H), 4.59 (m, 1H), 4.73 (m,
1H), 6.46 (m, 1H), 6.75 (m, 1H) FT-IR (NaCl): 2981, 2887, 178.
6, 1738, 1452, 1408, 1383, 135
8, 1246, 1178, 1144, 1115, 109
5,1014,993cm ^-1

[Synthesis Example 3] Synthesis of Monomer 3 below Monomer 3 was synthesized from raw material alcohol 2 in the same manner as above. The yield was 72.1%.

[0021]

[Chemical 10] ¹ H-NMR (CDCl ₃ , 270 MHz): δ1.62
~ 1.79 (m, 2H), 1.93-2.03 (m, 2
H), 2.52 to 2.71 (m, 2H), 3.33
(M, 1H), 4.45 (m, 1H), 4.78 (m,
1H), 6.41 (m, 1H), 6.71 (m, 1H) FT-IR (NaCl): 2980, 2885, 178.
2, 1734, 1452, 1408, 1383, 135
2, 1244, 1170, 1141, 1113, 109
5 cm ^-1

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) // C08F 20/28 G03F 7/039 601 G03F 7/039 601 C07D 307/32 Q (72) Inventor Hatakeyama Jun 28-1 Nishifukushima, Kubiki-mura, Nakakubiki-gun, Niigata Shin-Etsu Chemical Co., Ltd. Shin-Etsu Chemical Research Institute (72) Inventor Yoshio Kawai 28-1, Nishi-Fukushima, Kubiki-mura, Nakabuki-gun, Niigata Shin-Etsu Chemical Co., Ltd. New Functional Materials Technology Laboratory (72) Inventor Mitsutaka Otani 2805 Imafuku Nakadai, Kawagoe City, Saitama Central Glass Co., Ltd.Chemical Research Institute (72) Inventor Satoshi Miyazawa 2805 Imafuku Nakadai, Kawagoe City, Saitama Central Glass Co., Ltd. Company Chemical Research Institute (72) Inventor Kentaro Tsutsumi 2805 Imafuku Nakadai, Kawagoe City, Saitama Central Glass Co., Ltd. In-house (72) Inventor Kazuhiko Maeda 3-7 Kandanishiki-cho, Chiyoda-ku, Tokyo 1 F term inside Central Glass Co., Ltd. (reference) 2H025 AA14 AC04 AC06 AD01 AD03 BG00 4C037 FA10 4C062 BB60 4C071 AA03 BB02 CC11 CC21 EE13 FF14 KK11 KK11 4J100 AL26P BA11P BA51P BC53P CA01

Claims (3)

[Claims] 1. An ester compound represented by the following general formula (1): [Chemical 1] (In the formula, R ¹ is a fluorine atom or a linear, branched, or cyclic alkyl group having 1 to 15 carbon atoms and having at least one or more fluorine atoms. R ² is a hydrogen atom, a fluorine atom, or a carbon atom. A linear, branched or cyclic alkyl group or a fluorinated alkyl group having a number of 1 to 15 is shown. R ³ and R ⁴ are each a single bond or an alkylene group having a carbon number of 1 to 20.) 2. An ester compound represented by the following general formula (2). [Chemical 2] (In the formula, R ¹ is a fluorine atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms and having at least one fluorine atom. R ⁵ is an alkylene group having 1 to 10 carbon atoms. , Represents an oxygen atom or a sulfur atom.) 3. In the general formula (1) or (2),
The ester compound according to claim 1 or 2, wherein R ¹ is a trifluoromethyl group.