JP2007115989A - Organic semiconductor transistor element, its manufacturing method and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fast organic semiconductor transistor element that is manufactured easily by using a charge transport polyester having a good solubility/compatibility for solvents and resins, and a high carrier mobility. <P>SOLUTION: This organic semiconductor transistor element is composed of a source electrode, a drain electrode, an organic semiconductor with a charge transport polyester allowing continuity to both electrodes, and a gate electrode. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic semiconductor transistor element using an organic semiconductor, a semiconductor device using the organic semiconductor transistor element, and a method for manufacturing the organic semiconductor transistor element. More specifically, the present invention relates to electronic paper or digital paper, an organic EL element, Organic semiconductor transistor element suitable for use in fields such as electrophoretic display elements, drive circuits for display elements such as liquid crystal elements, electronic tags, smart cards, memory elements, gas sensors, and semiconductor devices using the same And a method of manufacturing the organic semiconductor transistor element.

Thin film transistors are widely used as display switching elements such as liquid crystal display elements. Conventionally, a thin film transistor is manufactured using amorphous or polycrystalline silicon. However, manufacturing of a thin film transistor using such silicon uses sputtering, a CVD apparatus, and other manufacturing processes using a vacuum system, which are very expensive. In addition, the manufacturing process of a vacuum system is repeatedly performed to form a thin film transistor, and each layer such as a semiconductor layer is formed. Therefore, an increase in the size of a display device using a thin film transistor has a problem with a significant increase in manufacturing cost. It was.
In addition, the process for forming amorphous or polycrystalline silicon is performed at a very high temperature, and the materials used as the base material are limited. Therefore, there is a problem that a resin substrate having a light weight and flexibility cannot be used.

On the other hand, research on organic semiconductors typified by organic EL elements has been actively conducted in recent years. At the same time, studies have been reported to incorporate organic materials into circuits that have characteristics of lightness and flexibility that are not found in silicon materials.
As an organic substance used for such a thin film transistor, a low molecular compound and a high molecular compound are used. As low molecular weight compounds, polyacene compounds such as pentacene and tetracene (for example, see Patent Documents 1 to 3) and phthalocyanine compounds such as copper phthalocyanine (for example, refer to Patent Documents 4 and 5) have been proposed.
However, in the case of a low molecular weight compound, it is necessary to repeat the manufacturing process using the same vacuum system as that of silicon, and the problem in the manufacturing process has not been solved.

  Examples of the polymer compound include aromatic compounds such as sexithiophene (for example, see Patent Document 6), polymer compounds such as polythiophene, polythienylene vinylene, and poly (p-phenylene vinylene) (for example, Patent Documents 7 to 7). 10, Non-Patent Document 1).

Such a polymer compound is highly soluble and is advantageous in the manufacturing process because it can be formed by a low-cost technique such as spin coating or dip coating, but has a problem of low carrier mobility. . In addition, since poly (p-phenylene vinylene) is heat-treated after spin-coating a soluble precursor, there is a problem that defects tend to occur in the main chain conjugated polymer and the electrical properties are remarkably lowered.
JP-A-5-55568 JP-A-10-270712 JP 2001-94107 A Japanese Patent Laid-Open No. 5-190877 JP 2000-174277 A JP-A-8-264805 JP-A-8-228034 JP-A-8-228035 Japanese Patent Laid-Open No. 10-125924 Japanese Patent Laid-Open No. 10-190001 Appl. Phys. Lett. , Vol. 73, 108 (1998)

  An object of the present invention is to solve the above problems. That is, an organic semiconductor transistor element that is excellent in solubility and compatibility with a solvent and a resin, has a high carrier mobility, has a high operation speed, and is easy to manufacture, its manufacturing method, and the organic It is an object of the present invention to provide a semiconductor device using a semiconductor transistor element.

〔式中、Ａｒは置換もしくは未置換の１価のベンゼン基、置換もしくは未置換の芳香環数２〜１０の１価の多核芳香族炭化水素、置換もしくは未置換の芳香環数２〜１０の１価の縮合芳香族炭化水素、または、置換もしくは未置換の１価の複素環を表し、Ｔは炭素数１〜６の２価の直鎖状炭化水素基または炭素数２〜１０の２価の分枝鎖状炭化水素基を表し、ｉ、ｊは０または１を表す。また、Ｘは、下記一般式（ＩＩ）で表される置換基を表す。〕

〔一般式（ＩＩ）中、Ａｒ_１は、置換もしくは未置換の２価のベンゼン環、置換もしくは未置換の芳香族数２〜１０の２価の多核芳香族炭化水素、炭素数１〜５の２価のアルキル基、置換もしくは未置換の２価のシクロヘキサン、置換もしくは未置換の芳香族数２〜１０の２価の縮合多環芳香族炭化水素、または、置換もしくは未置換の２価の複素環を表し、
Ｒ_１、Ｒ_２およびＲ_３は、水素原子、アルキル基、シアノ基、ハロゲン基、置換アミノ基、置換もしくは未置換のアリール基、または、置換もしくは未置換のアラルキル基を有し、それぞれ相違あるいは少なくとも二種以上が同一であってもよい。
また、ｑは１〜１０の整数を表し、ｒは０〜１０の整数を表し、ｕは０または１を表し、ｕとｒとの和は少なくとも１以上であり、ｒが０の場合は、Ａｒ_１は置換または未置換のチエニレン基である。〕 The above-mentioned subject is achieved by the following present invention. That is, the present invention
<1>
An organic including at least a source electrode, a drain electrode, an organic semiconductor provided to be conductive with the source electrode and the drain electrode, and a gate electrode insulated from the organic semiconductor and capable of applying an electric field In a semiconductor transistor element,
1 is a charge transporting polyester composed of a repeating unit in which the organic semiconductor includes at least one selected from the structures represented by the following general formulas (I-1) and (I-2) as a partial structure. It is an organic semiconductor transistor element characterized by containing at least seeds.

[In the formula, Ar represents a substituted or unsubstituted monovalent benzene group, a substituted or unsubstituted monovalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings, or a substituted or unsubstituted aromatic ring having 2 to 10 aromatic rings. Represents a monovalent condensed aromatic hydrocarbon or a substituted or unsubstituted monovalent heterocyclic ring, and T represents a divalent linear hydrocarbon group having 1 to 6 carbon atoms or a divalent hydrocarbon having 2 to 10 carbon atoms. And i and j each represents 0 or 1. X represents a substituent represented by the following general formula (II). ]

[In the general formula (II), Ar ₁ represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatics, A divalent alkyl group, a substituted or unsubstituted divalent cyclohexane, a substituted or unsubstituted divalent condensed polycyclic aromatic hydrocarbon having 2 to 10 aromatics, or a substituted or unsubstituted divalent complex Represents a ring,
R ₁ , R ₂ and R _{3 each} have a hydrogen atom, an alkyl group, a cyano group, a halogen group, a substituted amino group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group, At least two or more may be the same.
Q represents an integer of 1 to 10, r represents an integer of 0 to 10, u represents 0 or 1, the sum of u and r is at least 1 or more, and when r is 0, Ar ₁ is a substituted or unsubstituted thienylene group. ]

〔一般式（ＩＩＩ−１）および（ＩＩＩ−２）において、Ａ_１は前記一般式（Ｉ−１）および（Ｉ−２）で示される構造から選択された少なくとも１種以上を表し、Ｙ_１は２価のアルコール残基を表し、Ｚ_１は２価のカルボン酸残基を表し、ｍは１〜５の整数を表し、ｐは５〜５０００の整数を表す。〕 <2>
The organic semiconductor transistor element according to <1>, wherein the organic semiconductor is a charge transporting polyester represented by the following general formula (III-1) or (III-2).

[In General Formulas (III-1) and (III-2), A ₁ represents at least one selected from the structures represented by General Formulas (I-1) and (I-2), and Y ₁ Represents a divalent alcohol residue, Z ₁ represents a divalent carboxylic acid residue, m represents an integer of 1 to 5, and p represents an integer of 5 to 5000. ]

<3>
<1> or <2> is a method for producing an organic semiconductor transistor element, wherein the organic semiconductor transistor element according to <2> is produced using a solution containing at least one charge transporting polyester dissolved in a solvent,
The organic semiconductor is formed using a method of applying an external stimulus to the solution and discharging the solution in a droplet form from a nozzle.

<4>
<3> The method for producing an organic semiconductor transistor element according to <3>, wherein the external stimulus is pressure.

<5>
Using a solution containing at least one kind of the charge transporting polyester dissolved in a solvent, at least a coating film forming step for forming a coating film containing the solvent and a drying step for drying the coating film It is a manufacturing method of the organic-semiconductor transistor element which manufactures the organic-semiconductor transistor element as described in <1> or <2> by passing, Comprising: The said oxygen concentration is 100 ppm or less, and a moisture concentration is 100 ppm or less It is the manufacturing method of the organic-semiconductor transistor element characterized by being implemented in an environment.

<6>
A semiconductor device comprising a substrate and one or more organic semiconductor transistor elements according to <1> or <2> provided on the substrate.

  As described above, according to the present invention, an organic semiconductor transistor that is excellent in solubility and compatibility with solvents and resins, uses a charge transporting polyester having high carrier mobility, has a high operating speed, and is easy to manufacture. An element, a manufacturing method thereof, and a semiconductor device using the organic semiconductor transistor element can be provided.

The organic semiconductor transistor element of the present invention includes a source electrode, a drain electrode, an organic semiconductor provided to be conductive with the source electrode and the drain electrode, and an electric field insulated from the organic semiconductor and applying an electric field. An organic semiconductor transistor element including at least a possible gate electrode, wherein the organic semiconductor is at least one selected from the structures represented by the following general formulas (I-1) and (I-2): It is characterized by containing one or more kinds of charge transporting polyesters composed of repeating units included as a partial structure.
This charge transporting polyester is excellent in thermal stability during operation, solubility in solvents and resins and phase solubility, and has a high carrier mobility. Further, the organic semiconductor transistor element of the present invention comprises the charge transporting polyester. Therefore, the organic semiconductor containing the organic compound has a high operating speed and is easy to manufacture.

In the formula, Ar is a substituted or unsubstituted monovalent benzene group, a substituted or unsubstituted monovalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings, a substituted or unsubstituted 1 to 2 aromatic ring 1 Represents a condensed condensed aromatic hydrocarbon or a substituted or unsubstituted monovalent heterocyclic ring, and T represents a divalent linear hydrocarbon group having 1 to 6 carbon atoms or a divalent hydrocarbon having 2 to 10 carbon atoms. Represents a branched chain hydrocarbon group, i, j represents 0 or 1;
X represents a substituent represented by the following general formula (II).

In General Formula (II), Ar ₁ is a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic atoms, or 2 having 1 to 5 carbon atoms. Valent alkyl group, substituted or unsubstituted divalent cyclohexane, substituted or unsubstituted divalent condensed polycyclic aromatic hydrocarbon having 2 to 10 aromatics, or substituted or unsubstituted divalent heterocyclic ring R ₁ , R ₂ and R _{3 each} have a hydrogen atom, an alkyl group, a cyano group, a halogen group, a substituted amino group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group , Each different or at least two or more may be the same.
Q represents an integer of 1 to 10, r represents an integer of 0 to 10, u represents 0 or 1, the sum of u and r is at least 1 or more, and when r is 0, Ar ₁ is a substituted or unsubstituted thienylene group. R is preferably in the range of 1 to 10, and r is particularly preferably 1.

In the general formulas (I-1), (I-2) and (II), the polynuclear aromatic hydrocarbon and the condensed polycyclic aromatic hydrocarbon selected as the structure representing Ar and Ar ₁ are not particularly limited. In the present invention, the polynuclear aromatic hydrocarbon and the condensed aromatic hydrocarbon mean specifically defined as follows.
That is, “polynuclear aromatic hydrocarbon” refers to a hydrocarbon in which two or more aromatic rings composed of carbon and hydrogen are present and the rings are bonded by a carbon-carbon bond, and the rings are vinylene. And those bonded via an ethynylene group. Specific examples include biphenyl and terphenyl.
The “condensed aromatic hydrocarbon” represents a hydrocarbon in which two or more aromatic rings composed of carbon and hydrogen are present and the rings share a pair of carbon atoms. Specific examples include naphthalene, anthracene, phenanthrene, pyrene, and fluorene.

In addition, the number of atoms (Nr) constituting the ring skeleton of the heterocyclic ring is preferably Nr = 5 and / or 6. Further, the type and number of atoms (heterogeneous atoms) other than carbon atoms constituting the ring skeleton are not particularly limited. For example, a sulfur atom, a nitrogen atom, an oxygen atom and the like are preferably used, and two types are included in the ring skeleton. The above and / or two or more different atoms may be contained. In particular, as a heterocyclic ring having a 5-membered ring structure, thiophene, pyrrole and furan, or a heterocyclic ring in which the 3- and 4-position carbons of the compound are replaced with nitrogen are preferably used. Pyridine is preferably used.
The “polynuclear aromatic hydrocarbon” and the “condensed aromatic hydrocarbon” include a hydrocarbon group in which at least one of the aromatic rings constituting the hydrocarbon group is substituted with a heterocyclic ring.
For example, polynuclear aromatic hydrocarbons in which a part of the aromatic ring is substituted with a heterocyclic ring include those in which at least one of the aromatic rings constituting the biphenyl group is replaced with a heterocyclic ring such as thiophene, or a terphenyl group And those in which at least one benzene ring is replaced with a heterocyclic ring such as thiophene. In addition, examples of the condensed aromatic hydrocarbon in which at least one or more of the aromatic rings are substituted with a heterocyclic ring include carbazole.
Examples of the alkyl group include an alkyl group having 1 to 5 carbon atoms.

Ar and Ar ₁ benzene rings, polynuclear aromatic hydrocarbons, condensed polycyclic aromatic hydrocarbons and heterocyclic substituents include hydrogen atoms, alkyl groups, alkoxy groups, aryl groups, aralkyl groups, substituted amino groups, halogens An atom, a cyano group, etc. are mentioned.
As an alkyl group, a C1-C10 thing is preferable, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group etc. are mentioned. As an alkoxyl group, a C1-C10 thing is preferable, for example, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group etc. are mentioned. As the aryl group, those having 6 to 20 carbon atoms are preferable, and examples thereof include a phenyl group and toluyl group, and as the aralkyl group, those having 7 to 20 carbon atoms are preferable, and examples thereof include benzyl group and phenethyl group. In the case where the Ar group is a condensed polycyclic aromatic hydrocarbon, those having a monovalent vinyl group or ethynyl group in the side chain of thiophene are also suitable. Examples of the substituent of the substituted amino group include an alkyl group, an aryl group, an aralkyl group, and the like, and specific examples are as described above.

In the charge transporting polyester having the structure represented by the general formula (I), by introducing a thienylene group as represented by the general formula (II) as the X group, it becomes easier to improve the carrier mobility than before. In addition, when the charge transporting polyester is used by being dissolved in a solvent, a choice of usable solvents can be expanded.
The detailed reason why such an effect is obtained is unknown, but by introducing a thienylene group as shown in the general formula (II) as the X group, the planarity of the molecule is increased and the packing between molecules is improved. Therefore, it is considered that carrier mobility is improved. In addition to this, functional groups having high affinity for the solvent to be used can be easily introduced into the molecule, so that the solubility of the charge transporting polyester in the solvent can be easily controlled, and the choice of usable solvents is also possible. It can be expanded

  T represents a divalent linear hydrocarbon group having 1 to 6 carbon atoms or a divalent branched hydrocarbon group having 2 to 10 carbon atoms, preferably a divalent hydrocarbon group having 2 to 6 carbon atoms. It is selected from a linear hydrocarbon group and a divalent branched hydrocarbon group having 3 to 7 carbon atoms. A specific structure is shown below.

  Next, specific examples of the structure represented by the general formula (I-1) are shown in Tables 1 to 32, and specific examples of the structure represented by the general formula (I-2) are shown in Tables 33 to 65.

  Examples of the charge transporting polyester comprising a repeating unit containing at least one selected from the structures represented by the general formulas (I-1) and (I-2) as a partial structure include the following general formulas (III-1) and (III -2) is preferably used.

In the general formulas (III-1) and (III-2), A ₁ represents at least one selected from the structures represented by the general formulas (I-1) and (I-2), and one polymer structure a ₁ of 2 or more may be included in the.
In general formulas (III-1) and (III-2), Y ₁ represents a divalent alcohol residue, Z ₁ represents a divalent carboxylic acid residue, m represents an integer of 1 to 5, p represents an integer of 5 to 5000 Specific examples of Y ₁ and Z ₁ include groups selected from the following formulas (1) to (6).

In the formula, R ₄ and R ₅ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 4 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, or a halogen atom. D and e each represent an integer of 1 to 10, f represents an integer of 0, 1 or 2, h and i each represents 0 or 1, and V represents the following formula (V- It means a divalent substituent represented by 1) to (V-11).

  In formulas (V-1) to (V-11), g represents an integer of 1 to 5, and h and i represent an integer of 0 to 5.

  The weight average molecular weight Mw of the charge transporting polyester comprising a repeating unit containing at least one selected from the structures represented by formulas (I-1) and (I-2) as a partial structure used in the present invention is 5000 to 5000. A range of 300,000 is preferable.

Specific examples of the charge transporting polyesters represented by the general formulas (III-1) and (III-2) are shown in Tables 66 to 69 below, but the present invention is not limited to these specific examples. . In Tables 66 to 69, the numbers in the column of monomers are the structure numbers (specifications of “structure” in Tables 1 to 65) which are specific examples of the structures represented by the general formulas (I-1) and (I-2). Corresponding to the compound numbered in the column). M and p mean m and p in formulas (III-1) and (III-2). In Tables 66 to 69, examples in which the structure is shown only in the column “Y ₁ ” mean specific examples of the charge transporting polyester of the general formula (III-1), and “Y ₁ ” and “Z ₁ ”. The examples showing the structures in both columns mean specific examples of the charge transporting polyester of the general formula (III-2). Hereinafter, specific examples (compounds) with respective numbers, for example, 15

  The method for synthesizing the charge transporting polyester used in the present invention can be used in combination with known methods depending on the desired structure, and is not particularly limited, but as a specific example, the general formula (I- A charge transporting polyester comprising a repeating unit containing at least one selected from the structures represented by 1) and (I-2) as a partial structure is represented by the general formula (III-1) or (III-2). The case where it is such a polyester will be described in detail below.

  When the charge transporting polyester used in the present invention is a polyester represented by the general formula (III-1) or (III-2), a monomer represented by the following general formula (I-3) is used: For example, it can be synthesized by polymerization by a known method described in the 4th edition, Experimental Chemistry Course Vol. 28 (Maruzen, 1992).

However, in General Formula (I-3), A ₁ represents at least one selected from the structures represented by General Formulas (I-1) and (I-2), and A ′ represents a hydroxyl group or a halogen atom. Or the group —O—R ₆ , where R ₆ represents an alkyl group, a substituted or unsubstituted aryl group, or an aralkyl group.
That is, the polyesters represented by the general formulas (I-1) and (I-2) can be synthesized as follows.

1) When A ′ is a hydroxyl group, a dihydric alcohol represented by HO— (Y ₁ —O) m—H is mixed with the monomer in an approximately equivalent amount and polymerized using an acid catalyst. As the acid catalyst, those used for usual esterification reaction such as sulfuric acid, toluenesulfonic acid, trifluoroacetic acid and the like can be used, and 1 / 10,000 to 1/10 parts by weight, preferably 1 part by weight of monomer. It is used in the range of 1/1000 to 1/50 parts by weight. In order to remove water generated during polymerization, it is preferable to use a solvent azeotropic with water, and toluene, chlorobenzene, 1-chloronaphthalene and the like are effective, and 1 to 100 parts by weight per 1 part by weight of the monomer. It is used in the range of parts by weight, preferably 2 to 50 parts by weight. The reaction temperature can be arbitrarily set, but it is preferable to carry out the reaction at the boiling point of the solvent in order to remove water generated during the polymerization.

  When the solvent is not used after completion of the reaction, it is dissolved in a soluble solvent. When a solvent is used, the reaction solution is dropped as it is in a poor solvent in which alcohols such as methanol and ethanol and polymers such as acetone are difficult to dissolve, to precipitate the polyester, and after separating the polyester, Wash thoroughly with organic solvent and dry. Further, if necessary, the reprecipitation treatment in which the polyester is precipitated by dissolving in an appropriate organic solvent and dropping in a poor solvent may be repeated. The reprecipitation treatment is preferably carried out with efficient stirring with a mechanical stirrer or the like. The solvent for dissolving the polyester during the reprecipitation treatment is used in the range of 1 to 100 parts by weight, preferably 2 to 50 parts by weight, with respect to 1 part by weight of the polyester. The poor solvent is used in an amount of 1 to 1,000 parts by weight, preferably 10 to 500 parts by weight, based on 1 part by weight of the polyester.

2) When A ′ is halogen, a dihydric alcohol represented by HO— (Y ₁ —O) m—H is mixed with the monomer in an equivalent amount, and polymerization is performed using an organic basic catalyst such as pyridine or triethylamine. To do. An organic basic catalyst is used in 1-10 equivalent with respect to 1 equivalent of monomers, Preferably it is 2-5 equivalent. As the solvent, methylene chloride, tetrahydrofuran (THF), toluene, chlorobenzene, 1-chloronaphthalene and the like are effective, and in the range of 1 to 100 parts by weight, preferably 2 to 50 parts by weight with respect to 1 part by weight of the monomer. Used. The reaction temperature can be arbitrarily set. After the polymerization, reprecipitation treatment is performed as described above, and purification is performed.

  In the case of dihydric alcohols with high acidity such as bisphenol, an interfacial polymerization method can also be used. That is, it can polymerize by adding a dihydric alcohol to water, adding an equivalent base and dissolving it, and then adding a monomer solution equivalent to the dihydric alcohol with vigorous stirring. In this case, water is used in an amount of 1 to 1,000 parts by weight, preferably 2 to 500 parts by weight, based on 1 part by weight of the dihydric alcohol. As the solvent for dissolving the monomer, methylene chloride, dichloroethane, trichloroethane, toluene, chlorobenzene, 1-chloronaphthalene and the like are effective. The reaction temperature can be arbitrarily set, and in order to promote the reaction, it is effective to use a phase transfer catalyst such as an ammonium salt or a sulfonium salt. The phase transfer catalyst is used in an amount of 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, based on 1 part by weight of the monomer.

3) When A ′ is —O—R _6, an excessive amount of a dihydric alcohol represented by HO— (Y ₁ —O) _m —H is added to the monomer, an inorganic acid such as sulfuric acid or phosphoric acid, It can be synthesized by transesterification by heating using titanium alkoxide, acetates or carbonates such as calcium and cobalt, oxides of zinc and lead as catalysts. The dihydric alcohol is used in the range of 2 to 100 equivalents, preferably 3 to 50 equivalents, with respect to 1 equivalent of the monomer. The catalyst is used in the range of 1 / 10,000 to 1 part by weight, preferably 1 / 1,000 to 1/2 part by weight, based on 1 part by weight of the monomer. The reaction is carried out at a reaction temperature of 200 to 300 ° C. After the transesterification from the group —O—R ₆ to the group —O— (Y ₁ —O) _m —H is completed, HO— (Y—O) _m —H. In order to accelerate the polymerization due to the elimination of, it is preferable to carry out the reaction under reduced pressure. Also, HO- (Y ₁ -O) _m —H is removed azeotropically under normal pressure using a high boiling point solvent such as 1-chloronaphthalene that can be azeotroped with HO— (Y ₁ —O) _m —H. Can also be reacted.

  Further, polyester can be synthesized as follows. In each of the above cases, a compound represented by the following general formula (I-4) was produced by adding an excess of a dihydric alcohol and reacting, and then the compound was represented by the above general formula (I-3). What is necessary is just to make it react with a bivalent carboxylic acid or a bivalent carboxylic acid halide etc. by the method similar to the above using it instead of a monomer, and, thereby, polyester can be obtained.

However, in the general formula (I-4), _{A 1} represents or at least one selected from structures represented by the general formula (I-1) and (I-2), _{Y 1} is a divalent alcohol Represents a residue, and m represents an integer of 1 to 5.
Further, any molecule may be introduced into the terminal of the charge transporting polyester. In that case, the following method is mentioned. That is, when A ′ is a hydroxyl group, the terminal-introducing compound monocarboxylic acid can be copolymerized, or the electron transporting compound after the polymerization reaction of the polymer can be charged and reacted for introduction.
When A ′ is halogen, the monoacid chloride of the terminally introduced compound can be copolymerized, or after the polymerization reaction of the polymer, the monoacid chloride of the terminally introduced compound can be charged and reacted for introduction. When A ′ is —O—R ₆ , the monoester of the terminally introduced compound can be copolymerized, or after the polymerization reaction of the polymer, the monoester of the terminally introduced compound can be charged and reacted for introduction.

Next, the configuration of the organic semiconductor transistor element of the present invention will be described in detail with specific examples.
The organic semiconductor transistor element of the present invention includes a source electrode, a drain electrode, an organic semiconductor provided to be conductive with the source electrode and the drain electrode, and an electric field insulated from the organic semiconductor and applying an electric field. A possible gate electrode.
Here, the organic semiconductor includes at least one charge transporting polyester described above. In addition, although the shape of the organic semiconductor transistor element of this invention can be made into a desired shape as needed, it is preferable that it is a thin film form.

Hereinafter, the configuration of the organic semiconductor transistor element of the present invention will be described in more detail with reference to the drawings, but is not limited thereto.
1 to 3 are schematic cross-sectional views showing an example of the configuration of the organic semiconductor transistor element of the present invention. Here, FIGS. 1 and 2 show a case where the organic semiconductor transistor element of the present invention has a field effect transistor (Field Effect Transistor) structure. FIG. 3 shows a case where the organic semiconductor transistor element of the present invention has a static induction transistor (StatIc InductIon TransItor) structure.

1 to 3, members having the same functions are denoted by the same reference numerals, 1 being a substrate, 2 being a source electrode, 3 being a drain electrode, 4 being an organic semiconductor layer, 5 being a gate electrode, and 6 being insulating. Represents a layer. Hereinafter, the configuration of the organic semiconductor transistor element of the present invention shown in FIGS.
In the organic semiconductor transistor element of the present invention shown in FIG. 1, a gate electrode 5 and an insulating layer 6 are provided in this order on a substrate 1, and the source electrode 2 and the drain electrode 3 are separated from each other on the insulating layer 6. The organic semiconductor layer 4 is provided so as to cover the source electrode 2 and the drain electrode 3.

In the organic semiconductor transistor element of the present invention shown in FIG. 2, a gate electrode 5 and an insulating layer 6 are provided in this order on a substrate 1, and a source electrode 2 and the source electrode 2 are formed on the insulating layer 6. The organic semiconductor layer 4 is provided so as to cover the surface opposite to the side in contact with the insulating layer 6. Further, the drain electrode 3 is provided on the surface of the organic semiconductor layer 4 opposite to the side on which the insulating layer 6 is provided, at a position separated from the source electrode 2 in the planar direction of the substrate 1.
Further, in the organic semiconductor transistor element of the present invention shown in FIG. 3, a source electrode 2, an organic semiconductor layer 4, and a drain electrode 3 are stacked in this order on a substrate 1, and a plurality of gate electrodes 5 are formed in the organic semiconductor layer 4. (In the example shown in FIG. 3, four gate electrodes 5 are arranged in parallel with the planar direction of the substrate 1 and at equal intervals).

The gate electrode 5 is arranged in a direction perpendicular to the paper surface so as to be parallel to both the source electrode 2 and the drain electrode 3, and the gate electrodes 5 are also provided so as to be parallel to each other. Yes. In FIG. 3, the gate electrode 5 and the organic semiconductor layer 4 are insulated by an insulating layer (not shown) provided at the interface between them.
In the organic semiconductor transistor element as shown in FIGS. 1 to 3, the current flowing between the source electrode 2 and the drain electrode 3 can be controlled by the voltage applied to the gate electrode 5.

  In addition, when producing any electronic device using the organic semiconductor transistor element of the present invention, it is used as a configuration (semiconductor device) in which one or more organic semiconductor transistor elements of the present invention are mounted on a substrate. A desired electronic device can be manufactured by combining this semiconductor device with another element or circuit.

Next, each member which comprises the organic-semiconductor element and semiconductor device of this invention except an organic-semiconductor part is demonstrated in detail.
As an electrode material used for the source electrode, the drain electrode, and the gate electrode, a material capable of efficiently injecting charges is used. Specifically, a metal, a metal oxide, a conductive polymer, or the like is used.
Examples of the metal include magnesium, aluminum, gold, silver, copper, chromium, tantalum, indium, palladium, lithium, calcium, and alloys thereof. Examples of the metal oxide include metal oxide films such as lithium oxide, magnesium oxide, aluminum oxide, indium tin oxide (ITO), tin oxide (NESA), indium oxide, zinc oxide, and indium zinc oxide.

Examples of the conductive polymer include polyaniline, polythiophene, polythiophene derivatives, polypyrrole, polypyridine, and a complex of polyethylenedioxythiophene and polystyrene sulfonic acid.
In the case of a P-type transistor element, if the difference in ionization potential between the material used for the electrode and the above-described polymer compound used for the organic semiconductor (layer) is large, the charge injection characteristics deteriorate, so the drain electrode and / or The difference between the ionization potential of the material used for the source electrode and the polymer compound used for the organic semiconductor (layer) is preferably within 1.0 eV, more preferably within 0.5 ev. . In view of the difference in ionization potential between the electrode and the polymer compound, it is particularly preferable to use Au as the electrode material.

  As a method for forming an electrode, a thin film produced by using a known thin film forming method such as a vapor deposition method or sputtering as the electrode material described above is formed using a known photolithography method or a lift-off method, or an inkjet or the like. Thus, a method of etching into a desired pattern (electrode shape) using a resist or a method of directly transferring an electrode material such as aluminum can be used. When a conductive polymer is used as the electrode material, it may be dissolved in a solvent and patterned by ink jet or the like.

  Insulating members that insulate between each electrode or between the gate electrode and the organic semiconductor (layer) include inorganic substances such as silicon dioxide, silicon nitride, tantalum oxide, aluminum oxide, titanium oxide, polycarbonate resin, polyester resin, methacrylic resin, acrylic Resin, polyvinyl chloride resin, cellulose resin, urethane resin, epoxy resin, polystyrene styrene resin, polyvinyl acetate resin, styrene butadiene copolymer, vinyl chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer Examples thereof include, but are not limited to, organic insulating polymers such as silicon resin.

  As the substrate, silicon single crystal or glass doped with phosphorus or the like in high concentration, glass resin, polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, cellulose resin, urethane resin, epoxy resin, police styrene resin, polyvinyl acetate Examples thereof include, but are not limited to, resins, styrene butadiene copolymers, vinyl chloride-acrylonitrile copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, plastic substrates such as silicone resins, and the like.

  In particular, when the organic semiconductor transistor element of the present invention is used in an electronic circuit used in an electronic device (hereinafter referred to as “flexible electronic device”) that is required to be flexible, such as electronic paper, digital paper, or portable electronic equipment. It is desirable to use a flexible substrate as the substrate. In particular, by using a substrate having a flexural modulus of 1000 MPa or more, more preferably 5000 MPa or more as the substrate, the substrate can be applied to a flexible display element drive circuit or electronic circuit.

  This is because the organic semiconductor transistor element of the present invention has sufficient elasticity that the organic semiconductor portion contains the above-described polymer compound as a main component, and the element is placed on a flexible substrate. This is because even if formed, it can withstand large deformations and repeated deformations and can maintain stable performance. On the other hand, in an inorganic semiconductor transistor element, since the semiconductor portion is made of an inorganic material and lacks elasticity, it is extremely difficult to use it based on such deformation. Further, the process for manufacturing the inorganic semiconductor transistor element has a disadvantage that plastic cannot be used for the substrate because it requires a high temperature. In addition, even in an organic semiconductor transistor element in which the organic semiconductor portion is mainly composed of a low molecular material, since it lacks elasticity like a polymer material, it is difficult to use it assuming such deformation. Or it is inferior in reliability.

  In the present invention, the term “flexible electronic device” refers to [1] a usage state from a flat state, regardless of whether the power is on or off, such as the electronic paper and digital paper described above. It can be bent, bent, bent, or vice versa. [2] The substrate is provided with one or more components on the substrate. [3] means an electronic device that is required to be flexible at least in the substrate portion provided with the organic semiconductor transistor element.

As a method of forming the organic semiconductor portion in a layered manner, it is particularly preferable to use a liquid phase film forming method, for example, spin coating method, casting method, dipping method, die coating method, roll coating method, bar coating method, ink jet method, Each printing method is used, but is not limited thereto.
However, since it is not necessary to form a pattern by etching after coating, the manufacturing process can be simplified, and high productivity can be obtained even when a large number of organic semiconductor transistor elements are formed on a large-area substrate. Is preferably used.
That is, an image forming technique based on ink jet recording used in an ink jet printer can be used for forming an organic semiconductor portion of an organic semiconductor transistor element.

  In this case, instead of ink, a solution containing at least one kind of charge transporting polyester dissolved in a solvent (hereinafter referred to as “inkjet organic semiconductor solution” is used only for inkjet printing, and is limited to inkjet printing) Otherwise, it may be referred to simply as “organic semiconductor solution”), and the droplet-shaped organic semiconductor solution is ejected from the nozzle of the droplet ejection head to obtain a desired film thickness at a desired position on the substrate. -A shaped organic semiconductor can be formed.

  In addition, as a droplet discharge head, the same basic configuration and principle as those of a recording head used in an ink jet printer can be used. That is, by applying an external stimulus such as pressure or heat to the organic semiconductor solution, a method of ejecting the organic semiconductor solution for inkjet from the nozzle into droplets (a so-called piezoelectric inkjet method using a piezoelectric element, utilizing a thermal boiling phenomenon) Can be used.

  However, in the production of the organic semiconductor transistor element of the present invention, the external stimulus is more preferably pressure than heat. When the external stimulus is heat, in the inkjet printing process of forming (solidifying) a coating film by volatilization of the solvent of the organic semiconductor solution that has landed on the substrate from ejection of the inkjet organic semiconductor solution from the nozzle, Since the viscosity of the organic semiconductor solution is greatly changed by heat, it may be difficult to control leveling properties and patterning accuracy. In addition to this, charge transporting polyesters that are inferior in heat resistance cannot be used, and material options may be narrowed.

Moreover, as an apparatus used for manufacturing the organic semiconductor transistor element of the present invention using the inkjet method, in addition to the above-described droplet discharge head, for example, an organic semiconductor transistor element is formed as necessary. A fixing or conveying means for the substrate or the like, or a droplet discharge head scanning means for scanning the droplet discharge head with respect to the substrate plane direction may be provided.
The organic semiconductor solution for inkjet is not particularly limited as long as it contains at least the charge transporting polyester and the solvent as described above, but the viscosity of the organic semiconductor solution for inkjet is Although it varies depending on the film thickness to be formed, it is preferably within a range of 0.01 to 1000 cps at approximately 25 ° C., and preferably within a range of 1 to 100 cps.

When the viscosity is less than 0.01 cps, the organic semiconductor solution that has landed on the substrate tends to spread in the plane direction of the substrate, making it difficult to control the film thickness, and patterning accuracy may be degraded. Moreover, when the viscosity exceeds 1000 cps, the viscosity of the organic semiconductor solution for inkjet may be too high, which may cause ejection failure.
In addition, the viscosity of the organic semiconductor solution for inkjet can be set to a desired value by controlling the charge transporting polyester, the content of other additive components added as necessary, the molecular weight of the charge transporting polyester, and the like. Can be adjusted.

The solvent used in the organic semiconductor solution for inkjet is not particularly limited as long as it can dissolve the charge transporting polyester. For example, organic solvents such as hydrocarbon solvents, ester solvents, ether solvents, halogen solvents Examples thereof include a solvent, an alcohol solvent, water, a mixed solvent thereof, and the like.
Here, examples of the hydrocarbon solvent include toluene, benzene, xylene, hexane, octane, hexadecane, cyclohexane, cyclohexanone, lactone, tetralin, cumene and the like, and examples of the ester solvent include methyl acetate. , Ethyl acetate, isopropyl acetate, amyl acetate, and the like. Examples of the ether solvent include dibutyl ether and dibenzyl ether. Examples of the halogen solvent include 1,1-dichloroethane, 1 -Fluoroethane, 2,2,2-trifluoroethane, 2,2,3,3,3-pentafluoropropane, chloroform, carbon tetrachloride, monochlorobenzene, o-dichlorobenzene, etc., and the alcohol solvent As methanol, ethanol , I- and propyl alcohol.

In addition, when manufacturing an organic semiconductor transistor element using the inkjet method as described above or other liquid phase film forming methods, the organic semiconductor portion uses an organic semiconductor solution and forms a coating film containing a solvent. The coating film is formed by at least a coating film forming process and a drying process of drying the coating film to form a film made of an organic semiconductor.
Here, the drying step is preferably performed in an environment where the oxygen concentration is 100 ppm or less and the water concentration is 100 ppm or less. If the oxygen concentration or water concentration exceeds 100 ppm, oxygen atoms present as oxygen molecules or water molecules in the atmosphere may deteriorate the charge transporting polyether. If the heat treatment temperature during drying is high, this is the case. This is because excessive deterioration is more likely to occur.

  The oxygen concentration is more preferably 50 ppm or less, and further preferably 10 ppm or less. The water concentration is more preferably 50 ppm or less, and further preferably 10 ppm or less.

Further, a protective layer may be provided in order to prevent deterioration of the organic semiconductor transistor element due to moisture or oxygen. Specific examples of the protective layer material include metals such as In, Sn, Pb, Au, Cu, Ag, and Al, metal oxides such as MgO, SiO ₂ , and TiO ₂ , polyethylene resins, polyurea resins, and polyimide resins. Resin. For forming the protective layer, a vacuum deposition method, a sputtering method, a plasma polymerization method, a CVD method, or a coating method can be applied.
As described above, the organic semiconductor transistor element of the present invention has an on / off ratio of about 10 ² to 10 ⁵ by appropriately selecting the type of polymer compound used in the organic semiconductor portion, the structure of the element, and the like. Within the range, it can be adjusted according to the use of the organic semiconductor transistor element.

Hereinafter, the present invention will be described more specifically with reference to examples. However, these examples do not limit the present invention.
Example 1
A gold film was formed to a thickness of 100 nm on a glass substrate by vacuum vapor deposition to obtain a gate electrode. Then, the SiO ₂ to form an insulating layer with a film thickness of 300nm by sputtering on the gate electrode, further, by forming a gold film thickness of 150nm through a metal mask as a source electrode and a drain electrode. Note that the distance between the source electrode and the drain electrode is 50 μm.
Thereafter, an organic semiconductor solution obtained by filtering a dichloroethane solution containing 5% by weight of Exemplified Compound (2) through a PTFE filter having an opening of 0.1 μm so as to be electrically connected to the source electrode and the drain electrode has a thickness of 0. A 15 μm thin film was formed to produce an organic semiconductor transistor element.
The organic semiconductor thin film is formed by a dip method in a state where the source electrode and the drain electrode face each other in advance and masked with a resist except for a part of the source electrode and the drain electrode in contact with the region. Subsequently, this coating film was formed through a process of drying at 130 ° C. in an inert gas atmosphere having an oxygen concentration of 5 ppm and a water concentration of 5 ppm.

(Example 2)
An organic semiconductor transistor element was produced in the same manner as in Example 1 except that the exemplified compound (3) was used instead of the exemplified compound (2) used in Example 1.

(Example 3)
An organic semiconductor transistor element was produced in the same manner as in Example 1 except that the exemplified compound (5) was used instead of the exemplified compound (2) used in Example 1.

Example 4
An organic semiconductor transistor element was produced in the same manner as in Example 1 except that the exemplified compound (10) was used instead of the exemplified compound (2) used in Example 1.

(Example 5)
An organic semiconductor transistor element was produced in the same manner as in Example 1 except that the exemplified compound (11) was used instead of the exemplified compound (2) used in Example 1.

(Example 6)
An organic semiconductor transistor element was produced in the same manner as in Example 1 except that the exemplified compound (17) was used instead of the exemplified compound (2) used in Example 1.

(Example 7)
An organic semiconductor transistor element was produced in the same manner as in Example 1 except that the exemplified compound (22) was used instead of the exemplified compound (2) used in Example 1.

(Example 8)
An organic semiconductor transistor element was produced in the same manner as in Example 1 except that the exemplified compound (49) was used instead of the exemplified compound (2) used in Example 1.

(Comparative Example 1)
Example 1 except that the compound represented by the following structural formula (IV) was used in place of the exemplified compound (2) used in Example 1 above, and an organic semiconductor thin film was formed by vapor deposition instead of dipping. In the same manner, an organic semiconductor transistor element was produced.

(Comparative Example 2)
Poly [2-methoxy-5- (2-ethylhexyl) -1,4-phenylenevinylene] is used instead of the exemplified compound (2) used in Example 1 above, and vapor deposition is used instead of the dip method. An organic semiconductor transistor element was produced in the same manner as in Example 1 except that the organic semiconductor thin film was formed.

(Comparative Example 3)
An organic semiconductor transistor element was prepared in the same manner as in Example 1 except that the compound represented by the following structural formula (V) (weight average molecular weight = 32000) was used instead of the exemplified compound (2) used in Example 1. Produced.

-Evaluation-
The organic semiconductor transistor elements obtained in Examples and Comparative Examples were measured for current-voltage characteristics when a gate voltage was applied using a semiconductor parameter analyzer (manufactured by Agilent Technologies, 4155C), and carrier mobility (linear region) ) And the on / off ratio were calculated.

Table 70 shows the on / off ratio of the organic semiconductor transistor element manufactured as described above together with the carrier mobility of the charge transporting material used for forming the organic compound layer. As can be seen from Table 70, the drain-source current flowing between the source electrode, the organic semiconductor layer, and the drain electrode in the organic semiconductor transistor element shown in any of the examples is changed with the change of the voltage (gate voltage) applied to the gate electrode. It showed changing switching characteristics and a good on / off ratio.
However, in the comparative example, since the carrier mobility of the charge transporting material used for forming the organic semiconductor thin film was low, it was found that the on / off ratio was inferior to the elements of Examples 1-8. . Further, when forming an organic semiconductor thin film, there is a case where a liquid phase film forming method cannot be used / a vapor phase film forming method must be used.

In addition, the solubility evaluation shown in Table 70 was carried out by adding the materials used in place of the exemplified compounds used in the examples and the comparative examples to 2% by weight with respect to each of dichloroethane, toluene, and xylene. Then, the state of the solution after stirring was observed by visual observation. The evaluation criteria regarding solubility in Table 70 are as follows.
○ (good): completely dissolved
△ (Slightly good): Small amount of precipitate is generated × (Difficult): Almost unnecessary and large amount of precipitate is generated

It is the schematic block diagram which showed an example of the laminated constitution of the organic-semiconductor transistor element of this invention. It is the schematic block diagram which showed an example of the laminated constitution of the organic-semiconductor transistor element of this invention. It is the schematic block diagram which showed an example of the laminated constitution of the organic-semiconductor transistor element of this invention.

Explanation of symbols

1 Substrate 2 Source electrode 3 Drain electrode 4 Organic semiconductor layer 5 Gate electrode 6 Insulating layer

Claims (6)

An organic including at least a source electrode, a drain electrode, an organic semiconductor provided to be conductive with the source electrode and the drain electrode, and a gate electrode insulated from the organic semiconductor and capable of applying an electric field In a semiconductor transistor element,
1 is a charge transporting polyester comprising the organic semiconductor as a repeating unit containing at least one selected from the structures represented by the following general formulas (I-1) and (I-2) as a partial structure. An organic semiconductor transistor element comprising at least a seed.

[In the formula, Ar represents a substituted or unsubstituted monovalent benzene group, a substituted or unsubstituted monovalent polynuclear aromatic hydrocarbon having 2 to 10 aromatic rings, or a substituted or unsubstituted aromatic ring having 2 to 10 aromatic rings. Represents a monovalent condensed aromatic hydrocarbon or a substituted or unsubstituted monovalent heterocyclic ring, and T represents a divalent linear hydrocarbon group having 1 to 6 carbon atoms or a divalent hydrocarbon having 2 to 10 carbon atoms. And i and j each represents 0 or 1. X represents a substituent represented by the following general formula (II). ]

[In the general formula (II), Ar ₁ represents a substituted or unsubstituted divalent benzene ring, a substituted or unsubstituted divalent polynuclear aromatic hydrocarbon having 2 to 10 aromatics, A divalent alkyl group, a substituted or unsubstituted divalent cyclohexane, a substituted or unsubstituted divalent condensed polycyclic aromatic hydrocarbon having 2 to 10 aromatics, or a substituted or unsubstituted divalent complex Represents a ring,
R ₁ , R ₂ and R _{3 each} have a hydrogen atom, an alkyl group, a cyano group, a halogen group, a substituted amino group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group, At least two or more may be the same.
Q represents an integer of 1 to 10, r represents an integer of 0 to 10, u represents 0 or 1, the sum of u and r is at least 1 or more, and when r is 0, Ar ₁ is a substituted or unsubstituted thienylene group. ] The organic semiconductor transistor element according to claim 1, wherein the organic semiconductor is a charge transporting polyester represented by the following general formula (III-1) or (III-2).

[In General Formulas (III-1) and (III-2), A ₁ represents at least one selected from the structures represented by General Formulas (I-1) and (I-2), and Y ₁ Represents a divalent alcohol residue, Z ₁ represents a divalent carboxylic acid residue, m represents an integer of 1 to 5, and p represents an integer of 5 to 5000. ] A method for producing an organic semiconductor transistor element, wherein the organic semiconductor transistor element according to claim 1 or 2 is produced using a solution containing at least one kind of the charge transporting polyester dissolved in a solvent,
The method of manufacturing an organic semiconductor transistor element, wherein the organic semiconductor is formed using a method in which an external stimulus is applied to the solution and the solution is ejected in a droplet form from a nozzle.   4. The method of manufacturing an organic semiconductor transistor element according to claim 3, wherein the external stimulus is pressure.   Using a solution containing at least one kind of the charge transporting polyester dissolved in a solvent, at least a coating film forming step for forming a coating film containing the solvent and a drying step for drying the coating film 3. The method for producing an organic semiconductor transistor element according to claim 1, wherein the drying step is performed in an environment where the oxygen concentration is 100 ppm or less and the water concentration is 100 ppm or less. The manufacturing method of the organic-semiconductor transistor element characterized by the above-mentioned.   A semiconductor device comprising a substrate and one or more organic semiconductor transistor elements according to claim 1 or 2 provided on the substrate.

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