JP2762044B2 - Method and apparatus for producing molecular alignment film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of irradiating a solid raw material organic compound with a laser under reduced pressure to excite and activate the organic molecules, thereby precipitating the organic molecules on a substrate disposed on the opposite side to form a thin film. The present invention relates to a method and an apparatus for producing a molecular alignment film for controlling an arrangement of organic molecules constituting a thin film in a production process. The alignment film produced by the method of the present invention,
It can be used as a functional material having electrical properties such as pyroelectricity, piezoelectricity, and electrical conductivity, and optical properties such as non-linearity and electro-optics (such as the Pockels effect).

[0002]

2. Description of the Related Art As methods for producing an alignment film, (1) a mechanical stretching method, (2) an electric field application method (polling), and (3)
A rubbing method, (4) an epitaxial method, and (5) an LB method have been proposed. Hereinafter, each method will be briefly described. (1) The mechanical stretching method is that a polymer film is heated to a specific temperature region (secondary transition region) and uniaxially (horizontally or vertically) or biaxially (both horizontally and vertically) at a predetermined speed. This is a method of stretching and controlling the arrangement of constituent molecules, and in particular, it is possible to increase mechanical strength such as pulling and bending (for example, JOURNAL OF POLYMER).
SCIENCE, VOL. 59.413-423 (1
962)). (2) In the electric field application method (poling), electrodes are attached to the top and bottom of a thin film, and after heating the temperature of the thin film near the secondary transition point, a voltage of several tens of MV (megavolt) / m is applied to the thin film.
This is a method of inverting a molecule having a dipole moment (for example, Chemistry and Industry, Vol. 43, No. 9 (1990),
(See pages 99-101). There is also a method in which a corona discharge is generated without attaching an upper electrode, and a similar process is performed. (3) The rubbing method is a method discovered by Maugain in 1911. After the surface of the substrate is made unidirectional with a cloth, paper, or the like, for example, a concentrated solution of polyamino acid (m-cresol 20 wt%) is used. This is a method of performing molecular orientation by dropping on a substrate surface, or sandwiching a similar solution between two glass substrates or the like and shifting one of them to perform molecular orientation (for example, JOURNAL OF POLYM).
ER SCIENCE, VOL. 59.139-153
Pg. (1962)). (4) In the epitaxial method, the molecular arrangement is controlled by the interaction effect between the molecule and the substrate. Mica (10
No. 0) and a report of platinum phthalocyanine on a specific surface of KCl (313). (5) The LB (Langmuir-Blodgett) method is as follows:
It is a wet method, and is an orientation control method in which a monomolecular film of stearic acid or the like developed on the water surface is physically accumulated on the substrate. Structural control at the molecular level is possible. Japanese Patent Laid-Open No. 4-178434 discloses a method for producing an organic thin film utilizing magnetic force.
As described in Japanese Patent Application Laid-Open Publication No. H10-209, a raw material is vaporized and then irradiated with a photon beam.

[0003]

The above prior art has the following problems. (1) In the mechanical stretching method, it is difficult to treat a thin film deposited on a substrate, and the shape of the film is limited. (2) In the electric field application method, any of thin films or films deposited on a substrate can be treated, but since the applied voltage is as high as several tens of MV, it is difficult to treat with an organic substance having low withstand voltage. It is. In addition, the direction of the applied voltage is also limited to the direction perpendicular to the thin film surface, thereby limiting the orientation control direction. (3) In the rubbing process and the epitaxial method, the selection of the substrate is limited to a specific substrate. (4) The LB method is limited to compounds that develop on the water surface.

[0004] The present invention has been made in view of the above points, and an object of the present invention is to provide laser ablation (flying).
It is another object of the present invention to provide a method and an apparatus for producing a molecular orientation film which controls the arrangement of organic molecules constituting a thin film by applying a magnetic force together with the production of an organic thin film by the method described above.

[0005]

In order to achieve the above object, a method for producing a molecular alignment film according to the present invention is shown in FIG.
And as shown in FIG. 2, the reaction chamber 14, vinylene
Group, carbonyl group, methylene group, cyano group and benzene
A raw material organic compound 16 having at least one of a ring and a magnetic field is applied to the reaction chamber 14 to create a magnetic field space.
After the inside is evacuated to a reduced pressure state, a laser is irradiated to the raw material organic compound 16 to excite and activate the organic molecules, to eject the organic molecules, and to apply the magnetic force in the reaction chamber 14.
Within the substrate 20 disposed facing the raw material organic compound 16 in a space is, together with the precipitate the excited organic molecules to produce a thin film, anti array of organic molecules constituting the film
It is configured to be controlled by a magnetic force applied in the reaction chamber 14 . In this case, the inside of the reaction chamber 14 is 1
0 ^-3 to 10 ^-8 Torr, preferably 10 ^-5 to 10 Torr
It is sufficient to evacuate to a reduced pressure of ^-7 Torr. 26
Is a molecular alignment film.

In carrying out the above-mentioned method, as shown in FIG. 2, a solid raw material organic compound 16 is disposed in a reaction chamber 14 and a substrate 20 on which a thin film is to be deposited is taken into consideration in consideration of the direction of application of a magnetic force. , Set the angle. Thereafter, the inside of the reaction chamber 14 is evacuated and reduced to a predetermined pressure to control the temperature of the substrate surface. Then, a laser is irradiated to the raw material organic compound to excite and activate molecules to form a thin film. At this time, since a magnetic force is applied to the substrate 20 in a predetermined direction, molecules constituting the thin film are oriented by the magnetic force.

In the above method, it is preferable to control the direction in which the magnetic force is applied by changing the angle of the substrate 20. Further, the focusing mirror 44 on the side of the laser inlet 12 of the reaction chamber 14 is moved to change the laser irradiation position on the raw organic compound 16, so that the flight direction of the organic molecules generated by the laser excitation from the raw organic compound 16 is changed. It is preferable to control. Further, it is preferable to rotate the raw material organic compound 16 to change the laser irradiation position on the raw material organic compound 16 and control the flight direction of organic molecules generated by laser excitation from the raw material organic compound 16. With this, the size of the substrate diameter (about 50 mm square)
Even if the value changes, a uniform thin film can be produced.

The laser can have any wavelength from the ultraviolet region to the infrared region, that is, from 0.19 to 11 μm, and preferably from 1 to 4 μm, and can employ either continuous oscillation or pulse oscillation. As a raw material organic compound, a polymerizable compound is an acrylic acid derivative such as 1-4 phenylenebis {4- [6 (acryloyloxy) hexyloxy] benzoate} as shown in Chemical formula 1, and a non-polymerizable compound is Chemical formula 2 As examples, paracyanophenylmethoxybenzoate and the like are shown as examples, but a wide range of compounds such as introduction of a substituent on a benzene ring or substitution of a hydrogen molecule with a halogen molecule can be used.

[0009]

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[0010]

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The laser intensity at the time of laser irradiation is 0.1
~ 500mJ / cm ² · pulse, desirably 5-300mJ /
cm ² · pulse. The substrate temperature is 30 to 500C, preferably 100 to 300C. As the thin film deposition substrate, any of an organic material, an inorganic material, and a metal material may be used. The magnetic strength is 0.01 to 40T, preferably 1 to
20T. Magnetic force can be applied from 0 degree (horizontal) to 90 degrees.
Any of them is possible within the range of degrees (vertical). Furthermore, in the process of forming the thin film on the substrate, the substrate is irradiated with an ultraviolet laser, for example, a laser intensity of 0.1 to 10 mJ / cm ² · pulse, preferably 1 to 5 mJ / cm ² · pulse to form the thin film. It is also possible to promote the reaction / orientation of the molecules.

As shown in FIGS. 1 and 2, the apparatus for producing a molecular alignment film according to the present invention includes a reaction chamber 14 connected to a vacuum exhaust system 10 and having a laser inlet 12 at one end.
Disposed adjacent to the reaction chamber 14, reaction Ji
A magnetic force is applied to the chamber to remove the organic molecules that make up the thin film.
A magnetic force generator 15 for controlling the arrangement, and a vinyl group, a carbonyl group,
At least one of a methylene group, a cyano group and a benzene ring
A target holder 18 for mounting a solid raw material organic compound 16 having the same, a film-forming substrate 20 arranged in the reaction chamber 14 and arranged via a space facing the target holder 18; It comprises a substrate holder 22 for mounting the substrate 20 and a laser oscillator 24 for irradiating the raw organic compound 16 mounted on the target holder 18 with a laser. 40 and 42 are reflection mirrors.

In the above device, the magnetic force generator is preferably a horizontal magnetic force generator. Further, it is preferable that the cooling means 48 be connected to the target holder 18, the heating means 46 be connected to the substrate holder 22, and the controller 50 be connected to the cooling means 48 and the heating means. Further, a condenser mirror 44 is disposed between the laser oscillator 24 and the reaction chamber 14, and the condenser mirror 44 is used as a raw material compound.
The laser irradiation position on the object is changed,
Control the flight direction of organic molecules generated by laser excitation
It is preferable to be configured to be able to move back and forth and left and right so that it can be controlled . The substrate holder 22 is a substrate
By changing the angle and configured to be swingable and / or rotated to be able to control the magnetic force application direction, further, the target holder 18, the laser irradiation to the raw material organic compound
By changing the irradiation position, from raw material organic compound to laser excitation
It is preferable to be configured to be swingable and / or rotatable so that the flying direction of the generated organic molecules can be controlled . These configurations are appropriately combined. The substrate holder 22 rotates (oscillates) about the shaft 54 in the same plane direction as the paper surface of FIG.
Are configured to rotate in the direction perpendicular to the plane of FIG. Similarly, the target holder 18 also rotates (swings) about the shaft 56 in the same plane direction as the paper of FIG. 2 or / and rotates the target holder 18 in the direction perpendicular to the paper of FIG. It is configured to By doing so, the direction of the magnetic force on the substrate 20 can be arbitrarily changed. 52 is a thermocouple.

[0014]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples, and can be implemented with appropriate modifications. Example 1 In the apparatus shown in FIGS. 1 and 2, a molecular alignment film was formed by infrared laser ablation under application of a magnetic force. That is, a solid raw material organic compound 1-4phenylenebis {4- [6 (acryloyloxy) hexyloxy] is used as a target in a reaction chamber which is a film forming chamber.
Benzoate II and a substrate (made of calcium fluoride) were attached, and the inside of the film forming apparatus chamber was evacuated to 10 ^-6 Torr by a vacuum evacuation system. Thereafter, the film was irradiated with an infrared laser for 30 minutes under the conditions described below to produce a thin film. The application of the magnetic force was performed in the process of raising and maintaining the substrate temperature from room temperature to 140 ° C. and then lowering the temperature again to room temperature. Laser wavelength: 1.064 μm (Nd: YA
G laser, Q switch pulse) Laser intensity: 100 mJ / cm ² · pulse Laser repetition frequency: 10 Hz Distance between raw compound and substrate: 25 mm (distance D in FIG. 2) Substrate temperature: 140 ° C., raw compound temperature:
30 ° C. Magnetic strength: 15 T, direction of magnetic force applied to the substrate: 45 degrees

FIG. 3 shows the infrared spectrum of the raw material according to the KBr tablet method, and FIG. 4 shows the infrared spectrum (transmission method) of the obtained thin film. As the characteristic peaks of the raw material compound, the overtone of the out-of-plane bending vibration of unterminated vinyl (CH ₂ ＣＨCH—) is around 1900 cm ⁻¹ , and the stretching vibration of CＣC is 1640 cm ^−1.
At around ⁻¹ , the out-of-plane bending vibration of CH ₂ of the vinyl group (CH ₂ ＣＨCH—) is at around 1420 cm ⁻¹ . In addition, 3250cm
The peak at ^-1 is the absorption derived from the hydrate of KBr. On the other hand, in the infrared spectrum of the thin film shown in FIG. 4, the peaks mentioned above decrease, indicating that the polymerization reaction is progressing.

FIG. 5 shows a difference spectrum (a parallel polarization spectrum minus a vertical polarization spectrum) obtained by measuring the thin film by a polarization infrared method. When the arrangement of molecules constituting the thin film is random, that is, when the arrangement is not controlled, there is no peak difference in the difference spectrum, or the methylene group (-CH
₂ - stretching vibration unit (2900 cm around ^-1 between CH of)), carbonyl (-C = O stretching vibration of) (1730 cm around ^-1) plane skeleton vibration of the benzene (1600 cm ^-1, 15
A remarkable difference is observed in each peak at around 00 cm ⁻¹ and 1100 cm ⁻¹ ), indicating that the arrangement of the molecules constituting the thin film was controlled by the magnetic force together with the process of forming the thin film.

[0017]

As described above, the present invention has the following effects. (1) The conventional mechanical stretching method is limited to film processing, and cannot perform processing with a thin film deposited on a substrate.
However, in the method of the present invention, since the molecular orientation is performed together with the production of the thin film, the properties are not limited. (2) Even a substance having low withstand voltage can be subjected to a molecular orientation treatment. (3) It does not depend on the state of the substrate surface on which excited molecules are deposited. (4) Since the preparation of the thin film and the arrangement control of the constituent molecules are performed simultaneously, the process is extremely simple.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of a molecular alignment film manufacturing apparatus of the present invention.

FIG. 2 is a detailed internal view of the reaction chamber in FIG.

FIG. 3 is an infrared spectrum diagram of a raw material measured by a KBr tablet method in Example 1.

FIG. 4 is an infrared spectrum diagram (transmission method) of a thin film obtained in Example 1.

FIG. 5 is a difference spectrum diagram obtained by measuring the thin film obtained in Example 1 by a polarized infrared method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Vacuum exhaust system 12 Laser inlet 14 Reaction chamber (film formation chamber) 15 Magnetic force generator 16 Raw material organic compound (target) 18 Target holder 20 Substrate 22 Substrate holder 24 Laser oscillator 26 Molecular orientation film 40 Reflection mirror 42 Reflection mirror 44 Collection Optical mirror 46 Heating means 48 Cooling means 50 Controller 52 Thermocouple 54 axis 56 axis

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-60-86266 (JP, A) JP-A-1-96365 (JP, A) JP-A-62-235464 (JP, A) JP-A-63-63 255359 (JP, A) JP-A-5-173145 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C23C 14/00-14/58

Claims (10)

(57) [Claims] 1. A reaction system comprising a vinyl group, a carbohydrate
Nyl, methylene, cyano and benzene rings
A solid raw material organic compound having either of the above is placed and a magnetic force is applied to the reaction chamber to create a magnetic space.
After evacuation of the reaction chamber to reduce the pressure, a laser is applied to the raw organic compound to excite and activate the organic molecules, causing the organic molecules to fly out and reacting.
Was on a substrate disposed facing the raw material organic compound in the magnetic force of the bar is applied space, with precipitate the excited organic molecules to produce a thin film, a reaction chamber an array of organic molecules constituting the film A method for producing a molecular alignment film, wherein the method is controlled by a magnetic force applied to the inside . 2. The method according to claim 1, wherein the direction of the applied magnetic force is controlled by changing the angle of the substrate. 3. A converging mirror on a side of a laser inlet of a reaction chamber is moved to change a laser irradiation position on a raw material organic compound and to control a flight direction of organic molecules generated by laser excitation from the raw material organic compound. The method for producing a molecular alignment film according to claim 1. 4. A raw material organic compound is rotated to change a laser irradiation position on the raw material organic compound, and a flight direction of an organic molecule generated by laser excitation from the raw material organic compound is controlled. The method for producing a molecular alignment film according to the above. 5. A reaction chamber (1) connected to an evacuation system (10) and having a laser inlet (12) at one end.
4) and an anti-static device arranged adjacent to the reaction chamber (14).
The organic component forming the thin film by applying magnetic force to the reaction chamber
A magnetic force generator (15) for controlling the arrangement of the elements, and a vinyl group, disposed in the reaction chamber (14) .
Carbonyl, methylene, cyano and benzene rings
A solid raw material organic compound (1) having at least one of
6) Target holder for mounting (18)
And a substrate (20) for film formation arranged in the reaction chamber (14) and facing the target holder (18) via a space, and a substrate holder (20) for mounting the substrate (20). 2
2) and a laser oscillator (24) for irradiating a laser to the raw material organic compound (16) attached to the target holder (18). 6. The apparatus according to claim 5, wherein the magnetic force generator is a horizontal magnetic force generator. 7. A cooling means (48) is connected to the target holder (18), a heating means (46) is connected to the substrate holder (22), and a controller (50) is connected to the cooling means (48) and the heating means. The apparatus for producing a molecular alignment film according to claim 5, wherein the apparatus is connected. 8. A condensing mirror (44) is provided between the laser oscillator (24) and the reaction chamber (14), and the condensing mirror (44) is used to irradiate the raw material organic compound with a laser.
Laser irradiation from raw material organic compound by changing irradiation position
The apparatus for producing a molecular alignment film according to claim 5, 6 or 7, wherein the apparatus can be moved back and forth and left and right so that the flight direction of organic molecules generated by the control can be controlled . 9. A substrate holder (22) for adjusting the angle of the substrate.
Swingable so that the magnetic force application direction can be controlled by changing
The apparatus for producing a molecular alignment film according to claim 5, wherein the apparatus is rotatable. 10. The method according to claim 1, wherein the target holder is a raw material.
By changing the laser irradiation position on organic compounds,
Flight of organic molecules generated by laser excitation from compounds
The apparatus for producing a molecular alignment film according to any one of claims 5 to 9, wherein the apparatus is swingable and / or rotatable so that the direction can be controlled .