JPH0892312A - Polymeric compound having quantitatively having vinylidene group at terminal, its production and resist material using the same polymeric compound - Google Patents

Abstract

PURPOSE: To obtain a polymeric compound, capable of providing a resist of a high sensitivity and containing vinylidene quantitatively introduced into the terminal in high yield by carrying out the anionic polymerization of a vinyl monomer in the presence of an organometallic initiator, adding a vinyl monomer containing a halogen thereto and conducting the eliminating reaction. CONSTITUTION: This polymeric compound has quantitatively a vinylidene group structure at the terminal represented by the formula [R is an optional initiator fragment; R1 and R2 are each H, a 1-10C alkyl, an aryl or an aralkyl; R3 and R4 are each H, a 1-10C alkyl, an aryl, an aralkyl, F, Cl or Br; (n) is 5-10000]. This method for producing the polymeric compound comprises carrying out the anionic polymerization of a vinyl monomer in the presence of an organometallic initiator such as butyl-lithium or sodium naphthalene, then adding a vinyl monomer containing a halogen thereto and subsequently conduct the eliminating reaction. Furthermore, this resist material is obtained by depolymerizing the compound with visible light, electron rays, X-rays, etc.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polymer compound having a quantitative vinylidene group at its terminal, a method for producing the same, and a resist material using the polymer compound.

[0002]

2. Description of the Related Art Conventionally, a method of introducing an unsaturated group into a terminal of a polymer compound has been widely tried as a method for synthesizing a macromonomer (edited by Yuya Yamashita, Chemistry and Industry of Macromonomer, IP Publications 1989). Year). However, most of them are currently synthesized as precursors of block polymers and graft polymers. Therefore, most of the polymers obtained as macromonomers show a polymerization reaction by light or electron beam. The present inventors have shown that a positive resist which shows reactive activity efficiently by irradiation with light or electron beam and depolymerizes due to the generated active species having a structure similar to that of the growing chain, resulting in highly efficient depolymerization. Aimed at, repeated examination. Generally, in a cationic polymerization reaction of a vinyl monomer, a polymer represented by the structural formula (A) is partially produced by a chain transfer reaction (proton transfer), but there is no case where these unsaturated terminals are quantitatively introduced.

[0003]

The present inventors succeeded in obtaining a polymer compound having a structural formula (A) in which an unsaturated group is quantitatively introduced as a terminal structure in a high yield by a novel synthetic method. The present invention has been completed, and an object of the present invention is to provide a polymer compound having a structural formula (A) in which a vinylidene group, which is an unsaturated group, is quantitatively introduced at a terminal in a high yield by a novel structural method. And a method for manufacturing the same.

[0004]

The gist of the present invention is a polymer compound having a vinylidene group structure quantitatively at the terminal represented by the following structural formula (A).

[0005]

[Chemical 4]

(In the formula, R represents an arbitrary initiator fragment. R
₁ and R ₂ represent hydrogen or an alkyl group having 1 to 10 carbon atoms, an aryl group or an aralkyl group. R ₃ and R ₄ are hydrogen or an alkyl group having 1 to 10 carbon atoms, an aryl group,
Represents an aralkyl group or halogen such as F, Cl, Br. n represents an integer of 5 to 10,000. The compound (A) of the present invention is synthesized through a process of anionic polymerization of a vinyl monomer using an organic metal such as butyllithium or sodium naphthalene as an initiator and subsequent addition and elimination reactions of a halogen-containing vinyl monomer. This synthetic process, for example, using butyllithium as the reaction initiator and showing the chemical formula in the case of α-methylstyrene, the polymer (1) having a butyl group at one end and lithium at the other end is obtained as follows.

[0007]

[Chemical 5]

When this polymer (1) is treated with an end modifier, lithium is removed as shown by the following chemical formula.

[0009]

[Chemical 6]

Further, when α-monochloromethylstyrene is used as the terminal modifying agent, it is as follows.

[0011]

[Chemical 7]

This can be expressed by the following general formula, and the compound (A) according to the present invention having a quantitative vinylidene group bonded to the terminal can be obtained.

[0013]

Embedded image

Any monomer can be used in this reaction as long as it is a monomer that anionically polymerizes in a living manner, but an α-methylstyrene derivative having a substituent at the para position is particularly preferable. Examples of other monomers include conjugated hydrocarbon monomers such as styrene, α-methylstyrene, isoprene and butadiene, and conjugated polar monomers such as ethylene, acrylic acid ester and methacrylic acid ester, dialkyl acrylamide and vinyl ketone. be able to. The anionic polymerization method of this vinyl monomer is not different from the conventional anionic polymerization method. That is, using an organometallic initiator, polymerization is performed under the conditions of temperature and time under a solvent described later. The degree of polymerization of the obtained polymer is 5
~ 10,000.

The organometallic initiator used in this reaction is an organolithium such as methyllithium or butyllithium,
Organic sodium and organic potassium such as sodium naphthalene, potassium naphthalene and cumyl naphthalene mil potassium, and organic metal amides such as lithium diisopropylamide and potassium diisopropylamide are used. Further, α-methylstyrene living oligomer and the like can be used as the initiator. The amount of these initiators used is
The molar ratio to the monomer is 0.00001 to 100
It can be used in a double mole, and a 0.0001-fold to 1-fold mole is more preferable.

The terminal modifier used in this reaction is α-trifluoromethylstyrene, α-difluoromethylstyrene, α-fluoromethylstyrene, α-tribromomethylstyrene, α-dibromomethylstyrene, α-bromomethylstyrene, α-trichloromethylstyrene, α
-Dichloromethylstyrene, α-chloromethylstyrene and the like, and α-methylstyrene derivatives having a halogenomethyl group at the α-position can be mentioned. Further, a styrene derivative having a leaving group such as an alkoxymethyl group or a cyanomethyl group at the α-position can be used. The molar ratio of these end modifiers to the polymer produced is 0.01 to 100.
It can be used in a double mole, and a 1-fold to 10-fold mole is more preferable.

The reaction of the present invention can also be carried out in the presence of an inert solvent. Examples of the solvent include ethers such as diethyl ether, dioxane, tetrahydrofuran, dimethoxyethane, and diglyme, aliphatic hydrocarbons such as pentane, hexane, cyclohexane, and octane, benzene, aromatic hydrocarbons such as toluene dimethyl sulfoxide, N, N
A liquid that does not react with the alkali metal catalyst under the reaction conditions, such as an aprotic polar solvent such as dimethylformamide or hexamethylphosphoric triamide, can be used. Of these, ethers such as tetrahydrofuran, aromatic hydrocarbons such as benzene, aliphatic hydrocarbons such as hexane, and aliphatic hydrocarbons such as hexane are preferable.

The amount of solvent used is 0.1 of the volume of the monomer.
To 1000 times, preferably 0.5
To 100 times the amount. The reaction is generally slower with higher relative amounts of solvent. The temperature for carrying out the reaction in the present invention is not particularly limited, but is -150 ° C to 150 ° C.
Is more preferably -100 ° C to 0 ° C. The reaction time is not limited, but is preferably 1 minute to 1000 hours, more preferably 10 minutes to 100 hours. Since the reaction rate varies depending on the reaction conditions and the target product, gas chromatography or liquid chromatography-
It is desirable to determine the end time of the reaction by quantifying the raw materials and products by means such as.

The polymer compound of the structural formula (A) obtained in the present invention has a vinylidene group, which is an unsaturated group highly sensitive to ultraviolet light and electron beam, introduced quantitatively at the terminal. , Efficiently depolymerize by electron beam. Conventionally, a vinyl-type polymer having a quaternary carbon number in the main chain causes the main chain to be cleaved by ultraviolet rays, electron beams, etc., but at the same time, a cross-linking reaction by a side chain group also occurs. There wasn't. However, the polymer compound of the structural formula (A) according to the present invention is efficiently depolymerized by ultraviolet light, electron beam or the like. This process is shown below.

[0020]

[Chemical 9]

That is, the polymer compound represented by the structural formula (A) is entirely depolymerized into a monomer by UV light, electron beam, etc., and becomes soluble, so that a novel high-performance positive resist material can be provided. did it. In order to form a resist film from the compound (A), the compound (A) is dissolved in a solvent and a thin film is formed by a spinner or the like. As the solvent used at that time, ethers such as diethyl ether, dioxane, tetrahydrofuran, dimethoxyethane, diglyme, pentane, hexane,
Aliphatic hydrocarbons such as cyclohexane and octane, aromatic hydrocarbons such as benzene and toluene, dimethyl sulfoxide, aprotic polar solvents such as N, N-dimethylformamide and hexamethylphosphoric triamide can be used. The concentration of the solution is preferably 0.1 to 1000 times by volume, more preferably 1 to 20 times by volume of the compound (A). The higher the relative amount of solvent, the generally thinner the membrane.

The obtained film was exposed to visible light, ultraviolet rays, electron beams,
It is easily depolymerized by irradiation with X-rays to form a pattern. The solvent used for development is water, methanol or ethanol.
Alcohols such as alcohol and propanol are suitable, and in the case of vacuum irradiation such as electron beam or X-ray, a pattern can be obtained even without using a developer.

[0023]

EXAMPLES The present invention will be further described below with reference to examples, but these examples do not limit the scope of the present invention in any way. Example 1 The inside of the reaction vessel was replaced with argon, and 28.9 ml of tetrahydrofuran and 4bis [(trimethylsilyl) tetrahydrofuran were added at -78 ° C.
Methyl] isopropenylbenzene (15.3 ml) and sec-butyllithium hexane solution (6.7 ml) are added, and the mixture is reacted for 20 minutes. 2.4 ml of α-trifluoromethylstyrene was added to this solution, and the mixture was further reacted for 3 minutes. This solution was added to a large excess of methanol to obtain a polymer. The yield of the obtained polymer was 14.5 g (97%: sample 1). The number average molecular weight of Sample 1 determined from ¹ HNMR was 2,800. The Rf value in thin layer chromatography using a silica gel stationary phase was 0.65, which was one spot (mobile phase: hexane). ¹³ C NMR
From the spectrum, it was confirmed that a signal derived from the terminal of the unsaturated group appeared (FIG. 1). The decomposition start temperature by thermogravimetric analysis was 340 ° C.

Comparative Example 1 The atmosphere in the reaction vessel was replaced with argon, and 28.9 ml of tetrahydrofuran was added at −78 ° C. to 4bis [(trimethylsilyl).
Methyl] isopropenylbenzene (15.3 ml) and sec-butyllithium hexane solution (6.7 ml) are added, and the mixture is reacted for 20 minutes. 1 ml of methanol was added to this solution, and the mixture was further reacted for 3 minutes. This solution was added to a large excess of methanol to obtain a polymer. The yield of the obtained polymer is 1
It was 3.8 g (98%: sample 2). ¹ H NMR
The number average molecular weight of Sample 2 determined from the above was 2.600. The Rf value in thin layer chromatography using a silica gel stationary phase was 0.85 (mobile phase: hexane). It was confirmed from the ¹³ C NMR spectrum that no unsaturated group terminal was present (FIG. 2). The decomposition start temperature by thermogravimetric analysis was 350 ° C.

Example 2 The inside of the reaction vessel was replaced with argon, and 28.9 ml of tetrahydrofuran and 4bis [(trimethylsilyl) tetrahydrofuran were added at -78 ° C.
Methyl] isopropenylbenzene (15.3 ml) and sec-butyllithium solution (3.3 ml) in hexane are added, and the mixture is reacted for 20 minutes. 2.4 ml of α-trifluoromethylstyrene was added to this solution, and the mixture was further reacted for 3 minutes. This solution was added to a large excess of methanol to obtain a polymer. The yield of the obtained polymer was 13.8 g (96%: sample 3). The number average molecular weight of Sample 3 determined from ¹ HNMR was 5,400. The Rf value in thin layer chromatography using a silica gel stationary phase was 0.65, which was one spot (mobile phase: hexane). ¹³ C NMR
It was confirmed from the spectrum that a signal derived from the terminal of the unsaturated group appeared, as in FIG. The decomposition start temperature by thermogravimetric analysis was 340 ° C.

Example 3 The atmosphere in the reaction vessel was replaced with argon, and 28.9 ml of tetrahydrofuran was added at −78 ° C. to 4bis [(trimethylsilyl).
Methyl] isopropenylbenzene (15.3 ml) and sec-butyllithium hexane solution (6.7 ml) are added, and the mixture is reacted for 20 minutes. Α-Chloromethylstyrene 3.
1 ml was added and further reacted for 3 minutes. This solution was added to a large excess of methanol to obtain a polymer. The yield of the obtained polymer was 14.3 g (93%). ¹ HN
The number average molecular weight of the sample determined from MR was 2,800. Further, the Rf value in thin layer chromatography using a silica gel stationary phase was 0.70 per spot (mobile phase: hexane). ^{From the 13} C NMR spectrum, it was confirmed that a signal derived from the terminal of the unsaturated group appeared.

Example 4 The inside of the reaction vessel was replaced with argon, and at −78 ° C., 28.9 ml of tetrahydrofuran and 6.5 m of α-methylstyrene.
l, sec-Butyllithium hexane solution (6.7 ml) was added and reacted for 20 minutes. 2.4 ml of α-trifluoromethylstyrene was added to this solution, and the mixture was further reacted for 3 minutes. This solution was added to a large excess of methanol and the polymer
Got The yield of the obtained polymer was 5.9 g (93%: sample 4). The number average molecular weight of the sample determined from ¹ HNMR was 1,000. Further, the Rf value in thin layer chromatography using a silica gel stationary phase was 0.70 per spot (mobile phase: toluene).
^{From the 13} C NMR spectrum, it was confirmed that a signal derived from the terminal of the unsaturated group appeared (FIG. 3).

Example 5 Sample 1, 100 mg obtained in Example 1, 10 mg of the radical generator azobisisobutyronitrile and 10 mg of benzophenone were dissolved in 10 ml of tetrahydrofuran and irradiated with a 500 W mercury lamp for 1 hour. It was When the reaction product was traced by gel permeation chromatography, Sample 1 disappeared and was converted into a monomer.

Example 6 Sample 4, 100 mg obtained in Example 4, 10 mg of azobisisobutyronitrile as a radical generator and 10 mg of benzophenone were dissolved in 10 ml of tetrahydrofuran and irradiated with a 500 W mercury lamp for 1 hour. It was When the reaction product was traced by gel permeation chromatography, all sample 4 disappeared and was converted into a monomer.

Comparative Example 2 Sample 2, 100 mg obtained in Comparative Example 1, 10 mg of azobisisobutyronitrile as a radical generator and 10 mg of benzophenone were dissolved in 10 ml of tetrahydrofuran and irradiated with a 500 W mercury lamp for 1 hour. It was When the reaction product was traced by gel permeation chromatography, Sample 2 was not decomposed at all.

Example 7 Sample 3 obtained in Example 2 was dissolved in methyl ethyl ketone (10 vol%) and spin-coated (0.5 μm), and the film (0.5 μm) was irradiated with an electron beam by a scanning electron microscope ( 20 KeV). When developed with methanol containing 5% methyl ethyl ketone, the electron beam irradiation film disappeared completely. The electron beam irradiation intensity at the time of 50% remaining film is 5 μC /
cm ² . (Comparison, PMMA 50 μC / c
m ² )

Comparative Example 3 Sample 2 obtained in Comparative Example 1 was dissolved in methyl ethyl ketone (10 vol%) and spin-coated (0.5 μm), and the film (0.5 μm) was irradiated with an electron beam with a scanning electron microscope ( 20 KeV). When developed with methanol containing 5% methyl ethyl ketone, the electron beam irradiation film was crosslinked and decomposed at the same time, and a good pattern could not be obtained.

[0033]

The vinyl polymer having quaternary carbon in the main chain
Is known to have a low ceiling temperature and to be decomposed by light and electron beams, but at the same time, a crosslinking reaction occurs at the same time, so that it does not always show high performance as a positive resist. Here, the method of quantitatively introducing an unsaturated group to the terminal as in the present invention is a system in which the terminal reacts at a lower energy-irradiation dose (that is, higher sensitivity) than in the past and the decomposition proceeds quantitatively from the terminal. Can be achieved. Therefore, the resist created by the present invention can be a useful material in the semiconductor field which requires a fine processing technique as a positive resist having high sensitivity.

[Brief description of drawings]

FIG. 1 ¹³ C NMR spectrum of the polymer obtained in Example 1.

FIG. 2 ¹³ C NMR spectrum of the polymer obtained in Comparative Example 1.

FIG. 3 ¹³ C NMR spectrum of the polymer obtained in Example 4.

Claims (3)

[Claims] 1. A polymer compound quantitatively having a vinylidene group structure at the terminal represented by the following structural formula (A). [Chemical 1] (In the formula, R represents an arbitrary initiator fragment. R ₁ and R ₂ represent hydrogen or an alkyl group having 1 to 10 carbon atoms, an aryl group or an aralkyl group. R ₃ and R ₄ are Represents hydrogen or an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group or halogen such as F, Cl, Br, etc. n is 5 to 5
Represents an integer of 10,000. ) 2. An anionic polymerization of a vinyl monomer in the presence of an organometallic initiator such as butyllithium or sodium naphthalene, followed by addition of a halogen-containing vinyl monomer, followed by elimination reaction. A method for producing a polymer compound represented by the following structural formula (A). [Chemical 2] (In the formula, R represents any initiator fragment. R ₁ and R ₂ represent hydrogen or an alkyl group having 1 to 10 carbon atoms, an aryl group, or an aralkyl group. R ₃ , R ₄ are hydrogen or Represents an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group or halogen such as F, Cl, Br, etc. n is 5 to 10,
Represents an integer of 000. ) 3. A resist material which is characterized in that a polymer compound represented by the following structural formula (A) is depolymerized by visible light, ultraviolet rays, electron beams, X-rays and the like. [Chemical 3] (In the formula, R represents any initiator fragment. R ₁ and R ₂ represent hydrogen or an alkyl group having 1 to 10 carbon atoms, an aryl group, or an aralkyl group. R ₃ , R ₄ are hydrogen or Represents an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group or halogen such as F, Cl, Br, etc. n is 5 to 10,
Represents an integer of 000. )