JP2007096289A - Transistor, organic semiconductor device, and method of manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a transistor and an organic semiconductor device that can be formed satisfactorily on a surface on which an active layer should be formed, even if the active layer contains an organic semiconductor compound to which prescribed characteristics are given in advance. <P>SOLUTION: The method of manufacturing the transistor includes source and drain electrodes; the active layer that becomes the current path between the electrodes, and contains the organic semiconductor compound; a gate electrode for controlling current passing through the current path; and an insulating layer arranged between the active layer and the gate electrode. The manufacturing method includes a lamination process for interposing an application solution between the active and insulating layers to laminate the active and insulating layers together. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transistor, an organic semiconductor element, and a manufacturing method thereof.

  An organic semiconductor element is an element having an active layer containing an organic semiconductor compound. In such an organic semiconductor element, conventionally, the active layer is formed by various methods. For example, in a field effect transistor which is a typical example of an organic semiconductor element, the active layer is formed by depositing a powdered organic semiconductor compound on an insulating layer, or a solution of an organic semiconductor compound dissolved in a solvent on the insulating layer. It is known that it is formed by a method of spin coating, drop casting or printing (Non-patent Document 1).

  A method is also known in which a thin film of an organic semiconductor compound is formed on a donor substrate, and this thin film is stamped and transferred to an insulating layer provided with a source electrode and a drain electrode by applying pressure and heat ( Patent Document 1).

  Furthermore, a thin film of an organic semiconductor compound to be an active layer is formed on a silicon wafer, and this is copied onto a 1-5 mm thick polydimethylsiloxane rubber stamp, which is then attached to the insulating layer together with the stamp. A method for forming the film has also been reported (Non-patent Document 2).

Furthermore, a method is also known in which a single crystal of an organic semiconductor compound is formed and then bonded to an insulating layer provided with a source electrode and a drain electrode (Non-patent Document 3).
US Patent Application Publication No. 2005/0035374 Michael L. Chabinyc et al. , Journal of the American Chemical Society, Vol. 126, p13928-p13929, 2004 Vikram C.I. Sundar et al. , Science, Vol. 303, p1644-p1646, 2004 Vikram C.I. Sundar et al. , Science, Vol. 303, p1644-p1646, 2004

  In an organic semiconductor element, the characteristics of the active layer containing an organic semiconductor compound greatly affect the performance of the element. However, for example, in the first method for forming an active layer by vapor deposition or application of a solution as described in Non-Patent Document 1, it is difficult to form an active layer so as to have desired characteristics. Further, in the methods such as transfer and pasting as described in Patent Document 1 and Non-Patent Documents 2 and 3, it tends to be difficult to perform good transfer and pasting.

  For example, in the above-described transistor, it is known that the active layer is preferably oriented in order to obtain high carrier mobility. However, it has been difficult to form an active layer oriented in this way by coating or vapor deposition. In addition, it has been difficult to transfer and affix an active layer oriented in advance to an insulating layer or the like.

  Therefore, the present invention has been made in view of such circumstances, and even an active layer having desired characteristics can be satisfactorily formed on a surface on which the active layer is to be formed and an organic layer. An object of the present invention is to provide a method for manufacturing a semiconductor device. Another object of the present invention is to provide a transistor and an organic semiconductor device obtained by such a manufacturing method.

  In order to achieve the above object, a method of manufacturing a transistor of the present invention includes a source electrode and a drain electrode, an active layer that becomes a current path between these electrodes, and contains an organic semiconductor compound, a gate electrode that controls a current passing through the current path, And a method for manufacturing a transistor having an insulating layer disposed between an active layer and a gate electrode, wherein the active layer and the insulating layer are bonded to each other with a working liquid interposed between the active layer and the insulating layer. It is characterized by including the pasting process to match.

  In such a manufacturing method, since the construction liquid is interposed between the active layer and the insulating layer, these contact surfaces are wetted by the construction liquid, and thereby the active layer is satisfactorily stuck on the insulating layer. . Therefore, for example, even an oriented active layer can be satisfactorily stuck on an arbitrary surface such as an insulating layer. In addition, by using the construction liquid, good bonding is possible even when the active layer is warped, and the degree of manufacturing freedom is improved. Conventionally, when an active layer is formed by transfer or pasting, excessive pressurization is necessary to sufficiently adhere to the surface on which the active layer is to be formed. There was a risk of causing deformation of the element and occurrence of defects. On the other hand, in this invention, by using a construction liquid, an active layer can be favorably affixed without pressurization, and the occurrence of the above-described problems due to excessive pressurization is reduced. Furthermore, the use of the construction liquid improves the adhesion between the active layer and the surface on which it is formed.

  In the manufacturing method described above, when the active layer and the insulating layer are bonded together with a working solution interposed, it is important that the entire active layer is not eluted into the working solution. This can be easily controlled by appropriately selecting the amount of the construction liquid and the solubility of the construction liquid.

  The construction liquid preferably has a contact angle with the insulating layer of 120 degrees or less, more preferably 90 degrees or less, and still more preferably 60 degrees or less. According to such a construction liquid, the surface of the insulating layer can be better wetted, and as a result, the active layer and the insulating layer can be bonded better.

  It is preferable to use the active layer formed on the support film as the active layer to be bonded in the applying step. That is, using a laminate in which an active layer is formed on a support film, the active layer is disposed so that the active layer faces the insulating layer, and the construction liquid is interposed therebetween, and the active layer and the insulating layer Are preferably pasted together. In this case, since the active layer is previously supported by the support film, the handling becomes easy, and the active layer and the insulating layer can be more easily bonded.

  In the manufacturing method of this invention, it is good to implement the removal process which removes the volatile component in a construction liquid after a sticking process. In this case, the construction liquid may consist only of volatile components, or may consist of volatile components and non-volatile components. Moreover, all the volatile components may be removed, or only a part may be removed. When the construction liquid contains a non-volatile component, the non-volatile component exists near the interface between the active layer and the insulating layer, and a part of the non-volatile component may be contained in the active layer and / or the insulating layer.

  Moreover, in a sticking process, you may heat and / or pressurize. It is possible to improve the adhesion between the active layer and the insulating layer or to promote the removal of the construction liquid by performing appropriate heating or pressurization at the time of bonding. However, in the present invention, it is not necessary to perform excessive heating or pressurization because good bonding is possible by interposing a construction liquid as described above. Further, from the viewpoint of further improving the adhesion and further promoting the removal of the construction liquid, the pasting step may be performed under reduced pressure conditions.

  Furthermore, in the production method of the present invention, the active layer is preferably oriented. In the present invention, since a construction liquid is used, even an oriented active layer can be satisfactorily attached. According to the present invention, since the active layer can be adjusted in advance to have a desired orientation, good carrier mobility can be easily obtained in the transistor.

  The transistor manufacturing method of the present invention can also be applied to the case of forming a transistor having an active layer on a layer other than an insulating layer. That is, a method for manufacturing a transistor of the present invention includes a source electrode and a drain electrode, an active layer that becomes a current path between these electrodes and contains an organic semiconductor compound, and a gate electrode that controls a current passing through the current path. It is a manufacturing method, Comprising: It should just be characterized by including the sticking process which bonds an active layer to the surface in which this active layer is formed, interposing a construction liquid between the said surfaces. According to this manufacturing method, even if it is the active layer oriented, for example, it can be favorably affixed on the surface on which this is formed by interposing a construction liquid.

  The transistor manufactured by the manufacturing method of the present invention described above may further include, for example, a layer made of a compound different from the organic semiconductor compound between the source electrode and / or drain electrode and the active layer. By further providing such a layer, it is possible to reduce the contact resistance between the active layer containing an organic semiconductor compound and functioning as a carrier transport layer, and the source and drain electrodes.

  Moreover, the manufacturing method including the sticking process using the construction liquid as described above is not limited to the transistor, and can be applied to various organic semiconductor elements. That is, the method for producing an organic semiconductor element of the present invention is a method for producing an organic semiconductor element having an active layer containing an organic semiconductor compound, and an active layer and a layer to be adjacent to the active layer are applied between them. It includes a pasting step of pasting together by interposing a liquid.

  According to such a manufacturing method, as in the case of the transistor, an active layer having excellent characteristics can be satisfactorily formed by pasting with a working liquid interposed therebetween. Also in this method for manufacturing an organic semiconductor element, suitable conditions (contact angle with respect to a layer to be adjacent to the construction liquid, configuration of the active layer, etc.) are the same as in the case of manufacturing a transistor.

  Examples of such an organic semiconductor element include a transistor, a diode, a photodiode, a solar battery, a light emitting diode, a memory, a light emitting transistor, and a sensor. The transistor of the present invention is not particularly limited, and includes a bipolar transistor, a static induction transistor, a field effect transistor, and the like.

  The present invention also provides a transistor and an organic semiconductor device obtained by the production method of the present invention. That is, the transistor of the present invention includes a source electrode and a drain electrode, an active layer that becomes a current path between these electrodes and contains an organic semiconductor compound, a gate electrode that controls a current passing through the current path, and an active layer and a gate electrode. The active layer and the insulating layer are bonded to each other with a working liquid interposed therebetween.

  Such a transistor does not necessarily have an insulating layer as described above. That is, the transistor of the present invention is a transistor having a source electrode and a drain electrode, an active layer serving as a current path between these electrodes and containing an organic semiconductor compound, and a gate electrode for controlling a current passing through the current path, What is necessary is just to bond the active layer to the surface on which this active layer is formed with a working liquid interposed between the active layer and the surface.

  The organic semiconductor element of the present invention is an organic semiconductor element having an active layer containing an organic semiconductor compound, and the active layer has a working liquid interposed between the surface on which the active layer is formed. It is characterized by being pasted together.

  In the transistor and the organic semiconductor element thus obtained, the active layer is bonded to an arbitrary surface (such as the surface of the insulating layer) with a working solution interposed therebetween. Even if it is, the active layer is well formed while maintaining its characteristics. Therefore, for example, in the case of a transistor, excellent carrier mobility can be exhibited by the orientation of the active layer.

  In the transistor and the organic semiconductor element of the present invention, the construction liquid preferably has a contact angle with a surface (for example, an insulating layer) on which an active layer is formed of 120 degrees or less, and more preferably 90 degrees or less. The active layer is preferably an oriented active layer.

  Furthermore, the transistor of the present invention may further include a layer made of a compound different from the organic semiconductor compound between the source and drain electrodes and the active layer. Thereby, as described above, the contact resistance between the source and drain electrodes and the active layer can be reduced.

  According to the present invention, even an active layer containing an organic semiconductor compound to which predetermined characteristics have been imparted in advance can be satisfactorily formed on the surface on which the active layer is to be formed. A manufacturing method can be provided. Moreover, according to this invention, it becomes possible to provide the transistor and organic-semiconductor element which were obtained by this manufacturing method of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the drawings are partially exaggerated for easy understanding, and dimensional ratios do not necessarily match those described.

  Here, as an example of the organic semiconductor element, a preferred embodiment of a transistor and a manufacturing method thereof will be described. The transistor is a semiconductor element that amplifies or switches current and can be applied without particular limitation as long as it includes an active layer containing an organic semiconductor compound. The transistor has a configuration including at least an active layer and another layer adjacent to the active layer, and the active layer is formed on a surface of the other layer on which the active layer is formed. Is. Examples of such a transistor include a bipolar transistor, a static induction transistor, and a field effect transistor.

  In the following description, in particular, a source electrode and a drain electrode, an active layer that becomes a current path between these electrodes and contains an organic semiconductor compound, a gate electrode that controls a current passing through the current path, and an active layer and a gate electrode A transistor including an insulating layer disposed between and a manufacturing method thereof will be described. As the transistor having such a configuration, for example, in the case of a field effect transistor, there are various types of structures such as a planar type, an inverted staggered type, a staggered type, and the like.

  First, the configuration of the transistors of the first to sixth embodiments will be described with reference to FIGS.

  FIG. 1 is a schematic cross-sectional view of a transistor according to the first embodiment. A transistor 100 illustrated in FIG. 1 includes a substrate 10, a gate electrode 12 formed on the substrate 10, an insulating layer 14 formed on the substrate 10 so as to cover the gate electrode 12, and the insulating layer 14. And the active layer 20 formed on the insulating layer 14 so as to cover the source electrode 16 and the drain electrode 18.

  FIG. 2 is a schematic cross-sectional view of a transistor according to the second embodiment. A transistor 105 illustrated in FIG. 2 includes a gate electrode 12, an insulating layer 14 formed on the gate electrode 12, a source electrode 16 and a drain electrode 18 formed on the insulating layer 14, and a source electrode 16 and a drain electrode 18. And an active layer 20 formed on the insulating layer 14 so as to cover the surface. The gate electrode 12 in the transistor 105 also serves as the function of the substrate 10 in the transistor 100 of the first embodiment.

  FIG. 3 is a schematic cross-sectional view of a transistor according to the third embodiment. 3 includes a gate electrode 12, an insulating layer 14 formed on both surfaces of the gate electrode 12, a source electrode 16 and a drain electrode 18 formed on one insulating layer 14, a source electrode 16 and An active layer 20 formed on the insulating layer 14 so as to cover the drain electrode 18 and a support film 52 formed on the active layer 20 are provided. The gate electrode 12 in the transistor 110 also functions as the substrate 10 in the transistor 100 of the first embodiment.

  FIG. 4 is a schematic cross-sectional view of a transistor according to the fourth embodiment. A transistor 115 illustrated in FIG. 4 includes a gate electrode 12, an insulating layer 14 formed on the gate electrode 12, an active layer 20 formed on the insulating layer 14, and a source electrode 16 formed on the active layer 20. And the drain electrode 18.

  FIG. 5 is a schematic cross-sectional view of a transistor according to the fifth embodiment. The transistor 120 is a static induction organic thin film transistor. 5 includes a substrate 10, a source electrode 16 formed on the substrate 10, an active layer 20 formed on the source electrode 16, and a plurality (four in this case) formed on the active layer 20. The gate electrode 12, the active layer 24 formed on the active layer 20 so as to cover the gate electrode 12, and the drain electrode 18 formed on the active layer 24 are provided. In the transistor 120, the two active layers 20 and 24 may be layers made of the same material or layers made of different materials.

  FIG. 6 is a schematic cross-sectional view of a transistor according to the sixth embodiment. The transistor 125 includes a substrate 10, a source electrode 16 and a drain electrode 18 formed on the substrate 10, an active layer 20 formed on the substrate 10 so as to cover the source electrode 16 and the drain electrode 18, An insulating layer 14 formed on the active layer 20 and a gate electrode 12 formed on the insulating layer 14 are provided.

  In any of the transistors according to the first to fourth and sixth embodiments described above, the active layer 20 is a layer containing an organic semiconductor compound, and a current path (channel) between the source electrode 16 and the drain electrode 18. ) The gate electrode 12 controls a current passing through a current path (channel) in the active layer 20 by applying a voltage.

  In the transistor according to the fifth embodiment, the active layers 20 and 24 contain an organic semiconductor compound and form a current path between the source electrode 16 and the drain electrode 18. The gate electrode 12 controls the current passing through the current path in the same manner as described above.

Hereinafter, a method for manufacturing the transistor of each of the above embodiments will be described together with a more detailed configuration of the transistor.
(Method for Manufacturing Transistor of First Embodiment)

  First, a method for manufacturing the transistor of the first embodiment will be described. FIG. 7 is a process diagram illustrating the method for manufacturing the transistor according to the first embodiment. In this manufacturing method, first, the substrate 10, the gate electrode 12 formed on the substrate 10, the insulating layer 14 formed on the substrate 10 so as to cover the gate electrode 12, and the insulating layer 14 are formed. An element substrate 30 including the source electrode 16 and the drain electrode 18 is prepared (FIG. 7A). Separately from this, an active film 22 to be the active layer 20 containing an organic semiconductor compound is prepared (FIG. 7B).

  As the substrate 10, a substrate that does not impair the characteristics as a field effect transistor is used, and examples thereof include a silicon substrate, a glass substrate, a plastic substrate, and a stainless foil substrate. The insulating layer 14 is made of a material having high electrical insulation, and for example, silicon oxide, silicon nitride, aluminum oxide, tantalum oxide, an insulating polymer, or the like can be used. Here, examples of the insulating polymer include polyimide, poly (vinylphenol), polyester, methacrylic resin, polycarbonate, polystyrene, and valylene.

The surface of the insulating layer 14 may be physically and chemically modified by various methods. Examples of the physical modification method include treatment with ozone UV or O ₂ plasma. Moreover, as a chemical modification method, the process by surface treatment agents, such as a silane coupling agent, is mentioned, for example. Examples of the surface treating agent include alkylchlorosilanes, alkylalkoxysilanes, fluorinated alkylchlorosilanes, fluorinated alkylalkoxysilanes, and silylamine compounds such as hexamethyldisilazane. This surface treatment can be performed, for example, by bringing the insulating layer 14 into contact with the solution or gas of the surface treating agent and adsorbing the surface treating agent on the surface of the insulating layer 14. Prior to the surface treatment, the surface of the insulating layer 14 to be surface treated can be treated with ozone UV or O ₂ plasma.

  Examples of the method for forming the insulating layer 14 on the substrate 10 include a plasma CVD method, a thermal evaporation method, a thermal oxidation method, an anodic oxidation method, a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, and a bar coating. Examples thereof include a method such as a method, a roll coating method, a wire bar coating method, a dip coating method, a spray coating method, a screen printing method, a flexographic printing method, an offset printing method, and an inkjet printing method.

  The gate electrode 12, the source electrode 16, and the drain electrode 18 are made of a conductive material. Conductive materials include metals such as aluminum, gold, platinum, silver, copper, chromium, nickel, and titanium, conductive oxides such as ITO, and a mixture of poly (3,4-ethylenedioxythiophene) and polystyrenesulfonic acid. Examples include conductive polymers such as polymers. Further, a conductive material in which metal fine particles, carbon black, and graphite fine powder are dispersed in a binder may be used.

  The element substrate 30 having the above configuration can be manufactured by a known transistor manufacturing method, and for example, a method described in US Pat. No. 6,107,117 can be applied.

  On the other hand, the active film 22 to be the active layer 20 may be composed only of an organic semiconductor compound or may further contain additional components other than the organic semiconductor compound. Examples of the organic semiconductor compound include a low molecular organic semiconductor compound and a high molecular organic semiconductor compound. Examples of the additive component include a dopant, an adjustment material for adjusting carriers in the active layer 20, and a polymer material for enhancing the mechanical properties of the active film. The active film 22 may include a plurality of types of organic semiconductor compounds and a plurality of types of additive components. As the organic semiconductor compound, from the viewpoint of obtaining good film formability, a high molecular organic semiconductor compound is more preferable than a low molecular organic semiconductor compound. Moreover, the active film 22 for forming the active layer 20 may be comprised from the single crystal of these compounds. Even if it is the active film 22 which consists of a single crystal, the active layer 20 can be easily formed by sticking through a construction liquid.

  Examples of the low molecular organic semiconductor compound and the high molecular organic semiconductor compound include the compounds exemplified below. Note that the organic semiconductor compound contained in the active layer 20 in the transistor of the present invention is not necessarily limited to those exemplified below.

  Examples of the low-molecular organic semiconductor compounds include anthracene, tetracene, pentacene, benzopentacene, dibenzopentacene, tetrabenzopentacene, naphthopentacene, hexacene, heptacene, nanoacene, and other polyacene compounds; Coronene compounds such as perylene, terylene, diperylene, quaterylene; trinaphthine, heptaphene, obalene, rubicene, violanthrone, isoviolanthrone, chrysene, circum Anthracene, Bisanthene, Zesulene, Heptazesulene, Pyranthrene, Biolanten, Isoviolanthene, Bif Nyl, triphenylene, terphenyl, quarterphenyl, circophenyl, ketrene, phthalocyanine, porphyrin, fullerene (C60, C70), tetrathiofulvalene compound, quinone compound, tetracyanoquinodimethane compound, oligomer of polythiophene, oligomer of polypyrrole , Oligomers of polyphenylene, oligomers of polyphenylene vinylene, oligomers of polythienylene vinylene, copolymer oligomers of thiophene and phenylene, copolymer oligomers of thiophene and fluorene, and the like. In addition, derivatives of these low molecular organic semiconductor compounds can also be used. Examples of such include rubrene, which is a benzene ring addition derivative of tetracene. Moreover, the carbon nanotube etc. which expanded the conjugated system of fullerenes can be illustrated.

  Examples of the polymer organic semiconductor compound include polythiophene, polyphenylene, polyaniline, polyphenylene vinylene, polythienylene vinylene, polyacetylene, polydiacetylene, polytriphenylamine, a copolymer of triphenylamine and phenylene vinylene, thiophene and phenylene, And a copolymer of thiophene and fluorene. In addition, derivatives of these high molecular organic semiconductor compounds can also be used. Examples of such include poly (3-hexylthiophene), which is an alkyl-substituted product of polythiophene.

Specific examples of the polymer organic semiconductor compound include compounds having the following structures.

In the above formulas (1a) to (1i), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are each independently an alkyl group, an alkoxy group, an alkylthio Group, aryl group, aryloxy group, arylthio group, arylalkyl group, arylalkoxy group, arylalkylthio group, arylalkenyl group, arylalkynyl group, amino group, substituted amino group, silyl group, substituted silyl group, silyloxy group, substituted A silyloxy group, a monovalent heterocyclic group, a halogen atom or a cyano group is represented. n is an integer of 1 or more.

  Examples of the dopant which is an additive component other than the organic semiconductor compound include an acceptor dopant and a donor dopant.

  First, acceptor dopants include: halogens such as iodine, bromine, chlorine, iodine chloride, iodine bromide; sulfur oxide compounds such as sulfuric acid, sulfuric anhydride, sulfur dioxide, sulfates; oxidations such as nitric acid, nitrogen dioxide, nitrates, etc. Nitrogen compounds; halogenated compounds such as perchloric acid and hypochlorous acid; acids such as tetrafluoroboric acid, tetrafluoroborate, phosphoric acid, phosphate, trifluoroacetic acid or salts thereof; tetracyanoquinodimethane And tetrachlorotetracyanoquinodimethane, tetrafluorotetracyanoquinodimethane, tetracyanoethylene, dichlorocyanoethylene, dichlorodicyanoquinone, tetrachloroquinone, carbon dioxide, oxygen, and the like.

  Examples of the donor dopant include tetrathiafulvalene, tetramethyltetrathiafulvalene, tetraselenathiafulvalene; amine compounds such as diphenylphenylenediamine, tetraphenylphenylenediamine, tetraphenyldiaminodiphenyl, and polyvinylcarbazole; alkali metals, alkaline earths Examples of such metals include rare earth metals, rare earth metals, complexes of these metals with organic compounds, and the like.

  In addition, examples of the adjustment material for adjusting the carriers in the active layer 20 include conductive materials, for example, transition metals such as aluminum, iron, copper, nickel, zinc, silver, platinum, and gold, and fine particles thereof. .

  Furthermore, examples of the polymer material for enhancing the mechanical properties of the active film 22 include polycarbonate, polyacrylate, polymethyl acrylate, polymethyl methacrylate, polystyrene, polyvinyl chloride, and polysiloxane.

  In the production of such an active film 22, for example, first, an organic semiconductor compound or an organic semiconductor compound and other additive components are dissolved and dispersed in an organic solvent to form a solution. Next, after applying this solution onto, for example, a polytetrafluoroethylene resin plate, the organic solvent is volatilized. Thereby, the active film 22 is obtained. In addition, when using this active film 22, it is preferable to peel the active film 22 from a polytetrafluoroethylene resin board.

  Examples of the organic solvent used in the solution for producing the active film 22 include chlorine solvents such as chloroform, methylene chloride, dichloroethane, and trichlorobenzene; ether solvents such as tetrahydrofuran; toluene, xylene, mesitylene, tetralin, decalin, n- Examples include aromatic hydrocarbon solvents such as butylbenzene; aromatic solvents having an alkoxy group such as anisole.

  Moreover, as a coating method of the solution, spin coating method, casting method, micro gravure coating method, gravure coating method, bar coating method, roll coating method, wire bar coating method, dip coating method, spray coating method, screen printing method, Examples thereof include a flexographic printing method, an offset printing method, and an ink jet printing method.

  In a transistor having an active layer 20 containing an organic semiconductor compound, if the active layer 20 has orientation, molecules of the organic semiconductor compound are aligned in one direction. ) Tend to improve. Therefore, the active layer 20 is preferably subjected to an alignment treatment.

  In order to obtain the active layer 20 oriented in this way, it is also preferred that it be oriented at the stage of the active film 22. As a method for aligning, first, a method of stretching the active film 22 may be mentioned. Examples of the stretching method include methods such as uniaxial stretching, biaxial stretching, in-swelling stretching, and stretching using a roll.

  Uniaxial stretching is a method in which a pair of opposite sides of the rectangular active film 22 is sandwiched between chucks and stretched in the opposite direction. At this time, it may be pulled at room temperature or may be pulled while being heated appropriately. In addition, the tension can be performed in a specific gas atmosphere such as nitrogen gas.

  The biaxial stretching is a method in which two pairs of opposite sides of the rectangular active film 22 are sandwiched between chucks, and the film is pulled and stretched in two opposite sides simultaneously or sequentially. At this time, it may be pulled at room temperature or may be pulled while being heated appropriately. In addition, the tension can be performed in a specific gas atmosphere such as nitrogen gas.

  Furthermore, in-swelling stretching is a method in which the active film 22 is immersed in an appropriate solution that swells without dissolving the active film 22, and the film is stretched and stretched by uniaxial stretching or biaxial stretching. In this case, the pulling may be performed at room temperature or may be performed while heating appropriately.

  In the manufacturing method according to the first embodiment, as described above, after preparing the element substrate 30 and the active film 22, the construction liquid 40 is interposed between the active film 22 and the insulating layer 14 in the element substrate 30. Then, a pasting step of pasting them together is performed (FIG. 7C). The surface of the insulating layer 14 to which the active film 22 is attached corresponds to the surface on which the active layer 20 is formed.

  The construction liquid 40 used in the sticking step is a liquid substance (liquid) having a property capable of wetting both the insulating layer 14 and the active film 22. As such a construction liquid 40, the contact angle with the surface of the insulating layer 14 on which the active layer 20 is formed is preferably 120 degrees or less, more preferably 90 degrees or less, and 60 degrees or less. Is more preferable. Here, the “contact angle” refers to the tangent line drawn from the contact point of these three phases to the construction liquid 40 when the droplet of the construction liquid 40 is formed on the insulating layer 14 in the air and the insulating layer 14. Of the angles formed with the surface, it refers to the angle containing the construction liquid 40.

It is desirable that a suitable construction liquid 40 is appropriately selected according to the type of the insulating layer 14 (contact angle with the insulating layer 14). For example, when the surface of the insulating layer 14 is silicon oxide (SiO ₂ or the like), when it is silicon oxide modified with alkyltrichlorosilane (octadecyltrichlorosilane or the like), when it is silicon nitride, it is an organic insulating film. In some cases, the construction liquid 40 includes alcohol solvents having 1 to 8 carbon atoms such as methanol, ethanol and isopropanol, ketone solvents such as acetone, ether solvents such as diethyl ether, and halogen solvents such as chloroform (from Preferably mixed with alcohol etc.), aromatic hydrocarbon solvent such as toluene (more preferably mixed alcohol etc.), aliphatic hydrocarbon solvent such as hexane, heptane, octane, water (more preferably Surfactants), nitrile solvents such as acetonitrile, acetate An ester solvent such as chill and a solvent containing an amine compound such as aqueous ammonia are preferred.

  The application liquid 40 is used to adjust the concentration of carriers in the active layer 20, additives such as a surfactant for adjusting wettability to the insulating layer 14, dopants that can adjust transistor characteristics of the active layer 20, and the like. It may further contain materials and the like. In addition, said solvent illustrated as the construction liquid 40 may be used independently, and may mix and use 2 or more types.

  As a method of interposing the working liquid 40 between the active film 22 and the insulating layer 14 and bonding them together, for example, the working liquid 40 is applied on one surface of the active film 22 and the insulating layer 14. Then, the method of laminating the other on this construction liquid 40 is mentioned. Moreover, as a method other than this, the method etc. which hold | maintain between the active film 22 and the insulating layer 14 through the predetermined | prescribed gap (gap), and inject | pour the construction liquid 40 in this gap can be illustrated. In these methods, when the construction liquid 40 has a contact angle of 120 degrees or less with the insulating layer 14 as described above, the surface of the insulating layer 14 can be efficiently wetted, and bonding can be further performed. It is possible to perform well.

  It should be noted that all of the active film 22 is prevented from eluting into the construction liquid 40 during the bonding with the construction liquid 40. This is because if all of the active film 22 is eluted, it is difficult to form a uniform active layer 20. In order to avoid elution of the active film 22, it is preferable to use a construction liquid 40 having a solubility parameter different from the solubility parameter (SP value) of the active film 22. In addition, it is sufficient that the active film 22 is not completely dissolved in the bonding, and there is no problem even if partial dissolution occurs.

  In the sticking step, heating and / or pressurization may be performed. Thereby, the adhesiveness between the active film 22 and the insulating layer 14 can be improved, and the removal of volatile components in the removing step described later can be promoted. Only one or both of heating and pressurization may be performed. When both are performed, heating and pressurization may be performed simultaneously, or one may be performed first and then the other. In addition to the heating and / or pressurization, the pasting step may be performed under reduced pressure conditions for further improvement of adhesion and further promotion of removal of the construction liquid. In addition, depending on the type of organic semiconductor compound, undesirable changes in characteristics may occur in the atmosphere. Therefore, the pasting process may be performed under reduced pressure, an inert atmosphere such as nitrogen, light shielded, etc. as necessary. It may be performed under conditions or in an environment in which moisture, oxygen and the like are controlled.

  However, if heating and pressurization in the pasting step are performed under excessive conditions, the characteristics (for example, orientation) of the active film 22 may change, and it may be difficult to obtain the active layer 20 having the desired characteristics. is there. Therefore, it is preferable to perform heating and pressurization under appropriate conditions. Suitable heating conditions include a temperature condition that is room temperature or higher and does not cause deformation of the insulating layer 14 to be bonded, the element substrate 30 on which these are formed, and the like. For example, when the active film 22 is made of a polymer organic semiconductor compound, a temperature equal to or lower than the liquid crystal phase or the isotropic phase transition temperature is preferable. In addition, even if it is the temperature exceeding this, if it is heating for a short time of the grade which does not produce said inconvenience, it can implement.

  Further, the pressurization is performed in the stacking direction of the active film 22 and the insulating layer 14. For example, a load may be applied from above the active film 22, and the active film 22 and the element substrate 30 may be applied using a roll. You may make it pressurize the whole. The pressure at the time of pressurization is preferably set to such an extent that the active film 22, the insulating layer 14 constituting the element substrate 30, the substrate 10, the source electrode 16 and the drain electrode 18 are not deformed or defective.

  And after implementing a sticking process by the above method, the removal process which removes the unnecessary volatile component in the construction liquid 40 is implemented as needed. By removing unnecessary volatile components in the construction liquid 40 through this removal step, the transistor 100 of the first embodiment is obtained (FIG. 7D). In this removal step, all of the construction liquid 40 may be removed, or a part thereof may remain. For example, if the adhesiveness between the insulating layer 14 and the active layer 20 is kept good, the construction liquid 40 may be completely removed.

  The thickness of the active layer 20 in the transistor 100 is preferably 10 nm or more, more preferably 40 nm or more, and further preferably 200 nm or more. When the thickness of the active layer 20 is 10 nm or more, sufficiently good transistor characteristics can be obtained. By making the active layer 20 thicker, a transistor with higher mobility can be easily obtained. Further, by increasing the thickness of the active layer 20, there is a tendency that inconvenience due to physical damage or the like received during manufacturing is less likely to occur. In order to obtain the active layer 20 having a desired thickness, it is preferable to appropriately adjust the thickness at the stage of the active film 22. Note that the preferred thickness of the active layer is also applied to the transistors of the following second to third embodiments.

(Method for Manufacturing Transistor of Second Embodiment)
Next, a preferred method for manufacturing the transistor according to the second embodiment will be described.

  FIG. 8 is a process diagram showing a method for manufacturing a transistor according to the second embodiment. In this manufacturing method, first, an element substrate 32 including a gate electrode 12, an insulating layer 14 formed on the gate electrode 12, and a source electrode 16 and a drain electrode 18 formed on the insulating layer 14 is prepared. (FIG. 8 (a)). Here, the gate electrode 12 also functions as a substrate. As such a gate electrode 12, for example, a metal substrate such as highly doped silicon or aluminum is suitable. The insulating layer 14 and the source and drain electrodes 16 and 18 can be formed in the same manner as in the first embodiment.

  Moreover, the active film 22 which should become the active layer 20 containing an organic-semiconductor compound is prepared with manufacture of the element substrate 32 (FIG.8 (b)). Thereafter, a pasting process is performed in which the construction liquid 40 is interposed between the active film 22 and the insulating layer 14 and these are bonded together (FIG. 8C). These steps can be performed in the same manner as in the first embodiment.

  Then, after performing the above-described pasting step, a removing step for removing unnecessary volatile components in the construction liquid 40 is performed as necessary, whereby the transistor 105 according to the second embodiment is obtained (FIG. 8D). )).

(Method for Manufacturing Transistor of Third Embodiment)
Next, a method for manufacturing a transistor according to the third embodiment will be described.

  FIG. 9 is a process diagram illustrating a method for manufacturing a transistor according to the third embodiment. In this manufacturing method, first, an element substrate 34 including a gate electrode 12, an insulating layer 14 formed on both surfaces of the gate electrode 12, and a source electrode 16 and a drain electrode 18 formed on one insulating layer 14. Is prepared (FIG. 9A). Separately, instead of the active film 22 in the first embodiment, a laminate 50 (a laminate of the active film 22 on the support film 52) is prepared (FIG. 9B). The insulating layer 14, the source electrode 16 and the drain electrode 18 in the element substrate 34 can be formed in the same manner as in the first embodiment.

  The support film 52 in the laminate 50 may be made of either an inorganic material or an organic material. Examples thereof include polysiloxane, fluorine-based resin, polyethylene, polypropylene, methylpentene resin, polycarbonate, polyimide, polyamide, vinyl chloride, vinylidene chloride, acrylic resin, methacrylic resin, polystyrene, nylon, polyester, polyvinyl alcohol, and the like.

  Here, for example, when the active film 22 is aligned before being bonded to the insulating layer 14, there are a method of aligning the active film 22 alone and a method of aligning after forming the laminate 50. In the latter case, it is preferable that the support film 52 be capable of an orientation operation such as stretching. As such a support film 52, for example, polyethylene, polypropylene, methylpentene resin, polycarbonate, polyimide, polyamide, vinyl chloride, vinylidene chloride, methacrylic resin, nylon, polyester, polyvinyl alcohol, and the like are suitable.

  In addition, the support film 52 may include a layer having a functionality that promotes peeling from the active film 22 laminated on the support film 52. For example, examples of such a layer include a layer having a function of converting light into heat and a layer that expands by heat. These layers can promote peeling between the support film 52 and the active film 22 by heat. Therefore, when the support film 52 has these layers, the support film 52 is easily peeled off from the active layer 20 by performing light irradiation or heating after the attaching step of attaching the laminate 50 and the insulating layer 14 together. Will be able to.

  Furthermore, when the support film 52 has a layer having a function of converting light to heat as described above or a layer that expands by heat, patterning of the active layer 20 may be facilitated. That is, for example, after the laminated body 50 is attached to the insulating layer 14, a predetermined portion of the active film 22 is irradiated with light through the support film 52, or heated by a trowel. In this way, the light irradiated portion and the heated portion of the active film are transferred onto the insulating layer 14, while the other portions are easily peeled off together with the support film 52. As a result, only the predetermined portion of the active film 22 remains on the insulating layer 14, thereby forming the patterned active layer 20.

  The laminated body 50 is, for example, bonding of the support film 52 and the pre-formed active film 22, direct application of the organic semiconductor compound to the support film 52, and direct application of a solution of the organic semiconductor compound to the support film 52. Can be formed. For example, in the case of a solid organic semiconductor compound, direct application of the organic semiconductor compound to the support film 52 can be performed by vapor deposition of the organic semiconductor compound on the support film 52, spray coating of a melt, sublimation application, or the like. . In the case of a single crystal organic semiconductor compound, a technique such as natural adhesion on the support film 52 or bonding using an adhesive can be applied.

  Direct application of the organic semiconductor compound solution to the support film 52 includes, for example, spin coating, casting, micro gravure coating, gravure coating, bar coating, roll coating, wire bar coating, and dip coating. , Spray coating, screen printing, flexographic printing, offset printing, ink jet printing, and the like.

  When the active film 22 is oriented before being attached to the insulating layer 14, it can be performed in the state of the laminate 50. The orientation can be performed by uniaxial stretching, biaxial stretching, in-swelling stretching, and the like, as in the first embodiment. In this case, the support film 52 is also stretched together with the active film 22.

  In addition, when the organic semiconductor compound constituting the active film 22 has liquid crystallinity, the active film 22 may be aligned by other methods known as alignment methods of liquid crystal in addition to stretching. Good. As such a method, for example, “Fundamentals and Applications of Liquid Crystals” (Shinichi Matsumoto, Ryoko Kakuda, Industrial Research Society 1991), Chapter 5, “Structure and Physical Properties of Ferroelectric Liquid Crystals” (Fukuda Ikuo Co-authored by Hideo Takezoe, Corona, 1990) Chapter 7, “Liquid Crystal” Vol. 3, No. 1 (1999), pages 3 to 16 and the like.

  As such an alignment method, for example, a rubbing method, a photo-alignment method, a sharing method (shear stress application method) and a pulling coating method are simple and useful and particularly easy to use.

  The rubbing method is a method in which the support film 52 is lightly rubbed with a cloth or the like. As cloth for rubbing the support film 52, cloth such as gauze, polyester, cotton, nylon and rayon can be used. The cloth used for rubbing can be appropriately selected according to the film to be oriented. In this case, if an alignment film is separately formed on the support film 52, the alignment performance becomes higher. Examples of the alignment film include polyimide, polyamide, polyvinyl alcohol, polyester, nylon, and the like, and a commercially available alignment film for liquid crystal is also applicable. The alignment film can be formed by spin coating or flexographic printing.

  The photo-alignment method is a method of providing an alignment function by forming an alignment film on the support film 52 and irradiating polarized UV light or obliquely irradiating UV light. Examples of the alignment film include polyimide, polyamide, and polyvinyl cinnamate, and a commercially available alignment film for liquid crystal is also applicable.

  By such rubbing method or photo-alignment method, the organic semiconductor compound (active film 22) laminated on the support film 52 subjected to the above treatment can be oriented. This orientation occurs when the organic semiconductor compound has a liquid crystal phase or isotropic phase temperature on the support film 52. Moreover, the active film 22 formed on the support film 52 can also be oriented by providing the organic semiconductor compound on the support film 52 after the orientation treatment.

  Further, when an organic semiconductor compound is applied on the support film 52, the application is set to a temperature at which the organic semiconductor compound is placed on the support film 52 and the temperature is equal to or higher than the Tg, or a liquid crystal phase or an isotropic phase. The orientation can be caused by coating by unidirectional coating. Alternatively, a solution in which an organic semiconductor compound is dissolved in an organic solvent may be prepared and applied by spin coating, flexographic printing, or the like. In addition, even if the organic semiconductor compound does not have liquid crystallinity, if it can be vapor-deposited, this organic semiconductor compound is epitaxially vapor-deposited on the support film 52 subjected to the orientation treatment, A layer (active film 22) made of an oriented organic semiconductor compound can be obtained.

  In the sharing method, another substrate is placed on the organic semiconductor compound placed on the support film 52, and the upper substrate is shifted in one direction at a temperature at which the organic semiconductor compound becomes a liquid crystal phase or an isotropic phase. Is the method. At this time, when the support film 52 having a support layer subjected to the alignment treatment as described in the rubbing method or the photo-alignment method is used, the active film 22 having a higher degree of orientation can be obtained. Examples of the upper substrate include glass and a polymer film, and may be a metal rod or the like.

  Further, the pulling application method is a method of forming an oriented organic semiconductor compound layer (active film 22) on the support film 52 by immersing the support film 52 in an organic semiconductor compound solution and pulling it up. Conditions such as the organic solvent used in the organic semiconductor compound solution and the lifting speed of the support film 52 are not particularly limited, but it is preferable to select and adjust according to the desired degree of orientation of the organic semiconductor compound.

  As mentioned above, although several orientation methods of the active film 22 were demonstrated, in any of 1st-6th embodiment, it is preferable to perform orientation by extending | stretching from a viewpoint of simplicity or usefulness.

  Next, after the element substrate 34 and the laminated body 50 are prepared, the application film 40 is interposed between the laminated body 50 and the insulating layer 14 in the element substrate 34 to attach the active film 22 and the insulating layer 14 together. The process is carried out (FIG. 9C).

  In this attaching step, the laminated body 50 is arranged so that the active film 22 faces the insulating layer 14 side, and the construction liquid 40 is interposed between the laminated body 50 and the insulating layer 14. It can be performed in the same manner as in the case of. In this sticking step, heating and / or pressurization can be performed in the same manner as in the first embodiment, or a reduced pressure condition or the like may be used.

  And also in the manufacturing method of the transistor of 3rd Embodiment, the removal process which removes the unnecessary volatile component in the construction liquid 40 as needed can be implemented after a sticking process. Thereby, the transistor 110 according to the third embodiment in which the support film 52 is laminated on the active layer 20 is obtained (FIG. 9D). Note that the support film 52 may be removed after the transistor 110 is completed, or may be laminated as it is if there is no practical problem. When the support film 52 is laminated, the support film 52 having a function capable of protecting from the factors (physical damage, the influence of gas due to the atmosphere, charging, etc.) that deteriorate the characteristics of the active layer 20 is applied. It is preferable to do.

(Method for Manufacturing Transistor of Fourth Embodiment)
Next, a method for manufacturing a transistor according to the fourth embodiment will be described.

  FIG. 10 is a process diagram illustrating a method for manufacturing a transistor according to the fourth embodiment. In this manufacturing method, first, a first element substrate 36 including a gate electrode 12 and an insulating layer 14 formed thereon is prepared (FIG. 10A). The gate electrode 12 also has a function as a substrate. The configuration and manufacturing method of the gate electrode 12 and the insulating layer 14 can be performed in the same manner as in the second embodiment.

  Moreover, the active film 22 which should become the active layer 20 containing an organic-semiconductor compound is prepared with manufacture of the 1st element substrate 36 (FIG.10 (b)). Then, a pasting step is performed in which the working liquid 40 is interposed between the active film 22 and the insulating layer 14 of the first element substrate 36 to bond them together (FIG. 10C). This pasting step can also be performed in the same manner as in the first embodiment. In the pasting step, a laminate 50 as in the third embodiment may be used instead of the active film 22. In this case, after sticking, the support film 52 in the laminated body 50 is removed, and then an operation described later is performed.

  Next, a second element substrate 60 in which the active layer 20 is formed on the element substrate 36 is formed by performing a removing step of removing unnecessary volatile components in the construction liquid 40 as necessary (FIG. 10 ( d)). Then, the source electrode 16 and the drain electrode 18 are formed on the active layer 20 in the second element substrate 60 in the same manner as in the first embodiment, thereby obtaining the transistor 115 according to the fourth embodiment (FIG. 10 (e)).

(Method for Manufacturing Transistor of Fifth Embodiment)
Next, a preferred method for manufacturing a transistor according to the fifth embodiment will be described.

  11 and 12 are process diagrams showing a method for manufacturing a transistor according to the fifth embodiment. In this manufacturing method, first, a first element substrate 38 including a substrate 10 and a source electrode 16 formed thereon is prepared (FIG. 11A).

  Separately from this, an active film 22 to be the active layer 20 containing an organic semiconductor compound is prepared (FIG. 11B). Then, a first pasting step is performed in which the working liquid 40 is interposed between the active film 22 and the source electrode 16 in the first element substrate 38 to bond them together (FIG. 11C). This first sticking step can be performed in the same manner as in the first embodiment.

  Then, the 1st removal process which removes the unnecessary volatile component in the construction liquid 40 is performed as needed, and, thereby, the active layer 20 is formed on the 1st element substrate 38 (FIG.11 (d)). . Next, a plurality (four in this case) of gate electrodes 12 are formed on the active layer 20, thereby obtaining a second element substrate 62 (FIG. 11E). The same gate electrode 12 as in the first embodiment can be applied.

  Next, along with the second element substrate 62 (FIG. 12E), an active film 26 to be the active layer 24 containing the organic semiconductor compound is separately prepared (FIG. 12F). As the organic semiconductor compound constituting the active film 26, the same one as that of the active layer 20 may be applied, or a different one may be applied. Then, a second sticking step is performed in which the construction liquid 40 is interposed between the active film 26 and the active layer 20 in the second laminated substrate 62 to bond them together (FIG. 12G). Thereby, the active film 26 is affixed on the active layer 20 so as to cover the gate electrode 12. This 2nd sticking process can also be performed similarly to 1st Embodiment etc. The construction liquid 40 used in the second sticking step may be the same as or different from the first sticking step.

  Then, if necessary, a second removal step for removing unnecessary volatile components in the construction liquid 40 is performed, and the active film 26 is brought into close contact with the active layer 20 so as to sandwich the gate electrode 12 therebetween. Is formed (FIG. 12H). Then, the drain electrode 18 is formed on the active layer 24 thus formed in the same manner as in the first embodiment and the like, thereby obtaining the transistor 120 according to the fifth embodiment. In the manufacturing process of the transistor of the fifth embodiment, either one of the active layers 20 and 24 may be formed by a method described in, for example, Japanese Patent Application Laid-Open No. 2004-006476. Moreover, you may use the laminated body 50 like 3rd Embodiment instead of the active film 22 in the 1st and 2nd sticking process. In this case, after sticking, the support film 52 in the laminated body 50 is removed, and then the subsequent operation is performed.

(Method for Manufacturing Transistor of Sixth Embodiment)
Next, a preferable method for manufacturing the transistor according to the sixth embodiment will be described.

  13 and 14 are process diagrams showing a method for manufacturing a transistor according to the sixth embodiment. In this manufacturing method, first, a substrate 10 and an element substrate 64 including a source electrode 16 and a drain electrode 18 thereon are prepared (FIG. 13A). The source electrode 16 and the drain electrode 18 can be formed by the same method as in the first embodiment.

  Moreover, the active film 22 which should become the active layer 20 containing an organic-semiconductor compound is prepared with manufacture of the element substrate 64 (FIG.13 (b)). Then, the application liquid 40 is interposed between the active film 22 and the substrate 10 in the element substrate 64, and a pasting process is performed in which these are bonded together (FIG. 13C). This pasting step can also be performed in the same manner as in the first embodiment.

  Next, an active layer 20 is formed on the element substrate 64 so as to cover the source electrode 16 and the drain electrode 18 by performing a removing step of removing unnecessary volatile components in the construction liquid 40 as necessary (FIG. 13). (D)). Then, the insulating layer 14 is formed on the active layer 20 in the same manner as in the first embodiment (FIG. 14E). Then, on the insulating layer 14 thus formed, the gate electrode 12 is formed in the same manner as in the first embodiment, thereby obtaining the transistor 125 according to the sixth embodiment (FIG. 14F).

  In addition, also in manufacture of the transistor of this 6th Embodiment, the laminated body 50 like 3rd Embodiment can be used instead of the active film 22 in a sticking process. In this case, after sticking, after removing the support film 52 in the laminated body 50, operation which continues is performed. Moreover, when the support film 52 has the function as the insulating layer 14, it is good also as the insulating layer 14 as it is, without removing the support film 52.

  As mentioned above, although the transistor of 1st-6th embodiment and its manufacturing method were demonstrated as an example of a suitable organic-semiconductor element and its manufacturing method, the transistor in this invention is not necessarily limited to the thing of embodiment mentioned above. , May be changed as appropriate.

  For example, first, the active layer 20 (the active layers 20 and 24 in the fifth embodiment) in the transistor of each embodiment does not need to be a single layer, and may be composed of a plurality of layers. Good. When the active layers 20 and 24 are made of a plurality of layers, they may be made of the same material or different materials. The active layers 20 and 24 composed of a plurality of layers are formed on the active films 22 and 26 for forming the active layers 20 and 24, after removing the support film remaining on the active films 22 and 26, if necessary. It can be formed by further laminating the same or different types of active films.

  In the above-described embodiments, the source electrode 16 and the drain electrode 18 and the active layer 20 or 24 are in direct contact with each other. However, the present invention is not limited to this, and the source electrode 16 and / or the drain electrode are not limited thereto. A layer made of a compound different from the organic semiconductor compound may be interposed between 18 and the active layers 20 and 24. Thereby, the contact resistance between the source electrode 16 and the drain electrode 18 and the active layers 20 and 24 is reduced, and the carrier mobility of the transistor can be further improved. Examples of the compound different from the organic semiconductor compound include a donor compound, an acceptor compound, and a compound having a thiol group.

  Here, examples of the donor compound include tetrathiafulvalene, tetramethyltetrathiafulvalene, tetraselenathiafulvalene; amine compounds such as diphenylphenylenediamine, tetraphenylphenylenediamine, tetraphenyldiaminodiphenyl, and polyvinylcarbazole; alkali metals, alkalis Examples include earth metals, rare earth metals, complexes of these metals with organic compounds, and the like.

  Acceptable compounds include: halogens such as iodine, bromine, chlorine, iodine chloride and iodine bromide; sulfur oxide compounds such as sulfuric acid, anhydrous sulfuric acid, sulfur dioxide and sulfate; oxidation such as nitric acid, nitrogen dioxide and nitrate Nitrogen anhydride; halogenated compounds such as perchloric acid and hypochlorous acid; acids such as tetrafluoroboric acid, tetrafluoroborate, phosphoric acid, phosphate, trifluoroacetic acid or salts thereof; tetracyanoquinodi Examples include methane, tetrachlorotetracyanoquinodimethane, tetrafluorotetracyanoquinodimethane, tetracyanoethylene, dichlorocyanoethylene, dichlorodicyanoquinone, and tetrachloroquinone.

  Furthermore, as a compound having a thiol group, alkyl thiols, alkyl thiol compounds such as fluorinated alkyl thiols, aromatic thiols, fluorinated alkyl aromatic thiols, fluorinated aromatic thiols, nitro aromatic thiols And aromatic thiol compounds such as aminoaromatic thiols.

  The layer made of these compounds can be formed, for example, by bringing a solution or gas of the compound into contact with the surface of the source electrode 16 or the drain electrode 18 and adsorbing the compound onto the contact surface.

  Moreover, in the transistor of each embodiment described above, the thickness of the source electrode 16 and the drain electrode 18 is not particularly limited. However, when the active layers 20 and 24 are formed on the source electrode 16 and the drain electrode 18 as in the first to third and fifth embodiments, the adhesion to the active layers 20 and 24 is further improved. Therefore, it is preferable that the source electrode 16 and the drain electrode 18 be as thin as possible as long as the functions of these electrodes are not impaired.

  Furthermore, the transistors of the first to sixth embodiments can be sealed after completing the above-described element configuration to be a sealed transistor. As a result, the transistor is shielded from the atmosphere and protected from physical damage and the like, and it is possible to suppress deterioration of the transistor characteristics.

  As a sealing method, the device configuration is covered with an insulating polymer, UV curable resin, thermosetting resin, inorganic silicon oxide film or silicon nitride film, and the glass plate or film is UV cured for the device configuration. Examples include a method of bonding with a resin or a thermosetting resin. In order to effectively cut off from the atmosphere, the steps from the formation of the transistor to the sealing are performed without exposure to the atmosphere (for example, in a dry nitrogen atmosphere and stored in a vacuum). preferable.

  The organic semiconductor element of the present invention has an active layer containing an organic semiconductor compound, and the active layer is limited to the above-described transistor as long as the active layer is bonded to an adjacent layer through a working solution. Not. Examples of the organic semiconductor element other than the transistor include a diode, a photodiode, a solar battery, a light emitting diode, a memory, a light emitting transistor, and a sensor.

  Further, the above-described organic semiconductor element such as a transistor is preferably applied to a semiconductor device. Examples of the semiconductor device include a wireless tag, a display, a large surface sensor, and the like. In a semiconductor device, for example, a transistor can form a logic circuit by itself or in combination with a plurality of other transistors. Specifically, it is suitable as a switching transistor, a signal driver circuit element, a memory circuit element, a signal processing circuit element, or the like of a pixel of a display which is a semiconductor device. As the display, electronic paper, liquid crystal, organic LED, etc. can be widely applied.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.
<Organic semiconductor compound>

  Poly (3-hexylthiophene) and poly (3-octylthiophene) used were purchased from Aldrich. In addition, regioregular poly (3-hexylthiophene) and poly (3-octylthiophene) were used.

(Example 1: Formation of transistor and evaluation of physical properties by manufacturing method of third embodiment)
A transistor was manufactured according to a method based on the method of manufacturing the transistor of the third embodiment described above. 15 is a diagram illustrating manufacturing steps of the transistor of Example 1. FIG. That is, first, as shown in FIG. 15A, the surface of a heavily doped n-type silicon substrate 1 serving as a gate electrode also serving as a substrate is thermally oxidized to form a silicon oxide film serving as an insulating layer 3 with a thickness of 200 nm. What was formed was used as a support substrate. Next, as shown in FIG. 15B, gold is deposited to a thickness of 50 nm on the surface of one insulating layer 3 of this substrate by a vacuum deposition method, and a source electrode 4a and a drain electrode 4b having lead lines and pads are formed. Formed. At this time, the channel width of the electrode was 500 μm and the channel length was 20 μm.

  Subsequently, with reference to the method described in the literature (SR Wasserman, et al., Langmuir, Vol. 5, p1074, 1989), the surface of the insulating layer 3 was coated with an octadecyltrichlorosilane octane solution (6 mmol / The element substrate 6 was formed by immersing in 1) for 24 hours for modification.

  On the other hand, a chloroform solution (0.5 wt%) of poly (3-hexylthiophene) was prepared in a nitrogen atmosphere glove box. However, weighing of poly (3-hexylthiophene) was performed in the air. Then, a chloroform solution of poly (3-hexylthiophene) was applied on the polyethylene film as the support film 7 by a spin coating method (1000 rpm) in a glove box under a nitrogen atmosphere. Thereby, as shown in FIG.15 (c), the laminated body 5 by which the poly (3-hexyl thiophene) film 8 was laminated | stacked on the support film 7 of polyethylene was formed.

  Next, in a glove box in a nitrogen atmosphere, as shown in FIG. 15 (d), methanol droplets as a working liquid 9 are formed on the insulating layer 3 on which the source electrode 4 a and the drain electrode 4 b are formed as a spoid. placed. Then, the laminated body 5 was placed with tweezers so that the poly (3-hexylthiophene) film 8 faced the insulating layer 3 through the working liquid 9, and allowed to stand until methanol was dried and removed. At this time, the contact angle between the working liquid 9 and the insulating layer 3 was 40 degrees.

  After the methanol was removed by drying, the laminate 5 naturally adhered to the insulating layer 3 so as to cover the source electrode 4a and the drain electrode 4b. Then, in order to further remove methanol, heat treatment was performed at 60 ° C. for 15 minutes in a nitrogen atmosphere. Thereby, a transistor including the active layer 2 made of poly (3-hexylthiophene) was obtained (FIG. 15E).

The transistor characteristics were measured by applying the gate voltage V _G of 40 to −60 V and the source-drain voltage V _SD of −40 V in a nitrogen atmosphere to the transistor thus fabricated, using the silicon substrate 1 as a gate electrode. . As a result, good IV characteristics (curve (a) in FIG. 17) were obtained, and a drain current of about 9 μA was obtained when V _G = −60 V and V _SD = −40 V. The mobility obtained from the IV characteristics was 2.3 × 10 ⁻² cm ² / Vs, and the on / off ratio of the current was 10 ⁵ units.

(Comparative Example 1: Formation of transistor and evaluation of physical properties when no working solution is used)
Following the steps shown in FIGS. 15A to 15C, the steps shown in FIGS. 16A and 16B were performed, whereby the transistor of Comparative Example 1 was manufactured. That is, first, according to the manufacturing process shown in FIGS. 15A and 15B, an element substrate 6 was formed in the same manner as the method described in Example 1.

  Moreover, the chloroform solution (0.5 wt%) of poly (3-hexyl thiophene) was prepared in the glove box of nitrogen atmosphere. However, weighing of poly (3-hexylthiophene) was performed in the air.

  Next, in a glove box in a nitrogen atmosphere, a chloroform solution of poly (3-hexylthiophene) is applied onto the polyethylene film as the support film 7 by a spin coating method (1000 rpm). A laminate 5 in which the (3-hexylthiophene) film 8 was laminated was formed (FIG. 15C).

Then, in a glove box in a nitrogen atmosphere, the laminate 5 is placed on the insulating layer 3 on which the source electrode 4a and the drain electrode 4b are formed, and the poly (3-hexylthiophene) film 8 faces the insulating layer 3. It was put on with tweezers (FIG. 16 (a)). Thereby, a transistor provided with poly (3-hexylthiophene) as the active layer 2 was obtained (FIG. 16B). The transistor characteristics were measured by applying a gate voltage V _G of 40 to −60 V and a source-drain voltage V _SD of −40 V in a nitrogen atmosphere to the transistor thus obtained, using the silicon substrate 1 as a gate electrode. However, it did not operate and I-V characteristics could not be obtained.

(Comparative Example 2: Formation of transistor having active layer formed by casting method and evaluation of physical properties)
The element substrate 6 was prepared in accordance with the method described in Example 1. Further, poly (3-hexylthiophene) was weighed in the atmosphere, and the chloroform solution (0.1 wt%) was prepared in a glove box in a nitrogen atmosphere.

  Then, in a glove box in a nitrogen atmosphere, a chloroform solution of poly (3-hexylthiophene) is applied onto the insulating layer 3 on which the source electrode and the drain electrode are formed by a casting method, and poly (3-hexyl) is applied. An active layer 2 made of thiophene) was formed. Thereafter, a heat treatment was performed at 60 ° C. for 15 minutes in a nitrogen atmosphere in order to remove the solvent. As a result, a transistor having the structure shown in FIG.

The transistor characteristics were measured by applying the gate voltage V _G of 40 to −60 V and the source-drain voltage V _SD of −40 V in a nitrogen atmosphere to the transistor thus obtained using the silicon substrate 1 as a gate electrode. . As a result, an IV characteristic shown in the curve of FIG. 17B was obtained, and a drain current of −1 μA was obtained when V _G = −60 V and V _SD = −40 V. The mobility obtained from the IV characteristics was 1.5 × 10 ⁻³ cm ² / Vs, and the current on / off ratio was 10 ³ units.

Table 1 summarizes the characteristics of the transistors prepared in Example 1 and Comparative Examples 1 and 2. First, the transistor obtained by the method (Comparative Example 1) bonded without using the construction liquid did not operate. In addition, the transistor of Example 1 was significantly higher in mobility than Comparative Example 2. From this, it has been found that according to the method for manufacturing a transistor of the present invention, an active layer having excellent carrier mobility can be formed satisfactorily.

(Examples 2 to 9: Formation of transistors using various construction solutions and evaluation of physical properties)
A transistor including an active layer made of poly (3-hexylthiophene) was manufactured in the same manner as in Example 1 except for the following points. That is, first, in manufacturing the element substrate 6, a source electrode and a drain electrode having a thickness of 65 nm were formed. Moreover, the immersion time in the octane solution (6 mmol / l) of octadecyltrichlorosilane was set to 19.5 hours. Furthermore, in the production of the laminate 5, a chloroform solution (2 wt%) of poly (3-hexylthiophene) was prepared and used. Then, the laminate 5 was attached using various liquids shown in Table 2 as the construction liquid 9 instead of methanol. Moreover, the construction liquid was removed by drying only under the condition of standing at 25 ° C.

The transistor characteristics were measured by applying the gate voltage V _G of 40 to −60 V and the source-drain voltage V _SD of −60 V in a nitrogen atmosphere to the transistor thus obtained using the silicon substrate 1 as a gate electrode. Thus, the mobility in each transistor was obtained. The obtained results are shown in Table 2. In Table 2, the contact angle (°) with the insulating layer 3 of the construction liquid used in each example is also shown. Moreover, the graph which plotted the mobility obtained with the transistor obtained using the construction liquid with respect to the contact angle of the construction liquid is shown in FIG.

  In the manufacture of each transistor, the construction liquid 9 having a smaller contact angle with the insulating layer 3 was easier to wet the surface of the insulating layer 3 and the laminate 5 was more easily bonded to the insulating layer 3. And as shown in Table 2 and FIG. 18, when the construction liquid 9 with a small contact angle was used, it became clear that a high quality transistor with high mobility was obtained.

(Example 10: Formation and evaluation of physical properties of a transistor to be heated in the attaching step)
In the step of laminating the laminate 5 and the element substrate 6, after removing the construction liquid (acetonitrile) by drying, the element substrate 6 to which the laminate 5 is affixed is placed on a hot plate and is heated at 80 ° C. in a nitrogen atmosphere at 60 ° C. A transistor including an active layer made of poly (3-hexylthiophene) was manufactured in the same manner as in Example 8 except that the heat treatment for minutes was performed.

The transistor characteristics were measured by applying the gate voltage V _G of 40 to −60 V and the source-drain voltage V _SD of −60 V in a nitrogen atmosphere to the transistor thus obtained using the silicon substrate 1 as a gate electrode. Thus, the mobility in each transistor was obtained. The obtained results are shown in Table 3. As shown in Table 3, it was found that good mobility can be obtained by heating in the attaching step.

(Example 11: Formation of transistor using oriented active film and evaluation of physical properties)
After the formation of the laminate 5, the laminate 5 was subjected to a stretching operation, and the poly (3-hexylthiophene) was treated in the same manner as in Example 8 except that the laminate 5 after the stretching operation was bonded to the element substrate 6. An active layer transistor consisting of The stretching operation was performed by uniaxially stretching the laminate 5 at 100 ° C. 2.5 times in a nitrogen atmosphere. Bonding was performed so that the stretched direction of the laminated body 5 was parallel to the direction connecting the source electrode 4 a and the drain electrode 4 b in the element substrate 6.

  Here, the orientation state of the poly (3-hexylthiophene) film 8 in the laminated body 5 after stretching was confirmed as follows. That is, first, a part of the stretched laminate 5 was cut out, and this was pressure-bonded to a slide glass heated to 60 ° C. on a hot plate so that the surface of the poly (3-hexylthiophene) film 8 was in contact. . Then, the poly (3-hexylthiophene) film 8 was transferred to a slide glass by peeling only the support film 7 with tweezers. The transferred poly (3-hexylthiophene) film 8 was observed with a polarizing microscope. As a result, it was confirmed that the poly (3-hexylthiophene) film 8 was oriented in the stretching direction of the laminate 5 described above.

The transistor characteristics were measured by applying the gate voltage V _G of 40 to −60 V and the source-drain voltage V _SD of −60 V in a nitrogen atmosphere to the transistor thus obtained using the silicon substrate 1 as a gate electrode. Thus, the mobility in each transistor was obtained. The obtained results are shown in Table 3. From Table 3, it was confirmed that good mobility can be obtained by imparting orientation to the active layer.

(Example 12: Formation of a transistor in which a layer is provided between an electrode and an active layer and evaluation of physical properties)
As in Example 8, except that an element substrate 216 in which a layer 500 of 4- (trifluoromethyl) thiophenol was further formed on the source electrode 4a and the drain electrode 4b in the element substrate 6 was used as the element substrate. Thus, an active layer transistor made of poly (3-hexylthiophene) was manufactured. As a result, as shown in FIG. 19, a transistor having a 4- (trifluoromethyl) thiophenol layer 500 between the source electrode 4 a and the drain electrode 4 b and the active layer 2 was obtained. The 4- (trifluoromethyl) thiophenol layer 500 is formed by immersing the element substrate 6 in an ethanol solution (1 mmol / L) of 4- (trifluoromethyl) thiophenol for 0.5 hour. did.

The transistor characteristics were measured by applying the gate voltage V _G of 40 to −60 V and the source-drain voltage V _SD of −60 V in a nitrogen atmosphere to the transistor thus obtained using the silicon substrate 1 as a gate electrode. Thus, the mobility in the transistor was obtained. The obtained results are shown in Table 3. From Table 3, it was confirmed that good mobility can be obtained by providing the layer 500 of 4- (trifluoromethyl) thiophenol.

Examples 13 to 18: Formation of transistors having active layers of various thicknesses and evaluation of physical properties
Instead of poly (3-hexylthiophene), poly (3-octylthiophene) was used, and the heat treatment in the pasting step was performed at 60 ° C. for 30 minutes, in the same manner as in Example 10. A transistor having an active layer made of poly (3-octylthiophene) was manufactured. In Examples 13 to 18, the active layer 2 having various film thicknesses was formed by changing the concentration of the chloroform solution of poly (3-octylthiophene) when the laminate 5 was formed.

The transistor characteristics are measured by applying a gate voltage V _G of 20 to −60 V and a source-drain voltage V _SD of −60 V in a nitrogen atmosphere to the transistor thus obtained, using the silicon substrate 1 as a gate electrode. Thus, the mobility in each transistor was obtained. Table 4 shows the obtained results. In Table 4, the thickness of the active layer 2 included in each transistor of each example is also shown.

  From Table 4, it was found that the higher the thickness of the active layer, the higher the mobility.

1 is a schematic cross-sectional view of a transistor according to a first embodiment. It is a schematic cross section of a transistor according to a second embodiment. It is a schematic cross section of a transistor according to a third embodiment. It is a schematic cross section of a transistor according to a fourth embodiment. It is a schematic cross section of a transistor according to a fifth embodiment. It is a schematic cross section of a transistor according to a sixth embodiment. It is process drawing which shows the manufacturing method of the transistor which concerns on 1st Embodiment. It is process drawing which shows the manufacturing method of the transistor which concerns on 2nd Embodiment. It is process drawing which shows the manufacturing method of the transistor which concerns on 3rd Embodiment. It is process drawing which shows the manufacturing method of the transistor which concerns on 4th Embodiment. It is process drawing which shows the manufacturing method of the transistor which concerns on 5th Embodiment. It is process drawing which shows the manufacturing method of the transistor which concerns on 5th Embodiment. It is process drawing which shows the manufacturing method of the transistor which concerns on 6th Embodiment. It is process drawing which shows the manufacturing method of the transistor which concerns on 6th Embodiment. 7 is a diagram illustrating a manufacturing process of the transistor of Example 1. FIG. 10 is a diagram illustrating a part of the manufacturing process of the transistors of Comparative Example 1 and Comparative Example 2. FIG. It is a figure which shows the IV characteristic of the transistor used in Example 1 and Comparative Example 2. FIG. It is a graph which shows the mobility obtained with the transistor obtained using the construction liquid with respect to the contact angle of the construction liquid. 10 is a schematic cross-sectional view of a transistor obtained in Example 12. FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... N-type silicon substrate, 2 ... Active layer, 3 ... Insulating layer, 4a ... Source electrode, 4b ... Drain electrode, 5 ... Laminated body, 6 ... Element substrate, 7 ... Support film, 8 ... Poly (3-hexyl) Thiophene) film, 9 ... working solution, 10 ... substrate, 12 ... gate electrode, 14 ... insulating layer, 16 ... source electrode, 18 ... drain electrode, 20,24 ... active layer, 22,26 ... active film, 30,32 , 34, 64... Element substrate, 36, 38... First element substrate, 40... Construction liquid, 50. Transistors according to the second embodiment, 110 ... Transistor according to the third embodiment, 115 ... Transistor according to the fourth embodiment, 120 ... Transistor according to the fifth embodiment, 125 ... Sixth real Transistor according to the, 500 ... 4 layers of (trifluoromethyl) thiophenol.

Claims (20)

A source electrode and a drain electrode, an active layer that becomes a current path between these electrodes and contains an organic semiconductor compound, a gate electrode that controls a current passing through the current path, and an active layer disposed between the active layer and the gate electrode A method of manufacturing a transistor having an insulating layer comprising:
A method for manufacturing a transistor, comprising: a pasting step in which a construction liquid is interposed between the active layer and the insulating layer to bond the active layer and the insulating layer together.   The method for manufacturing a transistor according to claim 1, wherein the construction liquid has a contact angle with the insulating layer of 120 degrees or less.   The method for manufacturing a transistor according to claim 1, wherein the construction liquid has a contact angle with the insulating layer of 90 degrees or less.   The method for manufacturing a transistor according to any one of claims 1 to 3, wherein the active layer to be bonded in the bonding step is formed on a support film.   The manufacturing method of the transistor as described in any one of Claims 1-4 which further has the removal process which removes the volatile component in the said construction liquid after the said sticking process.   The manufacturing method of the transistor as described in any one of Claims 1-5 which performs a heating and / or pressurization in the said sticking process.   The method for manufacturing a transistor according to claim 1, wherein the active layer is an aligned active layer. A method of manufacturing a transistor having a source electrode and a drain electrode, an active layer that becomes a current path between these electrodes and contains an organic semiconductor compound, and a gate electrode that controls a current passing through the current path,
A method for manufacturing a transistor, comprising: an attaching step of attaching the active layer to a surface on which the active layer is to be formed by interposing a working liquid between the active layer and the surface.   9. The transistor according to claim 1, wherein the transistor includes a layer made of a compound different from the organic semiconductor compound between the source electrode and / or the drain electrode and the active layer. The manufacturing method of the transistor of description. A method for producing an organic semiconductor element having an active layer containing an organic semiconductor compound,
The manufacturing method of an organic-semiconductor element including the sticking process of bonding the said active layer to the surface in which this active layer is formed, interposing a construction liquid between the said surfaces. A source electrode and a drain electrode, an active layer that becomes a current path between these electrodes and contains an organic semiconductor compound, a gate electrode that controls a current passing through the current path, and an active layer disposed between the active layer and the gate electrode Having an insulating layer,
The active layer and the insulating layer are transistors which are bonded together with a construction liquid interposed therebetween.   The transistor according to claim 11, wherein the construction liquid has a contact angle with the insulating layer of 120 degrees or less.   The transistor according to claim 11, wherein the construction liquid has a contact angle with the insulating layer of 90 degrees or less.   The transistor according to claim 11, wherein the active layer is an aligned active layer. A transistor having a source electrode and a drain electrode, an active layer serving as a current path between these electrodes and containing an organic semiconductor compound, and a gate electrode for controlling a current passing through the current path;
A transistor in which the active layer is bonded to a surface on which the active layer is formed with a working liquid interposed between the active layer and the surface.   The transistor according to any one of claims 11 to 15, further comprising a layer made of a compound different from the organic semiconductor compound between the source electrode and / or the drain electrode and the active layer. An organic semiconductor element having an active layer containing an organic semiconductor compound,
The organic semiconductor element, wherein the active layer is attached to a surface on which the active layer is formed with a working liquid interposed between the active layer and the surface.   The organic semiconductor element according to claim 17, wherein the active layer is an aligned active layer.   A semiconductor device comprising the transistor according to claim 11.   A semiconductor device comprising the organic semiconductor element according to claim 17.

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