JPH0412884B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for producing a thin polymer film, characterized in that it is obtained by polymerizing a diethynylbenzene derivative by irradiating energy. Moreover, the present invention
The present invention relates to a method for producing a thin polymer film, which is obtained by accumulating a diethynylbenzene derivative on a substrate by Langmuir Blodget method and polymerizing it by irradiating energy. (Industrial Application Field) Diethynyl compounds, in which two ethynyl groups are directly bonded to a benzene ring, are generally resistant to energy irradiation such as gamma rays, electron beams, X-rays, ultraviolet rays, visible light, and infrared rays (heat). On the other hand, polymers which have extremely high sensitivity and can be obtained by energy irradiation have excellent etching resistance, and are therefore useful as pattern forming materials such as electron beam resists, X-ray resists, and photoresists, or as heat-sensitive materials. Also,
The polymer obtained by the above energy irradiation is
Since it becomes a conjugated polymer in which triple bonds open to form conjugated double bonds, it can also be used as electronic materials such as organic semiconductors and conductive materials. In addition, amphiphilic compounds, which have both a hydrophobic structural part such as a long-chain structure consisting of an appropriate number of methylene groups in the molecule and a hydrophilic structural part such as a carboxyl group, are Forms a monolayer. This monomolecular film is produced by the Langmuir Blosget method (hereinafter referred to as the "LB method". Also, the film produced by this method is referred to as the "LB film").
The molecules can be accumulated on a suitable substrate to form a highly oriented molecular accumulation film. In particular, the diethynylbenzene derivative used in the production method of the present invention is a parenteral compound that has both a hydrophobic structural part consisting of 9 to 21 methylene groups and a hydrophilic structural part such as a carboxyl group in the molecule. It is a medium molecule and can form a monolayer on the water surface. This monomolecular film can be accumulated on a suitable substrate by the LB method to form a highly blended monomolecular film or a molecular accumulation film. The LB film obtained in this way is polymerized by energy irradiation to produce a polymer thin film, which can be used for pattern forming materials such as resists, electronic materials such as organic semiconductors and conductive materials, and optoelectronic materials such as nonlinear optical materials. It can be used for development. (Prior art and problems) Until now, compounds represented by the general formula [Formula] (n = 1, 2, 4, 5, 6, 10) or the general formula [Formula] (R is a methyl group, a cyclohexyl group) or phenyl group)
The compound represented by is already known (WL
OlsenS, Journal of Bacteriology, 13 (3),
1443-6 (1979); US4536515, etc.). However, as in the diethynylbenzene derivative shown in the claims, two hydrogens in the benzene ring are replaced with ethynyl groups, and one of the hydrogens in the ethynyl group is -
(CH ₂ )n-COOH (n is an integer between 9 and 21)
No compounds substituted with are known. Diethynylbenzene compounds are resistant to gamma rays, electron beams,
It is sensitive to energy irradiation such as ultraviolet rays, visible light, and infrared rays (heat), but its small molecular weight makes it difficult to produce high-quality thin films, and its sublimation property makes it difficult to handle under reduced pressure. It was hot. The LB method may be suitable for producing thin films of compounds with a diethynylbenzene structure, but no diethynylbenzene compounds are known that have the amphiphilic properties necessary for producing LB films, and the raw materials for their production are also unknown. do not have. Further, there is also no known method for producing a polymer thin film by polymerizing the above-mentioned amphiphilic diethynylbenzene compound by energy irradiation. (Means for Solving the Problems) In view of these problems, the present inventors have made extensive studies and found that it is possible to produce a thin film, that the compound is a non-sublimable diethynylbenzene compound, and that
We have invented a method for producing polymer thin films by polymerizing diethynylbenzene derivatives, which are amphiphilic compounds applicable to LB technology, by energy irradiation. That is, the present invention provides a novel diethynylbenzene structure and a methylene chain in the molecule, a vinyl group at one end of the molecule, and a hydrogen or alkylsilyl group at the other end of the molecule, represented by the following general formula. The present invention relates to a method for producing a thin polymer film, characterized in that it is obtained by polymerizing an ethynylbenzene derivative by irradiation with energy. [R in the formula is hydrogen or -SiX ₁ X ₂ X ₃ , X ₁ , X ₂ ,
X ₃ is each independently hydrogen or an alkyl group having 1 to 7 carbon atoms (except when X ₁ , X ₂ , and X ₃ are all hydrogen), and n is an integer of 9 or more and 21 or less. ] The diethynylbenzene derivative in the production method of the present invention can be formed into a thin film on a substrate such as glass, quartz, silicon wafer, calcium fluoride, etc. by vapor deposition, sputtering, plasma coating, solution spin coating, or the like. Further, an LB film can also be produced on a substrate such as glass, quartz, silicon wafer, calcium fluoride, etc. by the LB method using the above-mentioned diethynylbenzene derivative. Hereinafter, a method for producing an LB film using the above-mentioned diethynylbenzene will be described. First, a diethynylbenzene derivative represented by the general formula (*) is dissolved in a water-insoluble volatile organic solvent such as chloroform, benzene, hexane, heptane, etc. to a concentration of 1×10 ^-4 mol/l to 1×
Prepare a solution of 10 ^-2 mol/l. When this solution is dropped onto a clean water surface and the solvent is evaporated, the diethynylbenzene derivative is spread out on the water surface. At this time, water contains 1×10 ^-4 mol/l ~ 1
Metal ions such as Cd ²⁺ and Fe ³⁺ Al ³⁺ may be contained at a concentration of ×10 ⁻² mol/l. Next, as the surface area of the monomolecular film of the diethynylbenzene derivative developed on the water surface is reduced, the surface pressure gradually increases, and a monomolecular solid film is formed on the water surface. By accumulating this monomolecular solid film in 1 to 500 layers on a glass substrate, quartz substrate, silicon wafer, calcium fluoride substrate, etc. according to the LB method,
LB film can be obtained. The thickness of the obtained LB film is about 20 to 18000 Å. The thin film or LB film of the diethynylbenzene derivative obtained as described above can be exposed to γ-rays, electron beams, X-rays,
By irradiating energy such as ultraviolet rays, visible light, and infrared rays (heat), the C≡C triple bond is polymerized to obtain a polymer thin film. In particular, when an LB film is used, a highly oriented polymer thin film can be obtained. In addition, a polymer thin film having an arbitrary shape can be formed by masking during energy irradiation or by scanning the irradiated energy in the form of a luminous flux. For example, arbitrary portions of the thin film can be polymerized by electron beam scanning or UV irradiation from above a mask. A diethynylbenzene derivative polymerized by energy irradiation has lower solubility in a solvent than the original low molecule. Therefore, for example, a thin film irradiated with energy in an arbitrary shape can be
By immersing it in acetone or ethanol and developing it, a negative pattern can be formed. This can be used as a resist material such as electron beam resist, X-ray resist, photoresist, etc. In particular, resists using LB films can have high resolution and high sensitivity due to their extremely thin film thickness and high degree of orientation. In addition, the C≡C structure is polymerized by energy irradiation to form a conjugated double bond, which can also be conjugated with a benzene ring or other C≡C bonds, thereby expanding the π-electron system. In this case, it becomes possible to apply it to electronic materials such as organic semiconductors and conductive materials, and optoelectronic materials such as nonlinear optical materials. In the general formula (*) of the diethynylbenzene derivative in the production method of the present invention, the substituent R is hydrogen or -SiX ₁ X ₂ X _3. Examples of -SiX _{1 X 2} silyl group,
Methyldiethylsilyl group, tributylsilyl group,
Examples include triheptylsilyl group and diethylsilyl group. However, for diethynylbenzene derivative compounds where R is hydrogen, R=
-SiX ₁ X ₂ X ₃ can be obtained by desilylation reaction of the derivative. Furthermore, the substitution mode of the two ethynyl groups on the benzene ring may be any of ortho, meta, and para. Next, an example of a method for synthesizing a diethynylbenzene derivative in the production method of the present invention will be explained. First, using diethynylbenzene 1 as one of the starting materials, two ethynyl groups of diethynylbenzene are metal-halogenated by the Grignard method to obtain compound 2 . This compound 2 is converted into X ₁ X ₂ X ₃ SiCl (X ₁ ,
X ₂ and X ₃ are each independently hydrogen or have a carbon number of 1 to
7 alkyl group, X ₁ , X ₂ , X ₃
are not all hydrogen at the same time),
Bisalkylsilylated ethynylbenzene 3 Synthesize. On the other hand, alkenyl alcohol 4 CH ₂ =CH−
(CH ₂ ) m-OH (where n is an integer of 9 to 21) is used as another starting material and reacted with tosyl chloride to form alkenyl tosylate 5 CH ₂ =
CH-( _CH2 )n-OTs (where n is an integer of 9 or more and 21 or less, and Ts is a tosyl group) is synthesized. By desilylating one alkylsilyl group of the above bisalkylsilylated ethynylbenzene 3 and alkenyl tosylate 5 using methyllithium etc. to form an organometallic compound 6 , and reacting it with the alkenyl tosylate 5 , [R' in the formula _is -SiX ₁ X _{2 X 3} , and _{X 1 ,} (except when all ₃ are hydrogen), and n is an integer of 9 or more and 21 or less ] can be synthesized. In addition, when R′ is hydrogen, the derivative 7′ is:
R' is a silyl group - SiX ₁ X ₂ X ₃ derivative 7 ,
R″ ₄ NF, KF, R″Li, etc. (R″, R has 1 or more carbon atoms
(representing five alkyl groups or phenyl groups) in the presence of a desilylating agent. When KF is used as a desilylating agent, it is preferably used together with a crown compound. Next, the vinyl group portion of the above diethynylbenzene derivative 7 or 7' is removed by ozone oxidation or the like.
By performing oxidative decomposition to form a carboxyl group, the diethynylbenzene derivative 8 or 8' in the production method of the present invention, that is, the diethynylbenzene derivative represented by the general formula (*) in the production method of the present invention is obtained. It will be done. Although an example of the method for producing the diethynylbenzene derivative compound of the present invention has been described above, the production method is not limited thereto. The diethynylbenzene derivative 8 or 8' in the production method of the present invention is IR
In the spectrum, the C-H stretching vibration of the benzene ring, the C-H stretching vibration of the methylene group, and the C≡C stretching vibration are 3000 to 3080 cm ^-1 and 2850 to 2960 cm, respectively.
^-1 , observed between 2100 and 2260 cm ^-1 . In addition, the absorption peculiar to the benzene ring is around 1600 cm ^-1 and around 1500 cm ^-1 , and the C-H out-of-plane bending vibration of the benzene ring is around 690 to 860 cm -1.
cm ^-1 , the C=0 stretching vibration of the carboxyl group is 1700
Observed around cm ^-1 . In addition, in the ¹ H-NMR spectrum, the protons of the benzene ring are 6.9 to 7.8 ppm, the protons of the methylene group adjacent to C≡C are 2.2 to 25 ppm,
Protons of methylene groups adjacent to carboxyl groups are observed at 2.25 to 2.5 ppm, and protons of other methylene groups are observed at 0.6 to 1.8 ppm. IR absorption attributable to the structure of substituent R, ¹ H-NMR
Signals are also seen in each spectrum. The aforementioned diethynylbenzene derivative is an amphipathic compound and is soluble in acetone, methyl ethyl ketone, ethanol, methanol, tetrahydrofuran, diethyl ether, ethyl acetate, and the like. Furthermore, it is soluble in volatile organic solvents that are not soluble in water, such as chloroform, hexane, benzene, and heptane. Next, the method for producing a polymer thin film of the present invention will be explained in more detail with reference to Examples. Example 1 0.2 mol of para-diethynylbenzene was dissolved in 350 ml of sufficiently dehydrated tetrahydrofuran and heated to -78°C.
Then, 0.4 mol of ethylmagnesium bromide was added and reacted at 25°C for 1 hour. Next, this reaction solution was cooled again to -78℃, and trimethylsilyl chloride was added.
0.4 mol was added and reacted at 25°C for 2 hours to obtain bis-(trimethylsilylethynyl)-benzene. Additionally, 0.04 mol of ω-heptadecenyl alcohol was dissolved in 30 ml of pyridine, and while the reaction vessel was immersed in an ice bath, 0.045 mol of toluenesulfonyl chloride (tosyl chloride) was added and reacted at 15°C for 24 hours to form heptadecenyl toxin. Got the rate. Next, bis-(trimethylsilyl)-benzene 0.01
mol was dissolved in 60 ml of sufficiently dehydrated tetrahydrofuran, 0.01 mol of methyllithium was added at -78°C, and the mixture was reacted at 25°C for 2 hours. The reaction solution was cooled again to -78°C, and hexamethylphosphoramide 35
ml and 0.01 mol of heptadecenyl tosylate were added and reacted at 25°C for 1 hour. To this reaction solution were added 250 ml of a saturated aqueous solution of sodium bicarbonate and 180 ml of diethyl ether, and the mixture was thoroughly shaken to extract the product into the ether phase. The ether phase was washed with a saturated aqueous sodium chloride solution and then dehydrated with magnesium sulfate. This ether solution was concentrated to give white yellow crystals. Purification by GPC yielded 1-(18-nonadecen-1-ynyl)-4-(trimethylsilylethynyl)-benzene. 40 mmol of white crystals were obtained. Next, the above 1-
(18-nonadecen- ₁ -ynyl)-4-(trimethylsilylethynyl-benzene in tetrahydrofuran solution, _{(C4H9)4NF in tetrahydrofuran solution, (C4H9)4NF is 25 equivalents of} trimethylsilyl group) The desilylation reaction was carried out by stirring and mixing at 25°C for 20 hours.Next, a small amount of water was added to this reaction solution, and after thorough shaking, the ether layer was separated.This procedure Repeat this step to combine the ether layers and concentrate to obtain 1-ethynyl-4-(18-nonadecen-1-ynyl)-benzene. 30 mmol of white crystals were obtained. Next, add the above 1-ethynyl-4-(18-nonadecen-1-ynyl)-benzene to 300 ml of ethyl acetate.
After cooling to -10°C, an equimolar amount of ozone was blown into the solution. After removing the refrigerant and evaporating the solvent by blowing argon gas, the residue was dissolved in acetone 60
ml and immersed the reaction vessel in an ice bath. John's reagent was added to this solution until the brown color was maintained, and the mixture was stirred and reacted at 25° C. for 15 minutes. to the reaction solution
350 ml of ice water was added, organic matter was extracted with diethyl ether, the ether phase was shaken with an aqueous sodium hydroxide solution, and the aqueous phase was separated. After making the aqueous phase acidic by adding an aqueous hydrochloric acid solution, the target product was extracted with diethyl ether. The ether solution was concentrated to obtain 26 mmol of white crystals of 18-(4-ethynyl phenyl)-17-octadecinoic acid [Formula]. Thus obtained 18-(4-ethynyl phenyl)-17
-Octadecinoic acid was dissolved in chloroform to prepare a solution with a concentration of 2mM. Also, dissolve CdCl ₂ in double-distilled water,
Add _KHCO3 , Cd2 ⁺ ion concentration 2mM, PH6.3
An aqueous solution was prepared. The above Cd ²⁺ aqueous solution was poured into a Langmieur trough (film balance) manufactured by LAUDA, and 0.1 ml of a 2 mM aqueous carboxylic acid chloroform aqueous solution was dropped onto the water surface. The barrier was moved to compress the monolayer, and the surface area and surface pressure were measured. FIG. 1 shows a surface pressure-area curve (π-A curve) measured with the horizontal axis representing the occupied area per single molecule and the vertical axis representing the surface pressure. The measurement temperature was 19°C. As can be seen from the π-A curve, the surface pressure curve rises sharply when the occupied area per monomolecule is around 25 A ² , indicating that a high-quality monomolecular film is formed. The surface pressure of the monomolecular film was maintained at a constant pressure of 25 dyn/cm, and a sufficiently clean SiO ₂ -coated silicon wafer was immersed perpendicularly into the water surface and then raised again to the water surface. This operation was repeated to produce a 59-layer cumulative film. The cumulative ratio was 0.995. Cover this LB film with a photoresist mask,
After exposure for 1 minute with a 100W low-pressure mercury lamp, rinsing with ethanol for 1 minute resulted in a negative patterned polymer thin film. Example 2 A similar reaction was carried out in Example 1 using ω-undecylenyl alcohol instead of ω-heptadecenyl alcohol, and first, 1-(12-tridecen-1-ynyl)-4-trimethylsilylethynyl ) - benzene Obtained 46 mmol. This compound was used in Example 1 as 1-(18-nonadecen-1-ynyl)-4-
A similar reaction was carried out using (trimethylsilylethynyl)-benzene instead of 1-ethynyl-4-
34 mmol of (12-tridecen-1-ynyl)-benzene [formula] was obtained. This compound was used in place of 1-ethynyl-4-(18-nonadecen-1-ynyl)-benzene in Example 1 to perform ozone oxidation, and 12-(4-ethynylphenyl)-11- 30 mmol of decinoic acid [formula] was obtained. A 2mM chloroform solution of the carboxylic acid thus obtained was mixed with a 2mM CdCl ₂ aqueous solution (PH
6.3) was dropped onto the water surface and the π-A curve was measured. FIG. 2 shows the π-A curve. A 13-layer cumulative film was produced on a SiO ₂ -coated silicon wafer in the same manner as in Example 1. Water temperature during measurement and accumulation was 19℃
It was hot. Cover this LB film with a photoresist mask,
After exposure for 1 minute with a 100W low-pressure mercury lamp, the film was developed with ethanol for 1 minute to obtain a negative patterned polymer thin film. Example 3 1-(18-nonadecen-1-ynyl)-4-(trimethylsilylethynyl)benzene obtained in Example 1 40 mmol was dissolved in 300 ml of ethyl acetate, and after cooling to -10°C, an equimolar amount of ozone was blown into the solution. After removing the refrigerant and evaporating the solvent by blowing argon gas, the residue was dissolved in 60 ml of acetone, and the reaction vessel was immersed in an ice bath. John's reagent was added to this solution until the brown color was maintained, and the mixture was stirred and reacted at 25° C. for 15 minutes. 350 ml of ice water was added to the reaction solution, organic matter was extracted with diethyl ether, the ether phase was shaken with an aqueous sodium hydroxide solution, and the aqueous phase was separated. After making the aqueous phase acidic by adding an aqueous hydrochloric acid solution, the product was extracted with diethyl ether. This ether solution was concentrated and 18-(4-
Trimethylsilylethynylphenyl)-17-octadecinoic acid 34 mmol of white crystals were obtained. Using the carboxylic acid compound thus obtained,
In the same manner as in Example 1, a 13-layer cumulative film was produced on a SiO ₂ -coated silicon wafer. Cover this LB film with a photoresist mask,
After exposure for 1 minute with a 100W low-pressure mercury lamp, the film was developed with ethanol for 1 minute to obtain a negative patterned polymer thin film. Example 4 The same reaction as in Example 1 was carried out using chlorotriethylsilane instead of trimethylsilyl chloride to obtain bis-(triethylsilylethynyl)-benzene. A similar reaction was carried out in Example 1 using this compound in place of bis-(trimethylsilylethynyl)-benzene, and 1-
White crystals of (18-nonadecen-1-ynyl)-4-(triethylsilylethynyl)-benzene were obtained.
A similar reaction was carried out in Example 1 using this compound in place of 1-(18-nonadecen-1-ynyl)-4-(trimethylsilylethynyl)-benzene, resulting in 18-(4-triethylsilylethynylphenyl). 32 mmol of white crystals of -17-octadecinoic acid was obtained. Using _the thus obtained carboxylic acid, 13
A cumulative film of layers was fabricated. Cover this LB film with a photoresist mask,
After exposure for 1 minute with a 100W low-pressure mercury lamp, the film was developed with ethanol for 1 minute to obtain a negative patterned polymer thin film. Example 5 The same reaction as in Example 1 was carried out using chlorotriheptylsilane instead of trimethylsilyl chloride to obtain bis-(triheptylsilylethynyl)-benzene. A similar reaction was carried out in Example 1 using this compound in place of bis-(trimethylsilylethynyl)-benzene, and 1-(18-nonadecen-1-(ynyl)-4-
White crystals of (triheptylsilylethynyl)-benzene were obtained. In Example 1, this compound was
A similar reaction was carried out using 1-(18-nonadecen-1-ynyl)-4-(trimethylsilylethynyl)-benzene instead of 1-(18-nonadecen-1-ynyl)-4-(trimethylsilylethynyl)-benzene, and the white color of 18-(4-ethynyl phenyl)-17-octadecinoic acid was obtained. 28 mmol of crystals were obtained. Using the thus obtained carboxylic acid, 59 _%
A cumulative film of layers was fabricated. Cover this LB film with a photoresist mask,
After exposure for 1 minute with a 100W low-pressure mercury lamp, the film was developed with ethanol for 1 minute to obtain a negative patterned polymer thin film. Example 6 First, ω-tricosenoic acid CH ₂ =CH
-( _CH2 ) ₂₀ -COOH was reduced with lithium aluminum hydride to give the ω-tricosenyl alcohol _CH2 =CH-( _CH2 ) ₂₁ -OH. In Example 1, this ω-tricosenyl alcohol was
- Carry out a similar reaction using heptadecenyl alcohol instead. First, 1-(24-pentacocene-
1-ynyl)-4-(trimethylsilylethynyl)
−Benzene Obtained 40 mmol. This compound was used in Example 1 as 1-(18-nonadecen-1-ynyl)-4-
A similar reaction was carried out using (trimethylsilylethynyl)-benzene instead of 1-ethynyl-4-
(24-pentacocen-1-ynyl)-benzene Obtained 30 mmol. Similar ozone oxidation was carried out using this compound in place of 1-ethynyl-4-(18-nonadecen-1-ynyl)-benzene in Example 1, and 24-(4-ethynylphenyl)-23-
Tetrachosinoic acid 22 mmol of white crystals were obtained. Using the thus obtained carboxylic acid, 59 _%
A cumulative film of layers was fabricated. Cover this LB film with a photoresist mask,
After exposure for 1 minute with a 100W low-pressure mercury lamp, the film was developed with ethanol for 1 minute to obtain a negative patterned polymer thin film. Example 7 A 25 wt% chloroform solution of 18-(4-ethynyl phenyl)-17-octadecinoic acid was prepared. A silicon wafer was placed in a spin coating device for resist evaluation, and the above chloroform solution was dropped while rotating at 2000 rpm.
A spin coating film of the above carboxylic acid was produced. A transparent thin film with a thickness of 1 μm was obtained. Cover this thin film with a photoresist mask,
After exposure for 1 minute with a 100W low-pressure mercury lamp, the film was developed with ethanol for 1 minute to obtain a negative patterned polymer thin film. Example 8 A 25 wt % chloroform solution of 18-(4-ethynyl phenyl)-17-octadecinoic acid was prepared. A silicon wafer was placed in a spin coating device for resist evaluation, and the above chloroform solution was dropped while rotating at 2000 rpm.
A spin coating film of the above carboxylic acid was produced. A transparent thin film with a thickness of 1 μm was obtained. An accelerating voltage is applied to the thin film using an electron beam drawing device.
After scanning with an electron beam at 20 kV, the film was developed with methyl ethyl ketone for 1 minute to obtain a negative patterned polymer thin film.

[Brief explanation of drawings]

Figure 1 shows Cd ²⁺ ion concentration 2mM, pH 6, temperature 19
FIG. 2 is a surface pressure-area curve of a monomolecular film of 18-(4-ethynyl phenyl)-17-octadecinoic acid measured on a water surface at .degree. C.; FIG. Figure 2 shows measurements taken on the surface of water at a Cd ²⁺ ion concentration of 2mM, pH 6, and temperature of 19℃.
1 is a surface pressure-area curve of a 12-(4-ethynyl phenyl)-11-dodecinoic acid monolayer.

Claims (1)

[Claims] 1 General formula (*) [R in the formula is hydrogen or -SiX ₁ X ₂ X ₃ , X ₁ ,
X ₂ and X ₃ are each independently hydrogen or have a carbon number of 1 to
7 alkyl group (excluding cases where X ₁ , X ₂ , _and A method for producing a thin polymer film, characterized in that it is obtained by polymerization. 2 General formula (*) [R in the formula is hydrogen or -SiX ₁ X ₂ X ₃ , X ₁ , X ₂ ,
Each of X ₃ is independently hydrogen or an alkyl group having 1 to 7 carbon atoms (excluding cases where X ₁ , X ₂ , and X ₃ are all hydrogen), and n is an integer of 9 to 21.] 1. A method for producing a thin polymer film, which is obtained by accumulating a diethynylbenzene derivative represented by the formula above on a substrate by Langmuir-Blodget method and polymerizing it by irradiating energy.