JP2004031801A - Organic transistor, organic electronic device and method of manufacturing the same - Google Patents

Abstract

An organic electronic transistor including an insulating film having excellent insulating properties, an organic semiconductor film in which crystal growth of organic molecules is promoted, and a method for manufacturing the organic electronic transistor.
An organic transistor includes a gate electrode formed on a substrate, a gate insulating film formed on the gate electrode, and a first organic material formed on the gate insulating film and containing a highly wettable organic material. Organic film 4, second organic film 5 formed on first organic film 4, including organic material comprising a plurality of organic molecules having a hydrophobic group, organic semiconductor material formed on second organic film 5 And a source electrode 7 and a drain electrode 8 formed on the organic semiconductor film 6.
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an organic electronic device having an insulating film and an organic semiconductor film, and a method for manufacturing the organic electronic device.
[0002]
[Prior art]
In recent years, organic transistors have been attracting attention as driving elements for various electronic devices. An organic transistor uses an organic material for a semiconductor film. For this reason, compared to inorganic transistors that often use a vacuum device, they can be manufactured at a low temperature by using a printing method or the like in which a uniform film can be easily manufactured, and the area can be easily increased. . Further, since an organic material capable of forming a semiconductor layer film at a low temperature is used, a soft plastic substrate can be used, and a flexible element can be manufactured.
[0003]
A general organic transistor has a configuration of a substrate, a gate electrode, a gate insulating film, source / drain electrodes, and an organic semiconductor film. In an organic transistor, by changing the voltage (gate voltage) applied to the gate electrode, the amount of charge at the interface between the gate insulating film and the organic semiconductor is controlled, and the current value between the source electrode and the drain electrode is changed to perform switching. Perform
[0004]
[Problems to be solved by the invention]
Here, the characteristics of the organic transistor largely depend on the insulating property of the gate insulating film and the orientation of the organic semiconductor film. In the case of using plastic as the material of the substrate, all the manufacturing steps need to be performed at a low temperature, and the temperature for forming the gate insulating film also needs to be low. However, when the gate insulating film is formed at a low temperature, pinholes and irregularities (porous) may be generated in the gate insulating film. As described above, if the gate insulating film has pinholes or irregularities, the insulating property of the gate insulating film is reduced, and there is a concern that a gate leakage current may occur.
[0005]
On the other hand, YY. Lin, D .; J. Gundlach, S .; F. Nelson, and T.W. N. Jackson, IEEE Electron Devices Letters vol. 8 No. 12 p. P. 606-P. P. According to 608 (1997), by forming a hydrophobic material on the surface of the gate insulating film, the surface energy of the surface on which the organic semiconductor film is formed is reduced, crystal grains of the organic semiconductor are grown, and high carriers are formed. It is reported that mobility was obtained.
[0006]
In addition, several reports have been made on a method of forming a gate insulating film and a surface treatment method. M. L. Swiggers, G .; Xia, J .; D. Slinker, A .; A. Gorodetsky, and G.W. G. FIG. Mallieras, Applied Physics Letters, vol. 79, No. 9P. P. In 1300-130 (2001), a thin film of polyvinyl alcohol (PVA) was formed on the surface of a gate insulating film SiO ₂ , and it was found that 0.02 cm / Vs was obtained as a carrier mobility of pentacene which is a material of an organic semiconductor. Reporting.
[0007]
However, in this method, since PVA is a material having high wettability, it is suitable for flattening a gate insulating film that fills pinholes and irregularities of the gate insulating film. When a film is formed, growth of crystal grains is not promoted, and high mobility cannot be expected.
[0008]
Japanese Patent Application Laid-Open No. 13-94107 discloses a method of forming a thin fluoropolymer layer on a gate insulating film. However, in this method, the growth of the crystal grains of the organic semiconductor is promoted by utilizing the hydrophobic group disposed on the surface of the fluoropolymer layer. Fine irregularities and pinholes cannot be sufficiently filled, and the insulating property of the gate insulating film cannot be improved.
[0009]
The present invention has been made in view of the above problems, and provides an organic electronic device including an insulating film having excellent insulating properties, an organic semiconductor film in which crystal growth of organic molecules is promoted, and a method for manufacturing the organic electronic device. The purpose is to do.
[0010]
[Means for Solving the Problems]
The invention according to claim 1 is an organic electronic device, wherein at least two electrodes, at least one insulating film formed on at least one electrode, and wettability formed on at least one insulating film are formed on the substrate. At least one first organic film including a high organic material, at least one second organic film including an organic material having a hydrophobic group formed on the at least one first organic film, and the at least one first organic film. It has at least one organic semiconductor film including an organic semiconductor material formed on the two organic films.
[0011]
According to the invention described in claim 1, at least two electrodes, at least one insulating film formed on at least one of the electrodes, and a highly wettable organic material formed on at least one of the insulating films on the substrate At least one first organic film including at least one second organic film including an organic material having a hydrophobic group formed on the at least one first organic film, and the at least one second organic film Since at least one organic semiconductor film containing an organic semiconductor material is formed on the film, an organic electronic device having an insulating film with excellent insulating properties and an organic semiconductor film in which crystal growth of organic molecules is promoted is provided. can do.
[0012]
According to a second aspect of the present invention, there is provided an organic transistor comprising a gate electrode formed on a substrate, a gate insulating film formed on the gate electrode, and an organic material having high wettability formed on the gate insulating film. An organic film formed on the first organic film, a second organic film containing an organic material comprising a plurality of organic molecules having a hydrophobic group, and an organic semiconductor material formed on the second organic film. And a source electrode and a drain electrode formed in the organic semiconductor film.
[0013]
According to the invention described in claim 2, a gate electrode formed on the substrate, a gate insulating film formed on the gate electrode, and a first organic material formed on the gate insulating film and containing an organic material having high wettability. A film, a second organic film formed on the first organic film, including an organic material comprising a plurality of organic molecules having a hydrophobic group, an organic film formed on the second organic film, including an organic semiconductor material Since there is a semiconductor film and a source electrode and a drain electrode formed in the organic semiconductor film, an organic transistor having an insulating film with excellent insulating properties and an organic semiconductor film in which crystal growth of organic molecules is promoted is provided. be able to.
[0014]
The invention according to claim 3 is the organic transistor according to claim 2, wherein the hydrophobic groups of the plurality of organic molecules are oriented in a certain direction.
[0015]
According to the third aspect of the present invention, since the hydrophobic groups of the plurality of organic molecules are oriented in a certain direction, an insulating film having excellent insulating properties and an organic semiconductor in which crystal growth of the organic molecules is promoted. An organic transistor having a film and an organic semiconductor film in which the orientation of organic molecules is arbitrarily controlled can be provided.
[0016]
According to a fourth aspect of the present invention, in the organic transistor according to the second or third aspect, the gate insulating film includes one or more layers, and the material of the one or more layers is an oxide, a nitride, or an oxide. It is characterized by being independently selected from the group consisting of nitride, hooker, and diamond-like carbon.
[0017]
According to the invention described in claim 4, the gate insulating film includes one or more layers, and the material of the one or more layers is an oxide, a nitride, an oxynitride, a hooker, and a diamond-like material. Since it is independently selected from the group consisting of carbon, it has an insulating film with excellent insulating properties, and an organic semiconductor film in which crystal growth of organic molecules is promoted, and a gate insulating film that can be formed by various methods. The organic transistor can be provided.
[0018]
According to a fifth aspect of the present invention, in the method for manufacturing an organic electronic device, a step of forming a first electrode on a substrate, a step of forming an insulating film on the first electrode, and a step of forming the insulating film with high wettability. Forming a first organic film containing an organic material, forming a second organic film containing an organic material having a hydrophobic group on the first organic film, forming an organic semiconductor on the second organic film; A step of forming an organic semiconductor film containing a material; and a step of forming a second electrode on the organic semiconductor film.
[0019]
According to the invention as set forth in claim 5, a step of forming a first electrode on the substrate, a step of forming an insulating film on the first electrode, and a step of forming the first insulating film containing an organic material having high wettability. Forming an organic film, forming a second organic film containing an organic material having a hydrophobic group on the first organic film, and forming an organic semiconductor film containing an organic semiconductor material on the second organic film. Forming a second electrode on the organic semiconductor film, so that an organic film having an insulating film with excellent insulating properties and an organic semiconductor film in which crystal growth of organic molecules is promoted. A method for manufacturing an electronic device can be provided.
[0020]
According to a sixth aspect of the present invention, in the method for manufacturing an organic electronic device according to the fifth aspect, the hydrophobic group of a plurality of organic molecules constituting the organic material having the hydrophobic group is obtained by rubbing the second organic film. Further comprising a step of orienting the particles in a certain direction.
[0021]
According to the invention described in claim 6, the method further includes a step of rubbing the second organic film to orient the hydrophobic groups of a plurality of organic molecules constituting the organic material having the hydrophobic group in a certain direction. A method for manufacturing an organic electronic device, comprising: an insulating film having excellent insulating properties; and an organic semiconductor film in which crystal growth of organic molecules is promoted, and an organic semiconductor film in which the orientation of organic molecules is arbitrarily controlled. can do.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0023]
The organic electronic device of the present invention is, for example, an organic transistor. Hereinafter, the organic electronic device of the present invention will be described as an organic transistor.
[0024]
The present invention relates to an organic transistor including a substrate, a gate electrode, a gate insulating film, a source electrode, a drain electrode, and an organic semiconductor film, including a first organic thin film and a second organic thin film. Here, the first organic thin film is formed on the surface of the gate insulating film, and the second organic thin film is formed on the surface of the first organic thin film. These first and second organic thin films are formed by sequentially applying an organic material corresponding to these two organic thin films to the surface of the gate insulating film, and the gate insulating film and the first and second organic thin films are formed. It becomes a (laminated) insulating film including a thin film.
[0025]
On the substrate, the gate electrode, the source electrode, and the drain electrode can be formed using a known metal material and method. As a material of the organic semiconductor film, pentacene or the like of an organic molecule can be used, and the organic semiconductor film may be formed by a printing method.
[0026]
The gate insulating film is made of an oxide such as SiO ₂ , Ta ₂ O ₅ , Al ₂ O ₃ , ZrO ₂ , La ₂ O ₃ , TiO ₂ , Y ₂ O ₃ , CeO ₂ , a nitride such as Si ₂ N ₃ , oxynitrides such as SiO _x N _y, composed of one or more layers comprising an inorganic material such as fluoride such CaF, and diamond-like carbon (DLC). When the gate insulating film is composed of a plurality of layers, the material of each layer is independently selected from the above inorganic materials.
[0027]
In the case where the gate insulating film is made of a metal oxide of the gate electrode, the oxide gate insulating film can be formed by oxidizing the surface of the gate electrode by an anodic oxidation method. In the case where plastic is used as the material of the substrate of the organic transistor, the gate insulating film can be formed at a low temperature by using an anodic oxidation method. However, as long as a gate insulating film can be formed over a plastic substrate at a low temperature, a sputtering method, a vacuum evaporation method, an ion beam sputtering method, a CVD method, or the like may be used instead of the anodic oxidation method.
[0028]
When the gate insulating film is made of a material other than oxide, the gate insulating film can be formed on a plastic substrate at a low temperature by using a sputtering method such as a magnetron sputtering method, a vacuum evaporation method, an ion beam sputtering method, a CVD method, or the like. it can.
[0029]
The first organic material is an organic material having high wettability. Here, an organic material having high wettability means an organic material having a contact angle of less than 90 degrees with the surface of the gate insulating film. _{Specifically,} CH ₂ CHOCOCH _3, compounds such as _{CH 3 CHO, (- CH 2} CHOH-) n, (- CH 2 CHCl-) n, (- CH 2 CHOCOCH 3 -) n polymer compound such as, In addition, a high molecular compound having —CH ₂ CHCl— or —CH ₂ CCl ₂ — as a repeating unit can be given. These highly wettable organic materials are dissolved in a solvent such as methanol, acetone, toluene, or an ester such as ethyl acetate, and are uniformly applied to the surface of the gate insulating film using a dip method, a spin coat method, or the like. One organic thin film is formed.
[0030]
Here, when the gate insulating film is formed at a low temperature as described above, pinholes and unevenness may be formed on the surface of the gate insulating film. Such pinholes and irregularities cause a decrease in the insulating property of the gate insulating film.
[0031]
Since such a first organic material has high wettability, the first organic material can fill pinholes and irregularities formed on the surface of the gate insulating film, and can make the insulating film dense and flat. Therefore, the insulating property of the gate insulating film can be maintained by applying the first organic material to the gate insulating film.
[0032]
The second organic material is an organic material having hydrophobicity. Specifically, C ₈ F ₁₇ SO ₂ N (C ₂ H ₅ ) (CH ₂ ) ₂ OH, C ₈ F ₁₇ SO ₂ N (C ₂ H ₅ ) SO ₄ Na, H (CF ₂ ) ₈ PO ( A fluorine-based surfactant represented by a molecular formula such as OH) ₂ , CF ₃ (CF ₂ ) ₆ (CH ₂ ) ₅ COONa, and a silicone-based surfactant represented by Si [O (CH ₂ ) _n OR] ₄ And organic materials having high hydrophobicity. _Also, C _{n F 2n + 1} - and _{H (CF 2) n CH 2} - surfactant having a fluorocarbon hydrophobic group such _{as, CH 3 [Si (CH 3} ) 2 O] as _n C 3 _{H 7} Alternatively, a surfactant having a silicone-based hydrophobic group may be used. In addition, a composition combining the above surfactants may be used. These hydrophobic organic materials are uniformly applied to the surface of the first organic thin film using a dip method, a spin coating method, or the like to form a second organic thin film.
[0033]
By forming the hydrophobic second organic thin film in this manner, the surface energy of the surface on which the organic semiconductor film is formed can be reduced, and the growth of crystal grains of the organic semiconductor film can be promoted. That is, by regularly arranging the organic molecules constituting the organic semiconductor film, the carrier mobility of the organic semiconductor film can be improved.
[0034]
In addition, the surface of the second organic thin film may be rubbed using a rubbing device to orient the hydrophobic groups of the molecules constituting the second organic thin film in a certain direction. As described above, by rubbing the surface of the second organic thin film, the orientation of the organic molecules constituting the organic semiconductor film to be laminated on the second organic thin film can be arbitrarily controlled by controlling the orientation of the hydrophobic group. can do.
[0035]
Therefore, according to the present invention, an organic material having high wettability and an organic material having a hydrophobic group are sequentially applied to the surface of the gate insulating film formed at a low temperature, and the first insulating film and the second organic thin film are formed. By forming the (laminated) insulating film, the film quality of the gate insulating film can be densified and the surface energy of the second organic thin film can be reduced. Accordingly, an organic transistor having a semiconductor film with high insulating property of the (laminated) insulating film and high carrier mobility can be manufactured. Therefore, when the (laminated) insulating film of the present invention is applied to a flexible organic transistor using a plastic substrate, an organic transistor having excellent responsiveness and being driven efficiently can be manufactured.
[0036]
[Example 1]
Next, a first embodiment of the organic transistor according to the present invention will be described with reference to FIG.
1A to 1D are cross-sectional views of an organic transistor schematically illustrating a method for manufacturing an organic transistor according to a first embodiment of the present invention.
[0037]
As shown in FIG. 1A, in the organic transistor according to the present embodiment, a gate electrode 2 made of a gate metal (tantalum: Ta) was first formed on a surface of a plastic substrate 1 made of polycarbonate. Next, the surface of the gate electrode 2 was anodized to form a gate insulating film 3 made of a gate metal oxide (tantalum pentoxide: Ta ₂ O ₅ ) on the surface of the gate electrode 2.
[0038]
Next, as shown in FIG. 1B, a first organic material is uniformly applied on the surface of the gate insulating film 3 by using a spin coating method or the like on the gate insulating film 3, Was formed. The thickness of the first organic thin film 4 is 10 nm or less. The first organic material is applied to the gate insulating film 3, polyvinyl acetate _(-CH 2 CHOCOCH _{3 -)} was used _n. Since this organic material has high wettability to the substrate and exhibits hydrophilicity, it was possible to fill pinholes and irregularities on the surface of the underlying gate insulating film 3 and make it dense. After applying the first organic material to the gate insulating film 3, the substrate was baked at a temperature of 120 ° C. or less to form a first organic thin film 4. The time required for baking was 1-2 hours.
[0039]
Next, as shown in FIG. 1C, a second organic material was uniformly applied on the surface of the first organic thin film 4 by a spin coating method to form a second organic thin film 5. As the second organic material applied to the first organic thin film 4, a fluorine-based surfactant was used.
[0040]
Next, as shown in FIG. 1D, pentacene which is an organic molecule was applied on the surface of the second organic thin film 5 by a printing method to form an organic semiconductor film 6. Here, since a highly hydrophobic fluorine-based surfactant was used as the second organic material, the growth of crystal grains of the organic semiconductor film 6 made of pentacene could be promoted. Further, on the surface of the organic semiconductor film 6, two conductive strips were provided as a source electrode 7 and a drain electrode 8 made of gold and spaced apart in the horizontal direction.
[0041]
As described above, by sequentially laminating the first organic thin film 4 having high wettability and the second organic thin film 5 having high hydrophobicity on the gate insulating film 3, the film quality of the gate insulating film is increased, and The growth of the crystal grains of the organic semiconductor film 6 can be promoted.
[0042]
[Example 2]
Next, a second embodiment of the organic transistor according to the present invention will be described with reference to FIG.
2A to 2D are cross-sectional views of an organic transistor schematically illustrating a method for manufacturing an organic transistor according to a second embodiment of the present invention.
[0043]
As shown in FIG. 2A, in the organic transistor of this example, first, a gate electrode 12 made of a gate metal (tantalum: Ta) was formed on a surface of a plastic substrate 11 made of polycarbonate. Next, by anodizing the surface of the gate electrode 12, a gate insulating film 13 made of a gate metal oxide (tantalum pentoxide: Ta ₂ O ₅ ) was formed on the surface of the gate electrode 2.
[0044]
Next, as shown in FIG. 2B, a first organic material is uniformly applied on the surface of the gate insulating film 13 by using a spin coating method or the like on the gate insulating film 13, Was formed. The first organic material is applied to the gate insulating film 3, polyvinyl acetate _(-CH 2 CHOCOCH _{3 -)} was used _n. Since this organic material has high wettability to the substrate and exhibits hydrophilicity, it was possible to fill pinholes and irregularities on the surface of the underlying gate insulating film 3 and make it dense. After applying the first organic material to the gate insulating film 13, the substrate was baked at a temperature of 120 ° C. or lower for 1 to 2 hours to form a first organic thin film 14.
[0045]
Next, as shown in FIG. 2C, a second organic material was uniformly applied on the surface of the first organic thin film 14 by a spin coating method to form a second organic thin film 15. As the second organic material applied to the first organic thin film 14, a fluorine-based surfactant was used. Here, the surface of the second organic thin film 15 was rubbed using a rubbing device. Thereby, the hydrophobic group of the fluorine surfactant constituting the second organic thin film 15 could be oriented in a certain direction with respect to the substrate.
[0046]
Next, as shown in FIG. 2D, pentacene, which is an organic molecule, was applied on the surface of the second organic thin film 15 by a printing method to form an organic semiconductor film 16. Here, since a highly hydrophobic fluorine-based surfactant was used for the second organic material, the growth of crystal grains of the organic semiconductor film 16 made of pentacene was promoted, and the surface of the second organic thin film 15 was rubbed. As a result, the molecular plane of pentacene could be uniformly oriented perpendicular to the surface of the second organic thin film 15. Further, two conductive strips spaced apart in the horizontal direction were formed on the surface of the organic semiconductor film 6 as a source electrode 17 and a drain electrode 18 made of gold.
[0047]
[Example 3]
Next, a third embodiment of the organic transistor according to the present invention will be described with reference to FIG.
FIG. 3 is a sectional view of an organic transistor according to a third embodiment of the present invention.
[0048]
As in the first and second embodiments, the organic transistor of this embodiment has a gate electrode 22 on the surface of a plastic substrate 21, a gate insulating film 23 on the surface of the gate electrode 22, and a gate electrode 22 on the gate insulating film 23. One organic thin film 24, a second organic thin film 25 on the first organic thin film 24, an organic semiconductor film 26 on the second organic thin film 25, and two conductive strips horizontally spaced on the organic semiconductor film 26. (Source electrode and drain electrode) 27 and 28.
[0049]
In the present embodiment, the material of the gate insulating film 23 is silicon nitride (Si ₂ N ₃ ), and the gate insulating film 23 is formed by a magnetron sputtering method. The temperature of the plastic substrate was 100 ° C. or less, and the thickness of the gate insulating film was 1000 °. Next, the first organic material and the second organic material as described above are sequentially and uniformly applied on the surface of the gate insulating film 23 by using a spin coating method, and the first organic thin film 24 and the second organic thin film are applied. 25 were formed.
[0050]
Further, oxides such as SiO ₂ , Ta ₂ O ₅ , Al ₂ O ₃ , ZrO ₂ , La ₂ O ₃ , TiO ₂ , Y ₂ O ₃ , CeO ₂ , CaF (fluoride film), An organic transistor using SiO _x N _y (oxynitride film) or DLC (diamond-like carbon film) was similarly manufactured. Thus, an organic field effect transistor (FET) having high current ON / OFF characteristics and high carrier mobility was obtained.
[0051]
As described above, the present invention has been described as the embodiments and examples of the present invention. However, the present invention is not limited to these embodiments and examples, and the present invention is not limited thereto. Various modifications, applications, and combinations of the embodiments and examples can be made. For example, the first organic material and / or the second organic material may be appropriately selected from the above-described materials as needed to form a (laminated) insulating film including a plurality of thin films. Further, in the embodiments of the present invention, the present invention has been described as an organic transistor.However, the present invention is not limited to an organic transistor. The present invention can be applied to an organic electronic device in which an organic semiconductor film in which crystal growth is promoted on an insulating film and a method for manufacturing the organic electronic device. Here, the organic electronic device has, on a substrate, at least two electrodes, at least one insulating film formed on at least one electrode, and at least one organic semiconductor film including an organic semiconductor material. Others include organic diodes.
[0052]
【The invention's effect】
According to the present invention, it is possible to provide an organic electronic device having an insulating film having excellent insulating properties, an organic semiconductor film in which crystal growth of organic molecules is promoted, and a method for manufacturing the organic electronic device.
[0053]
[Brief description of the drawings]
FIGS. 1A to 1D are cross-sectional views of an organic transistor schematically illustrating a method for manufacturing an organic transistor according to a first embodiment of the present invention.
FIGS. 2A to 2D are cross-sectional views of an organic transistor schematically illustrating a method for manufacturing an organic transistor according to a second embodiment of the present invention.
FIG. 3 is a sectional view of an organic transistor according to a third embodiment of the present invention.
[Explanation of symbols]
1, 11, 21 Plastic substrate 2, 12, 22 Gate electrode 3, 13, 23 Gate insulating film 4, 14, 24 First organic thin film 5, 15, 25 Second organic thin film 6, 16, 26 Organic semiconductor film 7, 17, 27 Source electrode 8, 18, 28 Drain electrode

Claims (6)

On a substrate, at least two electrodes, at least one insulating film formed on at least one electrode, and at least one first organic film containing a highly wettable organic material formed on at least one insulating film An at least one second organic film including an organic material having a hydrophobic group formed on the at least one first organic film, and an organic semiconductor material formed on the at least one second organic film. An organic electronic device comprising at least one organic semiconductor film. A gate electrode formed on the substrate, a gate insulating film formed on the gate electrode, a first organic film containing an organic material having high wettability formed on the gate insulating film, formed on the first organic film A second organic film including an organic material including a plurality of organic molecules having a hydrophobic group, an organic semiconductor film including an organic semiconductor material formed on the second organic film, and an organic semiconductor film formed on the organic semiconductor film. An organic transistor, comprising: a source electrode and a drain electrode. The organic transistor according to claim 2, wherein the hydrophobic groups of the plurality of organic molecules are oriented in a certain direction. The gate insulating film is composed of one or more layers,
4. The organic transistor according to claim 2, wherein the material of the one or more layers is independently selected from the group consisting of oxide, nitride, oxynitride, hooker, and diamond-like carbon. . Forming a first electrode on the substrate,
Forming an insulating film on the first electrode;
Forming a first organic film including a highly wettable organic material on the insulating film;
Forming a second organic film including an organic material having a hydrophobic group on the first organic film;
Forming an organic semiconductor film containing an organic semiconductor material on the second organic film, and
A method for manufacturing an organic electronic device, comprising a step of forming a second electrode on the organic semiconductor film. The method according to claim 5, further comprising rubbing the second organic film to orient the hydrophobic groups of a plurality of organic molecules constituting the organic material having the hydrophobic groups in a certain direction. Electronic device manufacturing method.

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