TW201308702A - Organic field effect transistor and organic semiconductor material - Google Patents

Abstract

A field-effect transistor contains organic semiconductor material (A) represented by general formula (1), and organic semiconductor material (B) that is not the organic semiconductor material represented by general formula (1) (X1 represents an optionally substituted aliphatic hydrocarbon residue or an optionally substituted aromatic residue).

Description

Airport efficient transistor and organic semiconductor materials

The invention relates to an organic field effect transistor. In detail, the semiconductor active layer is an organic field-effect transistor formed of a specific organic semiconductor material and an organic semiconductor material having a structure different from the above-described organic semiconductor material. More specifically, the semiconductor active layer is an airport effect transistor formed of a laminated structure of a layer containing an organic semiconductor material having a specific structure and a layer containing an organic semiconductor material different from the above-described organic semiconductor material.

Generally, a field effect transistor has a source electrode on a substrate, a drain electrode, and a gate electrode via the electrode and the insulator layer. At present, the field effect electro-crystal system uses an inorganic semiconductor material centered on silicon, in particular, amorphous silicon. A thin film transistor fabricated using such a semiconductor material on a substrate such as glass is used as a display or the like, or as a logical electric circuit element for use in an integrated electric circuit. In addition, it is widely used as a switching element. Furthermore, recent research on semiconductors using inorganic oxides for semiconductor materials is very popular. However, in the case of using such an inorganic semiconductor material, in the field effect transistor manufacturing It needs to be processed at high temperature or under vacuum, and it is not possible to use a film or plastic with poor heat resistance for its substrate, and because of the high investment in equipment or the need for a large amount of energy in manufacturing, the cost will become very high. Its range of applications is very limited.

In contrast, the development of field effect transistors using organic semiconductor materials that do not require high temperature processing during the fabrication of field effect transistors is also underway. When an organic semiconductor material can be used, it can be manufactured under a low temperature process, and the range of substrate materials that can be used can be expanded. As a result, a field effect transistor which is more flexible and lighter and less susceptible to damage can be produced. Moreover, in the fabrication of the field effect transistor, there is also the possibility of manufacturing a large-area field effect transistor at a low cost by a coating method including a solution of an organic semiconductor material, an inkjet or the like. Sex.

However, field-effect transistors using organic semiconductors having high mobility and excellent durability have not yet been put into practical use, and many studies are still underway to obtain various aptitudes. In particular, the improvement of stability is one of the important issues. A representative organic semiconductor for use in an airport effect transistor is exemplified by pentacene. Because of its practical mobility and easy availability, the province is often used, but there are still problems in the atmosphere that are easily oxidized and the electrical characteristics are reduced. Further, in order to compensate for the shortcomings, a semiconductor having improved atmospheric stability has been developed (Non-Patent Document 1, Patent Document 1, and Patent Document 2). However, due to the improvement of atmospheric stability, it may cause problems such as low mobility or low voltage charge injection specialty. Metal oxide treatment or self-organization monomolecular film formation (Patent Document 3, Patent Document 4, Non-Patent Document 2, Non-Patent Document 3). Some people are studying the improvement of the transistor characteristics by laminating organic semiconductor layers. For example, in Non-Patent Document 4, pentacene is used as a crystallizing control material of rubrene, and in Non-Patent Document 5, pentacene is used as a crystal of benzodithiophene dimer. The control material is used in order to enhance the crystallinity in order to achieve an increase in the mobility of erythroprene and benzodithiophene dimer.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. Patent Document 5] World Patent No. WO2010/058692 [Patent Document 6] Japanese Patent No. 4510662

[Non-patent literature]

[Non-Patent Document 1] J. Am. Chem. Soc., (Journal of the American Chemical Society), published in 2006, Vol. 128 (39), pp. 12604 to 12605 [Non-Patent Document 2] Applied Physics Letters (Applied Physics Letters) Communications) 92, 013301 pages (2008) [Non-Patent Document 3] Applied Physics Letters, Issue 89, 033504 (2006) [Non-Patent Document 4] Applied Physics Letters, 89, 163505 (2006) [Non-Patent Document 5] Applied Physics Letters, Issue 95, 263,307 (2009)

An object of the present invention is to provide a practical field effect that is practical and stable, and has excellent semiconductor characteristics such as carrier mobility, hysteresis, or threshold stability. Transistor.

The present inventors have found that a novel compound having a specific structure useful for a semiconductor active layer has been found as a result of solving the above problems, and it has been found that an organic semiconductor material having a specific structure is combined as a semiconductor active layer. With the organic semiconductor material having other structures, the fact that the electric charge transfer rate is fast and the stability is excellent, and the airport effect transistor is finally completed, the present invention has finally been completed.

That is, the present invention is as follows.

[1] A field effect transistor comprising: an organic semiconductor material (A) which can be represented by the general formula (1), and an organic semiconductor material other than the organic semiconductor material represented by the above general formula (1) (B) .

(wherein X ¹ represents an aliphatic hydrocarbon residue which may have a substituent or an aromatic residue which may have a substituent).

[2] The field effect transistor according to [1], wherein the organic semiconductor material (A) is an organic semiconductor material represented by the general formula (2).

(wherein R ¹ represents a hydrogen atom or an aliphatic hydrocarbon residue which may have a substituent).

[3] The field effect transistor according to [1] or [2], wherein the organic semiconductor material (B) is an organic semiconductor material represented by the general formula (3).

(wherein X ² represents an aliphatic hydrocarbon residue which may have a substituent or an aromatic residue which may have a substituent).

[4] The field effect transistor described in [3], wherein the general formula can be (3) The organic semiconductor material represented by the general formula (4).

(wherein R ² represents a hydrogen atom or an aliphatic hydrocarbon residue which may have a substituent).

[5] The field effect transistor according to any one of [1] to [4] wherein the layer-effect transistor includes a layer containing the organic semiconductor material (A) and a layer containing the organic semiconductor material (B). Construction.

[6] The field effect transistor according to [5], wherein the stagger type is a crystal structure builder.

[7] The field effect transistor according to [6], wherein the layer of the organic semiconductor material (B) and the organic semiconductor material (A) are laminated on the insulator layer provided on the gate electrode. The layer is placed in contact with the uppermost layer of the layer of the organic semiconductor material (A), and the uppermost layer of the active electrode and the germanium electrode is in contact with the top contact bottom gate type structure.

[8] The field effect transistor according to [6], wherein the active electrode and the ruthenium electrode are respectively provided on the substrate, and the layer containing the organic semiconductor material (A) and the organic layer are sequentially laminated thereon. The layer of the semiconductor material (B) is further provided with a gate electrode having a gate electrode in contact with the uppermost gate type of the insulator layer provided in contact with the uppermost layer of the layer containing the organic semiconductor material (B) (bottom contact top gate) Type structure) .

[9] A naphthobithiophene-based compound which can be represented by the general formula (5).

(wherein R ³ represents a C1-3 alkyl group).

[10] The naphthobithiophene compound according to [9], wherein R ³ is a methyl group.

[11] A compound which can be represented by the formula (6).

[12] A naphtho-dithiophene-based organic semiconductor material obtained by the compound according to any one of [9] to [11].

[13] A naphtho-dithiophene-based organic transistor material, which is obtained by the compound according to any one of [9] to [11].

[14] A field effect transistor comprising the organic semiconductor material described in [12].

Combining a specific structure of an organic semiconductor material such as a semiconductor active layer With organic semiconductor materials of other materials, it is possible to obtain an airport effect transistor with fast charge transfer speed and excellent stability.

[Best Embodiment of the Invention]

Hereinafter, the present invention will be described in detail.

The present invention is a combination of a semiconductor active layer and can be represented by the general formula (1). (heteroacene) is a P-type organic semiconductor material and is different from the general formula (1) As a result of the P-type organic semiconductor material having different P-type organic semiconductor materials, an airport-effect transistor having a fast charge transfer rate and excellent stability can be obtained.

Next, the organic semiconductor material (A) represented by the general formula (1) will be described. The organic semiconductor material having the skeleton of the general formula (1) may have a substituent (in the formula (1), the substituent is represented by X ¹ ). Specific examples of the substituent include an aliphatic hydrocarbon residue which may be substituted or an aromatic residue which may be substituted.

Here, the aliphatic hydrocarbon group may, for example, be a saturated or unsaturated linear, branched or cyclic aliphatic hydrocarbon group, preferably a linear or branched aliphatic hydrocarbon group, more preferably straight. A chain of aliphatic hydrocarbon groups. The carbon number is usually from C1 to C36, preferably from C1 to C24, more preferably from C1 to C20, most preferably from C1 to C12. The aliphatic hydrocarbon group may be substituted by a halogen atom.

Specific examples of the saturated aliphatic hydrocarbon group of a straight chain or a branched chain include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, Isoamyl, third amyl, second amyl, n-hexyl, isohexyl, n-heptyl, second heptyl, n-octyl, n-decyl, second fluorenyl, 正癸基,正十一基,正十二基,正十三基,正十四基,正十五基,正十六基,正七基,正十八基,正十九基,正正Twenty base, twenty-two base, positive twenty-fifth base, n-t-octadecyl, n-triacontyl, 5-(n-pentyl)fluorenyl, twenty-one base, twenty Tris, twenty-four, twenty-six, twenty-seven, twenty-nine, n-thyl, squalanyl, thirty-two, thirty-six, and the like.

Specific examples of the cyclic saturated aliphatic hydrocarbon group include a cyclohexyl group, a cyclopentyl group, an adamantyl group, and a norbornyl group.

Specific examples of the linear or branched chain unsaturated aliphatic hydrocarbon group include a vinyl group, an allyl group, an eicosadienyl group, and an 11,14-eicosadienyl group. Geranyl (trans-3,7-dimethyl-2,6-octadien-1-yl), farnesyl (anti, trans-3, 7-11) -trimethyl-2,6,10-dodecatrien-1-yl), 4-pentenyl, 1-propenyl, 1-hexenyl, 1-octenyl, 1-decynyl , 1-undecynyl, 1-dodecynyl, 1-tetradecynyl, 1-hexadecenyl, 1-nonadecanyl and the like.

Among the linear, branched chain and cyclic aliphatic hydrocarbon groups, a linear or branched chain aliphatic hydrocarbon group is preferred, and a linear aliphatic hydrocarbon group is more preferred. The saturated or unsaturated aliphatic hydrocarbon group means a saturated alkyl group, an alkenyl group having a carbon-carbon double bond, and an alkynyl group having a carbon-carbon triple bond, preferably an alkyl group or an alkynyl group, more preferably alkyl. Among the aliphatic hydrocarbon group residues, those in which the saturated or unsaturated aliphatic hydrocarbon group is combined, that is, the portion containing the carbon-carbon double bond and the carbon-carbon triple bond in the aliphatic hydrocarbon group are also included in the case. Inside. The aliphatic hydrocarbon residue may be substituted by a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, preferably a fluorine atom, a chlorine atom, a bromine atom, or more preferably a fluorine atom. Atom and bromine atoms.

The aromatic residue which may be substituted may, for example, be a phenyl group, a naphthyl group, an anthracenyl group or a phenanthryl group. Pyrenyl, benzo An aromatic hydrocarbon group such as a pyridyl group, a pyrazinyl group, a pyrimidinyl group, a quinolyl group, an isoquinolyl group, a pyrrolyl group, a porphyrin group, an imidazolyl group, a carbazolyl group, a thienyl group, a furyl group a heterocyclic group such as a pyranyl group or a pyridonyl group, such as a benzoquinolyl group, a fluorenyl group, a benzothienyl group or a benzofuranyl group. Among these, a phenyl group, a naphthyl group, a pyridyl group, and a thienyl group are preferable.

The example in which such an aromatic residue may have a substituent is not particularly limited, and the above-mentioned aliphatic hydrocarbon group or the aforementioned halogen atom may be mentioned. Among them, an aliphatic hydrocarbon group is preferred, and a C1 to C3 lower alkyl group such as a methyl group, an ethyl group or an isopropyl group is more preferred, and a methyl group is preferred.

The organic semiconductor material (A) which can be represented by the general formula (1) is more preferably a diphenyl derivative which can be represented by the general formula (2). In the general formula (2), R ¹ represents a hydrogen atom or an aliphatic hydrocarbon residue which may have a substituent. The aliphatic hydrocarbon residue may be the same as the aliphatic hydrocarbon residue described above, and is preferably a C1 to C3 lower alkyl group such as a methyl group, an ethyl group or an isopropyl group, and most preferably a methyl group.

The organic semiconductor material (B) other than the organic semiconductor material represented by the above general formula (1) may, for example, be 蒽, 四 , province, Philippine, , Hydrocarbon aromatic derivatives such as (chrysene), hydrazine, coronene, oligophenylene (n=4 to 12), rubrene, etc., oligothiophenes (n=4 to 12), silk flowers A heterocyclic aromatic derivative such as phthalocyanine, porphyrin, benzodithiophene, benzothienobenzophene, dinaphthylthiophenethiophene or naphtho-dithiophene, etc. a mixture of such.

The organic semiconductor material (B) other than the organic semiconductor material represented by the general formula (1) may, for example, be pentacene, phthalocyanine, oligothiophene or benzothiophene, thiophene or benzothiophene. Miscellaneous benzothiophene It is an organic semiconductor material. Among them, a derivative of the benzothienobenzothiophene represented by the general formula (3) is preferred. In the general formula (3), X ² represents an aliphatic hydrocarbon residue which may have a substituent or an aromatic residue which may have a substituent. X ² shown here may be of the same meaning as X ¹ described previously.

Further, the organic semiconductor (B) other than the organic semiconductor material represented by the general formula (1) is preferably a diphenyl derivative represented by the general formula (4). In the general formula (4), R ² represents a hydrogen atom or an aliphatic hydrocarbon residue which may have a substituent. The aliphatic hydrocarbon residue may be the same as the aliphatic hydrocarbon residue described above.

The method for producing the organic semiconductor material (A) represented by the formula (1) can be expressed, for example, according to the method described in Patent Document 5, that is, the following reaction formula. First, bromination is repeated using 2,6-dihydroxynaphthalene as a starting material to obtain a tetrabromide, and then tin is used for dehalogenation, followed by action of trifluoromethanesulfonic anhydride. Further, for this compound, the corresponding acetylene derivative is allowed to be in an aprotic polar solvent. When a reaction is carried out in the presence of a palladium (Pd) catalyst or the like, a precursor dibromodiynylnaphthalene derivative can be obtained. When a sulfide salt such as sodium sulfide hydrate or the like is used as the precursor to carry out a heating reaction, a compound of the general formula (1) of the object can be obtained.

The method for purifying the compound is not particularly limited, and a known method such as recrystallization, column chromatography, and vacuum sublimation purification can be employed. Also, these methods can be used in combination when needed.

Specific examples of the compound which can be represented by the general formula (1) are shown below.

The compound represented by the general formula (3) can be obtained by, for example, the methods described in Patent Document 1 and Patent Document 6.

Specific examples of the compound represented by the general formula (3) are shown below.

Next, the construction of the field effect transistor of the present invention will be described below with reference to the drawings, but the present invention is not limited by the configuration.

In the first drawing, several examples of the state effect transistor (element) of the present invention are shown. In each example, the source electrode, the 2: semiconductor layer, the 3: germanium electrode, the 4: insulator layer, the 5: gate electrode, and the 6: substrate are respectively shown. Here, the arrangement of each layer and the electrodes can be appropriately selected depending on the use of the element. A to D And F, the current flowing in parallel with the substrate is called a transverse field effect transistor. A is called the bottom gate contact type structure, and B is called the upper layer contact bottom gate type structure. B' divides the semiconductor layer of B into two, that is, the state in which two layers are laminated. Further, in the case of C, the source electrode, the germanium electrode, and the insulator layer are provided on the semiconductor, and the uppermost gate uppermost contact type structure of the gate electrode is formed thereon. D is called the structure of the underlying gate underlayer and the uppermost contact type transistor. E is a pattern diagram of an electrostatic discharge induction transistor (SIT) of a vertical type FET. If such an SIT structure is employed, a large number of carriers can be transferred at a time because the current flow is expanded to a planar shape. Further, since the source electrode and the ruthenium electrode are arranged in the longitudinal direction, the distance between the electrodes can be shortened, and the response is high. Therefore, it is suitable for use in applications such as high current flow or high-speed switching. Further, F is the uppermost gate underlayer contact type, and F' is a semiconductor layer of F which is divided into two, that is, a state in which two layers are laminated.

The constituent elements in each state example will be described.

The substrate 6 is required to be retained by the layers formed thereon without being peeled off. For example, it can be used for an insulating material such as a resin film, paper, glass, quartz, or ceramic, or a conductive substrate such as a metal or an alloy, and an insulating layer is formed by coating or the like. A material or the like made of various combinations such as an inorganic material. Examples of the resin film which can be used include polyethylene terephthalate, polyethylene naphthalate, polyether oxime, polyamine, polyimine, polycarbonate, and the like. Triacetate Cellulose, polyether quinone, etc. When a resin film or paper is used, the element can be made flexible, and it becomes flexible and lightweight, and the practicality can be improved. The thickness of the substrate is usually from 1 μm to 10 mm, preferably from 5 μm to 5 mm.

For the source electrode 1, the ytterbium electrode 3, and the gate electrode 5, a material having conductivity is used. For example, platinum, gold, silver, aluminum, chromium, tungsten, tantalum (Ta), nickel, cobalt, copper, iron, lead, tin, titanium, indium, palladium, molybdenum, magnesium, calcium, barium, lithium, potassium can be used. a metal such as sodium or an alloy containing the same; a conductive oxide such as InO ₂ (indium oxide), ZnO ₂ (zinc oxide), SnO ₂ (tin oxide), or ITO (indium tin oxide); polyaniline, Conductive polymer compounds such as polypyrrole, polythiophene, polyacetylene, polyparaphenylene vinylene, polydiacetylene, etc.; semiconductors such as germanium, germanium (Ge), gallium (Ga) arsenic, carbon black, fluorene Carbon materials such as carbon nanotubes and graphite. Further, doping may be performed on the conductive polymer compound or the semiconductor. In this case, for example, an acid such as hydrochloric acid, sulfuric acid or sulfonic acid, PF ₅ (phosphorus fluoride), AsF ₅ (arsenic fluoride) or FeCl ₃ (iron chloride) may be used. A halogen atom such as Lewis acid or iodine, or a metal atom such as lithium, sodium or potassium. Further, a conductive composite material in which carbon black or metal particles or the like is dispersed on the above material can also be used. These materials can make the work function of the electrode, and can produce a field effect transistor with good electric charge specialty.

Wiring is connected to each of the electrodes 1, 3, and 5, but the wiring may be made of a material similar to that of the electrode.

As the insulator layer 4, an insulating material can be used. For example, poly paraxylylene, polyacrylate, polymethyl methacrylate, polystyrene, polyvinyl phenol, polyamine, polyimide, polycarbonate, poly a polymer of ester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polyfluorene, epoxy resin, phenolic resin, fluorine-containing resin, etc., and a copolymer thereof; cerium oxide, aluminum oxide, titanium oxide An oxide such as cerium oxide; a ferroelectric oxide such as SrTiO ₃ (yttrium titanium oxide) or BaTiO ₃ (yttrium titanium oxide); a nitride such as tantalum nitride or aluminum nitride; a sulfide; A dielectric such as a compound or a polymer obtained by dispersing particles of such dielectrics. The film thickness of the insulator layer 4 varies depending on the material, but is usually 0.1 nm to 100 μm, preferably 0.5 nm to 50 μm, more preferably 5 nm to 10 μm.

As the material of the semiconductor layer 2, an organic semiconductor material (A) which can be represented by the general formula (1) may be used alone, or an organic semiconductor material (A) which can be represented by the general formula (1) may be used in combination, and the above general formula may be used. (1) An organic semiconductor material (B) other than the organic semiconductor material. In the present invention, the organic semiconductor material (A) and the organic semiconductor material (B) may be used in combination, or a layer of the organic semiconductor material (A) and a layer of the organic semiconductor material (B) may be laminated. The material of the semiconductor layer may further contain components other than the constituent components, but the total weight of the material is required to be 50% by mass or more, preferably 80%, of the organic semiconductor material (A) and the organic semiconductor material (B). The mass% or more is more preferably 95% by mass or more.

The film thickness of the semiconductor layer 2 does not lose the required function The thinner the better. In the field-effect transistor of the type shown in B and F, the migration of the charge in the film thickness direction is required, and if the film thickness is thickened, the leakage current may increase. In order to exhibit the desired function, it is usually from 1 nm to 1 μm, preferably from 5 nm to 500 nm, more preferably from 10 nm to 300 nm. Here, when the layer containing the organic semiconductor material (A) and the layer containing the organic semiconductor material (B) are in a laminated structure, the entire film thickness may be the same as the above. The film thickness can be arbitrarily adjusted without losing the required function. Further, by adjusting the mixing ratio or film thickness of these materials, a field effect transistor having good semiconductor characteristics can be obtained.

In the field effect transistor of the present invention, other layers are disposed between or between the layers as needed. For example, by forming a protective layer directly on or through another layer on the semiconductor layer, the influence of external air such as humidity or oxygen can be reduced, and the ON/OFF ratio of the element can be improved to make electrical characteristics. The advantages of stabilization.

The material of the protective layer is not particularly limited, and for example, an acrylic resin such as an epoxy resin or a polymethyl methacrylate, a polyurethane, a polyimide, a polyvinyl alcohol, or a fluorine-containing resin. A film formed of various resins such as polyalkenes or a dielectric film such as an inorganic oxide film such as cerium oxide, aluminum oxide or tantalum nitride or a nitride film is preferably used. In particular, a resin (polymer) having a low oxygen or moisture permeability or a low water absorption rate is preferred. In recent years, protective materials developed for organic EL displays can also be used. The film thickness of the protective layer may be any film thickness for the purpose, but is usually 100 nm to 1 mm.

Moreover, the table is applied to the substrate or the insulator layer on which the semiconductor is to be laminated. Surface processing can also improve the characteristics of components. For example, the degree of hydrophilicity/hydrophobicity of the surface of the substrate can be adjusted to improve the film quality of the film formed thereon. In particular, the organic semiconductor material may be greatly changed in characteristics due to the state of the film such as the orientation of the molecule. Therefore, it is possible to control the molecular orientation of the interface portion between the substrate and the semiconductor film formed later by the surface treatment of the substrate, and as a result, the characteristics of the carrier mobility and the like are improved. Such a substrate treatment may be carried out by using a hydrochloric treatment such as hexamethyldioxane, cyclohexene or octadecyltrichloromethane, or an acid treatment such as hydrochloric acid or sulfuric acid or acetic acid. Using alkali treatment such as sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, etc., ozone treatment, fluorination treatment, plasma treatment using oxygen or argon, etc., using the Langmuir project film (Langmuir project) The formation process of the film is performed by an electric treatment such as a film formation process of another insulator or a semiconductor, a mechanical treatment, a corona discharge, or the like, and a rubbing treatment such as fiber.

In the method of providing each layer in such a state, for example, vacuum evaporation deposition, sputtering, coating, printing, and sol-gel can be suitably employed. Sol-gel and the like.

Next, with respect to the manufacturing method of the field effect transistor of the present invention, the uppermost layer contact bottom gate type field effect transistor (FET) shown in the state example B of Fig. 1 is taken as an example, and is explained below based on Fig. 2 .

Such a manufacturing method is a field effect transistor or the like in the other states described above. The same is applicable.

(substrate and substrate processing)

A desired layer or electrode is provided on the substrate 6 to manufacture (refer to Fig. 2 (1)). For the substrate, the above description can be employed. The aforementioned surface treatment or the like can also be performed on the substrate. The thickness of the substrate 6 is preferably thinner within a range that does not affect the desired function. Although it varies depending on the material, it is usually from 1 μm to 10 mm, preferably from 5 μm to 5 mm. Further, the substrate may have a function as an electrode when necessary.

(formation of gate electrode)

The gate electrode 5 is formed on the substrate 6 (refer to Fig. 2 (2)). For the electrode material, those described above can be used. Various methods can be employed for the method of forming the electrode film. For example, vacuum deposition, sputtering, coating, thermal transipipulation, printing, sol-gel, etc. can be employed. . At the time of film formation or after film formation, patterning is preferably carried out as needed to achieve a desired shape. Various methods can be employed for the method of pattern formation, and a photolithography method in which pattern formation and etching are combined by photoresisting can be exemplified. Further, it is soft by a printing method such as inkjet printing, screen printing, offset printing, letterpress printing, or a micro contact printing method. The method of lithography and the combination of these techniques It is also possible to use a variety of techniques to form patterns. The film thickness of the gate electrode 5 varies depending on the material, but is usually 0.1 nm to 10 μm, preferably 0.5 nm to 5 μm, more preferably 1 nm to 3 μm. If the gate electrode also serves as a substrate, it may be thicker than the film thickness described above.

(formation of insulator layer)

An insulating layer 4 is formed on the gate electrode 5 (refer to Fig. 2 (3)). As the insulator material, those described above can be used. When the insulator layer 4 is formed, various methods can be employed. For example, spin coating, spray coating, dip coating, cast coating, bar coating, and scraper Coating method such as coating method, printing method such as screen printing, offset printing, inkjet, vacuum deposition method, molecular beam expitaxial growth method, ion clustering method (ion) Dry process such as cluster), ion plating, sputtering, atmospheric pressure plasma, and chemical vapor deposition. Others may be a method of forming an oxide film on a metal such as a sol-gel method or an alumite on aluminum or a thermal oxidation film of ruthenium.

Further, in the portion where the insulator layer and the semiconductor layer are in contact with each other, in order to make the semiconductor molecules have a good orientation at the interface between the two layers, the insulating layer can be subjected to a predetermined surface treatment. The surface treatment method can be the same as the surface treatment of the substrate. The film thickness of the insulator layer 4 does not affect its function It is better to be thinner inside. It is usually from 0.1 nm to 100 μm, preferably from 0.5 nm to 50 μm, more preferably from 5 nm to 10 μm.

(formation of a semiconductor layer)

As the semiconductor material, a material as described above can be used. When the film formation of the semiconductor layer is performed, various methods can be employed. The method of forming a vacuum process such as a sputtering method, a CVD method, a molecular beam epitaxial growth method, or a vacuum deposition method, and a dip coating method, a die coater method, and a roll type can be roughly classified. Application method such as a coating method such as a roll coater, a bar coater, or a spin coating method, an inkjet method, a screen printing method, an offset printing method, or a microcontact printing method The method of forming the process. Hereinafter, a method of forming a semiconductor layer will be described in detail.

First, a method of forming a semiconductor layer by using a vacuum process to form a semiconductor layer will be described.

a method of heating the semiconductor material in a crucible or a metal boat under vacuum and attaching (evaporating) the evaporated semiconductor material to the substrate (the insulator layer, the source electrode, and the exposed portion of the germanium electrode) ( Vacuum evaporation method is very suitable for use. In this case, the degree of vacuum is usually 1.0 × 10 ^-1 Pa (Pa) or less, preferably 1.0 × 10 ^-4 Pa or less. Since the characteristics of the semiconductor film or the field effect transistor change due to the difference in substrate temperature during vapor deposition, it is preferable to carefully select the substrate temperature. The substrate temperature at the time of vapor deposition is usually from 0 to 200 ° C, preferably from 10 to 150 ° C. Further, the vapor deposition rate is usually 0.001 nm/sec to 10 nm/sec, preferably 0.01 nm/sec to 1 nm/sec.

Moreover, in order to form a semiconductor material into a laminated structure, each material is sequentially ordered. It can be prepared by heating and evaporating and then laminating. When mixing is carried out, usually, a semiconductor layer having a structure of a mixed material can be obtained by co-evaporation of each material simultaneously by heating and evaporation.

Since the organic semiconductor material of the present invention is relatively low molecular compound, such a vacuum process is suitable for use. Such a vacuum process, although requiring a slightly expensive equipment, has the advantages of good film formation and easy production of a uniform film.

Next, a description will be given of a method in which a semiconductor material is formed into a film by a solution process to obtain a semiconductor layer. Such a method is generally used in the case of an organic semiconductor material which can be dissolved in a solvent. In this method, the above material is dissolved or dispersed in a solvent and applied to a substrate (an insulator layer, a source electrode, and an exposed portion of a tantalum electrode). Coating method, coating method such as flow coating, spin coating, dip coating, blade coating, wire strip coating, spray coating, or the like, or inkjet printing, screen printing, rubber sheeting A printing method such as printing or letterpress printing, a method of soft lithography such as a microcontact printing method, and the like, and a plurality of methods of combining these methods may be employed. The film thickness of the semiconductor layer formed by such a method is preferably thinner in a range that does not affect the function. If the film thickness is thickened, the leakage current increases, so that energy may be required for the migration of charges in the film thickness direction. The film thickness of the semiconductor layer is usually from 1 nm to 1 μm, preferably from 5 nm to 500 nm, more preferably from 10 nm to 300 nm.

Further, a mixed film of a semiconductor material can be easily obtained by dissolving each material together and forming a film by the above-described process. However, in order to form a laminated structure, there may be a problem that the solubility of each material in the solvent, or a solution in which the film which is first formed at the time of lamination is etched by a material which is formed later, The optimum conditions for film formation are required. When the formation of the semiconductor layer is carried out, when it is produced by using such a solution, there is an advantage that a large-area field effect transistor can be manufactured with relatively inexpensive equipment. Further, it is also possible to use a vacuum process or the like after the solution process, and to form a film by a combination.

The semiconductor layer thus formed (refer to Fig. 2 (4)) can be further improved in characteristics by post-processing. For example, by heat treatment, strain in the film which occurs during film formation can be alleviated to achieve improvement or stabilization of characteristics. Further, it may be exposed to an oxidizing or reducing gas or liquid of oxygen or hydrogen to cause a change in characteristics due to oxidation or reduction. Such an action can be utilized, for example, for the purpose of increasing or decreasing the density of the carrier in the film.

(formation of source electrode and germanium electrode)

The method of forming the source electrode 1 and the ytterbium electrode 3 can be formed by the method of forming the gate electrode 5 (see Fig. 2 (5)). In the case where the electrode is placed in the uppermost contact structure above the semiconductor layer, a vacuum evaporation method using a shadow mask is generally used, and conversely, an underlying contact structure in which the electrode is positioned below the semiconductor layer In the case, photolithography or various printing methods are often used to form the pattern of the electrodes.

(The protective layer)

When the protective layer 7 is to be formed on the semiconductor layer, various methods can be employed. If the protective layer is made of a resin, it may be exemplified by a coated resin. The solution is dried and dried to form a resin film, coated with a resin monomer or a method of performing polymerization after vapor deposition. It is also possible to carry out a bridging treatment after film formation. When the protective layer is formed of an inorganic material, for example, a method of forming a vacuum process using a sputtering method, a vapor deposition method, or the like, or a method of forming a solution process using a sol-gel method or the like can be employed.

In the field effect transistor of the present invention, in addition to the semiconductor layer, a protective layer may be provided between the layers as needed. These layers sometimes contribute to the stabilization of the electrical characteristics of the field effect transistor.

The dynamic characteristics of the field effect transistor depend on the carrier mobility of the semiconductor layer, the electrostatic capacitance of the insulating layer, the composition of the device (the distance between the source and the 汲 electrode, and the width). For the semiconductor material used for the field effect transistor, it is preferred that the carrier mobility is higher when the semiconductor layer is formed. The semiconductor layer of the field effect transistor of the present invention may contain a naphthalene dithiophene compound represented by the above formula (5), or may contain an organic semiconductor material (A) represented by the above formula (1). The layer is laminated as a semiconductor layer with a layer containing an organic semiconductor material (B) other than the organic semiconductor material represented by the above general formula (1). When the above-mentioned laminated field effect transistor is used, it has the advantages of being stable in the atmosphere and having a long service life. Moreover, since the hysteresis is lowered and the threshold voltage is lower, the driving voltage will be lowered in actual use, and as a result, the power consumption will be lower than that of the current one, so that energy saving can be achieved. . Furthermore, as a result of the injection barrier of the charge from the electrode to the semiconductor film due to the decrease in the threshold voltage, the half is half The durability of the conductor element and the semiconductor device itself having the element is also improved, and a field effect transistor having improved uniformity and reliability can be obtained.

[Examples]

In the following, the present invention will be described in more detail by way of examples, but the invention is not limited thereto. In the examples, unless otherwise specified, parts represent parts by mass, and % means mass%.

[Example 1]

Synthesis of (3,7-dibromo-2,6-bis(4-tolylethynyl)naphthalene)

3,7-dibromo-2,6-bis(trifluoromethanesulfonyloxy)naphthalene (1.2 g, 2.0 mmol (mole)) was dissolved in DMF (dimethylformamide) under a nitrogen atmosphere. (15 ml) and DIPA (didipropanolamine) (15 ml) were mixed and argon gas was used for degassing for 30 minutes. Pd(PPh ₃ ) ₂ Cl ₂ (bis(triphenylphosphine)palladium chloride) (0.14 g, 0.1 mmol, 10 mol%) and CuI (copper iodide) (0.076 g, 0.2 mmol, 20 mol%) were added thereto. And 4-ethynyltoluene was stirred at room temperature for 2 hours, and a Sonogashina coupling was carried out. Then, the precipitated product was collected by filtration and washed with water, ethanol and hexane. Recrystallization was carried out using chloroform to purify, and 3,7-dibromo-2,6-bis(4-methylphenylethynyl)naphthalene (0.57 g, 56%) was obtained as a white solid.

¹ H-NNR (hydrogen nuclear magnetic resonance) (400 MHz, CDCl ₃ ) δ 8.04 (s, 2H, ArH), 7.93 (s, 2H, ArH), 7.52 (d, 4H, J = 8.0 Hz, PhH), 7.21. (d, 4H, J = 8.0Hz , PhH), 2.35 (s, 6H, CH 3).

[Example 2]

Synthesis of (3,7-dibromo-2,6-bis(3-tolylethynyl)naphthalene)

The same procedure as in Example 1 was carried out except that 3-ethynyltoluene was not used instead of 3-ethynyltoluene, and 3,7-dibromo-2,6-bis(3-methylphenyl) was obtained as a yellow solid. Ethynyl) naphthalene (54%).

¹ H-NNR (400MHz, CDCl ₃ ) δ 8.05 (s, 2H, ArH), 7.94 (s, 2H, ArH), 7.45 (d, 2H, J = 12.0 Hz, PhH), 7.30 (t, 2H, J = 8.0Hz, PhH), 7.20 (d, 2H, J = 4.0Hz, PhH), 2.35 (s, 6H, CH 3).

[Example 3]

Synthesis of (2,7-bis(4-methylphenyl)-naphtho[2,3-b:7,6-b']dithiophene (Compound (6))

Dissolving Na ₂ S‧9H ₂ O (0.96 g, 4.0 mmol) in NMP (N-methyl phene (30 ml), after stirring at 190 ° C for 1 hour in the atmosphere, a solution of 3,7-dibromo-2,6-bis(4-methylphenylethynyl)naphthalene (0.57 g, 1.0 mmol) in NMP was added dropwise. Stir for 16 hours. Then, the reaction solution was poured into a saturated aqueous solution of ammonium chloride (300 ml) to precipitate a solid. This was filtered off and washed with water, ethanol, hexane, dichloromethane and chloroform. The obtained crude product was subjected to sublimation purification under vacuum at 360 ° C to obtain 2,7-bis(4-methylphenyl)-naphtho[2,3-b:7,6-b as a yellow solid. '] Dithiophene (0.26 g, 63%).

Mass analysis MS (mass spectrometry) (EI=70eV) m/z=420(M ⁺ ) (Shimadzu GCMS-QP2010SE)

Absorption spectrum: λmax 446, 478 nm (film) (Shimadzu automatic recording spectrophotometer UV-3600 (P/N206-13500))

Elemental analysis: Anal (Analysis) Calcd (calculated _{value) (%) for C 28 H} 20 S 2:. C79.96, H4.79; found ( actually measured) C80.04, H4.79.

[Example 4]

Synthesis of (2,7-bis(3-tolyl)-naphtho[2,3-b:7,6-b']dithiophene (compound (7))

Except that 3,7-dibromo-2,6-bis(4-tolylethynyl)naphthalene is used instead of 3,7-dibromo-2,6-bis(3-tolylethynyl)naphthalene, The same operation as in Example 3 was carried out to obtain 2,7-bis(3-methylphenyl)-naphtho[2,3-b:7,6-b']dithiophene (46%).

Mass Analysis MS (EI=70eV) m/z=420(M ⁺ ) (Shimadzu GCMS-QP 2010SE)

Absorption spectrum: λmax 446, 478 nm (film) (Shimadzu automatic recording spectrophotometer UV-3600 (P/N206-13500))

Elemental analysis: Anal. Calcd (%) for C ₂₈ H ₂₀ S ₂ : C79.96, H4.79; found C 80.22, H 4.59.

[Example 5]

(Production of field effect transistor of compound (6) (p-tolylNDT (p-tolyl-n-triene))

A positively doped yttrium wafer (face resistance of 0.02 Ω ‧ cm or less) with a 200 nm SiO ₂ thermal oxide film treated with octadecyltrichloromethane was placed in a vacuum evaporation apparatus, and the degree of vacuum in the apparatus was Exhaust can be performed up to 5.0 × 10 ^-3 Pa or less. The electrode (6) is vapor-deposited at a vapor deposition rate of 1 to 2 Å (Å)/sec (second) at a substrate temperature of about 100 ° C by resistance heating deposition. To a thickness of 50 nm to form a semiconductor layer (2). Next, a shadow mask for the substrate is attached to the substrate, and is placed in the vacuum vapor deposition apparatus, and the degree of vacuum in the apparatus is 1.0 × 10 ^-4 Pa or less, and the surface is heated by resistance heating. The gold electrode, that is, the source electrode (1) and the germanium electrode (3) are vapor-deposited to a thickness of 40 nm to obtain a field effect transistor (channel) of the present invention belonging to the TC (upper layer contact) type. The length is 50μm and the channel width is 1.5mm).

Here, in the field effect transistor of the present embodiment, the thermal oxide film in the n-doped germanium wafer with the thermal oxide film has the function of the insulating layer (4), and the n-doped germanium wafer has the function. The function of the substrate (6) and the gate electrode (5) (refer to Figure 3). The obtained field effect transistor was placed in a probe, and a semiconductor parameter analyzer 4200SCS (manufactured by Caselle Co., Ltd.) was used to measure the semiconductor characteristics. The semiconductor characteristic is that the 汲 voltage is taken as -60V, and the gate voltage is scanned from 60V to -60V to determine the 汲 current-gate voltage (transfer) characteristic. From the obtained voltage-current curve, the carrier mobility of the device was 1.31 cm ² /Vs, the threshold voltage was 48 V, and Ion/Ioff was 10 ⁶ .

[Example 6]

(Production of compound (7) (m-tolyl NDT (m-tolyl n-triene) field effect transistor)

A positively doped germanium wafer (face resistance of 0.02 Ω ‧ cm or less) with a 200 nm SiO ₂ thermal oxide film treated with octyltrichloromethane was placed in a vacuum evaporation apparatus, and the vacuum energy in the apparatus was Exhaust until 5.0 × 10 ^-3 Pa or less. The electrode (7) was vapor-deposited to a thickness of 50 nm at a deposition rate of 1 to 2 Å/sec at a substrate temperature of about 100 ° C by a resistance heating vapor deposition method to form a semiconductor layer (2). ). Next, a shadow mask for the substrate is attached to the substrate, and is placed in the vacuum vapor deposition apparatus, and the degree of vacuum in the apparatus is 1.0 × 10 ^-4 Pa or less, and the surface is heated by resistance heating. The electrode of gold, that is, the source electrode (1) and the ruthenium electrode (3) are vapor-deposited to a thickness of 40 nm to obtain a field effect transistor of the present invention belonging to the TC (topmost contact) type (channel length 50 μm, The channel width is 1.5mm).

The obtained field effect transistor was placed in a detector, and a semiconductor parameter analyzer 4200SCS (manufactured by Caselle) was used to measure the semiconductor characteristics. The semiconductor characteristic is that the 汲 voltage is taken as -60V, and the gate voltage is scanned from 20V to -60V to determine the 汲 current-gate voltage (migration) characteristics. From the obtained voltage-current curve, the carrier mobility of this element was 0.34 cm ² /Vs, the threshold voltage was -2 V, and Ion/Ioff was 10 ⁵ .

[Example 7]

(Production of a laminated field effect transistor of compound (6) (p-tolylNDT) and compound (23) (DPh (diphenyl)-BTBT)

A positively doped germanium wafer (face resistance of 0.02 Ω ‧ cm or less) with a 200 nm SiO ₂ thermal oxide film treated with octyltrichloromethane was placed in a vacuum evaporation apparatus, and the vacuum energy in the apparatus was Exhaust until 5.0 × 10 ^-3 Pa or less. The electrode (23) was vapor-deposited to a thickness of 50 nm at a deposition rate of 1 to 2 Å/sec at a substrate temperature of about 25 ° C by a resistance heating vapor deposition method, followed by a compound (6). The thickness was evaporated to a thickness of 5 nm at an evaporation rate of 1 to 2 Å/sec to form a semiconductor layer (2). Next, a shadow mask for the substrate is attached to the substrate, and is placed in the vacuum vapor deposition apparatus, and the degree of vacuum in the apparatus is 1.0 × 10 ^-4 Pa or less, and the surface is heated by resistance heating. The electrode of gold, that is, the source electrode (1) and the ruthenium electrode (3) are vapor-deposited to a thickness of 40 nm to obtain a field effect transistor of the present invention belonging to the TC (topmost contact) type (channel length 50 μm, The channel width is 1.5mm).

The obtained field effect transistor was placed in a detector, and a semiconductor parameter analyzer 4200SCS (manufactured by Caselle) was used to measure the semiconductor characteristics. The semiconductor characteristic is that the 汲 voltage is taken as -60V, and the gate voltage is scanned from 20V to -60V to determine the 汲 current-gate voltage (migration) characteristics. From the obtained voltage-current curve, the carrier mobility of the element was 3.1 cm ² /Vs, the threshold voltage was -7 V, and Ion/Ioff was 10 ⁷ .

[Example 8]

(Production of laminated field effect transistor of compound (5) (DPh-NDT) and compound (23) (DPh-BTBT))

A field effect transistor was obtained in the same manner as in Example 7 except that the compound (5) was used instead of the compound (6).

The obtained field effect transistor was measured for semiconductor characteristics in the same manner as in Example 7. From the obtained voltage-current curve, the carrier mobility of the device was 1.5 cm ² /Vs, the threshold voltage was -21 V, and Ion/Ioff was 10 ⁸ .

[Comparative Example 1]

(Production of single layer type field effect transistor of compound (23) (DPh-BTBT))

A positively doped germanium wafer (face resistance of 0.02 Ω ‧ cm or less) with a 200 nm SiO ₂ thermal oxide film treated with octyltrichloromethane was placed in a vacuum evaporation apparatus, and the vacuum energy in the apparatus was Exhaust until 5.0 × 10 ^-3 Pa or less. The electrode (23) was deposited by a resistance heating vapor deposition method at a substrate temperature of about 25 ° C at a deposition rate of 1 to 2 Å / sec to a thickness of 50 nm to form a semiconductor layer (2). ). Next, a shadow mask for electrode formation is attached to the substrate, and is placed in a vacuum vapor deposition apparatus, and the degree of vacuum in the apparatus is 1.0×10 ⁻⁴ Pa or less, and the resistance heating deposition method is performed. The gold electrode, that is, the source electrode (1) and the germanium electrode (3) are vapor-deposited to a thickness of 40 nm to obtain a field effect transistor of the present invention belonging to the TC (topmost contact) type (channel length 50 μm, channel) 1.5mm wide).

The obtained field effect transistor was placed in a detector, and a semiconductor parameter analyzer 4200SCS (manufactured by Caselle) was used to measure the semiconductor characteristics. The semiconductor characteristic is that the 汲 voltage is taken as -60V, and the gate voltage is scanned from 20V to -60V to determine the 汲 current-gate voltage (migration) characteristics. From the obtained voltage-current curve, the carrier mobility of the device was 0.8 cm ² /Vs, the threshold voltage was -24 V, and Ion/Ioff was 10 ⁸ .

From the voltage-current curves (Fig. 4) of Example 7, Example 8, and Comparative Example 1, it is known that the field effect type transistor of the present invention exhibits a transistor having a high mobility, a low threshold voltage, and no hysteresis. .

[Example 9]

The mobility was measured in the same manner as in Example 7, Example 8, and Comparative Example 1, except that the channel length L (20, 40 μm) of the field effect transistor was changed. The results are shown in Table 1.

[Example 10]

(Production of a laminated field effect transistor of compound (6) (p-tolylNDT) and compound (20) (C8-BTBT))

A positively doped germanium wafer (face resistance of 0.02 Ω ‧ cm or less) with a 300 nm SiO ₂ thermal oxide film treated with HMDS (hexamethyldioxane) was placed in a vacuum evaporation apparatus, and the apparatus was installed. The inside vacuum degree can be exhausted at 1.0 × 10 ^-3 Pa or less. The electrode (20) was vapor-deposited to a thickness of 50 nm at a deposition rate of 1 Å/sec at a substrate temperature of about 25 ° C by a resistance heating vapor deposition method, followed by a compound (6). The vapor deposition rate to 2 Å/sec was evaporated to a thickness of 5 nm to form a semiconductor layer (2). Next, a shadow mask for electrode formation is attached to the substrate, and is placed in a vacuum vapor deposition apparatus, and the degree of vacuum in the apparatus is 5.0×10 ⁻⁴ Pa or less, and the resistance heating deposition method is performed. The gold electrode, that is, the source electrode (1) and the germanium electrode (3) are vapor-deposited to a thickness of 50 nm to obtain a field effect transistor of the present invention belonging to the TC (topmost contact) type (channel length 200 μm, channel) Wide width 2.5mm).

The obtained field effect transistor was placed in a detector, and a semiconductor parameter analyzer 4200SCS (manufactured by Caselle) was used to measure the semiconductor characteristics. The semiconductor characteristic is to measure the 汲 current-gate voltage (migration) characteristic by taking the 汲 voltage as -100V and scanning the gate voltage from 20V to -100V. From the obtained voltage-current curve, the carrier mobility of the device was 10.5 cm ² /Vs, the threshold voltage was -43 V, and Ion/Ioff was 4 × 10 ⁸ .

[Comparative Example 2]

(Production of single layer type field effect transistor of compound (20) (C8-BTBT))

A field effect transistor was obtained in the same manner as in Example 10 except that the film of the compound (6) was not formed.

The obtained field effect transistor was placed in a detector, and a semiconductor parameter analyzer 4200SCS (manufactured by Caselle) was used to measure the semiconductor characteristics. The semiconductor characteristic is that the 汲 current is taken as -100V, and the gate voltage is scanned from 20V to -100V to determine the 汲 current-gate voltage (migration) characteristics. From the obtained voltage-current curve, the carrier mobility of the device was 6.0 cm ² /Vs, the threshold voltage was -36 V, and Ion/Ioff was 2 × 10 ⁸ .

From the above results, in Comparative Example 1, if the channel length becomes short, the mobility becomes low, but in the transistor of the present invention, there is no such tendency, and even if the channel becomes short, the mobility is still Not lowering. It is also known that the electromorphic system of the present invention can operate at a high mobility in a short channel length, allowing a large current to flow and being suitable for high density integration. Further, from the voltage-current curves of the short channel length, it is known that the field effect electro-crystal system of the present invention has less hysteresis and has good characteristics. From the above results, it is known that the field effect transistor in which the compound of the present invention is laminated clearly shows the fact that the mobility is high and the semiconductor characteristics are good.

1‧‧‧ source electrode

2‧‧‧Semiconductor layer

2'‧‧‧Layered second layer of semiconductor layer

3‧‧‧汲 electrode

4‧‧‧Insulation

5‧‧‧ gate electrode

6‧‧‧Substrate

7‧‧‧Protective layer

Fig. 1 is a schematic view showing an example of a structural state of a field effect transistor of the present invention.

Fig. 2 is a schematic view showing a process for producing a field effect transistor in which the uppermost layer of the present invention is in contact with the underlying gate type structure.

Fig. 3 is a schematic view showing a structural example of a field effect transistor in which the uppermost layer of the present invention is in contact with the underlying gate type structure.

Fig. 4 is a graph showing voltage and current curves of the field effect type transistor obtained in Example 7 (laminate type), Example 8 (laminate type), and Comparative Example 1.

Claims (14)

A field effect transistor characterized by comprising an organic semiconductor material (A) which can be represented by the general formula (1), and an organic semiconductor material (B) other than the organic semiconductor material represented by the above general formula (1), (wherein X ¹ represents an aliphatic hydrocarbon residue which may have a substituent or an aromatic residue which may have a substituent). For example, in the field effect transistor of claim 1, wherein the organic semiconductor material (A) is an organic semiconductor material represented by the general formula (2), (wherein R ¹ represents a hydrogen atom or an aliphatic hydrocarbon residue which may have a substituent). For example, in the field effect transistor of claim 1 or 2, wherein the organic semiconductor material (B) is an organic semiconductor material represented by the general formula (3), (wherein X ² represents an aliphatic hydrocarbon residue which may have a substituent or an aromatic residue which may have a substituent). For example, in the field effect transistor of claim 3, wherein the organic semiconductor material represented by the general formula (3) is the general formula (4), (wherein R ² represents a hydrogen atom or an aliphatic hydrocarbon residue which may have a substituent). A field effect transistor according to any one of claims 1 to 4, which has a structure in which a layer containing the organic semiconductor material (A) and a layer containing the organic semiconductor material (B) are laminated. For example, the field effect transistor of claim 5, which is a parallax type crystal structure builder. For example, in the field effect transistor of claim 6, wherein the layer of the organic semiconductor material (B) and the layer containing the organic semiconductor material (A) are laminated on the insulator layer provided on the gate electrode. Then, the top of the active electrode and the tantalum electrode are respectively placed in contact with the bottom gate type structure in such a manner as to be in contact with the uppermost portion of the layer containing the organic semiconductor material (A). For example, in the field effect transistor of claim 6, wherein the active electrode and the ruthenium electrode are respectively disposed on the substrate, and the layer containing the organic semiconductor material (A) and the organic semiconductor material are sequentially laminated thereon ( The layer of B) is placed on the insulator layer provided in contact with the uppermost layer of the layer containing the organic semiconductor material (B), and the bottom of the gate electrode is placed in contact with the top gate type structure. A naphtho-dithiophene-based compound characterized by being represented by the general formula (5), (wherein R ³ represents a C1-3 alkyl group). A naphtho-dithiophene-based compound according to claim 9 wherein R ³ is a methyl group. a compound characterized by being represented by formula (6), A naphtho-dithiophene-based organic semiconductor material obtained by the compound according to any one of claims 9 to 11. A naphtho-dithiophene-based organic electro-optic material obtained by the compound according to any one of the items 9 to 11 of the patent application. A field effect transistor characterized by comprising the organic semiconductor material described in claim 12 of the patent application.