JP3476783B2 - Copolymers of α, β-unsaturated nitrile-containing alicyclic polycyclic and methacrylate derivatives - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer of 2-norbornene-2-carbonitrile represented by the following structural formula (2) and a methacrylate derivative, and a photoresist composed of this novel polymer. The above novel polymer is useful as a functional polymer material for electrons, optics, pharmaceuticals, agricultural chemicals and the like.

[0002]

[Chemical 2]

2. Description of the Related Art A large number of unsaturated compounds having a norbornene skeleton are known, including norbornylene and 5-vinyl-2-norbornene, and many polymers having them as a main constituent are also known. , According to the present invention 2-
A copolymer with a methacrylate derivative containing norbornene-2-carbonitrile as a main constituent is not known. In addition, 1,2-substituted olefin compounds such as norbornylene are ring-opening polymerized by a Lewis acidic catalyst such as titanium tetrachloride, maleic anhydride having a double bond with a considerably low electron density, or a radical copolymer with maleimide. Only polymers are known.

[0003]

These copolymers have, for example, the disadvantage that the hardness of the polymer is too high and it is difficult to perform processing such as thinning, and the absorption of light in the far-ultraviolet region. It is also unsuitable as a photoresist in semiconductor manufacturing technology because of its drawbacks such as strong resistance. Further, in such a compound, it is impossible to obtain a copolymer with an acrylate derivative or a methacrylate derivative by using a radical initiator or an anion initiator, because of its property, it is not possible to modify the material. It was difficult to plan.

An object of the present invention is to eliminate these drawbacks, it is easy to process such as thinning, has a high light transmittance in the far ultraviolet region, and is suitable for a photoresist in semiconductor manufacturing technology. It is to provide a copolymer.

[0005]

The above object is achieved by a novel copolymer of 2-norbornene-2-carbonitrile represented by the formula (1) and a methacrylate derivative.
And with this 2-norbornene-2-carbonitrile
In the polymer with the methacrylate derivative , if the weight average molecular weight is 32000 and / or the composition ratio of 2-norbornene-2-carbonitrile and tetrahydropyranyl methacrylate is 36:64,
It has excellent properties when used as a photoresist described below. In addition, the above-mentioned 2-norbornene-2-cal
Even if the weight average molecular weight of the polymer of bonitrile and the methacrylate derivative is 17,000 and the composition ratio of 2-norbornene-2-carbonitrile and t-butylmethacrylate is 59:41, it is used as the photoresist described below. If it is, the characteristics are excellent. the above
Both polymers are extremely effective as photoresists
Der Ru.

The copolymer represented by the formula (1) is prepared by using 2-norbornene-2-carbonitrile and a methacrylate derivative as starting materials, and using aromatic hydrocarbons such as benzene and toluene to produce nitrogen / argon. Radical polymerization using an azo radical initiator such as azobisisobutyronitrile in an inert gas atmosphere such as
Anionic polymerization can also be carried out using alkyllithium such as n-butyllithium and Grignard reagent such as phenylmagnesium bromide. Further, it is easy to carry out anionic polymerization using tetrahydrofuran and a metal alkoxide reagent such as potassium t-butoxide in an atmosphere of an inert gas such as nitrogen and argon.

The compound which can be copolymerized with 2-norbornene-2-carbonitrile is not particularly limited in kind as long as it is a monomer having similar Q and e values in addition to the above-mentioned methacrylate derivative. Other examples of preferable copolymerizable monomers used as materials and optical materials include, but are not limited to, acrylate derivatives.

The method of copolymerization is not particularly limited, either.
Desirably, it is recommended to carry out the anionic copolymerization using a metal alkoxide reagent in an inert gas atmosphere such as nitrogen and argon using tetrahydrofuran. Further, a method for synthesizing 2-norbornene-2-carbonitrile is known in the literature (Brian Byrne et al., Tetrah.
edron Letters, 2189 (1976)), but since it could not be reproduced in the additional experiment of the present inventor, the following reaction formulas (3), (4)
It was synthesized using the method shown in (5).

[0009]

[Chemical 3]

[0010]

[Chemical 4]

[0011]

[Chemical 5]

The copolymer of 2-norbornene-2-carbonitrile and the methacrylate derivative of the present invention can be produced, for example, by the above method, but the production method itself is not limited in the present invention. In addition to the above method, it is of course possible to apply various known methods as appropriate, and all of them are included in the technical scope of the present invention as long as they satisfy the above structural formula (1). . The copolymer obtained in this way is a completely new compound and can realize properties that cannot be obtained with conventional materials, so it can be used as a functional polymer material such as electronic materials, optical materials, pharmaceuticals, agricultural chemicals, etc. Highly practical. Further, the disadvantages such as hardness and absorption in the far ultraviolet region of these copolymers, by using a norbornene derivative having a cyano group introduced, it becomes possible to copolymerize with a methacrylate derivative, and excellent in transparency, and It became possible to impart appropriate softness to the copolymer, and the processability was also improved. As a result, as a functional polymer material including an electronic material, the range of application as a functional polymer material can be expanded more than conventional polymers.

[0013]

The conventional phenol novolac photoresist has a high absorptivity for light having a short wavelength, and is opaque to ArF excimer laser light having a wavelength of 193 nm, and KrF excimer light having a wavelength of 248 nm. Since it has low transparency to laser light, it has disadvantages such as poor pattern shape and low sensitivity. On the contrary, the light transmittance of the polymer according to the present invention is 2
90% for light of 48 nm and 50% for light of wavelength 193 nm, which are higher than those of phenol novolac-based photoresists that have been conventionally used. Therefore, if an appropriate photo-acid generator is used. , KrF excimer laser light as well as ArF excimer laser light having a short wavelength can be used for exposure. In addition, the acid generated from the photo-acid generator in the exposed area has a high sensitivity because it causes a chemical reaction in a chain, and the acid solubilizes the base polymer in an alkaline aqueous solution. Development using an aqueous solution is possible, and swelling of the resist pattern after development is eliminated. As a result, a new type chemically amplified positive resist having high sensitivity, capable of forming a fine resist pattern, and having high dry etching resistance is realized.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The copolymers according to the two embodiments of the present invention will be described below.

First Embodiment A method for producing a copolymer of 2-norbornene-2-carbonitrile and tetrahydropyranyl methacrylate will be described. (A) First step (process for producing 2-cyano-2-trimethylsiloxynorbornane using reaction formula (3)) In a sufficiently dried 200 ml three-necked flask, a rubber septum and a calcium chloride tube, A Teflon-coated stirrer bar fitted with a Dimroth condenser and 20.19 g (183.3 g) of 2-norbornanone
mmol), 1 g of zinc iodide, and 5 of anhydrous methylene chloride.
0 ml was added and the mixture was stirred in a nitrogen atmosphere at -20 ° C.
Cyanotrimethylsilane 20 g (201.6 mmol)
Is slowly added dropwise to the reaction vessel using a Teflon tube cannula. After 2 hours, return to room temperature,
Stir for 6 hours. After confirming the completion of the reaction using thin layer chromatography, the solvent was distilled off using a rotary evaporator and purified using silica gel column chromatography to obtain 2-cyano-2-trimethylsiloxynorbornane (endo). : exo = 8: 1 mixture). This compound is a pale yellow liquid and the yield is 38.27 g.
(Quantitative) and IR (KBrneat, cm ⁻¹ ) is 296
2, 2877 (m), 2229 (w), 1456, 12
54, 1176, 1104, 910, 846, 758. (B) Second step (process for producing 2-cyano-2-hydroxynorbornane using reaction formula (4)) 38.37 g (183) of 2-cyano-2-trimethylsiloxynorbornane obtained in the first step .3 mmol)
And Teflon coated stirrer bar and 3
0 ml tetrahydrofuran, 10 ml water, 1 m
1 of 2N hydrochloric acid is put in a 200 ml eggplant-shaped flask and stirred vigorously at room temperature. After 3 hours, use thin layer chromatography to confirm that the raw material is gone. Then, 1 ml of 2N potassium hydrogen carbonate aqueous solution is added, and the mixture is vigorously stirred for 5 minutes. The reaction solution is transferred to a separating funnel, the oil layer is separated, and the aqueous layer is extracted three times with diethyl ether, combined with the previous oil layer, and washed with saturated saline. The ether solution obtained is dried using anhydrous sodium sulphate. The solvent is distilled off under reduced pressure to give a crude product. This is distilled under reduced pressure. bp
The fraction of 85.5-86.0 ° (0.35 mmHg) was taken, and as a colorless transparent liquid, 2-cyano-2-
Obtain hydroxynorbornane (mixture of endo and exo). The yield was 21.41 g, the yield was 84.5%, and the IR (KBrneat, cm ^-1 ) was 3420 (s), 29.
62, 2877, 2238 (m), 1455, 131
2, 1173, 1074 (s), 819, 981. (C) Third step (reaction formula (5) 2-norbornene-2-carbonitrile of the manufacturing process makes use of) obtained in about a second factory 2-cyano-2-hydroxy-norbornane 7.12 g (51 0.5 mmol) and a Teflon-coated stirrer bar were dried to 200
Place it in a ml eggplant-shaped flask and replace with nitrogen thoroughly,
60 ml of anhydrous pyridine and 14.1 ml of phosphorus oxychloride
(155 mmol) and the mixture is stirred under reflux. After 10 hours, the disappearance of the raw materials is confirmed using thin layer chromatography and allowed to cool at room temperature. Then, add 200 ml of 4N hydrochloric acid to the Erlenmeyer flask.
And ice, and while stirring at 0 ° C., 200 ml of the above reaction solution was diluted with diethyl ether,
Pour slowly. Timely, so that the temperature of the solution does not rise
Add ice, stir for 1 hour when all is poured. The oil layer is separated using a separating funnel, and the aqueous layer is extracted three times with ether, combined with the previous oil layer, and washed with a dilute aqueous potassium hydrogen carbonate solution, and then with a saturated saline solution. The diethyl ether solution obtained is dried using anhydrous sodium sulphate. After separation by filtration, the solvent is distilled off under reduced pressure and the residue is distilled under reduced pressure. bp 57-5
Collect the 8 ° (4-5 mm Hg) fractions. 2-
Norbornene-2-carbonitrile (purity 84%) is obtained as a colorless transparent liquid. The yield was 4.21 g, the yield was 68.0%, and the IR (KBrneat, cm ^-1 ) was 2.
973, 2876, 2215 (s), 1580 (m),
It was 1447 (m), 1314, 879 and 603.
¹ HNMR (CDCL ₃ , δ, TMS as inte
rnal standard is 6.89 (1H,
d, J = 3.2 Hz), 3.15 (1H, s), 3.0
7 (1H, m), 1.9-1.63 (2H, m), 1.
62-1.47 (1H, m), 1.32-1.03 (3
H, m) and ¹³ CNMR (CDCL ₃ , δ) is
152.7 (d), 118.9 (s), 116.5
(S), 48.5 (t), 45.3 (d), 43.3.
The values were (d), 24.2 (t) and 24.0 (t). (D) Fourth step (synthesis step of copolymer of 2-norbornene-2-carbonitrile and tetrahydropyranyl methacrylate) 5-norbornene-2-carbonitrile obtained in the third step 5 g (41.6 mmol) ), A Teflon-coated stirrer bar, 4.72 g (27.7 mmol) of tetrahydropyranyl methacrylate, and 13.9 ml of anhydrous tetrahydrofuran were sufficiently dried.
Place in a 0 ml three-necked flask and stir for 10 minutes in a nitrogen atmosphere at -17 ° C. 311 mg (2.8 mmol) of potassium-t-butoxide was added to 4 ml of dry TH.
Dissolve in F and slowly add dropwise using a syringe.
740 mg (2.8 mmol) 18 in 2 ml THF
-The solution in which Crown-6 is dissolved is slowly added dropwise using a syringe so that the temperature in the reaction system does not rise and stirred for 1.5 hours. The temperature in the reaction system is returned to room temperature and further stirred for 4 hours, and 10 ml of commercial grade THF is added to stop the reaction. The reaction solution
The mixture was added dropwise to 1.5 l of methanol to cause precipitation, and the resulting precipitate was separated by filtration using a glass filter at 40 ° C, 0.
Dry under reduced pressure at 5 mmHg for 6 hours. The white powder obtained is dissolved again in 30 ml of THF, reprecipitated in the same manner as above, separated by Roh and dried. The white powder obtained is dissolved, precipitated and filtered again, and the temperature is 40 ° C. and 0.5 mmH.
Dry under vacuum at 16g for 16 hours. The obtained copolymer is soluble in tetrahydrofuran and methylene chloride and insoluble in methanol and hexane. The yield is 3.
It was 85 g, the yield was 34.5%, the weight average molecular weight was 32000, the dispersion was 1.73, and the composition ratio was a ratio of norbornane to methacrylate (by NMR) of 36:64. Yes, IR (KRS-5, film, cm ^-1 )
Is 2945, 2878, 2229 (w), 1733,
1455, 1112, 1037, 900, 868, 82
It was 1.

Second Embodiment A method for producing a copolymer of 2-norbornene-2-carbonitrile and t-butyl methacrylate will be described.
Since the manufacturing process of 2-norbornene-2-carbonitrile is the same as the first to third processes of the first embodiment, the description thereof will be omitted. Fourth step (step of synthesizing copolymer of 2-norbornene-2-carbonitrile and t-butyl methacrylate) 2-norbornene-2-carbonitrile 7.5 g (6
2.4 mmol), a Teflon-coated stirrer bar, and 5.91 g of t-butyl methacrylate (4
1.6 mmol) and anhydrous tetrahydrofuran 20.8
ml and a 100 ml three-necked flask that has been sufficiently dried, and stirred for 10 minutes in a nitrogen atmosphere at -17 ° C. Potassium-t-butoxide 467 mg (4.2
(mmol) is dissolved in 5 ml of anhydrous THF and slowly added dropwise using a syringe so as not to raise the temperature in the reaction system. Stir for 30 minutes at -17 ° C and stop the reaction by adding 50 ml of commercial grade THF. The reaction solution was added dropwise to 2 l of methanol to cause precipitation,
The precipitate formed is filtered off using a glass filter,
Dry under reduced pressure at 0.5 ° C. and 0.5 mmHg for 6 hours. The obtained pale yellow powder is again dissolved in 100 ml of THF, reprecipitated in the same manner as above, separated by Roh and dried. The pale yellow powder obtained is again dissolved, precipitated, and filtered to obtain 60
Dry under reduced pressure at 0.5 ° C. and 0.5 mmHg for 16 hours. The obtained copolymer is soluble in methylene chloride and chlorobenzene, and insoluble in methanol, hexane and diethyl ether. The yield was 5.75 g and the yield was 42.
9%, the weight average molecular weight is 17,000, the dispersion is 1.57, the composition ratio is norbornane and methacrylate is 59:41 (by elemental analysis),
Elemental analysis (C: H: N) was 73.18: 8.47: 6.
46, and IR (KRS-5, film, cm ^-1 ) is 2975,
2937, 2881, 2229 (w), 1721, 14
60, 1369, 1252, 1138 (s) and 848.

[0017]

As described above, according to the present invention,
A copolymer of an alicyclic polycyclic group having a β-unsaturated nitrile and a methacrylate derivative has high transmittance even for light having a short wavelength. Therefore, by using an appropriate photoacid generator, ArF Exposure with short wavelength light such as excimer laser
Since it can be developed and has an appropriate softness, it can be easily formed into a thin film, and as a matter of course, as a photoresist used in a semiconductor device manufacturing process or the like in which fine pattern formation is required, -Useful as a functional polymer material in the technical fields of optics, medicine, agricultural chemicals, etc.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08F 220/12 C08F 232/04 CA (STN) REGISTRY (STN)

Claims (4)

(57) [Claims] 1. The following formula (1): However, R is a t-butyl group or a tetrahydropyranyl group, and m · n is a positive integer. 2- having a repeating unit represented by
A polymer of norbornene-2-carbonitrile and a methacrylate derivative. 2. The weight average molecular weight is 32000, 2
- norbornene-2-Cal Bonitoriru the composition ratio of tetrahydropyranyl methacrylate according to claim 1, which is a 36:64 2-norbornene-2
A polymer of carbonitrile and a methacrylate derivative. 3. a weight average molecular weight of 17000, 2
- norbornene-2-Cal Bonitoriru and t - polymer of 2-norbornene-2-carbonitrile and methacrylate derivative according to claim 1, wherein the composition ratio of butyl methacrylate is equal to or is 59:41. 4. The 2-norbornene-2- according to claim 1.
A photoresist made of a polymer of carbonitrile and a methacrylate derivative.