JP2008060117A - Organic thin-film transistor and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic thin-film transistor which has excellent thin film transistor characteristics and can be manufactured in a solution process having high production efficiency, and to provide a manufacturing method thereof. <P>SOLUTION: The organic thin-film transistor has at least a first electrode pattern formed on a substrate, an insulating layer formed so as to contact the first electrode pattern; a second electrode pattern formed so as to contact the insulating layer; a coating layer having a functional group having a chemical bonding force with a metal, and chemically bonded to the second electrode pattern via the functional group; and an organic semiconductor layer formed so as to contact the coating layer. In this case, an electrode surface processing agent used to form the coating layer is a compound represented by a formula (1), where A denotes a functional group having a chemical bonding force with a metal; L<SB>1</SB>denotes a bivalent linkage group selected from among a substituted or unsubstituted alkylene group, a cycloalkylene group, an alkene-1, 2-diyl group, an alkyne-1, 2 diyl group, and alylene group; Q denotes quadrivalent atom selected from among C, Si, Ge, Sn and Pb, R<SB>1</SB>-R<SB>3</SB>denote a substituted group selected from among an alkyl group, an alkyl halide group, an alkenyl group, a cycloalkyl group, an aryl group, a heteroaryl group, and an alkylcylyl group and may bond each other to form a cycle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an organic thin film transistor using an organic semiconductor film and a manufacturing method thereof.

  With the widespread use of information terminals, there is an increasing need for flat panel displays as computer displays. In addition, with the progress of computerization, the information that has been provided in paper media has been increasingly digitized. As a mobile display medium that is thin, light, and easy to carry, it has become electronic paper or digital paper. Needs are growing.

  In general, in a flat panel display device, a display medium is formed using elements utilizing liquid crystal, organic EL (organic electroluminescence), electrophoresis, or the like. In such a display medium, an active driving method using a thin film transistor element (TFT element) has become mainstream as an image driving method in order to ensure uniformity of screen luminance, screen rewriting speed, and the like. For example, in a normal computer display, these TFT elements are formed on a glass substrate, and liquid crystal, organic EL elements, etc. are sealed.

  Here, a semiconductor such as a-Si (amorphous silicon), p-Si (polysilicon) or the like is mainly used for the TFT element, and these Si semiconductors (and metal films as necessary) are multilayered, and the source, The TFT element is manufactured by sequentially forming the drain and gate electrodes on the substrate. The manufacture of such TFT elements usually requires sputtering or other vacuum manufacturing processes.

  However, in these Si-based TFT elements, it is necessary to form a large number of layers so that a plurality of semiconductor layers such as p-type and n-type are stacked only on the semiconductor layer that is necessary for the switching operation. Since a vacuum manufacturing process including a vacuum chamber is required to form the film, the apparatus cost and running cost are extremely enormous. Furthermore, it is necessary to pattern the layer formed by these vacuum manufacturing processes by means such as photolithography, and in this patterning process, it is necessary to perform a number of steps such as exposure, development, and washing, and as a result In order to form the element on the substrate, dozens of processes are required. In such a conventional manufacturing method using a Si semiconductor, it is not easy to change the equipment, for example, a design change of a manufacturing apparatus such as a vacuum chamber is required in response to the need for a large display screen.

  Further, since the formation of such a conventional TFT element using a Si material includes a high temperature process, the base material is restricted to be a material that can withstand the process temperature. Therefore, in practice, glass must be used, and when the above-described thin display such as electronic paper or digital paper is configured using such a conventionally known TFT element, the display is heavy and flexible. Products that may break due to chipping or dropping impact. These characteristics resulting from the formation of Si-based TFT elements on a glass substrate are undesirable in satisfying the need for an easy-to-carry-type thin display with the progress of computerization.

  On the other hand, in recent years, organic semiconductor materials have been energetically studied as organic compounds having high charge transport properties. In addition to charge transport materials for organic EL devices, these compounds are expected to be applied to, for example, organic laser oscillation devices and organic thin film transistor devices (organic TFT devices) reported in many papers.

  Materials that have been studied as semiconductor layers so far include acenes such as pentacene and tetracene, compounds having substituents introduced thereto, phthalocyanines and porphyrins, and precursors thereof, perylene and its tetracarboxylic acid derivatives, etc. Low molecular weight compounds, aromatic oligomers such as thiophene hexamers called α-thienyl or sexithiophene, compounds obtained by symmetrically condensing 5-membered aromatic heterocycles with naphthalene and anthracene, mono, oligo and polydithienopyridines Furthermore, conjugated polymers such as polythiophene, polythienylene vinylene, and poly-p-phenylene vinylene can be used.

  If a device in which such an organic material is a semiconductor layer can be realized, it may be possible to manufacture by vacuum or low pressure deposition at a low temperature. Manufacturing by such a low temperature process makes it possible to form TFT elements on a transparent resin substrate, making the display lighter and more flexible than conventional ones, and not broken (or very difficult to break) when dropped. It is thought that it can be.

  Furthermore, if it can be solubilized in a solvent by appropriately improving the molecular structure of these organic semiconductor materials, patterning is possible by a simple solution process such as an ink jet method or a printing method, and exposure and development associated with photolithography -It is expected that a number of processes such as washing can be reduced and a display can be manufactured by a simple process.

  By the way, in these TFT elements, the semiconductor layer is formed in contact with the source electrode and the drain electrode, carriers are injected from the source electrode into the semiconductor layer, the carriers pass through the surface or inside of the semiconductor layer, and from the semiconductor layer. Carriers are released to the drain electrode. Since these layers are formed of different materials, a carrier injection barrier exists between the semiconductor layer and the electrode in the TFT element. When the semiconductor layer is an organic semiconductor material, it is known that the carrier injection barrier is larger than that of the Si-based semiconductor layer, and it is difficult to create a high-performance TFT element.

  In order to improve such a problem of carrier injection at the interface between the electrode and the semiconductor layer, means for providing an intermediate thin film between the electrode and the organic semiconductor layer has been devised.

  For example, in Patent Document 1, a carbon nanotube is provided between an electrode and a semiconductor layer. In Patent Document 2, an intermediate layer made of a metal complex such as copper phthalocyanine is formed. In Patent Document 3, an intermediate layer having a permanent dipole moment such as polyvinylidene fluoride is formed. In Non-Patent Document 1, an attempt is made to improve the carrier mobility by improving the carrier injection efficiency between the electrode and the organic semiconductor layer by treating the electrode with pentafluorothiophenol.

However, since these intermediate layers must be formed by vapor deposition, not only the process is complicated but also the control of the film thickness is difficult, so that the characteristics are not stable or the solution is repelled. Since the material is easy, it has been difficult to form an organic semiconductor layer by a coating process. Also, the mobility obtained is still insufficient.
JP 2004-356530 A JP 2005-72495 A JP 2005-109028 A J. et al. Am. Chem. Soc. , Vol. 127 (2005), p. 4986

  An object of the present invention is to provide an organic thin film transistor that can be manufactured by a solution process having good thin film transistor characteristics and high production efficiency, and a method for manufacturing the same.

  The above object of the present invention can be achieved by the following configuration.

  1. At least a first electrode pattern formed on the substrate, an insulating layer formed in contact with the first electrode pattern, a second electrode pattern formed in contact with the insulating layer, a metal and a chemical And a coating layer chemically bonded to the second electrode pattern via the functional group, and an organic semiconductor layer formed in contact with the coating layer An organic thin film transistor, wherein the electrode surface treating agent used for forming the coating layer is a compound represented by the following general formula (1).

(In the formula, A represents a functional group having a chemical bonding force with a metal. L ₁ represents a substituted or unsubstituted alkylene group, cycloalkylene group, alkene-1,2-diyl group, alkyne-1,2-diyl. Group represents a divalent linking group selected from an arylene group, Q represents a tetravalent atom selected from C, Si, Ge, Sn, and Pb, R _{1 to} R ₃ represent a substituted or unsubstituted alkyl group, This represents a substituent selected from a halogenated alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, a heteroaryl group, and an alkylsilyl group, which may be linked to each other to form a ring.
2. 2. The organic thin film transistor according to 1 above, wherein the coating layer is formed of an electrode surface treatment agent in which the functional group A of the compound represented by the general formula (1) is a thiol group.

  3. 3. The organic thin film transistor according to 1 or 2 above, wherein the coating layer is formed of an electrode surface treatment agent in which the tetravalent atom Q of the compound represented by the general formula (1) is a silicon atom.

  4). An organic thin film transistor, wherein the electrode surface treating agent used for forming the coating layer is a compound represented by the following general formula (2).

(In the formula, L ₂ represents a divalent linking group selected from a substituted or unsubstituted alkylene group, a cycloalkylene group, and an arylene group. R ₄ represents a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group, alkyl group. It represents a substituent selected from silyl groups and may be linked to each other to form a ring.
5. 5. The organic thin film transistor according to any one of 1 to 4, wherein the metal forming the second electrode pattern is gold.

  6). Any one of 1 to 5 above, wherein the insulating layer has a second coating layer formed by treatment with a silane coupling agent represented by the following general formula (3). The organic thin-film transistor of Claim 1.

(Wherein, X is a halogen atom, an alkoxy group, selected from isocyanate groups, .Q representing a hydrolyzable substituent "are the same as tetravalent atoms and Q in the formula (1), R ₁ ′, R ₂ ′, R ₃ ′ represent the same substituents as R ₁ , R ₂ , R ₃ in the general formula (1), L ₃ represents a substituted or unsubstituted alkylene group, cycloalkylene group, alkene-1 , 2-diyl group, alkyne-1,2-diyl group, arylene group represents a divalent linking group.)
7). 7. The method for producing an organic thin film transistor, wherein the organic semiconductor layer of the organic thin film transistor according to any one of 1 to 6 is formed by coating.

  8). The formation of the coating layer of the organic thin film transistor according to any one of 1 to 6 includes a step of cleaning the surface of the second electrode pattern by atmospheric pressure plasma treatment, and a solution containing the electrode surface treatment agent. An organic thin film transistor manufacturing method comprising: supplying the cleaned second electrode pattern surface; and volatilizing and drying a solution in which the electrode surface treating agent is dissolved.

  ADVANTAGE OF THE INVENTION According to this invention, the organic thin-film transistor which can be manufactured with the solution process with favorable thin-film transistor characteristics and high production efficiency, and its manufacturing method can be provided.

  The present invention will be described in more detail.

  The organic thin film transistor of the present invention includes a first electrode pattern serving as a gate electrode pattern, an insulating layer covering the gate electrode, and a second electrode pattern serving as a source / drain electrode formed on the insulating layer. An organic thin film transistor comprising: a coating layer formed in contact with a source / drain electrode; and an organic semiconductor layer formed in contact with the coating layer, wherein the coating layer is between the source / drain electrode and the organic semiconductor layer. It is an organic thin film transistor with good characteristics that has improved coating of carriers from the source / drain electrode to the organic semiconductor layer by having a coating layer formed from a specific electrode surface treatment agent. Hereinafter, the surface treatment agent capable of forming such a coating layer, the layer constituting the organic thin film transistor, and the material thereof will be described in detail.

[Electrode surface treatment agent]
The organic thin film transistor of the present invention is characterized in that a coating layer made of the electrode surface treatment agent represented by the general formula (1) is provided between the source / drain electrodes and the organic semiconductor layer.

In the general formula (1), A represents a functional group having a chemical bonding force with a metal, specifically, an amino group, an imino group, a hydroxy group, an ether group, a thiol group, a sulfide group, a disulfide group, a phosphinyl group. , Pyridyl group, bipyridyl group, benzotriazolyl group (—C ₆ H ₄ N ₃ ), carbonyloxybenzotriazole group (—OC (═O) C ₆ H ₄ N ₃ ), oxybenzotriazole group (—O—) C ₆ H ₄ N _3), aminobenzotriazole group _{(-NH-C 6 H 4 N} 3), and _{-CONHOH, -COOH, -COSH, -C 5} H 4 N, -SO 3 H, -NC, - Examples include substituents represented by structural formulas such as CHO, —PO ₃ H ₂ , and —OPO ₃ H _2, but are not limited thereto.

  By having such a functional group having a chemical bonding force with a metal, a coating layer made of a monomolecular film bonded to an electrode can be formed. Therefore, the coating layer of the present invention can always be a coating layer having a constant thickness, and the organic thin film transistor having stable characteristics can be suppressed by suppressing the fluctuation of the carrier injection barrier due to the variation in the coating layer thickness. Obtainable.

In the general formula (1), L ₁ is a divalent group selected from a substituted or unsubstituted alkylene group, cycloalkylene group, alkene-1,2-diyl group, alkyne-1,2-diyl group, and arylene group. Represents a linking group, and Q represents a tetravalent atom selected from C, Si, Ge, Sn, and Pb. R _{1 to} R ₃ represent a substituent selected from a substituted or unsubstituted alkyl group, a halogenated alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, a heteroaryl group, and an alkylsilyl group, and are connected to each other. May form a ring.

  Specifically, 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.), Halogenated alkyl group (for example, trifluoromethyl group, 1,1,1-trifluoropropyl group, etc.), alkenyl group (for example, vinyl group, allyl group, etc.), alkynyl group (for example, ethynyl group, propargyl group, etc.) , Cycloalkyl groups (for example, cyclopentyl group, cyclohexyl group, etc.), aryl groups (for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group) Group, phenanthryl group, indenyl group, pyrenyl group, bif Nitryl group, etc.), heteroaryl group (for example, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, phthalazinyl group, etc.), alkyl A silyl group (for example, a trimethylsilyl group, a triethylsilyl group, a tripropyl (i or n) silyl group, a tributyl (i, t or n) silyl group, etc.), these substituents are further substituted by the above substituents Alternatively, a plurality of them may be bonded to each other to form a ring. Moreover, it is preferably a linear, branched or cyclic alkyl group.

  A conventionally known electrode surface treatment agent is an electrode surface treatment agent having a linear alkyl group or an aryl group, and forms a coating layer having a relatively high film density, whereas the electrode surface treatment agent of the present invention has a terminal end. By using an electrode surface treatment agent having a three-dimensionally bulky part, a coating layer having a low film density can be obtained. Although details are unknown, by forming such a coating layer between the electrode and the organic semiconductor layer, carrier injection from the electrode to the organic semiconductor layer is improved, and an organic thin film transistor having good characteristics is obtained. Estimated. In addition, when an organic solvent-based solution is applied, there is an effect that the solvent is less likely to be repelled than a coating layer formed from an electrode surface treatment agent having a linear alkyl group or an aryl group.

  Among the electrode surface treatment agents of the present invention, an electrode surface treatment agent in which the functional group having a chemical binding force with the metal represented by A is a thiol group is preferable. This is because the thiol group forms a strong bond close to a covalent bond with the metal and forms a coating layer that is difficult to peel off stably.

More preferably, it is an electrode surface treatment agent in which the atom represented by Q is a silicon atom. A silicon atom is an atom larger than carbon, can easily form a bulky end, and can form a coating layer having a lower film density. Further, atoms larger than silicon tend to be unstable in bonding with a substituent represented by R _{1 to} R ₃ or a linking group represented by L ₁ .

  A more preferable electrode surface treatment agent is a compound represented by the general formula (2).

In the general formula (2), L ₂ represents a divalent linking group selected from a substituted or unsubstituted alkylene group, a cycloalkylene group, and an arylene group, and R ₄ represents a substituted or unsubstituted alkyl group, a cycloalkyl group, It represents a substituent selected from an aryl group and an alkylsilyl group, and may be connected to each other to form a ring. Examples of the alkyl group, cycloalkyl group, aryl group, and alkylsilyl group include the groups described above for the alkyl group, cycloalkyl group, aryl group, and alkylsilyl group of the general formula (1).

Thus, since the substituents R _{1 to} R ₃ for substituting silicon atoms are all the same substituent R ₄ , it is possible to form a coating layer that is regular and has few defects, and thus has good characteristics. An organic thin film transistor can be obtained.

  Hereinafter, although the specific example of a compound represented by General formula (1) or (2) of this invention is shown, this invention is not limited to these.

  These compounds can be synthesized by referring to the following documents.

  Compounds having an alkylsilyl group at one end and a vinyl group at the other end are described in, for example, Tetrahedron Lett. , Vol. 26 (1985), page 5375; Org. Chem. , Vol. 70 (2005), 4865 pages and the like. Examples of the reaction for adding a thiol group to a vinyl group at the terminal include J. Org. Org. Chem. , Vol. 28 (1963), p. 3263, and the like.

  As the surface treatment agent used in the present invention, when the surface of the substrate is surface-treated, the surface contact angle with water is preferably in a specific range, and the surface contact angle with water after the surface treatment is 50 degrees. It is preferably ˜150 degrees, more preferably 70 to 120 degrees, and still more preferably 85 to 105 degrees. When the contact angle is low, the carrier mobility and on / off ratio of the transistor element are remarkably reduced. When the contact angle is too high, the solution containing the organic semiconductor material is easily repelled when the organic semiconductor layer is formed. This contact angle is measured under an environment of 20 ° C. and 50% RH using a contact angle meter (CA-DT • A type: manufactured by Kyowa Interface Science Co., Ltd.).

  The surface treatment agent according to the present invention can be used by mixing with other surface treatment agents. Examples of other surface treatment agents include alkyltrichlorosilane and alkyltrialkoxysilane.

  The thickness of the coating layer formed by the electrode surface treatment agent according to the present invention is preferably in the range of 0.5 to 20 nm, more preferably 0.7 to 10 nm, and still more preferably 1.0 to 3.0 nm. .

  The surface roughness Ra of the thin film surface is greatly influenced by the surface properties of the substrate, the gate electrode, and the gate insulating film when the thin film transistor is a bottom gate type described later. From the viewpoint of carrier mobility of the transistor element, it is preferable.

  As a method for forming the coating layer of the present invention, a solution containing the electrode surface treatment agent of the present invention is prepared by spin coating, screen printing, ink jet printing, air doctor coater, blade coater, rod coater, Knife coater method, squeeze coater method, reverse roll coater method, transfer roll coater method, gravure coater method, kiss coater method, cast coater method, spray coater method, slit orifice coater method, calendar coater method, dipping method, spray method, dropping method It can be formed by applying on the second electrode pattern using various solution processes such as the Langmyr-Blodgett method, washing, and drying.

〔electrode〕
Next, an electrode material for forming a first electrode pattern that is a gate electrode and a second electrode pattern that is a source / drain electrode and a method for forming the electrode material will be described.

  In the organic thin film transistor of the present invention, the material constituting the first electrode pattern that is the gate electrode and the wiring portion that connects the electrode and the power source is not particularly limited as long as it is a conductive material. It is formed. 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 Miniumu mixture, a magnesium / indium mixture, aluminum / aluminum oxide mixture, a lithium / aluminum mixture, or the like is used. Alternatively, known conductive polymers whose conductivity is improved by doping or the like, for example, conductive polyaniline, conductive polypyrrole, conductive polythiophene (polyethylenedioxythiophene and polystyrenesulfonic acid complex, etc.) are also preferably used.

  The material for forming the second electrode pattern that is the source / drain electrode is not particularly limited as long as it contains a metal that can be combined with the above-described electrode surface treatment agent, and is not particularly limited. , 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-cariou Alloy, magnesium, lithium, aluminum, magnesium / copper mixture, a magnesium / silver mixture, a magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, and lithium / aluminum mixtures. Among them, those having a small electric resistance at the contact surface with the semiconductor layer are preferable, and platinum, gold, silver, and copper are preferable when the semiconductor layer is a p-type semiconductor. Among them, gold is preferable because it has a small potential difference with respect to the organic semiconductor material and has a small carrier injection barrier from the electrode to the organic semiconductor. Further, since gold does not form an oxide film on the electrode surface due to oxidation or the like, there is no fear that the reactivity between the electrode surface and the electrode surface treating agent of the present invention is lowered.

  As a method for forming an electrode, a conductive thin film formed using a dry process such as vapor deposition or sputtering using the above as a raw material, and a method for forming an electrode shape using a known photolithography method or a lift-off method, aluminum, copper, or the like A method in which a resist is formed on a metal foil by thermal transfer, ink jet, etc., patterned by etching, transferred by laser ablation, etc., or a conductive polymer solution or dispersion containing metal fine particles, conductive ink, conductive And a method of forming a functional paste or the like by a printing process such as relief printing, intaglio printing, lithographic printing, screen printing, or a solution process such as an inkjet method.

  As a means for forming the shape of the source electrode and the drain electrode, it is preferable to use a photolithographic method or an inkjet method.

  Note that the electrode surface treatment agent described above is a coating having a controlled thickness because the surface of the electrode is oxidized to form an oxide film, or when dirt due to organic matter or the like is attached, the reactivity with the electrode decreases. Since it may be difficult to form a layer, when forming a coating layer using the above-described electrode surface treatment agent, clean the electrode surface using a known cleaning method immediately before forming the coating layer. It is preferable to wash it.

  Examples of such an electrode surface cleaning method include treatment with a strong acid / strong alkali, ultraviolet irradiation, ozone treatment, corona discharge treatment, plasma treatment and the like. Of these, plasma treatment is preferred, and atmospheric pressure plasma treatment is more preferred.

  The atmospheric pressure plasma treatment is a treatment in which a gas containing plasma generated by applying an electric field between opposing electrodes under atmospheric pressure is sprayed onto a substrate. In atmospheric pressure plasma processing, the density of active species is higher than in vacuum plasma processing, so the electrode surface can be processed at high speed and high efficiency. There is an advantage that you can. The atmospheric pressure plasma treatment can be performed with reference to JP-A No. 2003-309266.

[Organic semiconductor film]
As an organic semiconductor material constituting the organic semiconductor film, any material can be used as long as it can control the mobility of carriers by the electric field effect. However, a p-type semiconductor in which the carriers are holes and the carriers are electrons. It can be roughly divided into n-type semiconductors. However, up to now, there are few n-type organic semiconductor materials with high mobility and stability, and the majority are p-type organic semiconductor materials.

  Examples of such organic semiconductor materials include various condensed polycyclic aromatic compounds and conjugated compounds.

  Examples of the condensed polycyclic aromatic compound include anthracene, tetracene, pentacene, hexacene, heptacene, chrysene, picene, fluorene, pyrene, peropyrene, perylene, terylene, quaterylene, coronene, ovalene, thacumanthracene, bisanthene, zeslen, heptazelene. , Pyranthrene, violanthene, isoviolanthene, cacobiphenyl, anthradithiophene, and the like, and derivatives and precursors 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 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- An oligomer such as butoxypropyl) -α-sexithiophene can be preferably used.

  Furthermore, porphyrin, copper phthalocyanine, metal phthalocyanines such as fluorine-substituted copper phthalocyanine described in JP-A No. 11-251601, naphthalene 1,4,5,8-tetracarboxylic acid diimide, N, N′-bis (4-tri Fluoromethylbenzyl) 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 derivative, naphthalene tetracarboxylic acid diimides such as naphthalene 2,3,6,7 tetracarboxylic acid diimide, and anthracene 2,3,6,7 -Condensed rings such as anthracene tetracarboxylic acid diimides such as tetracarboxylic acid diimide Organics such as tracarboxylic acid diimides, tetrathiafulvalene (TTF) -tetracyanoquinodimethane (TCNQ) complex, bisethylenetetrathiafulvalene (BEDTTTTF) -perchloric acid complex, BEDTTTTF-iodine complex, TCNQ-iodine complex, etc. Molecular complexes, fullerenes such as C60, C70, C76, C78, and C84, carbon nanotubes such as SWNT, dyes such as merocyanine dyes and hemicyanine dyes, σ-conjugated polymers such as polysilane and polygerman, and JP-A 2000- An organic / inorganic hybrid material described in 260999 can also be used.

  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, metal phthalocyanines, and metal porphyrins is preferable.

As a method for forming the organic semiconductor layer, physical vapor deposition methods such as a vacuum deposition method, an MBE (Molecular Beam Epitaxy) method, an ion cluster beam method, a low energy ion beam method, an ion plating method, and a sputtering method ( Dry processes such as PVD and chemical vapor deposition (CVD),
Spin coating method, screen printing method, inkjet printing method, air doctor coater method, blade coater method, rod coater method, knife coater method, squeeze coater method, reverse roll coater method, transfer roll coater method, gravure coater method, kiss coater method, Examples of the solution process include cast coater method, spray coater method, slit orifice coater method, calender coater method, dipping method, spray method, dripping method, Langmyer-Blodgett method, etc., depending on the organic semiconductor material used. An appropriate method may be used.

  In the organic thin film transistor of the present invention, it is preferable to form the organic semiconductor layer by a solution process among the above processes. If it can be formed by a solution process, the number of steps can be greatly reduced, and not only can an organic thin film transistor be formed by a simple process, but also a crystal larger than that formed by a dry process can be formed. As a result, an organic thin film transistor having good mobility can be formed.

  However, in general, the above condensed polycyclic aromatic compounds and conjugated compounds have poor solubility, and in order to obtain a soluble organic semiconductor material, an organic group such as the above, an alkyl group, an alkylsilyl group, or a cycloalkyl group. It is preferable to use an organic semiconductor material solubilized in a solvent by adding a substituent such as a group or an aryl group.

  Examples of such a soluble organic semiconductor material include poly (3-hexylthiophene) and polythiophene compounds having an alkyl group as described in JP-A Nos. 2003-292588 and 2005-76030, An acene compound and a heteroacene compound having a trialkylsilylethynyl group as described in Patent Document 1, and a three-dimensional cyclic structure such as a bicyclo ring described in JP-A-2003-304104 Examples thereof include porphyrin compounds.

  The film thickness of these organic semiconductor films is not particularly limited, but the characteristics of the obtained transistor are often greatly influenced by the film thickness of the organic semiconductor film, and the film thickness varies depending on the organic semiconductor. In general, the thickness is 10 nm to 1 μm, preferably 20 nm to 500 nm, more preferably 30 nm to 300 nm.

[Gate insulation film]
Various insulating films can be used as the gate insulating layer of the organic thin film transistor of the present invention. For example, silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, titanium zirconate Barium oxide, lead zirconate titanate, lead lanthanum titanate, strontium titanate, barium titanate, barium fluoride magnesium, bismuth titanate, strontium bismuth titanate, strontium bismuth tantalate, bismuth tantalate niobate, trioxide yttrium Metal oxides, etc.
Metal nitrides such as silicon nitride, aluminum nitride, boron nitride, titanium nitride, polymethyl methacrylate (PMMA), polyvinyl phenol (PVP), polyvinyl alcohol (PVA), polyimide, polyamide, polyester, polyacrylate, radical photopolymerization system, Photo-curing resin such as epoxy resin and oxetane resin, or copolymer containing acrylonitrile component, polyvinylphenol, polyvinyl alcohol, novolac resin, and natural polysaccharides such as cyanoethyl pullulan and triacetyl cellulose And organic insulating materials such as resin, gelatin, and parylene formed by low-temperature chemical vapor deposition, and combinations thereof can also be used.

  Among these materials, it is preferable to use a material having a high dielectric breakdown voltage and a high relative dielectric constant. With a material having a high dielectric breakdown voltage, the film pressure of the insulating film can be reduced, the production speed can be increased, and the occurrence of cracks and peeling when the element is bent can be reduced. If a material having a high relative dielectric constant is used, a channel can be formed with a low gate voltage, and an organic thin film transistor that can be driven with a low voltage can be obtained. As the insulating film material satisfying such characteristics, silicon oxide, silicon nitride, polyvinylphenol, and polyimide can be preferably used.

  The insulating film can be formed by vacuum deposition, molecular beam epitaxial growth, ion cluster beam method, low energy ion beam method, ion plating method, chemical vapor deposition (CVD) method, sputtering method, atmospheric pressure plasma CVD. Dry processes such as spray coating, spray coating, spin coating, blade coating, dip coating, casting, roll coating, bar coating, die coating, etc. And a method of forming the surface of the gate electrode by oxidizing or nitriding, and can be used depending on the material. As a wet process, for example, for an Au electrode, an insulating molecule having a functional group capable of forming a chemical bond with a gate electrode, such as a hydrocarbon modified with a mercapto group at one end and an alkylsilane, is used. An insulating film can also be formed on the surface of the gate electrode by covering the surface of the gate electrode in a self-organizing manner by a method such as immersion. The insulating film can also be formed by using a technique such as oxidizing or nitriding the surface of the gate electrode. Examples of the method for oxidizing the gate electrode include an oxidation method using oxygen plasma and an anodic oxidation method. As a method for nitriding the surface of the gate electrode, a nitriding method using nitrogen plasma can be exemplified.

  Among these, the method for forming an inorganic thin film is preferably an anodic oxidation method, an atmospheric pressure plasma CVD method, or a method combining them.

The anodized film can be formed on the surface of the metal by anodizing a metal that can be anodized by a known method. Examples of the metal that can be anodized include aluminum and tantalum. 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. Acids or the like, or mixed acids obtained by combining two or more of these or salts thereof are 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 atmospheric pressure plasma CVD method is a fine particle generated by introducing a raw material compound that forms a thin film into a plasma generated by applying an electric field between opposing electrodes under atmospheric pressure, and causing a chemical reaction in the plasma. Is deposited on a substrate to form a thin film using a known technique described in JP-A-11-43781, JP-A-2003-179234, WO2004-75279, or the like. Can be created.

  As the method for forming an insulating film made of an organic compound, 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 addition, a second coating layer may be formed on the surface of the gate insulating layer for the purpose of modifying various characteristics such as flatness and surface energy.

  The second coating layer may form a thin film made of an inorganic oxide such as titanium oxide, aluminum oxide or tantalum oxide, a high dielectric constant polymer such as polyvinylidene fluoride, octadecyltrichlorosilane, trichloromethylsilazane, etc. It is also possible to use a self-assembled alignment film comprising a silane coupling agent, alkane phosphoric acid, alkane sulfonic acid, alkane carboxylic acid, etc., and compounds described in Japanese Patent Application No. 2006-82419.

  Among these, it is preferable to use a coating layer formed from a silane coupling agent. When such a coating material having a functional group having reactivity with the surface of the insulating film is used, a monomolecular film can be formed. Therefore, the thickness of the second coating layer can be made constant, and variations are caused. An organic thin film transistor element with a small amount can be obtained.

  More preferably, it has the 2nd coating layer formed using the silane coupling agent represented by the said General formula (3).

  Thus, by forming the first and second coating layers so that the surfaces of the source / drain electrodes and the insulating layer have the same substituent, the surfaces of adjacent layers such as the source / drain electrodes and the insulating layer are formed. It is possible to obtain a stable and high-performance organic thin film transistor element by suppressing the fluctuation of the characteristics of the organic semiconductor layer depending on the state.

[Substrate]
Various materials can be used as a base (also referred to as a substrate) for forming an organic thin film transistor. For example, glass, quartz, aluminum oxide, sapphire, silicon nitride, silicon carbide and other ceramic bases, silicon, germanium, gallium A semiconductor substrate such as arsenic, gallium phosphide, and gallium nitrogen, paper, non-woven fabric, and the like, and a substrate made of a metal such as stainless steel and aluminum having a thickness that can be bent can be used. Preferably, 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, it is possible to reduce the weight as compared to the case of using a glass substrate, to improve portability, and to improve resistance to impact. Further, it becomes possible to incorporate or integrate a field effect transistor into a display device or electronic device having a curved shape.

[Undercoat layer]
In the organic thin film transistor of the present invention, when the substrate is a plastic film, an undercoat layer containing a compound selected from an inorganic oxide and an inorganic nitride, and a polymer in order to improve the adhesion between the substrate and the organic thin film transistor It is preferable to have at least one of the undercoat layers containing.

  Inorganic oxides 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, as a method for forming an undercoat layer containing a compound selected from inorganic oxides and inorganic nitrides, the same method for forming an inorganic oxide or inorganic nitride as the above-described gate insulating film forming method is used. However, it is preferably formed by an atmospheric pressure plasma method.

  Polymers used for the undercoat layer containing polymer include polyester resin, polycarbonate resin, cellulose resin, gelatin, 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 Copolymers, ethylene-vinyl alcohol copolymers, polyvinyl alcohol, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymers, vinyl polymers such as ethylene-vinyl acetate copolymers, polyamide resins, ethylene-butadiene Down resin, a butadiene - rubber resin such as acrylonitrile resin, silicone resin, and fluorine resins.

[Protective layer]
It is also possible to provide a protective layer on the organic thin film transistor of the present invention. Examples of the protective layer include inorganic oxides or inorganic nitrides, metal thin films such as aluminum, polymer films with low gas permeability, and laminates thereof. By having such a protective layer, durability of organic thin film transistors can be mentioned. Improves. As a method for forming these protective layers, the same method as the method for forming the gate insulating film described above can be used. Further, the protective layer may be provided by a method such as simply laminating a film in which various inorganic oxides are laminated on the polymer film.

[Configuration of organic thin film transistor]
An example of the layer structure of the organic thin film transistor of the present invention will be described with reference to the drawings.

  The organic thin film transistor has a source electrode and a drain electrode connected with an organic semiconductor film (hereinafter also referred to as an organic semiconductor layer) on a base, and a top gate type having a gate electrode on the gate electrode via the gate electrode, First, it is roughly classified into a bottom gate type having a gate electrode on a substrate and having a source electrode and a drain electrode connected by an organic semiconductor film through a gate insulating layer. Further, the source / drain electrodes as viewed from the gate electrode can be distinguished into a bottom contact type in front of the organic semiconductor layer and a top contact type in the other side of the organic semiconductor layer. Various organic thin film transistor configurations are possible, but the organic thin film transistor of the present invention requires the formation of a coating layer on the source and drain electrodes. Therefore, the bottom gate / bottom contact type configuration and the top gate / top contact type configuration are applicable. Either is preferable. In addition, when a large number of layers are formed on the organic semiconductor layer, the organic semiconductor layer may be deteriorated by heat, light, or the like when these layers are formed. This is a bottom gate / bottom contact type device as shown in FIG.

  In FIG. 1, a first electrode pattern 2 is formed on a substrate 1, and an insulating layer 3 is formed so as to cover the entire first electrode pattern 2. A second electrode pattern 4 is formed on the insulating layer 3, a coating layer 5 chemically bonded to the second electrode pattern 4 is formed thereon, and an organic semiconductor layer 6 is formed on the coating layer 5. Has been.

  In the configuration of FIG. 2, the second coating layer 7 is also provided between the insulating layer and the organic semiconductor layer. In the present invention, since the first coating layer 5 and the second coating layer 7 can have the same surface characteristics, the organic semiconductor layer formed on these coating layers can reduce the influence of the base and is uniform. Since an organic semiconductor layer can be formed, an organic thin film transistor having better characteristics can be obtained.

  If a process that transfers the electrode pattern in which the coating layer is formed on the source / drain electrodes onto the organic semiconductor layer is used, the organic thin film transistor having the bottom gate / top contact type configuration and the top gate / bottom contact type configuration can be obtained. It is also possible to obtain.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

Example 1
The following electroless plating catalyst solution is used as an ink on an n-type Si wafer having a specific resistance of 0.02 Ω · cm having a 200 nm thick silicon oxide film formed by thermal oxidation. A voltage with a bias voltage of 2000 V was applied, and a pulse voltage (400 V) was further superimposed to eject ink according to the source and drain electrode patterns. The inner diameter of the nozzle outlet was 10 μm, and the gap between the nozzle outlet and the substrate was kept at 500 μm. The following prescription was used as the plating catalyst-containing ink.

(Electroless plating catalyst solution)
Soluble palladium salt (palladium chloride) 20% by mass (Pd ²⁺ concentration 1.0 g / L)
Isopropyl alcohol 12% by mass
Glycerin 20% by mass
2-Methyl-pentanethiol 5% by mass
1,3-butanediol 3% by mass
Ion exchange water 40% by mass
Furthermore, a catalyst pattern was formed by drying and fixing.

  Next, printing was performed on the region including the region where the plating catalyst pattern was formed by using the following electroless gold plating solution as an ink by a screen printing method. When the plating agent was in contact with the plating catalyst, the gold thin film was deposited only on the plating catalyst pattern.

(Electroless gold plating solution)
Dicyano gold potassium 0.1 mol / L
Sodium oxalate 0.1 mol / L
Sodium potassium tartrate 0.1mol / L
The substrate surface on which the gold thin film was dissolved was thoroughly washed with pure water and dried to form a source / drain electrode pattern made of gold. The source / drain electrodes were formed so that the channel length L was 50 μm and the channel width W was 5 mm (W / L = 100).

  Next, the Si wafer on which the source / drain electrodes are formed is subjected to a vacuum oxygen plasma treatment for 1 minute under the conditions of an oxygen flow rate of 50 sccm, a degree of vacuum of 10 Pa, and an output of 200 W using a dry etching apparatus DEM-451 manufactured by Anerva Corporation. The surface of the source / drain electrode was cleaned.

  After immersing the Si wafer with the surface of the source / drain electrode cleaned in toluene at a concentration of 10 mmol / L of the electrode surface treatment agent listed in Table 1 below, the solution is toluene. And dried, and surface treatment of the source / drain electrodes was performed.

  Next, the following organic semiconductor material (1) as a p-type organic semiconductor material is dissolved in toluene at a concentration of 0.5% by mass, and this solution is so sized as to completely cover the source / drain electrodes. After applying in a substantially circular shape and drying at room temperature, an organic semiconductor film was formed by performing heat treatment at 90 ° C. for 1 minute in a nitrogen gas atmosphere. At this time, the film thickness of the organic semiconductor film was 30 nm.

  The organic thin film transistor thus obtained was evaluated for carrier mobility as follows.

  In addition, the structure of the electrode processing agent used for the comparison is as follows.

<Evaluation of carrier mobility>
About the obtained organic thin-film transistors 1-7, carrier mobility was computed from the saturation area | region of the IV characteristic when drain bias was -50V and gate bias was swept from -50V to 0V.

  About the obtained organic thin-film transistor, carrier mobility was measured and the result is shown in Table 1.

  Thus, by using the electrode surface treating agent of the present invention, the injection of carriers from the electrode to the organic semiconductor layer was improved, and an organic thin film transistor with improved mobility and on / off ratio could be obtained.

Example 2
The Si wafer formed with the source / drain electrodes obtained in Example 1 was similarly subjected to vacuum oxygen plasma treatment to clean the surface of the source / drain electrodes, and then 10 mmol of Exemplified Compound 20 as an electrode surface treatment agent. / L and the following silane coupling agent 1 as a silane coupling agent are immersed in a solution of toluene at a concentration of 10 mmol / L for 30 minutes at 60 ° C., rinsed with toluene, dried, and source / drain electrodes And surface treatment of the insulating film.

  Thereafter, as in Example 1, a solution obtained by dissolving the organic semiconductor material (1) in toluene at a concentration of 0.5% by mass was applied with a dispenser and dried at room temperature, and then in a nitrogen gas atmosphere. By performing a heat treatment at 1 ° C. for 1 minute, an organic semiconductor film having a film thickness of 30 nm is formed, an organic thin film transistor 8 is formed, carrier mobility is similarly evaluated, and the results are shown in Table 2.

  Thus, by providing the second coating layer on the insulating film, an organic thin film transistor with improved mobility could be obtained.

  The above silane coupling agent 1 is disclosed in J. Org. Org. Chem. , Vol. 70 (2005), page 4865, and can be easily obtained by subjecting a terminal vinyl compound that can be synthesized with reference to a hydrosilylation reaction using trichlorosilane.

Example 3
An aluminum thin film was deposited to a thickness of 20 nm on a polyethersulfone (PES) film having a thickness of 180 μm, and the shape of the gate electrode was formed by photolithography.

  Further, a silicon oxide film having a thickness of 200 nm was formed on the gate electrode by sputtering to form a gate insulating film.

  Source / drain electrodes were formed on the PES film thus obtained using the same electroless plating catalyst solution and electroless gold plating solution as in Example 1.

  As the cleaning process for the surface of the source / drain electrode, two kinds of processes were performed: vacuum plasma treatment and atmospheric pressure plasma treatment. The vacuum plasma treatment was performed by the same method as that described in Example 1, and the atmospheric pressure plasma treatment was performed using the atmospheric pressure plasma treatment apparatus described in JP-A No. 2003-309266 under the following conditions.

<Atmospheric pressure plasma treatment>
Discharge gas: Argon 99.0% by volume
Reaction gas: Oxygen 1.0% by volume
Discharge conditions: 13.56 MHz, 4 W / cm ²
Treatment time: 0.6 seconds In a PES film subjected to these treatments, a solution in which Exemplified Compound 20 as an electrode surface treatment agent was dissolved in toluene at a concentration of 10 mmol / L and the silane coupling agent 1 at a concentration of 10 mmol / L. After immersing at 60 ° C. for 30 minutes, the substrate was rinsed with toluene, dried, and surface treatment of the source / drain electrodes and the insulating film was performed.

  Thereafter, a solution in which the organic semiconductor material (1) is dissolved in toluene at a concentration of 0.5% by mass is applied with a dispenser and dried at room temperature, followed by heat treatment at 90 ° C. for 1 minute in a nitrogen gas atmosphere. As a result, an organic semiconductor film having a thickness of 30 nm is formed, organic thin film transistors 9 and 10 are formed, and carrier mobility is evaluated in the same manner, and the results are shown in Table 3.

  As described above, good thin film transistor characteristics are obtained in both treatments, but it can be seen that the atmospheric pressure plasma treatment has a shorter treatment time, and can produce an organic thin film transistor with high efficiency and high productivity.

It is a figure which shows the structural example of the organic thin-film transistor of this invention. It is a figure which shows another structural example of the organic thin-film transistor of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base | substrate 2 1st electrode pattern 3 Insulating layer 4 2nd electrode pattern 5 1st coating layer 6 Organic-semiconductor layer 7 2nd coating layer

Claims (8)

At least a first electrode pattern formed on the substrate, an insulating layer formed in contact with the first electrode pattern, a second electrode pattern formed in contact with the insulating layer, a metal and a chemical And a coating layer chemically bonded to the second electrode pattern via the functional group, and an organic semiconductor layer formed in contact with the coating layer An organic thin film transistor, wherein the electrode surface treating agent used for forming the coating layer is a compound represented by the following general formula (1).

(In the formula, A represents a functional group having a chemical bonding force with a metal. L ₁ represents a substituted or unsubstituted alkylene group, cycloalkylene group, alkene-1,2-diyl group, alkyne-1,2-diyl. Group represents a divalent linking group selected from an arylene group, Q represents a tetravalent atom selected from C, Si, Ge, Sn, and Pb, R _{1 to} R ₃ represent a substituted or unsubstituted alkyl group, This represents a substituent selected from a halogenated alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aryl group, a heteroaryl group, and an alkylsilyl group, which may be linked to each other to form a ring. 2. The organic thin film transistor according to claim 1, wherein the coating layer is formed of an electrode surface treatment agent in which the functional group A of the compound represented by the general formula (1) is a thiol group. 3. The organic thin film transistor according to claim 1, wherein the coating layer is formed of an electrode surface treatment agent in which the tetravalent atom Q of the compound represented by the general formula (1) is a silicon atom. . An organic thin film transistor, wherein the electrode surface treating agent used for forming the coating layer is a compound represented by the following general formula (2).

(In the formula, L ₂ represents a divalent linking group selected from a substituted or unsubstituted alkylene group, a cycloalkylene group, and an arylene group. R ₄ represents a substituted or unsubstituted alkyl group, cycloalkyl group, aryl group, alkyl group. It represents a substituent selected from silyl groups and may be linked to each other to form a ring. The organic thin film transistor according to any one of claims 1 to 4, wherein the metal forming the second electrode pattern is gold. The first coating layer according to claim 1, further comprising a second coating layer formed by treating with a silane coupling agent represented by the following general formula (3) on the insulating layer. The organic thin-film transistor of any one.

(Wherein, X is a halogen atom, an alkoxy group, selected from isocyanate groups, .Q representing a hydrolyzable substituent "are the same as tetravalent atoms and Q in the formula (1), R ₁ ′, R ₂ ′, R ₃ ′ represent the same substituents as R ₁ , R ₂ , R ₃ in the general formula (1), L ₃ represents a substituted or unsubstituted alkylene group, cycloalkylene group, alkene-1 , 2-diyl group, alkyne-1,2-diyl group, arylene group represents a divalent linking group.) The method for producing an organic thin film transistor, wherein the organic semiconductor layer of the organic thin film transistor according to claim 1 is formed by coating. 7. The organic thin film transistor coating layer according to any one of claims 1 to 6, wherein the step of cleaning the surface of the second electrode pattern by atmospheric pressure plasma treatment and a solution containing the electrode surface treatment agent A method of manufacturing an organic thin film transistor, comprising: supplying the surface of the cleaned second electrode pattern to the surface of the second electrode pattern; and volatilizing and drying a solution in which the electrode surface treating agent is dissolved.

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