JP4933051B2 - FIELD EFFECT TRANSISTOR, ITS MANUFACTURING METHOD, AND LAMINATE MANUFACTURING METHOD - Google Patents

Description

  The present invention relates to a field effect transistor, a method for manufacturing the field effect transistor, and a method for manufacturing a stacked body.

  The development of thin film transistors using organic semiconductors has been gradually active since the late 1980s, and in recent years, the characteristics of amorphous silicon thin film transistors have been exceeded as basic performance. Since organic materials are easy to process and often have a high affinity with plastic substrates on which thin film FETs (Field Effect Transistors) are formed, the use of organic materials as semiconductor layers in thin film devices is attractive. As researches on organic semiconductors, there have so far been acenes such as pentacene and tetracene disclosed in Patent Document 1, phthalocyanines including lead phthalocyanine disclosed in Patent Document 2, and perylene and its tetracarboxylic acid derivatives. Molecular compounds, aromatic oligomers represented by thiophene hexamers called α-thienyl or sexualthiophene disclosed in Patent Document 3, and polymers such as polythiophene, polythienylene vinylene, poly-p-phenylene vinylene Compounds, etc. have been proposed. Many of these are described in Non-Patent Document 1.

  Characteristics such as nonlinear optical characteristics, conductivity, and semiconductivity required when a device is formed from these compounds as a semiconductor layer greatly depend on crystallinity and orientation as well as material purity. A compound with an expanded π-conjugated system is usually insoluble or hardly soluble in a solvent. For example, since pentacene has high crystallinity and is insoluble in a solvent, a pentacene thin film is formed by using a vacuum evaporation method. Although the pentacene thin film formed by using the vacuum evaporation method has been shown to have a high field effect mobility, there has been a problem that it is unstable in the atmosphere, easily oxidized, and easily deteriorated.

  On the other hand, an organic semiconductor using a π-conjugated polymer as an organic semiconductor film is being developed for application because it has excellent moldability, such as being able to easily form a thin film by a solution coating method or the like (Non-patent Document 2). In the case of π-conjugated polymers, it is known that the arrangement state of molecular chains has a large effect on electrical conductivity. Similarly, the field-effect mobility of π-conjugated polymer field-effect transistors in the semiconductor layer It has been reported that it greatly depends on the arrangement state of molecular chains (Non-patent Document 3). However, since the molecular chains of the π-conjugated polymer are arranged between the application of the solution and the drying, there is a possibility that the arrangement of the molecular chains may change greatly due to changes in the environment and differences in the application method. It was.

  An FET using a film in which a soluble precursor thin film of pentacene is formed by coating and converted to pentacene by heat treatment has also been reported (Non-Patent Document 4). In this case, high-temperature treatment is required for the conversion to pentacene, and a desorbed component having a large mass must be removed by decompression.

Furthermore, it has been reported that tetrabenzoporphyrin obtained by heating a porphyrin condensed with a bulky bicyclo [2.2.2] octadiene skeleton at 210 ° C. or more can be used as an organic semiconductor (Non-patent Document 5, Patent Document 4 and Patent Document 5). However, the carrier mobility shown in these publications is by no means excellent. That is, in order to obtain sufficient characteristics as an organic semiconductor, it is considered that further studies are necessary to obtain an optimal crystal arrangement in order to improve carrier mobility.
JP-A-5-55568 Japanese Patent Laid-Open No. 5-190877 JP-A-8-264805 JP 2003-304014 A JP 2004-6750 A Advanced Material, 2002, No. 2, p. 99-117 “Japan Journal of Applied Physics”, Applied Physics Society, 1991, Vol. 30, p. 596-598 “Nature” Nature Publishing Group, 1999, vol. 401, p. 685-687 “J. Appl. Phys.” 79, 1996, p. 2136 The 81st Annual Meeting of the Chemical Society of Japan 2002 Preliminary Proceedings II, p. 990 (2F9-14)

  As described above, a field effect transistor using an organic semiconductor compound has conventionally formed a semiconductor layer having crystallinity and orientation through a process such as vacuum film formation. There was a problem that the products were easily oxidized and deteriorated. In addition, in the case where a simple method is adopted by the coating method, establishment of a method for forming a film having excellent orientation and crystallinity has been an issue.

  The present invention has been made to solve this problem, and it is an object of the present invention to provide a field effect transistor that can form an organic semiconductor layer having high crystallinity and orientation and that exhibits high field effect mobility.

  Moreover, this invention is providing the manufacturing method of the field effect transistor which can obtain said field effect transistor by a simple method.

The present invention is a field effect transistor having an organic semiconductor layer, wherein an organic semiconductor layer containing at least a porphyrin and a layer made of at least a polysiloxane compound are adhered and laminated ,
The polysiloxane compound is a compound obtained by heating methylsilsesquioxane,
The porphyrin is a tetrabenzoporphyrin copper complex,
The Bragg angle (2θ) of CuKα X-ray diffraction in the organic semiconductor layer has peaks at 8.4 ° ± 0.2 °, 11.9 ° ± 0.2 °, and 16.9 ° ± 0.2 °. A field effect transistor is provided.

According to the present invention, a field effect transistor having excellent crystallinity and orientation and high field effect mobility can be provided.
In addition, according to the present invention, it is possible to provide a method for manufacturing a field effect transistor that can obtain the above-described field effect transistor by a simple method.

Hereinafter, the present invention will be described in detail.
The field effect transistor according to this embodiment is an element having at least an organic semiconductor, an insulator, and a conductor. The insulator is an insulating film (layer) for covering a conductor as an electrode. An organic semiconductor is an organic semiconductor layer that responds to a stimulus (electric field) generated by such a conductor (electrode). Specifically, it is a layer whose electrical characteristics change with respect to an electric field. More specifically, it is a layer in which the conductivity, that is, the current flowing through the organic semiconductor layer changes in accordance with the change in the electric field.

  FIG. 1A is a schematic schematic cross-sectional view showing a field effect transistor according to this embodiment. 8 is a base material, 1 is a gate electrode, 2 is a gate insulating layer, 4 is a source electrode, 5 is a drain electrode, 6 is an organic semiconductor layer, and 7 is a sealing layer. In this element, a gate electrode 1 is provided on the surface of a substrate 8, a gate insulating layer 2 is provided thereon, and a source electrode 4 and a drain electrode 5 are provided on the surface of the insulating layer 3 at intervals. . An organic semiconductor layer 6 is provided in contact with both the electrodes 4 and 5 on the source electrode 4 and the drain electrode 5 and on the insulating layer 2 which is a separation region thereof. The insulating layer 2 is provided so as to cover the gate electrode 2. Furthermore, the organic semiconductor layer 6 is covered with a sealing layer 7. Moreover, the base material 8 and the sealing layer 7 can also be replaced.

  In the field effect transistor according to the present embodiment, when a voltage is applied to the gate electrode 1, positive or negative charges are induced at the interface between the gate insulating layer 2 and the organic semiconductor layer 6. Further, when a voltage is applied between the source electrode 4 and the drain electrode 5, the charge moves between the two electrodes, and a current can be obtained. Therefore, when a voltage is applied to the gate electrode 1, charges are uniformly generated at the interface between the gate insulating layer 2 and the organic semiconductor layer 6, and further when a voltage is applied between the source electrode 4 and the drain electrode 5. High field-effect mobility can be exhibited by efficient movement of charges with few barriers.

  The present inventors have intensively studied to find a method for forming an organic semiconductor layer interface in which charges are uniformly generated and the generated charges can efficiently move. Then, by sandwiching a specific organic semiconductor material and a layer for promoting crystallization (crystallization promoting layer) across the gate insulating layer 2 and the organic semiconductor layer 6), the interface is continuously uniform at the interface. Thus, a crystal with few defects can be formed, and it has been found that high field-effect mobility is exhibited.

  The field effect transistor of the present invention is a field effect transistor having an organic semiconductor layer, and preferably, an organic semiconductor layer containing at least a porphyrin and at least a layer made of a polysiloxane compound are closely adhered to each other. It is characterized by that. The adhesion mentioned here refers to a state in which the organic semiconductor layer and the layer made of the polysiloxane compound are in contact with each other without any other layer.

  In the present invention, an electric field in which a layer made of a polysiloxane compound (hereinafter referred to as A layer) and a porphyrin-containing organic semiconductor layer (hereinafter referred to as B layer) are laminated in close contact with each other in part or on the entire surface of the device. An effect transistor is preferable because it exhibits high field-effect mobility. As will be described later, if the porphyrin precursor is made soluble, both the A layer and the B layer can be prepared using a coating process, and thus the device can be manufactured by a simple process.

  Furthermore, as will be described later, it is possible to use another crystallization promoting layer having a crystallization promoting function instead of the A layer, and crystallization is promoted by the crystallization promoting layer instead of the B layer. It is possible to use such an organic semiconductor layer.

  In the present invention, the underlying structure on which the crystallization promoting layer is formed (generally a structure comprising a base material, a gate electrode, and a gate insulating layer. However, the gate insulating layer may be omitted in some cases. Depending on the order of lamination, the substrate may be used alone, or other layers may be formed). In the present invention, the crystallization promoting function refers to a function of promoting stabilization of crystal grains (sometimes accompanied by movement or rotation) and / or joining of crystal grains, Is a layer that promotes the stabilization of crystal grains (sometimes accompanied by movement and rotation) and / or the bonding of crystal grains.

  In the following, the B layer is formed on the A layer, but the present invention is not limited thereto. However, from the viewpoint of giving influence by the A layer when forming the B layer, it is preferable to form the B layer on the A layer.

  The polysiloxane compound of the present invention is a polymer having a siloxane structure (—Si—O—) and an organic silane structure, and may be a copolymer with other organic polymer or inorganic polymer. In the case of a polymer with another polymer, the siloxane structure and the organosilane structure may be introduced into the main chain or may be grafted to the side chain. Due to the effect of the combination of the siloxane structure (—Si—O—) and the organic silane structure, the organic semiconductor layer of the B layer is less likely to be bound by the A layer during the crystallization process, and thus crystallization is promoted.

  The polysiloxane compound of the present invention may be linear or cyclic, but more preferably has a high-order crosslinked or branched structure. The higher-order bridged or branched structure described here includes a net-like, ladder-like, cage-like, star-like, and dendritic structure. In addition, the crosslinked or branched structure does not necessarily have to be formed via a siloxane structure, and a structure in which organic groups such as vinyl group, acryloyl group, epoxy group, cinnamoyl group are crosslinked with each other, or a trifunctional or more functional group. A structure branched via an organic group may be included.

  The polysiloxane compound layer of the present invention is different from a monomolecular layer formed by reacting octyltrichlorosilane or hexamethyldisilazane with an active group on the substrate surface by having a high-order crosslinked or branched structure. The amorphous layer can be formed over a wide area regardless of the state and shape of the substrate surface. For this reason, the interface between the A layer and the B layer is uniform at least in a wide range beyond the region where the channel is formed, and is combined with the above-described effect of the combination of the siloxane structure and the organosilane structure, so that the crystal is continuously uniform and has few defects. Is formed.

  The polysiloxane compound used in the A layer of the present invention has, for example, a structure represented by the following general formula (1), a main chain having a siloxane unit, and a side chain having an organic group such as a hydrogen atom or a carbon atom. It is a group.

In the formula, each of R _{1 to} R ₄ is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, an alkenyl group, a substituted or unsubstituted phenyl group, or a siloxane unit. Each of R _{1 to} R ₄ may be the same or different. n is an integer of 1 or more.

The substituents R _{1 to} R ₄ may be siloxane units as shown below.

(Wherein R is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, an alkenyl group, a substituted or unsubstituted phenyl group, or a siloxane unit represented above, each having the same functionality. Or a different functional group.)

  Depending on the type of the substituent in the general formula (1), the polysiloxane may have a linear, cyclic, network, ladder, or cage structure, and any of the polysiloxanes used in the present invention may be used. .

  In the present invention, particularly preferred as the polysiloxane compound used in the A layer is at least a specific silsesquioxane skeleton as shown in the following general formula (2) and / or as shown in the following general formula (6). It is a polysiloxane compound having a specific organosiloxane skeleton.

(Wherein R _{7 to} R ₁₀ are any of substituted or unsubstituted alkyl groups having 1 to 5 carbon atoms, alkenyl groups, or substituted or unsubstituted phenyl groups. Each of R _{7 to} R ₁₀ is the same. However, m and n are integers greater than or equal to 0, and the sum of m and n is an integer greater than or equal to 1. The form of copolymerization may be random copolymerization or block copolymerization. good.)

(In the formula, each of R _{21 to} R ₂₄ is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, an alkenyl group, or a substituted or unsubstituted phenyl group. Each of R _{21 to} R ₂₄ is R and p are integers greater than or equal to 0, and the sum of r and p is an integer greater than or equal to 1. The form of copolymerization is random copolymerization or block copolymerization, Is also good.)
The silsesquioxane skeleton represented by the general formula (2) and the organosiloxane skeleton represented by the general formula (6) may include either one or both.

The substituents R _{7 to} R ₁₀ and R _{21 to} R ₂₄ having carbon atoms corresponding to the side chains of the silsesquioxane skeleton and organosiloxane skeleton are substituted or unsubstituted alkyl having 1 to 5 carbon atoms. A group, an alkenyl group, or a substituted or unsubstituted phenyl group, which may be the same functional group or different functional groups depending on the position. For example, an unsubstituted alkyl group such as a methyl group or an ethyl group / an unsubstituted phenyl group / a substituted phenyl group such as a dimethylphenyl group or a naphthyl group. Further, the substituents R _{7 to} R ₁₀ may contain various atoms such as oxygen atom, nitrogen atom and metal atom in addition to carbon atom and hydrogen atom.

Hereinafter, the silsesquioxane skeleton of the compound used in the present invention will be described. In the general formula (2), m silsesquioxane units having substituents R ₇ and R ₈ (hereinafter referred to as first unit) are repeated, and silsesquioxane units having substituents R ₉ and R _10. A structural formula is shown in which n (second unit) repeats are connected (m and n are integers greater than or equal to 0, and m + n is an integer greater than or equal to 1). It does not mean that the repetition of the unit and the repetition of the second unit are separated. Both units may be connected separately or may be connected randomly.

In the general formula (6), a diorganosiloxane unit having substituents R ₂₁ and R ₂₂ (hereinafter referred to as the first unit) and a diorganosiloxane unit having substituents R ₂₃ and R ₂₄ (hereinafter referred to as the first unit) are repeated. , The second unit) is a p-linked structure (r and p are integers greater than or equal to 0, and r + p is an integer greater than or equal to 1). It does not mean that the repetition and the repetition of the second unit are separated. Both units may be connected separately or may be connected randomly.

  In order to form the layer A in the present invention mainly containing a polysiloxane compound having a silsesquioxane skeleton and / or an organosiloxane skeleton as shown in the general formula (2) or the general formula (6), for example, A polyorganosilsesquioxane compound represented by the following general formula (4) and / or general formula (5) and / or a polyorgano represented by the following general formula (7) and / or general formula (8) There are a method in which a solution containing a siloxane compound is applied on a substrate and heat-dried, and a method in which a sol obtained by hydrolyzing a silicon monomer is applied on a substrate and heat-dried.

  The polyorganosilsesquioxane compound represented by the general formula (4) and / or the general formula (5) and / or the polyorgano represented by the following general formula (7) and the general formula (8) or any one of the following: In the method of heating and drying the coating film of the siloxane compound, the polyorganosilsesquioxane compound is connected in a ladder form by condensing the ends of the compound by heating through dehydration or dealcoholization reaction, while the polyorganosiloxane compound Increases in molecular weight and densifies. However, at this time, the drying temperature is not so high that the organic matter is completely disappeared. A silsesquioxane skeleton or an organosiloxane skeleton as shown in FIG.

  Commercially available polyorganosilsesquioxane compounds represented by general formula (4) and general formula (5) and polyorganosiloxane compounds represented by general formula (7) and general formula (8) can be used. Generally, a polyorganosilsesquioxane compound and a polyorganosiloxane compound are synthesized by the reactions shown in the following reaction formula (11) and reaction formula (12), respectively.

  The reaction formulas (11) and (12) will be described. A trifunctional organosilicon monomer and / or a bifunctional organosilicon monomer having an organic group R ′ is hydrolyzed in a solvent such as alcohol to produce a silanol compound. The silicon monomer shown in the above formula is an alkoxide, and R ″ OH is eliminated by hydrolysis, but chloride can also be used as the silicon monomer. However, hydrogen chloride is generated as a desorbing component in this case. The silanol compound obtained by hydrolysis is further subjected to dehydration condensation by heating or the like to produce a polyorganosilsesquioxane compound and a polyorganosiloxane compound. By removing the solvent and the catalyst, the polyorganosilsesquioxane compound and the polyorganosiloxane compound are isolated as solids. The structure, molecular weight, type of terminal group, and the like of the resulting compound can be changed depending on the catalyst, solvent, pH, concentration, etc. during the reaction.

(Wherein R ₇ and R ₈ are either substituted or unsubstituted alkyl groups having 1 to 5 carbon atoms, alkenyl groups or substituted or unsubstituted phenyl groups, and R ₇ and R ₈ are the same functional group. R _{13 to} R ₁₆ are an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and z is an integer of 1 or more.)

(In the formula, R ₉ and R ₁₀ are each a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, an alkenyl group, or a substituted or unsubstituted phenyl group, and R ₉ and R ₁₀ are the same functional group. R _{17 to} R ₂₀ are each an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and y is an integer of 1 or more.)

(In the formula, R ₂₅ and R ₂₆ are either substituted or unsubstituted alkyl groups having 1 to 5 carbon atoms, alkenyl groups, or substituted or unsubstituted phenyl groups, and R ₂₅ and R ₂₆ are the same functional group. R ₂₇ and R ₂₈ are each an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and q is an integer of 1 or more.)

(Wherein R ₂₉ and R ₃₀ are either a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, an alkenyl group, or a substituted or unsubstituted phenyl group, and R ₂₉ and R ₃₀ have the same functionality. R ₃₁ and R ₃₂ may be an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and s is an integer of 1 or more.)
In addition, a small amount of acid such as formic acid may be added to the coating solution for the purpose of assisting the reaction in which the oligomeric silsesquioxane compounds cross-link each other during the drying step.

  The amount of acid to be added is not particularly limited, but in the case of formic acid, it is added in the range of 1 to 30% by weight with respect to the solid weight of the polyorganosilsesquioxane compound contained in the coating solution. Cross-linking reaction is promoted. If the addition amount is less than 1% by weight, the effect of promoting the crosslinking reaction is not sufficient, and conversely if the addition amount is more than 30% by weight, film formation after drying may be hindered.

  On the other hand, a method of applying a sol obtained by hydrolyzing a silicon monomer on a substrate and drying by heating will be described. When the trifunctional silicon monomer and / or the bifunctional silicon monomer shown in the reaction formula (11) and the reaction formula (12) are stirred in a solvent in the presence of water and a catalyst at room temperature or with heating, the reaction formula (11) And a sol is prepared through hydrolysis and dehydration condensation reaction similar to the reaction formula (12). When the obtained sol coating is heated, silanols and unreacted alkoxides are condensed by dehydration or dealcoholization reaction, resulting in a dense silsesquioxane skeleton or organo group as shown in general formulas (2) and (6). A siloxane skeleton is formed.

  Typical silicon monomers that can be used to prepare the sol include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, butyltrimethoxysilane, vinyltrimethoxysilane, 3-aminopropyl Examples thereof include trifunctional silicon monomers such as triethoxysilane and phenyltrimethoxysilane, and bifunctional silicon monomers such as dimethyldimethoxysilane and diphenyldimethoxysilane.

  To prepare the sol, water and a catalyst can be added to promote hydrolysis of the monomer. The amount of water added is 0.1 to 20 equivalents relative to the OR ″ group of the monomer in the reaction formula (11) or the reaction formula (12). On the other hand, an acid or base catalyst can be used as the catalyst. Hydrochloric acid, nitric acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, acetic acid, formic acid, trifluoroacetic acid, alkyl phosphoric acid, etc. can be used as the acid catalyst, but it is low corrosive and volatilizes when the coating is heated and dried. Formic acid is more preferable because it does not remain in it. Sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, etc. can be used as the base catalyst, but the remaining of alkali metals such as sodium causes deterioration of the electrical characteristics of the device, so tetramethylammonium hydroxide Is preferred. When the catalyst is added in an amount of 1 to 30% by weight based on the solid content weight of the silicon monomer contained in the solution, the hydrolysis reaction is promoted. If the addition amount is less than 1% by weight, the crosslinking reaction is not sufficiently promoted. Conversely, if the addition amount is more than 30% by weight, the film properties after drying may be deteriorated.

  Further, the polyorganosilsesquioxane compound represented by the general formula (4) and the general formula (5) and the polyorganosiloxane compound represented by the general formula (7) and the general formula (8) and the above reaction formula (11) or the reaction formula The silicon monomer in (12) can also be mixed and used. In this case, water and a catalyst can be added similarly to preparation of sol. The amount of water added is 0.1 to 20 equivalents relative to the OR ″ group of the monomer, and the amount of catalyst added is the solid content of the polyorganosilsesquioxane compound and / or polyorganosiloxane compound and the silicon monomer. The content is preferably 1% by weight to 30% by weight based on the weight.

Furthermore, tetrafunctional silicon monomers such as tetramethoxysilane and tetraethoxysilane can be used in combination in order to improve the coating property and solvent resistance after heating.
A preferable heat treatment temperature is 140 ° C. or higher, and more preferably 150 to 230 ° C. If it is heated below 140 ° C., the hydrolysis reaction may be insufficient.

In the process of cross-linking reaction and solvent removal, the stabilizer that does not evaporate, volatilize or burn out in the temperature region is removed from the solution system as much as possible.
Arbitrary things, such as alcohol and ester, can be used for the solvent of a coating solution. A solvent may be selected in consideration of wettability to the substrate.

  The coating method of the raw material solution for the A layer is not particularly limited, and a conventional coating method such as a spin coating method, a casting method, a spray coating method, a doctor blade method, a die coating method, a dipping method, a printing method, or an ink jet method. Apply by a dropping method or the like. Among these methods, a preferable method is a spin coating method, a dipping method, a spray coating method, and an ink jet method in that a film thickness of a desired thickness can be formed by controlling the coating amount. Further, in order to maintain the insulating properties of the obtained film, it is important that dust and the like are not mixed in the coating solution as much as possible, and it is desirable to filter the raw material solution with a membrane filter in advance.

It is preferable to adjust the liquid concentration so that the thickness of the A layer is 10 nm or more, preferably 15 to 500 nm. This is because when the thickness is less than 10 nm, it is difficult to obtain a uniform film.
Before applying the A layer, the substrate may be subjected to surface modification for improving wettability by ultrasonic treatment with an alkaline solution or UV irradiation.

  Next, the preferable aspect of B layer of this invention is demonstrated. The B layer preferably contains at least a porphyrin compound represented by the following general formula (3).

In the formula, R ₁₁ represents at least one selected from a hydrogen atom, a halogen atom, a hydroxyl group, or an alkyl group having 1 to 12 carbon atoms, an oxyalkyl group, a thioalkyl group, and an alkyl ester group, and R ₁₁ is the same. Or it may be different. Further, adjacent R ₁₁ may form an aromatic ring which may have a substituent. Further, through the aromatic ring between R ₁₁ adjacent is formed, it may be linked with good porphyrin ring which may have a substituent. R ₁₂ represents at least one selected from a hydrogen atom or an aryl group which may have a substituent. R ₁₂ may be the same or different. X represents a hydrogen atom or a metal atom. Examples of X include various metals such as H, Cu, Zn, Ni, Co, Mg, and Fe, and atomic groups such as AlCl, TiO, FeCl, and SiCl ₂ . X is not particularly limited, but is particularly preferably a hydrogen atom or a copper atom. Examples of the aromatic ring include a benzene ring, a naphthalene ring, and an anthracene ring.

These porphyrin compounds can be formed on a substrate on which the A layer is formed by a general method such as a vacuum deposition method or a dispersion coating method.
An example of a porphyrin compound is shown below. Although the structure of an unsubstituted and metal-free body is mainly shown, the substituent, the central metal, and the central atomic group are not limited. Of course, the compound of this invention is not limited to these.

As described above, it is preferable that at least one pair of adjacent R ₁₁ of the porphyrin compound represented by the general formula (3) forms an aromatic ring, and this aromatic ring is bicyclo [2 2.2.2] If it is obtained by heating a coating film obtained by solvent coating of a precursor having an octadiene skeleton structure (hereinafter referred to as bicyclo form), it is more preferable in order to promote crystallization of the porphyrin compound. In addition, it is also possible to use other energy addition means, such as light irradiation, instead of heating. More generally speaking, it is preferable to use a reverse Diels-Alder reaction (retro Diels-Alder reaction) in terms of facilitating use of the coating process.

  As a method for producing the B layer when the bicyclo body is used as a precursor, the bicyclo body is dissolved in an organic solvent, and then applied to the base material on which the A layer is formed, and then heated to obtain a porphyrin compound. A method for obtaining a crystallized film is preferable.

It is sufficient that the A layer and the B layer are in close contact with each other, and another element component such as a partial electrode may exist between the A layer and the B layer.
Before applying the B layer, the surface of the A layer may be modified using a general method as necessary.

  The organic solvent used for dissolving the bicyclo form is not particularly limited as long as the bicyclo form does not react or precipitate. Two or more organic solvents may be mixed and used. In consideration of the smoothness of the coating film surface and the uniformity of the film thickness, it is preferable to use a halogen solvent. Examples of the halogen solvent include chloroform, methylene chloride, dichloroethane, chlorobenzene, dichlorobenzene, trichlorobenzene, 1,2-dichloroethylene, and the like. The concentration of the solution is arbitrarily adjusted depending on the desired film thickness, but is preferably 0.01 to 5% by weight.

  The application method of the B layer when using a bicyclo compound is not particularly limited as in the case of the A layer. Conventional coating methods such as a spin coating method, a casting method, a spray coating method, a doctor blade method, and a die coating are used. It is applied by the method, dipping method, printing method, ink jet method, dropping method or the like. Among these methods, a preferable method is a spin coating method, a dipping method, a spray coating method, and an ink jet method in that a film thickness of a desired thickness can be formed by controlling the coating amount.

  Further, it is desirable to filter with a membrane filter in advance in order to prevent dust and the like from entering the semiconductor layer as much as possible. This is because insoluble matters and external dust contamination prevent uniform orientation and increase the OFF current and decrease the ON / OFF ratio. Moreover, it can also be pre-dried at 130 ° C. or lower during the bicyclo coating.

  The bicyclo skeleton formed by coating causes a reverse Diels-Alder reaction (retro Diels-Alder reaction) by heating, and is converted into an aromatic ring (benzo) with the elimination of the ethylene skeleton. Simultaneously with the formation of the aromatic ring, crystal growth is caused by stacking of the porphyrin rings, and a crystallized film of the porphyrin compound is obtained. The elimination reaction occurs at 140 ° C. or higher, and the heating temperature for obtaining higher field effect mobility is preferably 150 to 280 ° C., preferably 170 to 230 ° C. If the temperature is lower than 150 ° C., a crystallized film with sufficient crystal growth cannot be obtained. If the temperature exceeds 280 ° C., cracks occur due to rapid film shrinkage.

  Heating is performed on a hot plate, in a hot-air circulating oven or a vacuum oven, but the heating method is not limited. In order to obtain uniform alignment, a method of instantaneously heating on a hot plate is preferable.

  Further, in order to obtain higher crystallinity, a rubbing treatment in which the coating film before heating is lightly rubbed with a cloth or the like can be performed. The cloth used for the rubbing treatment includes, but is not limited to, rayon, cotton, silk and the like.

  An example of a bicyclo form is shown below. Although the structure of an unsubstituted and metal-free body is mainly shown, the substituent, the position where the bicyclo ring exists in the molecule, the central metal, and the central atomic group are not limited. Of course, the compound of this invention is not limited to these.

The film thickness of the B layer obtained by these operations is 10 to 200 nm, preferably 20 to 150 nm. The film thickness can be measured with a surface roughness meter or a step gauge.
It is also conceivable to replace the B layer with another general organic semiconductor compound such as phthalocyanine.

The organic film obtained in the present invention is most preferably used for a field effect transistor, but can be applied to other devices.
FIG. 1B is a schematic cross-sectional view showing an enlarged part of the field effect transistor of the present invention. The field effect transistor of the present invention comprises a gate electrode 1, an insulating layer 2, an A layer 3 (polysiloxane compound layer), a source electrode 4, a drain electrode 5, and a B layer 6 (organic semiconductor layer). Although omitted in FIG. 1B, the base material 8 exists on the opposite side of the insulating layer of the gate electrode 1.

  The gate electrode, source electrode, and drain electrode are not particularly limited as long as they are conductive materials. Platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, aluminum, zinc, magnesium , And alloys thereof, conductive metal oxides such as indium / tin oxide, or inorganic and organic semiconductors whose conductivity has been improved by doping, such as silicon single crystal, polysilicon, amorphous silicon, germanium, graphite, Examples include polyacetylene, polyparaphenylene, polythiophene, polypyrrole, polyaniline, polythienylene vinylene, polyparaphenylene vinylene, and the like. Examples of the method for producing the electrode include a sputtering method, a vapor deposition method, a printing method from a solution and a paste, an ink jet method, and a dipping method. Further, among the electrode materials mentioned above, those having low electric resistance at the contact surface with the semiconductor layer are preferable.

  As the insulating layer, any material can be used as long as the A layer can be applied uniformly, but a material having a high dielectric constant and a low electrical conductivity is preferable. Examples include inorganic oxides and nitrides such as silicon oxide, silicon nitride, aluminum oxide, titanium oxide, tantalum oxide, polyacrylate, polymethacrylate, polyethylene terephthalate, polyimide, polyether, polyamide, polyamideimide, polybenzoxazole, Examples thereof include polybenzothiazole, phenol resin, polyvinyl phenol, and epoxy resin. Among the insulating materials, those having high surface smoothness are preferable. In the case where the A layer itself is excellent in insulating properties, the A layer itself may be used as a gate insulating layer by adjusting the film thickness so as to exhibit insulating properties. The configuration in this case is the same as that shown in FIG.

As described above, although omitted in FIG. 1B, the base material 8 exists on the opposite side of the insulating layer of the gate electrode 1. This is the same as in FIG.
Examples of the base material 8 suitably used in the present invention include those obtained by processing silicon, glass, metal, resin or the like into a plate shape, foil shape, film shape or sheet shape. In particular, a resin base material is preferable from the viewpoints of flexibility and processability. The resin base material used is polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polyetherimide (PEI), polyethersulfone (PES), polysulfone (PSF), polyphenylene sulfide. (PPS), polyetheretherketone (PEEK), polyarylate (PAR), polyamideimide (PAI), polycycloolefin resin, acrylic resin, polystyrene, ABS, polyethylene, polypropylene, polyamide resin, polycarbonate resin, polyphenylene ether resin, A cellulose resin is mentioned. An organic-inorganic composite material base material in which inorganic oxide fine particles are mixed with these resin materials or an inorganic material is bonded may be used.

  The field effect transistor structure in the present invention may be any of a top contact electrode type, a bottom contact electrode type, and a top gate electrode type. Moreover, it is not limited to a horizontal type, A vertical type may be sufficient.

  In addition, according to the present inventors' detailed examination, the step of obtaining the B layer by heating the bicyclo precursor on the A layer (that is, the step of forming the B layer using the reverse Diels-Alder reaction) It is considered that the layer is important for functioning as a crystallization promoting layer of the B layer.

  That is, when a bicyclo precursor is overheated to cause an elimination reaction, it is observed that a gap is formed between crystal grains made of the obtained compound, but when such a reaction is performed on the A layer, This confirmed the phenomenon that the gaps between the crystal grains of the B layer were filled.

This is presumably because the A layer promotes the stabilization of crystal grains of the B layer (which may involve movement and rotation) and the bonding of crystal grains.
The present inventor believes that the crystallinity of the B layer is improved by such an action of the A layer is the reason that the A layer functions as a crystallization promoting layer. Note that it is particularly preferable that the crystal grains are bonded to each other.

  According to a further experimental study by the present inventor, such crystallization is achieved by imparting to the precursor or the converted compound more energy than is necessary to convert the precursor of the compound constituting the B layer. The reaction is accelerated. Even after the conversion (desorption) from the precursor is completed, the crystallization reaction is further promoted by continuing to apply energy such as heating.

  That is, instead of the layer (A layer) made of a specific polysiloxane compound as described above, the crystallization promoting function as described above (the function of stabilizing crystal grains and the function of promoting bonding of crystal grains). A layer having a slag can be used as the crystallization promoting layer of the present invention.

  Further, the organic semiconductor layer is not limited to a layer (B layer) having a porphyrin compound, and is a layer made of a compound accompanied by conversion from a precursor, and the crystallization promoting layer promotes crystallization as described above. Any layer can be used. As the organic semiconductor material contained in the organic semiconductor layer, a compound whose molecular weight decreases by conversion from the precursor is preferable. More specifically, a layer containing pentacene obtained by detaching these groups from a dicyclo group having a diazo group or a dicarbonyl group is also an organic semiconductor layer suitably used in the present invention.

  In the organic semiconductor layer forming step, at least one of the movement, rotation, and bonding of the crystal grains described above can be promoted by the presence of the crystallization promoting layer, and the electric field effect by the presence of the crystallization promoting layer. It can be confirmed that the organic field effect transistor and the manufacturing method thereof can be confirmed to be within the scope of the present invention if the mobility is increased.

  Furthermore, the concept of the present invention is to improve the performance of the organic semiconductor layer not only in the method of manufacturing the field effect transistor, but also in the manufacturing method of other organic devices, and more generally, the manufacturing method of the laminate having the organic semiconductor layer. These are all effective within the scope of the present invention.

Synthesis Examples and Examples are shown below, but the present invention is not limited to these Examples.
Synthesis example 1
Step 1-1
A mixture of 3.16 g (39.5 mmol) of 1,3-cyclohexadiene, 10.5 g (34.1 mmol) of trans-1,2-bis (phenylsulfonyl) ethylene and 200 ml of toluene was refluxed for 7 hours, and then cooled. The reaction mixture was obtained by concentration under reduced pressure. The crude reaction product was recrystallized (chloroform / hexane) to give 5,6-bis (phenylsulfonyl) -bicyclo [2.2.2] oct-2-ene (13.8 g, 35.6 mmol, yield 90). %).

Step 1-2
The reaction system of the resulting mixture of 5,6-bis (phenylsulfonyl) -bicyclo [2.2.2] oct-2-ene (7.76 g, 20 mmol) and anhydrous tetrahydrofuran (50 ml) was purged with nitrogen to obtain ethyl isocyanoacetate. 2.425 ml (22 mmol) was added and cooled to 0 ° C. Potassium t-butoxide (50 ml / 1 M THF (tetrahydrofuran) solution) was added dropwise over 2 hours, followed by stirring at room temperature for 3 hours. After completion of the reaction, dilute hydrochloric acid was added, and the reaction mixture was washed with a saturated aqueous sodium hydrogen carbonate solution, distilled water and saturated brine in that order, and dried over anhydrous sodium sulfate. Purification by silica gel column chromatography (chloroform) gave ethyl-4,7-dihydro-4,7-ethano-2H-isoindole-1-carboxylate (3.5 g, 16 mmol, 80% yield).

Step 1-3
Under an argon atmosphere, a mixed solution of the obtained ethyl-4,7-dihydro-4,7-ethano-2H-isoindole-1-carboxylate 0.42 g (1.92 mmol) and anhydrous THF 50 ml was cooled to 0 ° C. Then, 0.228 g (6 mmol) of lithium aluminum hydride powder was added and stirred for 2 hours. Then, THF was removed, extracted with chloroform, washed with a saturated aqueous sodium hydrogen carbonate solution, distilled water and saturated brine in that order, and dried over anhydrous sodium sulfate. This reaction solution was filtered, purged with argon, protected from light, 10 mg of p-toluenesulfonic acid was added, and the mixture was stirred at room temperature for 12 hours. Further, 0.11 g of p-chloranil was added and stirred at room temperature for 12 hours. The extract was washed with a saturated aqueous sodium hydrogen carbonate solution, distilled water, and saturated brine in that order, and dried over anhydrous sodium sulfate. After the solution was concentrated, a metal-free tetrabicyclo compound represented by the following formula (9) was obtained by alumina column chromatography (chloroform) and recrystallization (chloroform / methanol) (0.060 g, 0.097 mmol, yield 20). %).

Step 1-4
A solution of 0.02 g (0.032 mmol) of the obtained metal-free tetrabicyclo and 0.019 g (0.1 mmol) of copper (II) acetate monohydrate in 30 ml of chloroform and 3 ml of methanol was stirred at room temperature for 3 hours. The reaction solution was washed with distilled water and saturated brine, and then dried over anhydrous sodium sulfate. The solution was concentrated and recrystallized with chloroform / methanol to obtain a tetrabicyclocopper complex (0.022 g, yield 100%).

Synthesis example 2
Step 2-1
2,4-pentanedione (205.4 ml, 2.0 mol), acetone (100 ml), n-butyl bromide (54 ml, 0.5 mol), potassium carbonate (34.55 g, 0.25 mol) were placed in a reaction vessel and purged with nitrogen. Refluxed for 48 hours. The produced solid was filtered off, the solvent was distilled off with an evaporator, and unreacted 2,4-pentanedione was distilled off under reduced pressure with a diaphragm. And 3-n-butyl 2,4-pentanedione was obtained by vacuum distillation (43.25 g, yield 55%).

Step 2-2
97 ml (560 mmol) of benzyl acetoacetate and 81 ml of acetic acid were placed in a reaction vessel, an aqueous solution of 37.8 g of sodium nitrite and 115 ml of water was added dropwise at 10 ° C. or less, and the mixture was stirred at room temperature for 3 hours. In a separate container, a solution of 43.16 g (280 mmol) of 3-n-butyl 2,4-pentanedione obtained in step 2-1 in 45 ml of acetic acid was mixed with a mixture of 36.6 g of zinc powder and 25.9 g of sodium acetate, The solution was added at 60 ° C. or lower and stirred at 80 ° C. for 1 hour, and then the reaction solution was poured into 1.12 L of ice water, and the resulting precipitate was filtered and washed with water. This precipitate was dissolved in chloroform, washed with water, saturated aqueous sodium hydrogen carbonate, and saturated brine, the organic layer was dried over anhydrous sodium sulfate, concentrated, and distilled under reduced pressure with a diaphragm to remove excess liquid. The residue was purified by silica gel column chromatography (EtOAc / Hexane) and further recrystallized (MeOH) to give 4-n-butyl-3,5-dimethylpyrrole benzyl ester (22.92 g, yield). Rate 24%).

Step 2-3
To the reaction vessel, 200 ml of acetic acid and 3.09 ml of acetic anhydride were added. Then, 8.56 g (30 mmol) of 4-n-butyl-3,5-dimethylpyrrole benzyl ester was dissolved therein, and then 15.38 g (31.5 mmol) of lead tetraacetate was slowly added. After stirring for 2 hours, it was confirmed by TLC that the reaction was complete, the reaction vessel was poured into ice water, and the resulting precipitate was filtered and washed thoroughly with water. This precipitate was dissolved in chloroform, washed with water, saturated aqueous sodium hydrogen carbonate and saturated brine, the organic layer was dried over anhydrous sodium sulfate, concentrated under reduced pressure, and triturated with hexane to give benzyl 5-acetoxymethyl-4- n-Butyl-3-methylpyrrole-2-carboxylate was obtained (8.93 g, 87% yield).

Step 2-4
The reaction vessel was purged with nitrogen, and 8.93 ml (100 mmol) of 1-nitropropane and 50 ml of dry-THF were added. Then, 1.5 ml (10 mmol) of DBU (1,8-diazabicyclo [5.4.0] -7-undecene) was added, and then 4.68 ml (100 mmol) of propionaldehyde was added while cooling in an ice bath. After stirring at room temperature for 10 hours, 100 ml of ethyl acetate was added, washed with dilute hydrochloric acid, water and saturated brine, and the organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain 4-hydroxy-3-nitrohexane. (12.33 g, 84% yield).

Step 2-5
4-hydroxy-3-nitrohexane (14.7 g, 100 mmol), acetic anhydride (14.8 ml, 157.3 mmol), chloroform (50 ml) and several drops of concentrated sulfuric acid were placed in a reaction vessel, and the mixture was stirred at room temperature for 10 hours. After completion of the reaction, 50 ml of chloroform was added, washed with water, 5% aqueous sodium hydrogen carbonate, and saturated brine, and the organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain 4-acetoxy-3-nitrohexane. (16.3 g, 86% yield).

Step 2-6
To the reaction vessel, 11.34 g (60 mmol) of 4-acetoxy-3-nitrohexane was added, the atmosphere was replaced with nitrogen, and 150 ml of dry-THF and 7.28 ml (66 mmol) of ethyl isocyanoacetate were added. Then, while cooling in an ice bath, 20.76 ml (144 mmol) of DBU was slowly added dropwise and stirred at room temperature for 12 hours. After completion of the reaction, 1N hydrochloric acid was added, extracted with chloroform, washed with water and saturated brine, the organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. Then, ethyl 3,4-diethylpyrrole-2-carboxylate was obtained by purifying with silica gel column chromatography (10.97 g, yield 94%).

Step 2-7
1.95 g (9.6 mmol) of ethyl-4,7-dihydro-4,7-ethano-2H-isoindole-1-carboxylate synthesized in Step 1-2 was placed in a reaction vessel fitted with a reflux condenser and shielded from light. 100 ml of ethylene glycol and 2.0 g of sodium hydroxide were added. The atmosphere was replaced with nitrogen, and the mixture was stirred at 175 ° C. for 2 hours. Thereafter, the reaction solution cooled to room temperature was poured into ice water, extracted with chloroform, washed with saturated brine, and the organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to give 4,7-dihydro-4,7-ethano- 2H-isoindole was obtained (0.98 g, yield 70.4%).

Step 2-8
In a reaction vessel fitted with a reflux condenser and shielded from light, 2.056 g (10.53 mmol) of ethyl 3,4-diethylpyrrole-2-carboxylate obtained in Step 2-6, 100 ml of ethylene glycol, and potassium hydroxide were added. 5 g was added. The mixture was purged with nitrogen and stirred at 160 ° C. for 2.5 hours. Thereafter, the reaction solution cooled to room temperature was poured into ice water, extracted with ethyl acetate, washed with aqueous sodium bicarbonate, water and saturated brine, and the organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. Again, a reflux condenser was attached to a light-shielded reaction vessel, and 3,4-diethylpyrrole obtained in this reaction and benzyl-5-acetoxymethyl-4-n-butyl-3-methyl obtained in Step 2-3 were used. Pyrrol-2-carboxylate (7.21 g, 21 mmol), acetic acid (10 ml) and ethanol (150 ml) were added and refluxed for 18 hours. After refluxing, the reaction mixture was cooled to room temperature, 50 ml of ethanol was added, and the mixture was allowed to stand at 0 ° C. for 5 hours. The precipitated crystals were filtered and washed thoroughly with ethanol, whereby 2,5-bis (5-benzylcarbonyl-3-n-butyl-4 -Methyl-2-pyroylmethyl) -3,4-dimethyl-1H-pyrrole was obtained (5.25 g, 72% yield).

Step 2-9
To a three-necked flask, 0.5 g of Pd / C and 20 ml of dry-THF were added to replace with hydrogen, and the mixture was stirred for 30 minutes. 2,5-bis (5-benzylcarbonyl-3-n-butyl-4-methyl-2-pyroylmethyl) -3,4-dimethyl-1H-pyrrole (2.09 g, 3.03 mmol) was added to 30 ml of dry-THF. The dissolved solution was slowly added dropwise and the mixture was stirred at room temperature overnight. After stirring, the solution was filtered through Celite, and the filtrate was concentrated under reduced pressure, protected from light, purged with nitrogen, and then cooled in an ice bath. As it was, 5 ml of TFA was added dropwise and stirred for 10 minutes, and then 10 ml of CH (OMe) ₃ was slowly added dropwise and stirred at 0 ° C. for 1 hour. The solution was neutralized with 1M NaOH (MeOH / H ₂ O = 1/1 solution) and poured into ice water to precipitate a brown solid. The solid was filtered, washed with water and rinsed with hexane to give 2,5-bis (5-formyl-3-n-butyl-4-methyl-2-pyroylmethyl) -3,4-diethyl-1H. -Pyrrole was obtained (1.94 g, 60% yield).

Step 2-10
In a light-shielded reaction vessel, 0.12 g (0.84 mmol) of 4,7-dihydro-4,7-ethano-2H-isoindole obtained in Step 2-7 and 2,5 obtained in Step 2-9 -Bis (5-formyl-3-n-butyl-4-methyl-2-pyroylmethyl) -3,4-diethyl-1H-pyrrole (0.40 g, 0.84 mmol) and chloroform (200 ml) were added and the atmosphere was replaced with nitrogen. To the solution, 10.0 ml of TFA was added and stirred at 50 ° C. for 18 hours. After stirring, 18.0 ml of triethylamine was slowly added dropwise for neutralization, and then 0.21 g (0.84 mmol) of chloranil was added and stirred overnight. Quenched with aqueous sodium thiosulfate solution, the organic layer was washed with water and saturated brine, and dried over anhydrous sodium sulfate. Zinc acetate was added thereto, and the mixture was stirred at room temperature for 2 days, washed with water and saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain a monobicyclozinc complex ( 0.17 g, yield 32%).

Step 2-11
0.052 g (0.08 mmol) of the obtained monobicyclozinc complex was placed in a reaction vessel, purged with nitrogen, and dissolved in 10 ml of chloroform. Thereto was slowly added 4.5 ml of trifluoroacetic acid and allowed to stir for 1 hour. The reaction solution is poured into water, extracted with chloroform, washed with saturated brine, and the organic layer is dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain a metal-free monobicyclo compound represented by the following formula (10). (0.038 g, 81% yield).

Step 2-12
0.041 g (0.07 mmol) of the obtained metal-free monobicyclo compound was placed in a reaction vessel, purged with nitrogen, and dissolved in 25 ml of chloroform. Thereto was added 0.028 g (0.14 mmol) of copper (II) acetate monohydrate and stirred overnight. The reaction solution was poured into water, extracted with chloroform, washed with saturated brine, and the organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain a monobicyclocopper complex (0.038 g, yield 87%).

Preparation of Resin Solution a Dissolve 1.0 g of commercially available flaky methylsilsesquioxane (MSQ) (trade name GR650, manufactured by Showa Denko) in a mixed solvent consisting of 49.5 g of ethanol and 49.5 g of 1-butanol. Thus, a resin solution a was prepared.

Preparation of Resin Solution b 0.975 g of commercially available flake-shaped methylsilsesquioxane (MSQ) (trade name GR650, manufactured by Showa Denko) and tetraethoxysilane in a mixed solvent consisting of 49.4 g of ethanol and 49.5 g of 1-butanol 0.025 g was completely dissolved. To this solution, 0.02 g of distilled water and 0.05 g of formic acid were added and stirred at room temperature for 48 hours to prepare a resin solution b.

Preparation of Resin Solution c 0.8 g of commercially available flaky phenylsilsesquioxane (PSQ) (trade name GR950, manufactured by Showa Denko) and tetraethoxysilane in a mixed solvent consisting of 49.3 g of ethanol and 49.5 g of 1-butanol 0.2 g was completely dissolved. To this solution, 0.14 g of distilled water and 0.05 g of formic acid were added and stirred at room temperature for 48 hours to prepare a resin solution c.

Preparation of silica sol d 1.0 g of methyltrimethoxysilane was completely dissolved in a mixed solvent composed of 49.5 g of ethanol and 49.5 g of 1-butanol. To this solution, 0.83 g of distilled water and 0.05 g of formic acid were added and stirred at room temperature for 48 hours to prepare silica sol d.

Preparation of silica sol e 0.8 g of dimethyldimethoxysilane and 0.2 g of tetramethoxysilane were completely dissolved in a mixed solvent composed of 48.8 g of ethanol and 49.5 g of 1-butanol. To this solution, 0.67 g of distilled water and 0.05 g of formic acid were added and stirred at room temperature for 48 hours to prepare silica sol e.

Example 1
FIG. 1B shows the structure of the field effect transistor in this example.
First, a highly doped N-type silicon substrate was used as the gate electrode 1. A 5000 シ リ コ ン silicon oxide film obtained by thermally oxidizing the surface layer of the silicon substrate was used as the insulating layer 2. Next, the resin solution a was applied to the surface of the insulating layer by spin coating (rotation speed: 5000 rpm). Next, this coating film was transferred onto a hot plate and heated at 100 ° C. for 5 minutes and at 200 ° C. for 20 minutes. The film thickness was 50 nm as measured by a stylus profilometer. This was designated as A layer 3 (polysiloxane layer).

Next, the metal-free tetrabicyclo compound synthesized in Synthesis Example (1) on this substrate is converted into a benzo compound by heating at 200 ° C. in a vacuum in a powder state, and then vacuum evacuation is performed using a diffusion pump. A film was formed using the apparatus. This was designated as B layer 6 (organic semiconductor layer). The conditions for producing the deposited film are as follows. The degree of vacuum in the vapor deposition apparatus chamber is 1 × 10 ⁻⁶ torr, the substrate temperature is 220 ° C., the vapor deposition temperature is calculated from the crystal oscillator, and the vapor deposition rate is 100 nm, 0.5 to 1.5 Å / s, respectively. Met. Then, the gold source electrode 4 and the drain electrode 5 were produced using the mask. The electrode fabrication conditions are as follows. The degree of vacuum in the vapor deposition apparatus chamber was 1 × 10 ⁻⁶ torr, the substrate temperature was room temperature, and the film thickness was 100 nm.

A field effect transistor having a channel length L = 50 μm and a channel width W = 3 mm was produced by the above procedure. V _d -I _d and V _g -I _d curves of the prepared transistor were measured using a parameter analyzer 4156C (trade name) manufactured by Agilent.

The mobility μ (cm ² / Vs) was calculated according to the following formula (1).

Here, Ci is the capacitance per unit area of the gate insulating film (F / cm ² ), and W and L are the channel width (mm) and channel length (μm) shown in the examples, respectively. I _d , V _g , and V _th are a drain current (A), a gate voltage (V), and a threshold voltage (V), respectively. The ratio of V _g = −80 V and I _d of 0 V at V _d = −80 V was defined as the ON / OFF ratio. The results are shown in Table 1.

Example 2
A device was prepared in the same manner as in Example 1 except that the metal-free tetrabicyclo compound used in Example 1 was changed to the tetrabicyclocopper complex synthesized in Synthesis Example 1, and electrical characteristics were evaluated. The results are shown in Table 1.

Example 3
The same operation as in Example 1 was performed until the layer A was produced. A coating film was formed on this substrate by spin coating from a 1 wt% chloroform solution of a metal-free tetrabicyclo synthesized in Synthesis Example 1 (rotation speed: 1000 rpm). Further, the substrate was heated at 220 ° C. to form a B layer 6 made of benzo. The film thickness of the organic semiconductor layer was 100 nm. A gold electrode was deposited thereon to form a source electrode 4 and a drain electrode 5.

A field effect transistor having a channel length L = 50 μm and a channel width W = 3 mm was prepared by the above procedure, and the same electrical characteristics were evaluated. The results are shown in Table 1.
Further, CuKα X-ray diffraction measurement of the fabricated transistor substrate was performed under the following conditions. The results are shown in FIG.

Machine used: RAD-RX wide-angle X-ray diffractometer manufactured by Rigaku Corporation X-ray tube: Cu
Tube voltage: 50KV
Tube current: 150 mA
Scan method: 2θ / θ scan Scan speed: 2 deg. / Min.
Sampling interval: 0.02 deg.
Integration time: 1s
Integration count: 14 times Measurement temperature: Room temperature (20 ° C)
Note that θ = 0 ° was set on the substrate plane.

  Further, in the present invention, the shape and position of the peak of X-ray diffraction may be slightly different depending on the difference in manufacturing conditions. In addition, the peak tip may split.

Example 4
FIG. 2 shows the structure of the field effect transistor in this embodiment.
First, a highly doped N-type silicon substrate was used as the gate electrode 1. A 5000 シ リ コ ン silicon oxide film obtained by thermally oxidizing the surface layer of the silicon substrate was used as the insulating layer 2. A resin solution a was coated thereon in the same manner as in Example 1. The film thickness was 50 nm. This was designated as A layer 3. On top of that, gold vapor deposition was performed in the same manner as in Example 1 to obtain a source electrode 4 and a drain electrode 5. A coating film was formed on this substrate by spin coating from a 1 wt% chloroform solution of a metal-free tetrabicyclo synthesized in Synthesis Example 1 (rotation speed: 1000 rpm). Further, the substrate was heated at 220 ° C. to form a B layer 6 made of benzo. The film thickness of the B layer was 100 nm.

A field effect transistor having a channel length L = 50 μm and a channel width W = 3 mm was produced by the above procedure.
The same electrical characteristics as in Example 1 were evaluated. The results are shown in Table 1.

Example 5
A device was prepared in the same manner as in Example 3 except that the metal-free tetrabicyclo compound used in Example 3 was changed to a tetrabicyclocopper complex, and electrical characteristics were evaluated. The results are shown in Table 1 and FIG. Further, CuKα X-ray diffraction measurement of the fabricated transistor substrate was performed under the same conditions as in Example 3. The results are shown in FIG.

Comparative Example 1
In Example 4, the step of forming the A layer was omitted, the thickness of the silicon oxide film was 3000 mm, the metal-free tetrabicyclo solution was 2% by weight, the substrate was baked at 210 ° C. for 10 minutes, the channel length L = 25 μm, the channel width The same operation as in Example 4 was performed except that W was changed to 0.25 mm. The results are shown in Table 1.

Example 6
A device was prepared in the same manner as in Example 3 except that the metal-free tetrabicyclo isomer used in Example 3 was changed to the metal-free monobicyclo synthesized in Synthesis Example 2, and electrical characteristics were evaluated. The results are shown in Table 1. Further, CuKα X-ray diffraction measurement of the fabricated transistor substrate was performed under the same conditions as in Example 3. The results are shown in FIG.

Example 7
A device was produced in the same manner as in Example 3 except that the metal-free tetrabicyclo compound used in Example 3 was changed to the monobicyclocopper complex synthesized in Synthesis Example 2, and electrical characteristics were evaluated. The results are shown in Table 1. Further, CuKα X-ray diffraction measurement of the fabricated transistor substrate was performed under the same conditions as in Example 3. The results are shown in FIG.

Example 8
A resin solution b was coated on the highly doped N-type silicon substrate with a silicon oxide film as in Example 4 by the same operation as in Example 1. The film thickness was 50 nm. This was designated as A layer 3. A coating film was formed on this substrate by spin coating from a 1 wt% chloroform solution of a tetrabicyclocopper complex (rotation speed: 1000 rpm). Further, the substrate was heated at 220 ° C. to form a B layer 6 made of benzo. The film thickness of the organic semiconductor layer was 100 nm. On top of that, gold vapor deposition was performed in the same manner as in Example 1 to obtain a source electrode 4 and a drain electrode 5. The results are shown in Table 1.

Example 9
A device was prepared in the same manner as in Example 8 except that a coating film having a thickness of 50 nm was formed using the resin solution c and this was changed to the A layer 3, and electrical characteristics were evaluated. The results are shown in Table 1.

Example 10
A device was prepared in the same manner as in Example 8 except that a 50 nm-thick coating film was formed using silica sol d, and this was used as the A layer 3, and electrical characteristics were evaluated. The results are shown in Table 1.

Example 11
A device was produced in the same manner as in Example 8 except that a 50 nm-thick coating film was formed using silica sol e, and this was used as the A layer 3, and electrical characteristics were evaluated. The results are shown in Table 1.

Example 12
FIG. 8 shows the structure of the field effect transistor in this embodiment.
First, a silver nanoparticle paste (Finesphere SVE102, manufactured by Nippon Paint Co., Ltd.) is coated on a PET substrate 9 provided with a 3 μm-thickness flattening layer on the substrate surface, and a hot air circulating oven at 180 ° C./30 minutes. By heating in the gate electrode 1 having a thickness of 130 nm was formed. On top of this, thermosetting of phenol novolac resin / hexamethoxymethylmelamine / p-toluenesulfonic acid / 1-butanol / ethanol = 10.5 / 4.5 / 0.075 / 59.5 / 25.5 (weight ratio) The insulating resin 2 having a film thickness of 600 nm was formed by coating the conductive resin composition and heating in a hot air circulating oven at 180 ° C./60 minutes.

  Next, the resin solution b was applied to the surface of the insulating layer by spin coating (rotation speed: 3000 rpm). Next, this coating film was heated at 180 ° C. for 20 minutes in a hot air circulating oven. The film thickness was 60 nm. This was designated as A layer 3. A coating film was formed on this substrate by spin coating from a 1 wt% chloroform solution of a metal-free tetrabicyclo synthesized in Synthesis Example 1 (rotation speed: 1000 rpm). Further, the substrate was heated at 220 ° C. to form a B layer 6 made of benzo. The film thickness of the organic semiconductor layer was 100 nm. On top of that, gold vapor deposition was performed in the same manner as in Example 1 to obtain a source electrode 4 and a drain electrode 5. The results are shown in Table 1.

Example 13
A device was prepared in the same manner as in Example 12 except that the metal-free tetrabicyclo compound used in Example 12 was changed to a tetrabicyclocopper complex, and electrical characteristics were evaluated. The results are shown in Table 1. In addition, CuKα X-ray diffraction measurement was performed on the manufactured transistor substrate under the same conditions as in Example 3. The results are shown in FIG.

Example 14
An element was produced in the same manner as in Example 13 except that the heating time for forming the B layer 6 from the tetrabicyclocopper complex was changed to 1, 5, and 10 minutes, and electrical characteristics were evaluated. The results are shown in FIG.

Example 15
The element was fabricated in the same manner as in Example 5 except that the heating for forming the B layer 6 from the tetrabicyclocopper complex was performed in a hot air circulating oven at 180 ° C. and the heating time was changed to 30, 60, and 90 minutes. Fabricated and evaluated for electrical characteristics. The results are shown in FIG. Further, CuKα X-ray diffraction measurement was performed on a transistor substrate manufactured by heating for 90 minutes under the same conditions as in Example 3. The results are shown in FIG.

Comparative Example 2
Except for omitting the process of forming the A layer 3, an element was produced in the same manner as in Example 14, and the electrical characteristics were evaluated. The results are shown in FIG.

Comparative Example 3
Except for omitting the process of forming the A layer 3, an element was produced in the same manner as in Example 15, and the electrical characteristics were evaluated. The results are shown in FIG.

  Since the field effect transistor of the present invention is excellent in crystallinity and orientation and has a large field effect mobility, it can be used for plastic IC cards, information tags, displays, and the like.

It is a typical schematic sectional drawing which shows a part of one embodiment of the field effect transistor of this invention. It is a typical schematic sectional drawing which shows a part of field effect transistor of Example 4 of this invention. It is a figure which shows the electrical property of the field effect transistor obtained in Example 5 of this invention. It is an X-ray diffraction pattern on the transistor substrate obtained in Example 3 of the present invention. It is an X-ray diffraction pattern on the transistor substrate obtained in Example 5 of the present invention. It is an X-ray diffraction pattern on the transistor substrate obtained in Example 6 of the present invention. It is an X-ray diffraction pattern on the transistor substrate obtained in Example 7 of the present invention. It is a typical schematic sectional drawing which shows the field effect transistor of Example 12 of this invention. It is an X-ray diffraction pattern on the transistor substrate obtained in Example 13 of the present invention. It is a figure which shows the electrical property evaluation of the field effect transistor of Examples 14 and 15 and Comparative Examples 2 and 3 of the present invention. It is an X-ray diffraction pattern on the transistor substrate obtained in Example 15 of the present invention.

Explanation of symbols

1 Gate electrode 2 Insulating layer 3 A layer (crystallization promoting layer)
4 Source electrode 5 Drain electrode 6 B layer (organic semiconductor layer)
7 Sealing layer 8 Base material 9 Flattened PET substrate

Claims (2)

A field effect transistor having an organic semiconductor layer, wherein an organic semiconductor layer containing at least a porphyrin and a layer made of at least a polysiloxane compound are laminated in close contact ,
The polysiloxane compound is a compound obtained by heating methylsilsesquioxane,
The porphyrin is a tetrabenzoporphyrin copper complex,
The Bragg angle (2θ) of CuKα X-ray diffraction in the organic semiconductor layer has peaks at 8.4 ° ± 0.2 °, 11.9 ° ± 0.2 °, and 16.9 ° ± 0.2 °. A characteristic field-effect transistor. The field effect according to claim 1, wherein the source electrode and the drain electrode are not disposed between the organic semiconductor layer and the layer made of the polysiloxane compound, but are disposed in the organic semiconductor layer. Type transistor.

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