JP2009065011A - Fabrication process of organic thin film transistor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To fabricate a high mobility organic thin film transistor in which positional precision of a semiconductor layer is enhanced by preventing impairment of the semiconductor layer caused by the process in a bottom contact type organic thin filter transistor element. <P>SOLUTION: In the fabrication process of an organic thin filter transistor, a water repellent pattern is formed on a source electrode and a drain electrode, organic semiconductor solution is introduced between the source electrode and the drain electrode and then the solvent is removed thus forming an organic semiconductor layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an organic thin film transistor that does not deteriorate a semiconductor layer due to a process and exhibits high carrier mobility with good positional accuracy in forming an organic semiconductor layer.

  As one method for producing an organic thin film transistor, a method for producing an organic thin film transistor is described in which an electrode material is supplied onto an electrode material repellent layer on which a water repellent pattern is formed, and an electrode is formed on a portion other than the water repellent pattern. (For example, patent document 1).

  Since these organic thin film transistors are of the top contact type, the source electrode and the drain electrode are formed after the organic semiconductor layer is formed.

  Therefore, the semiconductor layer may be deteriorated due to the influence of the material and process of the source electrode and the drain electrode, and the mobility of the organic semiconductor layer may be lowered.

On the other hand, in the method for manufacturing the bottom contact type organic thin film transistor, the source electrode and the drain electrode are formed prior to the formation of the organic semiconductor layer, so there is no influence of the electrode material or the process. In the case of forming a semiconductor layer, there is a problem in the positional accuracy and mobility of the organic semiconductor layer.
JP 2004-221573 A

  An object of the present invention is to produce a bottom-contact type organic thin film transistor element that prevents deterioration of the semiconductor layer due to the process, and has a good position accuracy of the semiconductor layer and high mobility.

  The above object of the present invention is achieved by the following means.

  1. A method for producing an organic thin film transistor, comprising forming a water repellent pattern on a source electrode and a drain electrode, then introducing an organic semiconductor solution between the source electrode and the drain electrode, and removing the solvent to form an organic semiconductor layer .

  2. 2. The method for producing an organic thin film transistor according to 1 above, wherein a protective layer is formed on the organic semiconductor layer.

  3. 3. The method for producing an organic thin film transistor according to 2 above, wherein the protective layer is formed by a casting method.

  4). 4. The method for producing an organic thin film transistor according to any one of 1 to 3, wherein the water repellent pattern region is formed by surface treatment with a silane coupling agent or a titanium coupling agent.

  5). 5. The method for producing an organic thin film transistor according to any one of 1 to 4, wherein the water repellent pattern region is made of a siloxane polymer.

  6). 6. The method for producing an organic thin film transistor according to any one of 1 to 5, wherein the source electrode and the drain electrode are formed from a fluid electrode material.

  According to the present invention, after the source electrode and the drain electrode are formed, the organic semiconductor layer can be formed with high positional accuracy, so that an organic thin film transistor having high carrier mobility can be obtained.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The present invention relates to a method of manufacturing an organic thin film transistor, wherein after forming a water repellent pattern on each of a source electrode and a drain electrode, an organic semiconductor solution is introduced between the source electrode and the drain electrode, and the solvent is removed to remove the organic semiconductor layer. It is characterized by forming.

  The manufacturing method of the organic thin-film transistor of this invention is demonstrated using figures below.

  FIG. 1 is a schematic cross-sectional view showing each step of a method of manufacturing an organic thin film transistor for forming a water repellent pattern on a source electrode and a drain electrode. That is, after forming a gate electrode and a gate insulating layer on a support, a source electrode and a drain electrode each having a water-repellent pattern are formed, and an organic semiconductor solution is applied and introduced between the source electrode and the drain electrode. Then, the organic semiconductor layer is formed by removing the solvent.

  FIG. 1 (1) shows a support 1, for example, a metal vapor-deposited layer is first formed on a resin support such as a polyethersulfone resin film (200 μm), and a resist is formed using a photosensitive resin. Then, the gate electrode 2 is formed by etching. Further, after the gate electrode 2 is formed, a schematic cross-sectional view of the substrate on which the silicon oxide layer is provided by the atmospheric pressure plasma method or the like and the gate insulating layer 3 is formed is shown.

  A process for forming a source electrode and a drain electrode on which a water-repellent pattern is formed using this will be described below.

First, the electrode layer 4 is formed on the gate insulating layer 3 of the substrate of FIG.
The electrode layer is uniformly formed on the entire surface of the gate insulating layer, for example, by applying a metal deposition layer, or a fluid electrode material, for example, a gold nanoparticle that is a fluid electrode material containing metal fine particles, or PEDOT / PSS. (FIG. 1 (4)).

  Next, a water repellent layer is formed on the electrode layer 4 as follows.

  The water repellent layer that forms the water repellent pattern is, for example, a silicone rubber layer made of a siloxane polymer.

  In order to form a water repellent pattern with this silicone rubber layer, patterning is performed in combination with the photosensitive resin layer. For example, after forming the photosensitive resin layer 5, a silicone rubber layer 6 is formed on the photosensitive resin layer 5, and patterned by a semiconductor laser or the like, so that the adhesion between the photosensitive layer and the water repellent layer (silicone rubber layer) is increased. Is changed ((4) in FIG. 1), and the silicone rubber layer 6 other than the electrode pattern portion (exposed portion) is removed by brushing together with the photosensitive resin layer 5 (FIG. 1 (5)).

  If the electrode layer is removed in the region where the electrode layer 4 without the silicone rubber layer 6 is exposed by gold etching processing if gold, the electrode layer and the silicone rubber layer 6 remain only in the source electrode and drain electrode regions. .

  Thus, the source electrode 7 and the drain electrode 8 in which the water repellent pattern is formed by the silicone rubber layer 6 are formed on each electrode (FIG. 1 (5)).

  In this way, after forming the water repellent pattern on the source electrode 7 and the drain electrode 8, an organic semiconductor solution is introduced between the source electrode and the drain electrode, and the solvent is removed to form the organic semiconductor layer. Since the drain electrode has a water-repellent pattern having a water-repellent layer (low surface energy layer) on the surface, when an organic semiconductor solution is dropped (FIG. 1 (6)), the source electrode 7 and the drain electrode 8 Since the upper surface has a water-repellent pattern, the organic semiconductor solution is repelled and no semiconductor layer is formed on the upper surface of the electrode. The organic semiconductor solution is naturally repelled from the electrode surface (FIG. 1 (7)), is in close contact with the side surface of the electrode layer and dried as it is, and connects the side surfaces of the respective electrodes between the source electrode and the drain electrode. 9 is formed (FIG. 1 (8)).

  By this method, the positional accuracy at the time of forming the organic semiconductor layer is improved, and the contact resistance at the interface between the electrode and the organic semiconductor layer is thereby stabilized, so that an organic thin film transistor having good characteristics can be obtained.

  As a material for forming these water-repellent patterns, there is silicone rubber, and the silicone rubber layer can be appropriately selected from known materials as described in JP-A-7-164773. Two types, a condensation cross-linking type that cures a silicone rubber layer composition by a condensation reaction and an addition cross-linking type that cures a silicone rubber layer composition by an addition reaction, described in Japanese Patent No. 244773 are preferably used.

  Examples of the condensation-crosslinking type silicone rubber layer include a linear organopolysiloxane having hydroxyl groups at both ends and a reactive silane compound that crosslinks with the organopolysiloxane to form a silicone rubber layer as essential components.

  The condensation-crosslinking type silicone rubber layer is used to increase the reaction efficiency of the condensation-crosslinking reaction between the organopolysiloxane having a hydroxyl group at both ends and a reactive silane compound, so that the organic carboxylic acid, titanate, stannate, aluminum organic A condensation catalyst such as an ether or a platinum-based catalyst can be appropriately reacted to perform a condensation reaction and be cured. The compounding ratio in the silicone rubber layer of the organopolysiloxane having a hydroxyl group at both ends, a reactive silane compound and a condensation catalyst is 80 to 80% of the organopolysiloxane having a hydroxyl group at both ends with respect to the solid content of the entire silicone rubber layer. 98% by mass, preferably 85-98% by mass, the reactive silane compound is usually 2-20% by mass, preferably 2-15% by mass, more preferably 2-7% by mass, and the condensation catalyst is 0.05-5%. It is 0.1 mass%, Preferably it is 0.1-3 mass%, More preferably, it is 0.1-1 mass%.

  The condensation-crosslinking type silicone rubber layer contains 2-15% by mass, preferably 3-12% by mass, of the polysiloxane other than the polyorganosiloxane having hydroxyl groups at both ends with respect to the total solid content of the silicone rubber layer. It can be made. Examples of the polysiloxane include polydimethylsiloxane having Mw of 10,000 to 1,000,000 having both ends trimethylsilylated.

  On the other hand, the addition-crosslinking type silicone rubber layer is composed of an organopolysiloxane having at least two aliphatic unsaturated groups in one molecule and a silicone rubber layer that is crosslinked with the organopolysiloxane to form Si-- Examples thereof include an organopolysiloxane having at least two H bonds as an essential component.

  The structure of the organopolysiloxane having at least two aliphatic unsaturated groups in one molecule may be any of a chain, a ring, and a branch, but a chain is preferable. Examples of fatty acid unsaturated groups include vinyl, allyl, butenyl, pentenyl, hexenyl and other alkenyl groups; cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl and other cycloalkenyl groups; ethynyl, Examples thereof include alkynyl groups such as propynyl group, butynyl group, pentynyl group, and hexynyl group. Among these, an alkenyl group having an unsaturated bond at the terminal is preferable from the viewpoint of reactivity, and a vinyl group is particularly preferable. Further, the remaining substituent other than the aliphatic unsaturated group is preferably a methyl group.

  The Mw of the organopolysiloxane having at least two aliphatic unsaturated groups in one molecule is usually 500 to 500,000, preferably 1000 to 3000000.

  The structure of the organopolysiloxane having at least two Si—H bonds in one molecule may be any of a chain, a ring, and a branch, but a chain is preferable. The Si—H bond may be either at the end or in the middle of the siloxane skeleton, and the proportion of hydrogen atoms to the total number of substituents is usually 1 to 60%, preferably 2 to 50%. The remaining substituents other than hydrogen atoms are preferably methyl groups. Mw of the organopolysiloxane having at least two Si-H bonds in one molecule is usually 300 to 300,000, preferably 500 to 200,000. If Mw is extremely high, sensitivity and image reproducibility are liable to be lowered.

  An addition reaction catalyst is usually used for addition reaction of an organopolysiloxane having at least two aliphatic unsaturated groups in one molecule and an organopolysiloxane having at least two Si-H bonds in one molecule. The addition reaction catalyst can be arbitrarily selected from known catalysts, but a platinum-based catalyst is preferable, and one or a mixture of two or more selected from a platinum group metal and a platinum-based compound is used.

  Examples of the platinum group metal include platinum alone (eg, platinum black), palladium alone (eg, palladium black), and rhodium alone. Platinum group compounds include chloroplatinic acid, platinum-olefin complexes, platinum-alcohol complexes, platinum-ketone complexes, platinum and vinylsiloxane complexes, tetrakis (triphenylphosphine) platinum, tetrakis (triphenylphosphine) palladium, and the like. Is exemplified. Among these, those obtained by dissolving chloroplatinic acid or a platinum-olefin complex in an alcohol solvent, a ketone solvent, an ether solvent, a hydrocarbon solvent, or the like are particularly preferable.

  The blending ratio of each composition forming the silicone rubber layer is 80 to 98% by mass of organopolysiloxane having at least two fatty acid unsaturated groups in one molecule with respect to the total solid content of the silicone rubber layer. , Preferably 85 to 98% by mass, 2 to 20% by mass, preferably 2 to 15% by mass of the organopolysiloxane having at least two Si—H bonds in one molecule, and the addition reaction catalyst is It is 0.00001-10 mass%, Preferably it is 0.0001-5 mass%.

  In addition to the above composition, the addition-crosslinking type silicone rubber layer has a water content represented by the general formula (VII) described in JP-A-10-244773 for the purpose of increasing the film strength of the silicone rubber layer. An amino-based organosilicon compound having a decomposable group can be added.

  The amino-based organosilicon compound is 0 to 10% by mass, preferably 0 to 5% by mass, based on the total solid content of the silicone rubber layer.

  A curing retarder can be added to the addition-crosslinking type silicone rubber layer. The curing retarder can be arbitrarily selected from generally known acetylenic alcohols, maleic esters, silylated products of acetylenic alcohols, silylated products of maleic acid, triallyl isocyanurate, vinyl siloxane and the like.

  Although the addition amount of this hardening retarder changes with desired hardening speed | rates, it is 0.0001-1.0 mass part normally with respect to the total solid of a silicone rubber layer.

  The silicone rubber layer composition is dissolved in an appropriate solvent and used as a solution.

  Coating solvents include n-hexane, cyclohexane, petroleum ether, aliphatic hydrocarbon solvent Exxon Chemical Co., Ltd .: Isopar E, H, G and these solvents and ketones such as methyl ethyl ketone and cyclohexanone, butyl acetate, acetic acid Esters such as amyl and ethyl propionate, hydrocarbons and halogenated hydrocarbons such as toluene, xylene, monochlorobenzene, carbon tetrachloride, trichloroethylene and trichloroethane, ethers such as methyl cellosolve, ethylthrosolve, tetrahydrofuran, and more A mixed solvent with propylene glycol monomethyl ether acetate, bentoxone, dimethylformamide and the like can be used.

  The thickness of the silicone rubber layer used in the present invention is preferably 0.05 to 100 μm, more preferably 0.5 to 20 μm, and in the case of an organic thin film transistor element, preferably 0.05 to 10 μm, more preferably 0. .1 to 2 μm.

  In the present invention, the silicone rubber layer patterning method may be combined with a photosensitive resin layer. For example, after a silicone rubber layer is provided on the photosensitive layer, exposure and development are performed on the photosensitive layer, thereby exposing the photosensitive layer. Remove the silicone rubber layer. Any photosensitive resin layer may be used as long as it can pattern the silicone rubber layer. About the photosensitive resin layer, the photosensitive resin layer used with the patterning method used for the technique of a waterless flat plate, for example can be used. Preferably, it is an ablation layer.

  The ablation layer refers to an insulating layer that is ablated by irradiation with high-density energy light and changes the adhesion between the electrode material repellent layer and the lower layer of the ablation layer. Ablation as used herein means that the ablation layer completely scatters due to physical or chemical changes, a part of the ablation layer breaks or scatters, and is physically or chemically only near the interface of the support or the conductive polymer layer. This includes a phenomenon in which the adhesiveness between the electrode material repulsive layer and the lower layer changes as a result of ablation.

  The ablation layer used in the present invention can be composed of an energy light absorber, a binder resin, and various additives added as necessary.

  As the energy light absorber, various organic and inorganic materials that absorb the energy light to be irradiated can be used. For example, when the laser light source is an infrared laser, pigments, dyes, metals, metal oxides, metals that absorb infrared rays Ferrite metal powder such as metal magnetic powder mainly composed of nitride, metal carbide, metal boride, graphite, carbon black, titanium black, Al, Fe, Ni, Co, etc. can be used. Black, cyanine-based pigments, and Fe-based ferromagnetic metal powders are preferred. Content of an energy light absorber is about 30-95 mass% of an ablation layer formation component, Preferably it is 40-80 mass%.

  The binder resin for the ablation layer can be used without particular limitation as long as it can sufficiently retain the colorant fine particles.

  Examples of such binder resins include polyurethane resins, polyester resins, vinyl chloride resins, polyvinyl acetal resins, cellulose resins, acrylic resins, phenoxy resins, polycarbonates, polyamide resins, phenol resins, and epoxy resins. Can be mentioned. The content of the binder resin is about 5 to 70% by mass, preferably 20 to 60% by mass, of the ablation layer forming component.

  The ablation layer may contain a cross-linking agent or a polymer material and be cured in order to improve the adhesion with the adjacent electrode material repulsive layer or the lower layer. Moreover, the material used for the photosensitive layer of the so-called heat mode waterless lithographic printing plate can be used.

The high-density energy light can be used without particular limitation as long as it is active light that generates ablation. As an exposure method, flash exposure using a xenon lamp, a halogen lamp, a mercury lamp, or the like may be performed through a photomask, or scanning exposure may be performed by converging laser light or the like. An infrared laser, particularly a semiconductor laser, whose output per laser beam is 20 to 200 mW is most preferably used. The energy density is preferably 50 to 500 mJ / cm ^2, more preferably a 100~300mJ / cm ^2.

  As the other photosensitive resin layer, a photosensitive resin layer can be preferably used, and known materials of positive type and negative type can be used. Examples of such photosensitive resin materials include (1) dye-sensitized photopolymerization photosensitive materials such as JP-A-11-271969, JP-A-2001-117219, JP-A-11-311859, and JP-A-11-352691. (2) Negative type having sensitivity to infrared laser such as JP-A-9-179292, US Pat. No. 5,340,699, JP-A-10-90885, JP-A-2000-321780, 2001-154374 Photosensitive materials, (3) JP-A-9-171254, 5-115144, 10-87733, 9-43847, 10-268512, 11-194504, 11-223936, 11-84657, 11-174681, 7-285275, JP 2000-56452, WO 97/39894, 98 Positive photosensitive material having photosensitivity to infrared laser, such as 42507 and the like. Preference is given to (2) and (3) in that the process is not limited to a dark place.

  Solvents for forming the coating solution of photosensitive resin include propylene glycol monomethyl ether, propylene glycol monoethyl ether, methyl cellosolve, methyl cellosolve acetate, ethyl cellosolve, ethyl cellosolve acetate, dimethylformamide, dimethyl sulfoxide, dioxane, acetone, cyclohexanone , Trichlorethylene, methyl ethyl ketone and the like. These solvents are used alone or in admixture of two or more.

  As a method for forming the photosensitive resin layer, a spray coating method, a spin coating method, a blade coating method, a dip coating method, a casting method, a roll coating method, a bar coating method, a die coating method, or the like is used.

  As a light source for performing patterning exposure on the photosensitive resin layer, a laser is preferable, and examples thereof include an Ar laser, a semiconductor laser, a He-Ne laser, a YAG laser, a carbon dioxide gas laser, and the like, preferably those having an oscillation wavelength in the infrared Thus, it is a semiconductor laser. The output is suitably 50 mW or more, preferably 100 mW or more. Thereby, patterning can be performed with high accuracy.

  In the present invention, the silicone rubber layer can be patterned by exposing and developing the photosensitive resin layer. Specifically, the photosensitive resin layer is exposed to light by developing the photosensitive resin layer. In this state, the silicone rubber layer is developed by brushing or the like to form a pattern on the silicone rubber layer.

  In the present invention, a silicone rubber layer is formed on the electrode, an organic semiconductor solution is supplied, and an organic semiconductor material thin film (layer) pattern with high positional accuracy is formed by utilizing repulsion of the semiconductor solution by the silicone rubber layer.

  Further, the water repellent layer for forming the water repellent pattern according to the present invention is obtained by directly applying a silicone rubber layer composition, for example, an electrostatic suction ink jet (SIJ) apparatus as described in Japanese Patent Application No. 2004-274754. Thus, the composition may be directly patterned and formed at a predetermined position on the electrode pattern on the substrate.

  In the present invention, the water-repellent layer that forms the water-repellent pattern can also be formed using, for example, a silane coupling agent, a titanium coupling agent, or the like. In order to bond the silane coupling agent to the metal electrode layer, these materials may be applied under irradiation of ultraviolet rays. Irradiation with high energy ultraviolet light having a wavelength of 160 to 300 nm. The metal surface and these surface treatment agents react with actinic rays to form a water-repellent film on the surface.

  Therefore, for example, after forming a metal thin film by vapor deposition or applying and fusing metal nanoparticles, a source electrode and a drain electrode pattern are formed by patterning using a photosensitive resin layer, and then, for example, octyltrichlorosilane or the like is formed. In the presence of a silane coupling agent, titanium coupling agent, etc., UV light is irradiated to react with the metal surface to form a bond, so that hydrophobic groups are connected to the surface on the source and drain electrodes, thereby repelling the surface. A water pattern is formed.

  In addition, electrodes may be formed in advance using a mask, and further a water-repellent pattern may be formed.

  Examples of the silane coupling agent include alkylsilanes and alkyldisilazanes, and groups having reactivity with hydroxyl groups on the substrate surface such as halogen atoms and alkoxy groups may be substituted.

Examples of these alkylsilanes and alkyldisilazanes include methyltriethoxysilane, ethyltriethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, butyltrimethoxysilane, octyltrimethyl. Ethoxysilane, trimethylethoxysilane, etc.
In addition, methyltrichlorosilane, ethyltrichlorosilane, dimethylchlorosilane, dimethyldichlorosilane, isopropyltrichlorosilane, isopropyltrichlorosilane, butyltrichlorosilane, octyltrichlorosilane, trimethylchlorosilane, octadecyltrichlorosilane, etc., and alkyldisilazanes are hexamethyl. Disilazane etc. are mentioned.

  Specifically, a silicon compound reagent manufactured by Shin-Etsu Chemical Co., Ltd., or Gelest, Inc. of the United States. Alkylsilanes and alkyldisilazanes may be selected from those described in compound catalogs such as Metal-Organics for Material & Polymer Technology, Chisso SILICON CHEMICALS, and the like.

  Silanes and alkylsilazanes containing a fluorine-containing alkyl group (fluoroalkyl group) can also be used. These typical examples are shown below.

(Heptadecafluoro-1,1,2,2-tetrahydrodecyl) trichlorosilane (Heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane (Heptadecafluoro-1,1,2,2- Tetrahydrodecyl) trimethoxysilane (heptadecafluoro-1,1,2,2-tetrahydrodecyl) dimethylchlorosilane (tridecafluoro-1,1,2,2-tetrahydrooctyl) trichlorosilane (tridecafluoro-1,1 , 2,2-tetrahydrooctyl) triethoxysilane (tridecafluoro-1,1,2,2-tetrahydrooctyl) methyldichlorosilane perfluorododecyl-1H, 1H, 2H, 2H-triethoxysilane (3,3, 3-trifluoropropyl) trichlorosilane (3,3,3 Trifluoropropyl) trimethoxysilane (Shin-Etsu Chemical Co. KBM7103)
Bis (trifluoropropyl) tetramethyldisilazane (3-heptafluoroisopropoxy) propyltrichlorosilane Pentafluorophenyltriethoxysilane Pentafluorophenyldimethylchlorosilane Pentafluorophenylpropyltrichlorosilane Pentafluorophenylpropyltrimethoxysilane 1,8-bis (trichloro Silylethyl) hexadecafluorooctane These compounds are available as products from Shin-Etsu Chemical, Amax, etc.

  In the present invention, octyltriethoxysilane, octyltrichlorosilane, and hexamethyldisilazane are particularly preferable surface treatment agents.

  The water contact angle on the surface of the water repellent pattern is preferably 70 degrees or more. The contact angle of toluene is more preferably 15 to 100 degrees, and further preferably 20 to 90 degrees.

  Titanium coupling agents can be used in the same manner, and those having a structure in which the silicon atom of the silane coupling agent is replaced with a titanium atom are available and can be used in the same manner.

  In order to form a water-repellent pattern on the source and drain electrodes, as described above, a water-repellent layer and a photosensitive resin layer are formed on the electrode layer on which the electrodes are uniformly formed. In addition to removing the resin from the region other than the electrode and drain electrode portions and etching the electrode, for example, after patterning using a photosensitive resin on the substrate gate insulating layer and forming a resist, the source electrode and the drain electrode are A water-repellent pattern may be formed again on the formed electrode surface after being formed by vapor deposition, sputtering, or application using a fluid electrode material.

  Alternatively, an electrode pattern may be directly formed by an ink jet method, a printing method, or the like, and a water repellent pattern may be formed by aligning the positions by a similar method. The patterning method of an electrode and the formation method of a water repellent pattern on an electrode are not ask | required.

  The surface of the source electrode and drain electrode on which the water repellent pattern is formed by the silicone rubber layer or the silane coupling agent has low surface energy and repels the organic semiconductor solution. It can be disposed between the electrode and the drain electrode, and the contact resistance between the semiconductor layer and the electrode does not vary. Therefore, stable performance can be obtained.

  As will be described later, a protective film is preferably formed on the organic semiconductor layer by applying an aqueous solution such as polyvinyl alcohol in order to avoid deterioration due to water vapor or gas such as oxygen.

[Protective film]
In the present invention, it is preferable to form a protective film on the organic semiconductor layer. The protective film may be an inactive material that does not affect the organic semiconductor material.

  Examples of such materials include the following polymer materials, particularly materials containing a hydrophilic polymer, and more preferably, an aqueous solution or aqueous dispersion of a hydrophilic polymer.

  The hydrophilic polymer is a polymer having solubility or dispersibility with respect to water or an acidic aqueous solution, an alkaline aqueous solution, an alcohol aqueous solution, or an aqueous solution of various surfactants. For example, homopolymers and copolymers composed of components such as polyvinyl alcohol, HEMA, acrylic acid, and acrylamide can be suitably used. As other materials, materials containing inorganic oxides and inorganic nitrides are also preferable because they do not affect the organic semiconductor and do not affect other coating processes. Further, a material for a gate insulating layer described later can also be used.

  The organic semiconductor protective layer containing an inorganic oxide or inorganic nitride that is a gate insulating layer material is preferably formed by an atmospheric pressure plasma method.

  The method of forming a thin film by the plasma method under atmospheric pressure is a process in which a thin film is formed on a substrate by discharging at atmospheric pressure or a pressure near atmospheric pressure to excite a reactive gas to form a thin film on a substrate. JP-A-11-61406, JP-A-11-133205, JP-A-2000-121804, JP-A-2000-147209, JP-A-2000-185362 (hereinafter also referred to as atmospheric pressure plasma method). Accordingly, a highly functional thin film can be formed with high productivity.

  Further, when patterning the protective film, it is preferable to use a photoresist. As the photoresist layer, a known positive or negative material can be used, but a laser-sensitive material is preferably used. Examples of such a photoresist material include (1) dye-sensitized photopolymerization photosensitive materials such as JP-A-11-271969, JP-A-2001-117219, JP-A-11-311859, and JP-A-11-352691. (2) Negative type photosensitivity having sensitivity to infrared lasers such as JP-A-9-179292, US Pat. No. 5,340,699, JP-A-10-90885, JP-A-2000-321780, and JP-A-2001-154374. Materials, (3) JP-A-9-171254, 5-115144, 10-87733, 9-43847, 10-268512, 11-194504, 11-223936, 11 -84657, 11-114681, 7-285275, JP 2000-56452, WO 97/39894, Positive photosensitive material having photosensitivity to infrared lasers such as 98/42507 and the like. Preference is given to (2) and (3) in that the process is not limited to a dark place. When removing the photoresist layer, positive type (3) is most preferred.

  The organic semiconductor layer (thin film) of the present invention is formed with high positional accuracy using a water repellent pattern formed on the electrode surface.

  Subsequently, the organic thin-film transistor produced using the organic-semiconductor thin film of this invention and the other component of an organic thin-film transistor are demonstrated.

[Organic semiconductor thin film: Organic semiconductor thin layer]
In the present invention, as the organic semiconductor material constituting the organic semiconductor thin film (also referred to as “organic semiconductor thin layer”), various condensed polycyclic aromatic compounds and conjugated compounds described later can be applied.

  Examples of the condensed polycyclic aromatic compound as the organic semiconductor material include, for example, anthracene, tetracene, pentacene, hexacene, heptacene, chrysene, picene, fluorene, pyrene, peropyrene, perylene, terylene, quaterylene, coronene, ovalene, circumcamanthracene, Examples thereof include bisanthene, zestrene, heptazethrene, pyranthrene, violanthene, isoviolanthene, cacobiphenyl, phthalocyanine, porphyrin, and derivatives thereof.

  Examples of the conjugated compound include polythiophene and its oligomer, polypyrrole and its oligomer, polyaniline, polyphenylene and its oligomer, polyphenylene vinylene and its oligomer, polythienylene vinylene and its oligomer, polyacetylene, polydiacetylene, tetrathiafulvalene compound, quinone And compounds, cyano compounds such as tetracyanoquinodimethane, fullerenes and derivatives or mixtures thereof.

  In particular, among polythiophene and oligomers thereof, thiophene hexamer, α-seccithiophene α, ω-dihexyl-α-sexualthiophene, α, ω-dihexyl-α-kinkethiophene, α, ω-bis (3- Oligomers such as butoxypropyl) -α-sexithiophene can be suitably used.

  Furthermore, metal phthalocyanines such as copper phthalocyanine and fluorine-substituted copper phthalocyanine described in JP-A No. 11-251601, naphthalene 1,4,5,8-tetracarboxylic acid diimide, N, N′-bis (4-trifluoromethylbenzyl) Along with naphthalene 1,4,5,8-tetracarboxylic acid diimide, N, N'-bis (1H, 1H-perfluorooctyl), N, N'-bis (1H, 1H-perfluorobutyl) and N, N'- Dioctylnaphthalene 1,4,5,8-tetracarboxylic acid diimide derivatives, naphthalene 2,3,6,7 tetracarboxylic acid diimides and other naphthalene tetracarboxylic acid diimides, and anthracene 2,3,6,7-tetracarboxylic acid Anthracene tetracarboxylic acid diimides such as diimide Phosphate diimides, C60, C70, C76, C78, C84, such as fullerenes, carbon nanotubes, such as SWNT, merocyanine dyes, such as dyes such as hemicyanine dyes, and the like.

  Among these π-conjugated materials, at least one selected from the group consisting of condensed polycyclic aromatic compounds such as pentacene, fullerenes, condensed ring tetracarboxylic acid diimides, and metal phthalocyanines is preferable.

  Other organic semiconductor materials include tetrathiafulvalene (TTF) -tetracyanoquinodimethane (TCNQ) complex, bisethylenetetrathiafulvalene (BEDTTTTF) -perchloric acid complex, BEDTTTTF-iodine complex, TCNQ-iodine complex. Organic molecular complexes such as can also be used. Furthermore, (sigma) conjugated polymers, such as polysilane and polygermane, and organic-inorganic hybrid material as described in Unexamined-Japanese-Patent No. 2000-260999 can also be used.

  Of the polythiophene and oligomers thereof, a thiophene oligomer represented by the following general formula (2) is preferable.

  In the formula, R represents a substituent.

<< Thiophene oligomer represented by formula (2) >>
The thiophene oligomer represented by the general formula (2) will be described.

  In the general formula (2), examples of the substituent represented by R include an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, Dodecyl group, tridecyl group, tetradecyl group, pentadecyl group etc.), cycloalkyl group (eg cyclopentyl group, cyclohexyl group etc.), alkenyl group (eg vinyl group, allyl group etc.), alkynyl group (eg ethynyl group, propargyl etc.) Group), aryl group (for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, Biphenylyl group, etc.), aromatic heterocyclic groups (for example, furyl) , Thienyl group, pyridyl group, pyridazyl group, pyrimidyl group, pyrazyl group, triazyl group, imidazolyl group, pyrazolyl group, thiazolyl group, benzoimidazolyl group, benzoxazolyl group, quinazolyl group, phthalazyl group, etc.), heterocyclic group (for example, , Pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxyl group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxyl Group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexyl) O group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, etc.) , Ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group) Methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dode Silylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group) 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecyl) Carbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, Pyrcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, amino Carbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, Naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylurei group) Group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group) , Cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexyl) Sulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group) Group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino) Group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl) Group), cyano group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.).

  These substituents may be further substituted with the above substituents, or a plurality thereof may be bonded to each other to form a ring.

  Among them, a preferable substituent is an alkyl group, more preferably an alkyl group having 2 to 20 carbon atoms, and particularly preferably an alkyl group having 6 to 12 carbon atoms.

<End group of thiophene oligomer>
The terminal group of the thiophene oligomer used for this invention is demonstrated.

  The terminal group of the thiophene oligomer used in the present invention preferably does not have a thienyl group, and preferred groups as the terminal group include aryl groups (for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group). Group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.), alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group) Tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), halogen atoms (for example, fluorine atom, chlorine atom, bromine atom etc.) and the like.

<Stereoscopic properties of repeating units of thiophene oligomers>
The thiophene oligomer used in the present invention preferably has no head-to-head structure in the structure, and more preferably, the structure has a head-to-tail structure or a tail- It preferably has a to-tail structure.

  Regarding the head-to-head structure, head-to-tail structure, and tail-to-tail structure according to the present invention, for example, “π-electron organic solid” (1998, published by the Japan Society for the Science of Chemistry, edited by Japan Chemical Industry) 27-32, Adv. Mater. 1998, 10, no. Reference can be made to pages 2, 93 to 116, etc. Here, specific structural features of each are shown below.

  In addition, R is synonymous with R in the said General formula (2) here.

  Hereinafter, although the specific example of these thiophene oligomers used for this invention is shown, this invention is not limited to these.

  A method for producing these thiophene oligomers is described in Japanese Patent Application No. 2004-172317 (filed on June 10, 2004) by the present inventors.

  In this invention, it is preferable that an organic-semiconductor material has an alkyl group from solubility and affinity with the thin film formed with the said pretreatment agent. From this viewpoint, in the organic semiconductor thin film according to the present invention, the organic semiconductor material forming the organic semiconductor thin film preferably has the partial structure represented by the general formula (1).

  From the above viewpoint, a compound represented by the following general formula (OSC1) is particularly preferable as the organic semiconductor material.

In the formula, R _{1 to} R ₆ represent a hydrogen atom or a substituent, Z ₁ or Z ₂ represents a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocyclic ring, and n1 or n2 Represents an integer of 0 to 3.

In the general formula (OSC1), examples of the substituent represented by R _{1 to} R ₆ include an alkyl group (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, tert-pentyl group). Group, hexyl group, octyl group, tert-octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, vinyl group, for example) Allyl group, 1-propenyl group, 2-butenyl group, 1,3-butadienyl group, 2-pentenyl group, isopropenyl group, etc.), alkynyl group (for example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon group (Also called aromatic carbocyclic group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, Til group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group), aromatic heterocyclic group (also called heteroaryl group, For example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3- Triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group , Indolyl group, carbazolyl group , Carbolinyl group, diazacarbazolyl group (in which one of carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc. ), Heterocyclic groups (eg, pyrrolidyl, imidazolidyl, morpholyl, oxazolidyl, etc.), alkoxy groups (eg, methoxy, ethoxy, propyloxy, pentyloxy, hexyloxy, octyloxy, dodecyl) Oxy group etc.), cycloalkoxy group (eg cyclopentyloxy group, cyclohexyloxy group etc.), aryloxy group (eg phenoxy group, naphthyloxy group etc.), alkylthio group (eg methylthio group, ethylthio group, propylthio group, Pencil Group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxy Carbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group etc.), aryloxycarbonyl group (eg phenyloxycarbonyl group, naphthyloxycarbonyl group etc.), sulfamoyl group (eg amino Sulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminos Phonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, Octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group) Group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonyl group) Ruamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group ( For example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylamino Carbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group) Ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl) Group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, Cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group (phenylsulfonyl group, naphthyls) Phonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino) Group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl) Group), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), and the like.

  These substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

In the general formula (OSC1), the aromatic hydrocarbon group and aromatic heterocyclic group represented by Z ₁ or Z ₂ are aromatic carbon atoms described as substituents represented by R _{1 to} R ₆ , respectively. It is synonymous with a hydrogen group and an aromatic heterocyclic group, respectively.

  Furthermore, a compound represented by the following general formula (OSC2) is preferable.

In the formula, R ₇ or R ₈ represents a hydrogen atom or a substituent, Z ₁ or Z ₂ represents a substituted or unsubstituted aromatic hydrocarbon ring, or a substituted or unsubstituted aromatic heterocyclic ring, and n1 or n2 Represents an integer of 0 to 3.

In the general formula (OSC2), the substituent represented by R ₇ or R ₈ has the same meaning as the substituents represented by R _{1 to} R ₆ in the general formula (OSC1). In addition, the aromatic hydrocarbon group and aromatic heterocyclic group represented by Z ₁ or Z ₂ are aromatic hydrocarbon groups and aromatic groups described as substituents represented by R _{1 to} R ₆ , respectively. Each has the same meaning as a heterocyclic group.

In the general formula (OSC2), the substituents R ₇ — and R ₈ — are preferably represented by the general formula (SG1).

In the formula, R _{9 to} R ₁₁ represent substituents, and X represents silicon (Si), germanium (Ge), or tin (Sn).

In the said general formula (SG1), the substituent represented by R < ₉ > -R < ₁₁ > is synonymous with the substituent represented by R < ₁ > -R < ₃ > in the said General formula (1).

  Specific examples of the compound represented by the general formula (OSC2) are shown below, but are not limited thereto.

  In the present invention, for example, a material having a functional group such as acrylic acid, acetamide, dimethylamino group, cyano group, carboxyl group, nitro group, benzoquinone derivative, tetracyanoethylene and tetracyanoquino Materials that accept electrons, such as dimethane and their derivatives, materials having functional groups such as amino, triphenyl, alkyl, hydroxyl, alkoxy, and phenyl, phenylenediamine, etc. Including substituted amines, anthracene, benzoanthracene, substituted benzoanthracenes, pyrene, substituted pyrene, carbazole and derivatives thereof, tetrathiafulvalene and derivatives thereof, and the like materials that serve as donors of electrons, So-called doping treatment It may be.

  The doping means introducing an electron-donating molecule (acceptor) or an electron-donating molecule (donor) into the thin film as a dopant. Accordingly, the doped thin film is a thin film containing the condensed polycyclic aromatic compound and the dopant. A well-known thing can be employ | adopted as a dopant used for this invention.

  These organic semiconductor layers are formed by applying a printing method, an ink jet method, a spin electrode method, a die coat method, a dip coat method, or the like to apply an organic semiconductor material solution to a source electrode or drain having a water repellent layer as described above. It can be formed by applying to the substrate surface channel region between the electrodes.

  Among these, from the viewpoint of productivity, an ink jet method capable of forming a thin film easily and precisely using an organic semiconductor solution is preferable.

  As the solvent used for forming the solution of the organic semiconductor material, any solvent can be used as long as it can dissolve the organic semiconductor material. For example, hydrocarbon-based, alcohol-based, ether-based, ester-based, The organic solvent is selected from organic solvents having a wide range of appropriate vapor pressure or boiling point, such as ketones and glycol ethers, depending on the organic semiconductor material, and has a normal pressure boiling point in the range of 80 ° C to 250 ° C. Solvents are preferable because they have an appropriate evaporation rate of the solvent at the crystallization interface or the coating liquid end face. More preferably, it is 80 degreeC-150 degreeC. For example, chain ether solvents such as diethyl ether and diisopropyl ether, cyclic ether solvents such as tetrahydrofuran and dioxane, ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone, aromatic hydrocarbon solvents such as xylene and toluene, o- Aromatic solvents such as dichlorobenzene, nitrobenzene, m-cresol, aliphatic hydrocarbon solvents such as hexane, cyclohexane, tridecane, α-terpineol, and alkyl halide solvents such as chloroform and 1,2-dichloroethane, N -Methylpyrrolidone, carbon disulfide and the like can be preferably used, but in particular, alicyclic hydrocarbon solvents such as cyclohexane and cyclopentane, and aromatic hydrocarbon solvents such as toluene and xylene. Etc. are preferred And the like as.

  The surface energy of the solvent is preferably 10 N / m to 40 N / m at 25 ° C. Furthermore, the solvent which is 15 N / m-30 N / m is preferable.

  In addition, as described in Advanced Material 1999 No. 6, p. 480 to 483, a precursor such as pentacene is soluble in a solvent, a target organic material formed by heat treatment of a precursor film formed by coating A thin film may be formed.

  The film thickness of these organic semiconductor layers is not particularly limited, but the characteristics of the obtained transistor are often greatly influenced by the film thickness of the organic semiconductor layer, and the film thickness varies depending on the organic semiconductor. Generally, 1 μm or less, particularly 10 to 300 nm is preferable.

  In the thin film transistor element of the present invention, the gate electrode, the source electrode, and the drain electrode are formed of a known electrode material. The electrode material is not particularly limited as long as it is a conductive material. Platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium, tellurium, rhenium, iridium, aluminum, ruthenium, Germanium, molybdenum, tungsten, tin oxide / antimony, indium tin oxide (ITO), fluorine doped zinc oxide, zinc, carbon, graphite, glassy carbon, silver paste and carbon paste, lithium, beryllium, sodium, magnesium, potassium, calcium , Scandium, titanium, manganese, zirconium, gallium, niobium, sodium, sodium-potassium alloy, magnesium, lithium, aluminum, magnesium / copper mixture, magnesium / silver mixture, magnesium / Aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, a lithium / aluminum mixture, or the like is used. Alternatively, a known conductive polymer whose conductivity is improved by doping or the like, for example, conductive polyaniline, conductive polypyrrole, or conductive polythiophene (polyethylenedioxythiophene and polystyrenesulfonic acid complex, etc.) is also preferably used.

  As a material for forming the source electrode or the drain electrode, among the materials listed above, those having low electrical resistance at the contact surface with the semiconductor layer are preferable. In the case of a p-type semiconductor, platinum, gold, silver, ITO, conductive Polymer and carbon are preferred.

  In the case of a source electrode or a drain electrode, those formed using a fluid electrode material such as a solution, paste, ink, or dispersion containing the above conductive material, in particular, a conductive polymer, or platinum, gold, A fluid electrode material which is a solvent or dispersion medium containing 60% or more, preferably 90% or more of water containing metal fine particles containing silver and copper is preferable.

  As the fluid electrode material containing metal fine particles, for example, a known conductive paste or the like may be used. Preferably, metal fine particles having a particle diameter of 1 to 50 nm, preferably 1 to 10 nm are used as necessary. It is a material dispersed in a dispersion medium that is water or any organic solvent using a dispersion stabilizer.

  Platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium, tellurium, rhenium, iridium, aluminum, ruthenium, germanium, molybdenum, tungsten, zinc, etc. Can be used.

  As a method for producing such a dispersion of fine metal particles, metal ions are reduced in the liquid phase, such as a physical generation method such as gas evaporation method, sputtering method, metal vapor synthesis method, colloidal method, coprecipitation method, etc. A chemical production method for producing metal fine particles, preferably colloidal methods described in JP-A-11-76800, JP-A-11-80647, JP-A-11-319538, JP-A-2000-239853, etc. A dispersion of fine metal particles produced by a gas evaporation method described in JP-A Nos. 2001-254185, 2001-53028, 2001-35255, 2000-124157, 2000-123634, and the like. After forming an electrode using these metal fine particle dispersions and drying the solvent, the metal fine particles are obtained by heating in a shape within a range of 100 to 300 ° C., preferably 150 to 200 ° C. as necessary. An electrode pattern having a target shape is formed by heat fusion.

  As a method for forming an electrode, in addition to a fluid electrode material, a conductive thin film formed using a method such as vapor deposition or sputtering using the above as a raw material, a known photolithographic method or a lift-off method using a photosensitive resin layer There is a method of forming an electrode by using a photo resist and a method of forming a resist on a metal foil such as aluminum or copper by using a photosensitive resin layer by thermal transfer, ink jet or the like and etching it. Alternatively, a conductive polymer solution or dispersion, a dispersion containing metal fine particles, or the like may be directly patterned by an ink jet method, or may be formed from a coating film by lithography or laser ablation. Further, a method of patterning a conductive ink or conductive paste containing a conductive polymer or metal fine particles by a printing method such as relief printing, intaglio printing, planographic printing, or screen printing can also be used.

  As the photosensitive resin layer, the same positive and negative photosensitive resins used for patterning the protective layer can be used.

  In the photolithographic method, there is a method of patterning using a metal fine particle-containing dispersion or a conductive polymer as a material for the source electrode and the drain electrode, and then heat-sealing as necessary.

  The solvent for forming the photosensitive resin coating solution, the method for forming the photosensitive resin layer, and the like are as described in the patterning of the protective film.

  The same applies to the light source used for patterning exposure after the formation of the photosensitive resin layer and the developer used for developing the photosensitive resin layer. In addition, an ablation layer which is another photosensitive resin layer may be used for electrode formation. As for the ablation layer, the same ones as those used for the patterning of the protective layer may be mentioned.

  Various insulating films can be used as the gate insulating layer of the organic thin film transistor element of the present invention, and an inorganic oxide film having a high relative dielectric constant is particularly preferable. Inorganic oxides include silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, barium zirconate titanate, lead zirconate titanate, lead lanthanum titanate, strontium titanate, Examples thereof include barium titanate, barium magnesium fluoride, bismuth titanate, strontium bismuth titanate, strontium bismuth tantalate, bismuth tantalate niobate, and yttrium trioxide. Of these, silicon oxide, aluminum oxide, tantalum oxide, and titanium oxide are preferable. Inorganic nitrides such as silicon nitride and aluminum nitride can also be suitably used.

  Examples of the method for forming the film include a vacuum process, a molecular beam epitaxial growth method, an ion cluster beam method, a low energy ion beam method, an ion plating method, a CVD method, a sputtering method, an atmospheric pressure plasma method, and a spray process. Wet processes such as coating methods, spin coating methods, blade coating methods, dip coating methods, casting methods, roll coating methods, bar coating methods, die coating methods, and other wet processes such as printing and ink jet patterning methods, etc. Can be used depending on the material.

  The wet process is a method of applying and drying a liquid in which fine particles of inorganic oxide are dispersed in an arbitrary organic solvent or water using a dispersion aid such as a surfactant as required, or an oxide precursor, for example, A so-called sol-gel method in which a solution of an alkoxide body is applied and dried is used.

  Among these, the atmospheric pressure plasma method is preferable.

  For the plasma CVD method or the atmospheric pressure plasma CVD method, for example, an apparatus disclosed in JP-A-10-1553, JP-A-2002-113805, JP-A-2003-303520, or JP-A-2004-238455 is used. Can be implemented.

  It is also preferable that the gate insulating layer is composed of an anodized film or the anodized film and an insulating film. The anodized film is preferably sealed. The anodized film is formed by anodizing a metal that can be anodized by a known method.

Examples of the metal that can be anodized include aluminum and tantalum, and the anodizing method is not particularly limited, and a known method can be used. An oxide film is formed by anodizing. Any electrolyte solution that can form a porous oxide film can be used as the anodizing treatment. Generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, boric acid, sulfamic acid, benzenesulfone, and the like can be used. An acid or the like, a mixed acid obtained by combining two or more of these, or a salt thereof is used. The treatment conditions for anodization vary depending on the electrolyte used, and thus cannot be specified in general. In general, the electrolyte concentration is 1 to 80% by mass, the electrolyte temperature is 5 to 70 ° C., and the current density. A range of 0.5 to 60 A / dm ² , a voltage of 1 to 100 volts, and an electrolysis time of 10 seconds to 5 minutes are suitable. A preferred anodizing treatment is a method in which an aqueous solution of sulfuric acid, phosphoric acid or boric acid is used as the electrolytic solution and the treatment is performed with a direct current, but an alternating current can also be used. The concentration of these acids is preferably 5 to 45% by mass, and the electrolytic treatment is preferably performed for ²⁰ to 250 seconds at an electrolyte temperature of 20 to 50 ° C. and a current density of 0.5 to 20 A / dm ² .

  The channel region on the gate insulating layer where the organic semiconductor layer is formed is described in, for example, Japanese Patent Application Laid-Open No. 2003-234522 and Japanese Patent Application No. 2006-82419 so that the formed organic semiconductor layer has a preferable orientation. As described above, the self-assembled film having an atomic group common to the molecules constituting the organic semiconductor material may be subjected to a surface treatment with a silane compound (for example, a silane coupling agent having an affinity for the organic semiconductor molecules). This is preferable because the carrier mobility of the organic semiconductor layer formed by the orientation of the organic semiconductor material molecules is improved.

  In addition, a region that does not form the organic semiconductor layer other than the channel region may be subjected to a surface treatment that repels the organic semiconductor material solution with the silane coupling agent or the like.

  In order to selectively perform surface treatment on these regions, a technique such as forming a resist using a mask or a photosensitive resin can be used.

  In addition, as the organic compound film, polyimide, polyamide, polyester, polyacrylate, photo radical polymerization type, photo cation polymerization type photo curable resin, or a copolymer containing an acrylonitrile component, polyvinyl phenol, polyvinyl alcohol, novolac resin, Also, cyanoethyl pullulan or the like can be used.

  As the method for forming the organic compound film, the wet process is preferable.

  An inorganic oxide film and an organic oxide film can be laminated and used together. The thickness of these insulating films is generally 50 nm to 3 μm, preferably 100 nm to 1 μm.

  In the present invention, when an organic semiconductor layer is formed on the gate insulating layer, the surface treatment of the present invention is performed on the surface of the gate insulating layer, and then the solution containing the organic semiconductor material is applied, whereby the organic semiconductor The layer is formed in a pattern.

[About the board]
Various materials can be used as the support material constituting the substrate. For example, ceramic substrates such as glass, quartz, aluminum oxide, sapphire, silicon nitride, silicon carbide, silicon, germanium, gallium arsenide, gallium phosphide. In addition, a semiconductor substrate such as gallium nitrogen, paper, and non-woven fabric can be used. In the present invention, the support is preferably made of a resin, for example, a plastic film sheet can be used. Examples of plastic films include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), and cellulose. Examples include films made of triacetate (TAC), cellulose acetate propionate (CAP), and the like. By using a plastic film, the weight can be reduced as compared with the case of using a glass substrate, the portability can be improved, and the resistance to impact can be improved.

  An element protective layer can be provided on the organic thin film transistor element of the present invention. Examples of the protective layer include the inorganic oxides and inorganic nitrides described above, and the protective layer is preferably formed by the atmospheric pressure plasma method described above. Thereby, durability of an organic thin-film transistor element improves.

  In the thin film transistor element of the present invention, when the support is a plastic film, it preferably has at least one of an undercoat layer containing a compound selected from inorganic oxides and inorganic nitrides, and an undercoat layer containing a polymer.

  Examples of the inorganic oxide contained in the undercoat layer include silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, barium zirconate titanate, lead zirconate titanate, titanate Examples thereof include lead lanthanum, strontium titanate, barium titanate, barium fluoride magnesium, bismuth titanate, strontium bismuth titanate, strontium bismuth tantalate, bismuth tantalate niobate, and yttrium trioxide. Examples of the inorganic nitride include silicon nitride and aluminum nitride.

  Of these, silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, and silicon nitride are preferable.

  In the present invention, the undercoat layer containing a compound selected from inorganic oxides and inorganic nitrides is preferably formed by the atmospheric pressure plasma method described above.

  Polymers used for the undercoat layer containing polymer include polyester resin, polycarbonate resin, cellulose resin, acrylic resin, polyurethane resin, polyethylene resin, polypropylene resin, polystyrene resin, phenoxy resin, norbornene resin, epoxy resin, vinyl chloride-vinyl acetate Copolymer, vinyl chloride resin, vinyl acetate resin, copolymer of vinyl acetate and vinyl alcohol, partially hydrolyzed vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer Polymer, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, vinyl polymers such as ethylene-vinyl acetate copolymer, polyamide resin, ethylene-butadiene resin, Tajien - rubber-based resin such as acrylonitrile resin, silicone resin, and fluorine resins.

  Hereinafter, preferred embodiments of the method for producing a thin film transistor of the present invention will be described in detail, but the present invention is not limited thereto.

(Preferred embodiment)
Although the preferred embodiment of the present invention is shown, the present invention is not limited thereto.

  Hereinafter, in the same manner as described above, with reference to FIG. 1, each step of a method for manufacturing an organic thin film transistor in which a water repellent pattern is formed on a source electrode and a drain electrode and an organic semiconductor layer is formed between the source and drain electrodes by introducing an organic semiconductor solution. Indicates.

  FIG. 1A shows a substrate in which a gate electrode and a gate insulating layer are formed on a resin support.

First, as a resin support 1, using polyethersulfone resin film (200 [mu] m), on the, first, subjected to corona discharge treatment under the condition of 50W / m ² / min. Next, an undercoat layer was formed to improve adhesion as follows.

(Formation of undercoat layer)
A coating solution having the following composition was applied to a dry film thickness of 2 μm, dried at 90 ° C. for 5 minutes, and then cured for 4 seconds from a distance of 10 cm under a 60 W / cm high-pressure mercury lamp.

Dipentaerythritol hexaacrylate monomer 60g
Dipentaerythritol hexaacrylate dimer 20g
Dipentaerythritol hexaacrylate trimer or higher component 20g
Diethoxybenzophenone UV initiator 2g
Silicone surfactant 1g
75g of methyl ethyl ketone
Methyl propylene glycol 75g
Further, a silicon oxide film having a thickness of 50 nm was formed on the layer by continuous atmospheric pressure plasma treatment under the following conditions, and these layers were used as the undercoat layer 2a (not shown in the figure). As the atmospheric pressure plasma processing apparatus, an apparatus according to FIG. 6 described in JP-A No. 2003-303520 was used.

(Used gas)
Inert gas: Helium 98.25% by volume
Reactive gas: 1.5% by volume of oxygen gas
Reactive gas: Tetraethoxysilane vapor (bubbled with helium gas) 0.25% by volume
(Discharge conditions)
Discharge output: 10 W / cm ²
(Electrode condition)
Here, discharge was performed at a frequency of 13.56 MHz using a high-frequency power source manufactured by Pearl Industries.

  The electrode is coated with 1 mm of alumina by ceramic spraying on a stainless steel jacket roll base material having cooling means with cooling water, and then a solution obtained by diluting tetramethoxysilane with ethyl acetate is applied and dried, and then sealed by ultraviolet irradiation. This is a roll electrode having a dielectric (relative dielectric constant of 10) having a pore surface, smoothed surface and having a maximum surface roughness (Rmax) defined by JIS B 0601 of 5 μm (relative dielectric constant 10). On the other hand, as the application electrode, a hollow rectangular stainless steel pipe was coated with the same dielectric as described above under the same conditions.

<Formation of gate bus line and gate electrode>
Next, a gate bus line and a gate electrode 2 were formed.

That is, a photosensitive resin composition liquid 1 having the following composition is applied on the undercoat layer and dried at 100 ° C. for 1 minute to form a photosensitive resin layer having a thickness of 2 μm. The gate bus line and gate electrode patterns were exposed with an energy density of 200 mJ / cm ² with a semiconductor laser of 830 nm and an output of 100 mW, developed with an alkaline aqueous solution to obtain a resist image, and a thickness of 300 nm was formed thereon by sputtering. After the aluminum film was formed on the entire surface, the remaining part of the photosensitive resin layer was removed with MEK to produce the gate bus line and the gate electrode 2.

(Photosensitive resin composition liquid 1)
Dye A 7 parts novolak resin (novolak resin co-condensed with phenol and m-, p-mixed cresol and formaldehyde (Mw = 4000, molar ratio of phenol / m-cresol / p-cresol is 5/57/38, respectively)) 90 parts Crystal violet 3 parts Propylene glycol monomethyl ether 1000 parts

  The patterning is not patterning by resist formation using a photosensitive resin, but a pattern of gate lines and gate electrodes may be formed by electroless plating by combining an ink jet apparatus and the like and electroless plating.

  Next, an anodized film was formed on the gate electrode as an auxiliary insulating film for smoothing and improving the insulating properties by an anodized film forming step (not shown in the figure).

(Anodized film forming process)
After forming the gate electrode, the substrate is washed thoroughly, and the thickness of the anodic oxide film reaches 120 nm using a direct current supplied from a low-voltage power supply of 30 V in a 10 mass% ammonium phosphate aqueous solution for 2 minutes. Anodized. After thoroughly washing, steam sealing treatment was performed in a saturated steam chamber at 1 atm and 100 ° C. In this way, a gate electrode having an anodized film was produced on a polyether sulfone resin film subjected to a subbing treatment.

  Subsequently, at a film temperature of 200 ° C., a silicon oxide layer having a thickness of 30 nm is formed using the following gas by the atmospheric pressure plasma method as described above, and the gate insulating layer 3 is formed by combining the anodic oxide film (alumina film). (FIG. 1 (1)).

(Used gas)
Inert gas: helium 98.25% by volume
Reactive gas: oxygen gas 1.5 volume%
Reactive gas: Tetraethoxysilane vapor (bubbled with helium gas) 0.25% by volume
Next, a silver nanoparticle ink (toluene dispersion of silver fine particles having an average particle diameter of 8 nm) as a liquid electrode material was applied on the gate insulating layer 3 and dried at 80 ° C. to form the electrode layer 4. The film thickness was 100 nm. (Fig. 1 (2).)
Next, a silicone rubber layer 6 was formed on the electrode layer 4 as a water repellent layer in combination with the photosensitive resin layer 5 as follows (FIG. 1 (3)).

<Photosensitive resin layer forming process>
The following composition 1 was kneaded and dispersed, and then 5.90 parts of a polyisocyanate compound (manufactured by Nippon Polyurethane Industry Co., Ltd., Coronate 3041; active ingredient 50%) was added, followed by stirring with a dissolver to prepare a coating solution. .

Composition 1
Fe-Al ferromagnetic metal powder [Fe: Al atomic ratio = 100: 4, average major axis diameter: 0.14 μm] 100 parts Vinyl chloride resin [manufactured by Nippon Zeon Co., Ltd., MR-110] 10.0 Part Polyurethane resin [Toyobo Co., Ltd., Byron UR-8200] 5.0 parts Phosphate ester [Toho Chemical Co., Ltd., Phosphanol RE610] 3.0 parts Methyl ethyl ketone 105.0 parts Toluene 105.0 Part Cyclohexanone 90.0 parts The above coating solution was applied onto the electrode layer 4 and treated at 100 ° C for 5 minutes to form a photosensitive resin layer 5 having a thickness of 0.3 µm.

<Water repellent layer forming process>
A liquid obtained by diluting the following composition 2 on the photosensitive resin layer 5 with a single solvent of Isopar E ″ (isoparaffinic hydrocarbon, manufactured by Exxon Chemical Co., Ltd.) to a solid content concentration of 10.3% by mass is coated. A 0.4 μm silicone rubber layer 6 was formed (FIG. 1 (3)).

Composition 2
α, ω-divinylpolydimethylsiloxane (molecular weight about 60,000) 100 parts HMS-501 (both terminal methyl (methylhydrogensiloxane) (dimethylsiloxane) copolymer, SiH group number / molecular weight = 0.69 mol / g, Chisso 7 parts vinyl tris (methyl ethyl ketoximino) silane 3 parts SRX-212 (platinum catalyst, manufactured by Toray Dow Corning Silicone Co., Ltd.) 5 parts
<Photosensitive resin layer exposure process and development process>
The exposure between the photosensitive layer and the water-repellent layer (silicone rubber layer) is changed by exposure with an energy density of 200 mJ / cm ² with a semiconductor laser having an oscillation wavelength of 830 nm and an output of 100 mW (FIG. 1 (4)). The silicone rubber layer other than the electrode pattern portion (exposed portion) was removed by brush treatment.

  Further, after thoroughly washing with water, the photosensitive resin layer and the electrode material layer in the exposed area were removed.

  Next, the substrate was heat-treated at 200 ° C. for 20 minutes. Thereby, the electrode material layer which consists of silver nanoparticles was fuse | melted, and it converted into the source electrode and the drain electrode (FIG. 1 (5)).

<Organic semiconductor layer formation process>
Thereafter, a toluene solution (0.5% by mass) of an organic semiconductor solution, OSC2-1 was prepared, and this was supplied to the channel region between the source electrode and the drain electrode by a piezo ink jet (FIG. 1 (6)). .

Since the upper surface of each of the source electrode 7 and the drain electrode 8 having the silicone rubber layer 6 on the surface repels the organic semiconductor solution, a part of the solution supplied on the electrode also enters the channel region between the source electrode and the drain electrode. By gathering (FIG. 1 (7)) and removing the solvent by drying, the organic semiconductor layer was disposed between the electrodes with high positional accuracy (FIG. 1 (8)).

This thin film transistor was driven well and showed a p-type enhancement operation. An increase in drain current (transfer characteristics) was observed when the drain bias was −15 V and the gate bias was swept from +10 V to −20 V. The carrier mobility estimated from the saturation region was 0.6 cm ² / Vs, the on / off ratio (logarithm of the ratio of the maximum value and the minimum value of the drain current) was 7.3, and the threshold value was −3V.

Example 2
A thin film transistor was produced in the same manner as in Example 1 except that the <water repellent layer forming step> was changed as follows.

  A 3% toluene solution of poly (p-trimethylsilylstyrene) (polymerization degree n = 1000) was applied to a dry film thickness of 0.3 μm and dried at a drying temperature of 90 ° C.

  Next, using the same apparatus as the atmospheric pressure plasma method described above, oxygen plasma treatment was performed for 1 minute using the following gas at room temperature of 25 ° C.

(Used gas)
Inert gas: Nitrogen 98.25% by volume
Reactive gas: oxygen gas 1.75% by volume
Thus, a layer having the surface layer 3 containing silicon oxide and having a thickness of about 10 nm was formed.

  Further, using octyltriethoxysilane as a source gas, the surface layer 3 was continuously subjected to atmospheric pressure plasma treatment for 20 seconds under the following conditions. As the atmospheric pressure plasma processing apparatus, an apparatus according to FIG. 6 described in JP-A No. 2003-303520 was used.

(Atmospheric pressure plasma treatment conditions)
[Used gas]
Inert gas: Nitrogen 98.25% by volume
Source gas: Octyltriethoxysilane 1.75% by volume
[Discharge conditions]
Discharge output: 5 W / cm ² .

  By the above method, a monomolecular film having an octyl group on the surface was formed on the entire surface to form a water repellent layer.

This thin film transistor was driven well and showed a p-type enhancement operation. An increase in drain current (transfer characteristics) was observed when the drain bias was −15 V and the gate bias was swept from +10 V to −20 V. The carrier mobility estimated from the saturation region was 0.5 cm ² / Vs, the on / off ratio (the logarithm of the ratio between the maximum value and the minimum value of the drain current) was 7.0, and the threshold value was −5V.

Example 3
On the transistor manufactured in Example 1, an aqueous dispersion of polydimethylsiloxane (solid content: 1%) was supplied to a channel region (semiconductor) between a source electrode and a drain electrode using a piezo ink jet. The water repellent layer was repelled by the water repellent layer and collected on the semiconductor layer. Furthermore, the protective layer of the thin-film transistor was formed by making it dry at 100 degreeC for 5 minutes (FIG. 1 (9), (10)).

  Through the above method, a thin film transistor in which a protective layer was formed was manufactured. This thin film transistor operated well as in Example 1.

  As described above, according to the present invention, a bottom-gate organic thin film transistor having high mobility and good characteristics can be obtained by a simple method.

It is a schematic sectional drawing which shows each process of the manufacturing method of the organic thin-film transistor which forms a water-repellent pattern on a source electrode and a drain electrode, and forms a machine semiconductor layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support body 2 Gate electrode 3 Gate insulating layer 4 Electrode layer 5 Photosensitive resin layer 6 Silicone rubber layer 7 Source electrode 8 Drain electrode 9 Organic-semiconductor layer

Claims (6)

A method for producing an organic thin film transistor, comprising forming a water repellent pattern on a source electrode and a drain electrode, then introducing an organic semiconductor solution between the source electrode and the drain electrode, and removing the solvent to form an organic semiconductor layer . The method for producing an organic thin film transistor according to claim 1, wherein a protective layer is formed on the organic semiconductor layer. The method for producing an organic thin film transistor according to claim 2, wherein the protective layer is formed by a casting method. The method for producing an organic thin film transistor according to any one of claims 1 to 3, wherein the water repellent pattern region is formed by surface treatment with a silane coupling agent or a titanium coupling agent. The method for producing an organic thin film transistor according to any one of claims 1 to 4, wherein the water repellent pattern region is made of a siloxane polymer. The method for producing an organic thin film transistor according to any one of claims 1 to 5, wherein the source electrode and the drain electrode are formed of a fluid electrode material.

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