Composition for forming gate dielectric film of thin film transistor

Technical Field

The invention relates to a thin-film crystal tube composition for forming a gate insulating film, and further relates to the use of the thin film transistor gate insulating film for making a composition for forming the organic transistor.

Background Art

Now, as a flexible device, such as electronic paper, research the use of polycarbonate, polyethylene terephthalate, and the like of the electronic device of a plastic substrate. As a result of these plastic base plate is slightly expanded in the heating of the shrink · existence of such problems, it was therefore imperative is to improve the heat resistance (low thermal expansion characteristic).

Therefore, in order to make the plastic substrate itself to reduce the thermal stress, also studied the process for manufacturing the electronic device temperature. In addition other than manufacturing an electronic device, one of the most high-temperature process is a gate insulating film of the organic transistor · solidification of the film, on the gate insulating film required in the manufacturing process of temperature.

Here, as in the low temperature method of forming a gate insulating film, the electrode surface of the anode oxidation method (reference Patent document 1), the method of using a chemical vapor deposition method (reference Patent document 2), and the like. However, these methods are relatively complicated manufacturing process.

Therefore, expectations can be through such as spin coating method, printing method to easily coating to the film-forming material. As a coating to make a gate insulating film of example, by spin-coating to coating contains poly-4-vinyl phenol and poly (melamine-formaldehyde) solution, and then in its 200 the method of solidifying the [...] (reference valeant literature 1). However, in this method, the treatment temperature is as high as 200 the [...] , at this temperature, notably plastic substrate the heat expansion impact on performance, it is difficult to the requirement of fine pixels used in the manufacture of paper and the like.

On the other hand, as can be detected in a relatively low temperature manufacturing, can expect to be one of high insulating property of the insulating material, known soluble polyimide. Report the high decomposition temperature of polyimide in general, resistance is high, as the insulating material of the electronic device and widely used, for example, the use of the report 180 the polyimide after curing under [...] a high precision in gate insulating film for organic crystal method (reference valeant literature 2).

Furthermore, in recent years, particularly in the organic transistor to be representative of the mechanical flexibility in thin-film transistor with excellent, for the purpose of reducing the manufacturing cost, through the high-energy ultraviolet irradiation to form the electrode, the wiring.

Patent literature 1: Japanese opens especially 2003-258260, the

Patent document 2: Japanese opens especially 2004-72049, the

Valeant literature 1:J.Appl.Phys. , Section 93 roll (Vol. 93), section 5 (No. 5), , 1 March 2003, paragraph 2977-2981 page

Valeant literature 2: Appl.Phys.Lett. , Section 84 roll (Vol. 84), section 19 (No. 19), , 10 May 2004, paragraph 3789-3791 page

Content of the invention

As mentioned above, in order to obtain a high reliability of the organic transistor, of the insulating film material is very high quality requirements, requirements can be the same in, for example, by a simple process the 180 below [...] producing a relatively low temperature, high solvent resistance and light resistance, and high insulation and the like.

However, in the in the manufacturing process of the organic transistor, although insulating film production processes of the temperature is important, but also could not be said that the coating and the 180 [...] the following process to manufacture, and have good electrical characteristics of the insulating film more of material selection. Furthermore, even if these conditions is regarded as soluble polyimide can be completely satisfied, there is also low solubility of the solvent to coating, the light fastness is low.

Therefore, this invention is proposed in view of the above-mentioned situation, the purpose is to, provide, especially from the point of view of practicality, when using the gate insulating film when the organic transistor to, even by ultraviolet irradiation to the electrical wiring and other after the process of taking into account the electrical characteristics of the new gate insulating film forming composition.

The inventors in order to achieve the above-mentioned purpose and carry on the in-depth study, the result was the discovery that, by containing 1 molecule having 2 isocyanate group of a compound of the above-mentioned closed and having a triazine triketone link the compounds of the specific repeating unit to form the cured film of the composition, thus has the following characteristic: and the formation of the gate insulating film, the gate insulation film formed with satisfactory insulating, and to date lack of the insulating film material in the solvent resistance and light resistance are excellent.

In other words, in the present invention, as the section 1 view, relates to a thin film crystal affective gate insulating film forming composition, comprising the following ingredients (i) and ingredient (ii):

Ingredient (i): comprises the following repeating unit of the oligomer or polymer, the repeating unit has the nitrogen atom by a triazine triketone link via a hydroxy alkyl and other [...] combination of the nitrogen atoms into the structure,

Ingredient (ii): 1 molecules having 2 isocyanate group of a compound of the above-mentioned closed.

As section 2 view, relates to section 1 of the thin film crystal affective the viewpoint states gate insulating film forming composition, said ingredient (i) comprises the following formula (1) of the repeating unit of the shown compound,

In the formula, R₁ and R₂ carbon atoms that independently 1-6 alkyl, the carbon atom number 3-6 alkenyl, comprising carbon atom number 6-10 of the aromatic ring of 1 bivalent organic group, trifluoromethyl or pentafluoropropane ethyl, A₁, A₂ and A₃ each independently represents a hydrogen atom, methyl or ethyl, said n 2-500 integer.

As the section 3 view, relates to paragraph 1 or paragraph 2 the viewpoint states for the thin-film crystal composition for forming a gate insulating film, said ingredient (ii) is the following formula (2)-type (4) in a compound represented by the formula of at least one compound,

In the formula, X expressed 2-4 organic group of price, R₃ the sealing section of said 1 bivalent organic group.

As the section 4 view, relates to section 1 perspective-section 3 to any one of the thin film crystal tube composition for forming a gate insulating film, said ingredient (ii) is the following formula (5)-formula (7) in a compound represented by the formula of at least one compound,

In the formula, Y represents the carbon atom number 1-10 alkylene, R₃ the sealing section of said 1 bivalent organic group.

As section 5 view, relates to section 1 perspective-section 4 a of the thin film crystal tube composition for forming a gate insulating film, said ingredient (ii) is the following formula (10) a compound represented by the formula.

As section 6 view, relates to section 1 perspective-section 5 to any one of the thin film crystal tube composition for forming a gate insulating film, said ingredient (i) is the following formula (8) of the formula (9) of the two shown in the reaction product compound.

In the formula, R₁, R₂, A₁, A₂ and A₃ is respectively connected with the above-mentioned formula (1) same meaning as in the definition of recorded.

As the section 7 view, relates to section 1 perspective-section 6 to any one of the thin film crystal tube composition for forming a gate insulating film, based on the component (i) 100 parts by mass, containing 10-100 parts by mass of the ingredient (ii).

As section 8 view, relates to a gate insulating film, is the use of paragraph 1 perspective-section 7 to any one of the thin film crystal affective gate insulating film formed of the composition for forming.

As the section 9 view, relates to a thin film transistor, with section 8 the viewpoint states of the gate insulating film.

As article 10 view, relates to a grid for thin film transistor manufacturing method of an insulating film, comprising the following steps: the section 1 perspective-section 7 to any one of the thin film transistor gate insulating film for coating the composition for forming the base plate, and then the the 180 carried out under the following [...] the temperature of the baking.

As the section 11 view, relates to a method for manufacturing thin film transistor, comprising the following steps:

Paragraph 1 perspective-section 7 to any one of the thin film transistor gate insulating film for coating the composition for forming the base plate, and then the the 180 [...] the following the temperature of the baking is carried out, so as to obtain for thin film transistor gate insulating film, and,

In the gate insulating film through the coating of the organic semiconductor thin-film transistor formed by the process of the semiconductor layer.

The thin film transistor of the present invention a gate insulating film for the composition for forming the multi-kind of solvent solubility, that is, solvent solubility is high, the solid component concentration is easy to be adjusted, so as to be easily formed with suitable for the film thickness of the gate insulating film.

Furthermore, by the above-mentioned thin-film crystal affective gate insulating film formed of the composition for forming a gate insulating film of the present invention is insoluble in the organic solvent, as a gate insulating film to meet the required level of insulation, and there is little leakage current of the gate electrode.

A gate insulating film of the present invention, in particular, has caused by ultraviolet radiation of the above-mentioned insulating quality deterioration is very small, excellent light resistance such characteristics, but also the transparency is excellent.

And, a gate insulating film of the present invention, because the compound comprises [...]constitution membrane , the existing to acrylic acid skeleton is compared with the main body of the insulating film, and the like, the dielectric breakdown withstand voltage is high, as the needs of high electric field to the gate insulating the membrane executes the organic crystal for high reliability of the gate insulating film.

Furthermore, with the invention the gate insulation film of the organic transistor can be source · drain less leakage current between the, opening/ guan Bida , field effect mobility is high, the drift of the threshold voltage of the organic transistor is, in addition, can be maintained over the long period of their electrical characteristics.

Description of drawings

Figure 1 is compend profiles of display has a gate insulating film of the present invention article 1 example of the structure of the thin film transistor.

Figure 2 is compend profiles of display has a gate insulating film of the present invention article 2 example of the structure of the thin film transistor.

Figure 3 is compend profiles of display has a gate insulating film of the present invention article 3 example of the structure of the thin film transistor.

Figure 4 is compend profiles of display has a gate insulating film of the present invention article 4 example of the structure of the thin film transistor.

Figure 5 is graph of display in the embodiment 5 in, A obtained with the composition of the gate insulating film of the organic thin-film transistor of the drain current (  Current Drain) and the grid voltage (  Voltage Gate) the relationship between.

Mode of execution

The following, the present invention a more detailed description.

Thin film transistor of the present invention the affective gate insulating film forming composition comprising the following ingredients (i) and ingredient (ii): is an ingredient (i), comprises the following repeating unit of the oligomer or polymer, the repeating unit has the nitrogen atom by a triazine triketone link via a hydroxy alkyl and other [...] a nitrogen atom of the structure of the combination of, an ingredient (ii), is 1 in a molecule and 2 or more isocyanate group of the compound.

[Ingredient (i)]

The components used in the present invention (i) comprises the following repeating unit of the oligomer or polymer, the repeating unit has the nitrogen atom by a triazine triketone link via a hydroxy alkyl and other [...] combination of the nitrogen atoms into the structure. Preferably includes the following formula (1) of the repeating unit of the shown compound.

In the above-mentioned, R₁ and R₂ carbon atoms that independently 1-6 alkyl, the carbon atom number 3-6 alkenyl, comprising carbon atom number 6-10 of the aromatic ring of 1 bivalent organic group, trifluoromethyl or penta-ethyl.

Furthermore, A₁, A₂ and A₃ each independently represents a hydrogen atom, methyl or ethyl.

In addition n expressed 2-500 integer.

As the above-mentioned carbon atom number 1-6 alkyl, can be enumerated for example, methyl, ethyl, are amyl, isopropyl, and cyclohexyl, and the like.

As the above-mentioned carbon atom number 3-6 alkenyl, can be enumerated for example, allyl, 2-butenyl, 3-butenyl, 2-pentenyl, and the like.

As includes the above-mentioned carbon atom number 6-10 of the aromatic ring of 1 bivalent organic group, can be enumerated for example, phenyl, benzyl, naphthyl, and the like.

Used in the present invention for the above-mentioned the oligomer or polymer highly transparent in the ultraviolet region. This is because in order to prevent the organic crystal affective the gate insulating film by an ultraviolet irradiation causes the deterioration of the insulating quality of the excellent light resistance required. This means that even if light with high energy (several J/cm²) irradiating the gate insulating film when the hydrophilic/hydrophobic changes of the required wavelength 254 nm ultraviolet radiation, the insulating quality is not deteriorated. Therefore, as long as that the 254 nm wavelength is in the vicinity of the transparent will not absorb energy, therefore, is not easy to cause insulation deterioration.

As mentioned above, in the above-mentioned formula (1) shown in the repeating unit, R₁ and R₂ shown in the substituent is preferably in the ultraviolet region of high transparency. As such a substituent, alkyl, alkenyl, perfluoroalkyl and/or cyclohexyl group, alicyclic group is the most suitable. Furthermore, without damaging the transparency of the range, but also to be able to use the phenyl, benzyl, naphthyl, aromatic group.

As used in the present invention the above-mentioned of the optimal molecular weight of the oligomer or polymer, there is no particular restriction, however, if the molecular weight is too low, the solvent solubility is too high, it may not be possible to tolerate the manufacturing process of the transistor. On the other hand, if the molecular weight is too high, the solvent solubility is reduced, in turn, may not have access to the high-solid component concentration for the thin-film crystal composition for forming a gate insulating film. Therefore, the molecular weight of the as suitable for, for example, as a weight average molecular weight (polystyrene conversion), to 1,000-200,000, more preferably 5,000-50,000.

For obtaining this invention as used in the method of the above oligomer or polymer, there is no particular limitation, for example, can be the following formula (8) with a compound represented by the following formula (9) a compound represented by the formula in the appropriate organic solvent obtained by polycondensation reaction.

In the above-mentioned, R₁, R₂, A₁, A₂ and A₃ is respectively connected with the above-mentioned formula (1) same meaning as in the definition of recorded.

As the above-mentioned formula (8) of a compound represented by the formula for example, the following formula can be cited (A-1)-type (A-9) a compound represented by the formula.

Furthermore, as the above-mentioned formula (8) a compound represented by the formula, the electrical characteristics of the thin-film transistor in the range of, in addition to the above-mentioned type (A-1)-type (A-9) other than a compound represented by the formula, the following formula can also be used (A-10)-type (A-12) a compound represented by the formula.

As the above-mentioned formula (9) is a compound represented by the formula of the specific example, the following formula can be cited (B-1)-type (B-4) a compound represented by the formula.

Furthermore, as the above-mentioned type (9) a compound represented by the formula, the electrical characteristics of the thin-film transistor in the range of, in addition to the above-mentioned type (B-1)-type (B-4) other than a compound represented by the formula, the following formula can also be used (B-5)-type (B-7) a compound represented by the formula.

Furthermore, by only selecting the above-mentioned type (A-1)-type (A-9) as a compound represented by the formula (8) a compound represented by the formula, only choose the above-mentioned type (B-1)-type (B-4) as a compound represented by the formula (9) a compound represented by the formula, re-enable them to conduct polycondensation reaction, thereby to obtain the high insulation, and has high transparency in the ultraviolet region of the oligomer or polymer. But also, is used as a thin film transistor of the present invention a gate insulating film for the composition for forming the most suitable compound.

As the above-mentioned formula (8) with the above-mentioned type (9) a compound represented by the formula mix in an organic solvent in the method of the polycondensation reaction, can be enumerated for example, by the following formula (8) the compound as shown in formula (9) a compound represented by the dispersed or dissolved in the organic solvent by heating the solution, stirring, the appropriate catalyst is dissolved in an organic solvent reaction is carried out in the method of adding to, or, by the following formula (8) a compound represented by the formula, formula (9) a compound represented by the formula and appropriate catalyst is dispersed or dissolved in the organic solvent by heating the solution, stirring to carry out the reaction of the method and the like.

Furthermore, in the presence of more of the formula (8) the compound as shown in formula (9) shown in the case of the compound, the compound can be a pre-mixed state polycondensation reaction, can also be sequentially carry out polycondensation reaction, respectively.

In the above-mentioned polycondensation reaction, the above-mentioned type (8) with a compound represented by the formula (9) with a compound represented by the formula than, that is, formula (8) the moles of a compound represented by the formula: formula (9) shown in the molar number of the compound is preferably the 1 [...] 0.5-1 the [...] 1.5.

The usual polycondensation reaction similarly, the mole compared to Vietnam close to the 1 [...] 1, the compound generated of the greater the degree of polymerization, molecular weight increase.

As the above-mentioned polycondensation reaction of an organic solvent used in, for example, can be cited, ethyl lactate, butyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, N, N-dimethyl formamide, N, N-dimethyl acetamide, N-methyl-2-pyrrolidone, N-methyl caprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulphone, rokko sulfoxide, γ-butyrolactone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, propylene glycol, propylene glycol monoethyl ether acetate, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-hydroxy-propionic acid ethyl ester, 2-hydroxy-2-methyl propane acid ethyl ester, ethoxy-acetic acid ethyl ester, hydroxy-acetic acid ethyl ester, 2-hydroxy-3-methyl-butyric acid methyl ester, 3- methoxy propionic acid methylphenidates, 3- methoxy propionic acid diethlyl, 3- ethoxy group propionic acid diethlyl, 3- ethoxy group propionic acid methyl ester, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, and the like.

In the above-mentioned polycondensation reaction, as a reaction catalyst, can preferably use benzyl triethyl ammonium chloride, tetrabutyl ammonium chloride, quaternary ammonium salt such as ammonium bromide four ethyl bromides , or triphenylphosphine, brominated ethyl triphenyl Four butyl bromide and the like Salt and the like.

The above-mentioned polycondensation reaction, the reaction temperature and the reaction time depends on the use of compounds, such as the concentration of, for example, from the reaction time is 0.1-100 hours, the reaction temperature 20-200 the appropriate selection [...] in the range of.

The use of the quaternary ammonium salt or Salt, the reaction of a catalyst, preferably with respect to the reaction of the compound (i.e., the above-mentioned type (8) and (9) a compound represented by the formula) in the total mass of the 0.001-50% using the range of quality.

Obtained as above can be directly used as the reaction solution for thin-film crystal composition for forming a gate insulating film, however, the reaction solution contains reaction catalyst, such as unreacted monomers, and therefore preferably the reaction product, used as washing after the composition for forming a gate insulating film.

In the recovery of the reaction product, the addition of a poor solvent of the reaction solution to precipitate the reaction product, the method of filtering out the precipitate is simple and convenient. As the poor solvent used at that time, there is no particular limitation, can be instantiated methanol, hexane, heptane, ethanol, toluene, water, ethyl ether and the like. Recovery after the precipitate is filtered, preferably with the above-mentioned poor solvent to wash the reaction product. Recovery of the reaction product can be carried out at normal pressure or under reduced pressure and a normal temperature or heating and drying to form a powdery form.

If making the above-mentioned powdery reaction product in re-dissolved in a good solvent, in the poor solvent to precipitate the operation repeated 2-10 time, impurities in the reaction product can be further reduced. As the poor solvent at this moment, if the use of such as alcohols, ketones, such as 3 or more bad solvent, will further improve the purification efficiency.

[Ingredient (ii)]

The components used in the present invention is (ii) 1 molecule having 2 isocyanate group of a compound of the above-mentioned closed. By using the ingredient (ii), organic crystal tube of this invention composition for forming a gate insulating film can effectively prevent the semiconductor material of the coating, electrode material, and the 2nd layer gate insulating film of the lower layer film for forming electrodes of mixing.

Furthermore, lower layer film for forming electrodes is used for by the organic polymer forming the surface of the insulating film of the pre-treatment such as ultraviolet ray is irradiated, thus pre-patterning a hydrophilic hydrophobic different 2 regional, of the electrode-forming film.

The above-mentioned ingredient (ii) of the isocyanate groups contained in closed, protecting group by heating (closed portion) is removed from the pyrolysis, lie between the generated and the isocyanate group with hydroxy alkyl as a substituent on the nitrogen atom of the triazine triketone link of the repeating unit of the heat between the oligomer or polymer is cross-linked.

As the above-mentioned 1 molecule having 2 isocyanate group of a compound of the above-mentioned closed, can be enumerated the following formula (2)-type (4) in a compound represented by the formula of at least one compound.

In the formula, X expressed 2-4 organic group of price, R₃ the sealing section of said 1 bivalent organic group.

In the above-mentioned isocyanate group (-NCO) is R₃base seal the protection is shown.

In the above-mentioned type as R₃ the specific example, the following formula may be mentioned (C-1)-type (C-8) of shown 1 bivalent organic group.

In the formula, Q₁ is independently methyl, ethyl, propyl, butyl, hexyl, methoxy methyl and carbon atoms such as ethoxy ethyl 1-6 the 1 bivalent organic group.

Q₂ is independently a hydrogen atom, a halogen atom, or methyl, ethyl and propyl, and the like the carbon atom number 3 the following 1 monovalent substituent.

Furthermore, Q₃ are that the carbon atom number 8-18 can be branched alkyl.

Because R₃ is a protecting group (closed portion), therefore the thin film formed from the pyrolysis of heating and remove. Organic crystal affective gate insulating film from the heating temperature of the heat resistance of a plastic substrate is preferably the point of view of the 180 [...] the following, the temperature of the protecting group is also preferably the thermal decomposition leaves the 180 [...] the following. However, if the pyrolysis from temperature is too low, the solution may be carried out under a state of cross-linked, thus is not preferred. As preferred the thermal decomposition leaves temperature range, the the 100-180 [...] , more preferably the 100-150 [...].

As a protection-based (R₃) more bodies, can be enumerated the following formula (D-1)-type (D-15) of the group is shown. A particularly preferred protecting group is of the following formula (D-7), (D-11) and (D-14).

As mentioned above, in order to prevent the organic crystal affective gate insulating film caused by ultraviolet radiation of the deterioration of the insulating performance, require excellent light resistance, to think that as long as 254 nm wavelength is in the vicinity of the transparent will not absorb the energy, is not easy to cause insulation deterioration.

From this point of view, as the above-mentioned ingredient (ii) of the specific example of the particularly preferred, can be enumerated from isophorone diisocyanate derivative of the following formula (5)-type (7) a compound represented by the formula, and by the 1, 6-hexamethylene diisocyanate derivative of the following formula (11) and (12) in a compound represented by the compound of choice. The following formula (7) from a compound represented by the insulating, the point of view of light resistance is preferred.

In the formula, Y represents the carbon atom number 1-10 alkylene, R₃ expressed by the formula (2)-type (4) of the sealing section of the definition of in 1 bivalent organic group.

In particular the following formula (10) from the pyrolysis a compound represented by the formula from the temperature, the point of view of the insulating property and the light is the most preferred.

The above-mentioned ingredient (ii), i.e., 1 in a molecule and 2 or more isocyanate group of closed according to the addition amount of the compound for organic crystal composition for forming a gate insulating film in the kind of the solvent used, such as the solution viscosity of the requirements vary, however, with respect to the as the above-mentioned ingredient (i) oligomer or polymer of 100 parts by mass as 10-100 parts by mass. Because the unreacted component, insulating, solvent resistance may be worse, thus preferably 10-55 parts by mass. Furthermore, if the cross-linking agent is too small, the solvent resistance may be worse, therefore more preferably 30-55 parts by mass.

[Solvent]

Thin film transistor of the present invention the affective gate insulating film forming composition containing the above-mentioned ingredient (i) and ingredient (ii), according to needs and containing the latter other additives. The composition in fact, often as a dissolved in the solvent of the coating liquid. Furthermore, in the present invention, "composition" also includes dissolved in the solvent in the state of the coating liquid.

At this moment, for example, solid content of 0.5-30 mass %, in addition, for example for 5-30 quality %. Here the so-called solid component is for from the thin film crystal composition for forming a gate insulating film after the solvent is removed in the quality.

As the solvent used in a modulation coating liquid, can be enumerated for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monomethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol n-butyl ether, propylene glycol n-butyl ether acetate, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-hydroxy-propionic acid ethyl ester, 2-hydroxy-2-methyl propane acid ethyl ester, ethoxy-acetic acid ethyl ester, hydroxy-acetic acid ethyl ester, 2-hydroxy-3-methyl-butyric acid methyl ester, 3- methoxy propionic acid methylphenidates, 3- methoxy propionic acid diethlyl, 3- ethoxy group propionic acid diethlyl, 3- ethoxy group propionic acid methyl ester, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate, butyl lactate, methyl lactate, ethyl lactate, lactic acid n-propyl, n-butyl lactate, lactic acid isopentyl ester, N, N-dimethyl formamide, N, N-dimethyl acetamide, N-methyl-2-pyrrolidone, N-methyl caprolactam, dimethyl sulfoxide, tetramethyl urea, pyridine, dimethyl sulphone, rokko sulfoxide and γ-butyrolactone, and the like.

In the above-mentioned solvent, as long as according to the present invention for thin film transistor of the gate insulating film included in the composition for forming the above-mentioned of the molecular weight of the oligomer or polymer can be appropriately selected for use. Furthermore, in order to adjust the surface tension of the composition or adjusting the wettability of the substrate, can also be mixed use many kinds of solvents.

Furthermore, as mentioned above, can also be in the above-mentioned formula (8) with a compound represented by the formula (9) a compound represented by the formula after the polymerization reaction, the resulting reaction solution directly adding the above-mentioned ingredient (ii), for forming a thin film crystal composition for forming a gate insulating film. In this case, as a solvent for dilution, the polymerization reaction can be added in the same solvent of the solvent, the solvent can also be added with different.

[Other additives]

< 表面活性剂 >

In order to inhibit the pinhole, the striation (stration), is not further improve the coatability of the surface of, can be in the present invention for thin film transistor of the gate insulating film for forming a mating surface active agent in the composition.

As the surface active agent, can be enumerated for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene whale ceryl ether , polyoxyethylene alkyl ethers such as polyoxyethylene oil base ether ; polyoxyethylene octyl phenol ether , such as polyoxyethylene nonyl phenol ether polyoxyethylene alkyl aryl ether; polyoxyethylene/polyoxypropylene block copolymer; dehydration sorbitol monolaurate, sorbitol mono-palmitate dehydration, dehydration sorbitol monostearates, dehydration sorbitol shan You ester, dehydration sorbitol trioleate, dehydration of dehydration of sorbitol three stearyl ester, sorbitol fatty acid ester; polyoxyethylene dehydration sorbitol monolaurate, polyoxyethylene dehydration sorbitol mono-palmitate, polyethylene glycol dehydration sorbitol monostearates, polyoxyethylene dehydration sorbitol trioleate, polyoxyethylene dehydration sorbitol three stearyl ester, sorbitol fatty acid esters such as polyoxyethylene dehydration of nonionic surfactant; EF301 [...] , EF303, EF352 (Mitsubishi [...] electronic formation (strain) (old (strain) [...]) systems), [...] F171, F173 (DIC (strain) (old dainihon [...] chemical industrial (strain)) systems), a [...][...] FC430, FC431 (live [...] a [...] (strain) systems), a [...] AG710 [...] , S-382 [...] , SC101, SC102, SC103, SC104, SC105, SC106 ((strain) systems are) fluorine-based surface active agent, and the like; organic siloxane polymer KP341 (Shin-Etsu chemical industry (strain) systems), and the like.

These surfactant relative to the use level of the thin film transistor of the present invention a gate insulating film for the total mass of the composition for forming is usually 0.2% of the following quality, is preferably 0.1 mass % the following. These surfactant can be added alone, can also be 2 or more kinds combined added.

< 偶联剂 >

Furthermore, the composition in order to improve the adhesiveness with the substrate, as long as they do not damage the effect of the present invention, the method of the thin film crystal tube composition for forming a gate insulating film can be further contains a coupling agent. As the above-mentioned coupling agent, for example, can be cited, the functional silane-containing compound, the compound containing an epoxy group.

Specifically, can give 3-amino propyl trimethoxy silane, 3-amino propyl triethoxy silane, 2-amino propyl trimethoxy silane, 2-amino propyl triethoxy silane, N-(2-amino ethyl)-3-amino propyl trimethoxy silane, N-(2-amino ethyl)-3-amino propyl methyl dimethoxy silane, 3-ureido-propyl trimethoxy silane, 3-ureido-propyl triethoxy silane, N-ethoxycarbonyl-3-amino propyl trimethoxy silane, N-ethoxycarbonyl-3-amino propyl triethoxy silane, N-trimethoxy silyl propyl Sanya ethyl triamine, N-triethoxy silyl propyl Sanya ethyl triamine, 10-trimethoxy silyl -1, 4, 7-tri-aza decane, 10-triethoxy silyl -1, 4, 7-tri-aza decane, 9-trimethoxy silyl -3, 6-diaza mixed ninth stem yl ester, 9-triethoxy silyl -3, 6-diaza mixed ninth stem yl ester, N-benzyl-3-amino propyl trimethoxy silane, N-benzyl-3-amino propyl triethoxy silane, N-phenyl-3-amino propyl trimethoxy silane, N-phenyl-3-amino propyl triethoxy silane, N-bis (epoxy ethyl)-3-amino propyl trimethoxy silane, N-bis (epoxy ethyl)-3-amino propyl triethoxy silane compound containing functional silane, and the like; ethylene glycol diglycidyl ether, poly ethylene glycol diglycidyl ether, diglycidyl ether trimethylene glycol two , three c glycol diglycidyl ether, polyethylene trimethylene glycol two diglycidyl ether, new pentamethylene glycol two diglycidyl ether, 1, 6-hexamethylene glycol diglycidyl ether, glycerol diglycidyl ether, 2, 2-di- the bromine is newpentamethylene glycol two diglycidyl ether, 6-tetra glycidyl -2, 4-hexanediol, N, N, N ', N' -tetra glycidyl m-dimethylamine, 1, 3-bis (N, N-bis glycidyl amino methyl) cyclohexane, N, N, N ', N' -tetra glycidyl -4, the 4 [...] -diamino diphenyl methane, etc. the compound containing an epoxy group.

In the case of using the above-mentioned coupling agent, its content is preferably relative to the of the present invention for thin-film crystal composition for forming a gate insulating film 100 parts by mass of the added 0.1-30 parts by mass, more preferably 1-20 parts by mass.

Furthermore, in the present invention, the cross-linking catalyst does not exist, the cross-linking temperature can be realized-temperature, such as the cross-linking time, the organic crystal tube has a full characteristic of the gate insulating film.

< 涂膜和固化膜(栅极绝缘膜)的制造方法 >

Thin film transistor of the present invention the affective gate insulating film-forming composition can be through dipping method, spin coating method, transfer printing, specification small amount products, ink jet method, a spraying method, the coating method such as brushes spreads the law polypropylene, polyethylene, polycarbonate, polyethylene terephthalate, polyethersulfone, polynaphthalic acid terephthalate, polyimide and other general plastic substrate, the glass substrate, etc., such as the electric hot plate or oven for drying, thereby forming a coating film.

Furthermore, the coating film through the heat treatment (baking) to form the gate insulating film can be used as a cured film.

As the above-mentioned method of heat treatment, there is no particular limitation, can be instantiated in the appropriate atmosphere, in other words atmosphere, an inert gas, such as nitrogen, vacuum medium, the use of electric heating plate, method for processing oven.

From the baking temperature of the film, reduce the residual solvent is preferably the point of view of 40 the above [...] , more preferably 150 the more [...]. Furthermore, if we consider the heat resistance of the plastic substrate, it is more preferably in the 180 the [...].

Baking can be 2 stage of the temperature change of the above. Through the step-by-step baking to further improve the uniformity of the cured film.

Obtained from this gate insulating film of the present invention the film thickness is preferably 5-5000nm, more preferably 50-1000nm, most preferably 200-600nm. If gate insulating the membrane is excessively thin , in the low electric field will be the dielectric breakdown can not work as a transistor. On the other hand, if the gate insulating film thickness, because in order to make the transistor-resistor logic work and requires high voltage, therefore, are preferably employed to form the film thickness of the above-mentioned range.

Furthermore, the adoption of a coated · heating processing not to the required thickness of the cured film (gate insulating film) under the condition of, coating · as long as repeated until a step of heat treating to a thickness of the can.

< 薄膜晶体管 >

Thin-film transistor of the present invention, as long as using the above gate insulating film of the present invention can be, no special restrictions to the same. As one example, Figure 1-Figure 4 indicate that the use of the invention in the gate insulation film of the embodiment is formed of the thin-film transistor.

In Figure 1-Figure 3 example, thin-film transistor of the present invention, on the base plate 1, there are formed gate 2, the gate 2 is the gate electrode of the present invention the insulating film 3 (or 3a, 3b) is covered.

In the Figure 1 example, on the gate insulating film 3 is provided with an active electrode 4 and drain 4, the semiconductor layer 5 is formed in such a manner so as to cover them.

On the other hand, in the Figure 2 example, on the gate insulating film 3 is formed with a semiconductor layer 5, in the semiconductor layer 5 is provided on the source electrode 4 and drain 4.

Furthermore, in the Figure 3 example, on the gate insulating film 3a, there are formed gate insulating film 3b, in the gate insulating film 3b is provided with an active electrode 4 and drain 4. Semiconductor layer 5 is formed in such a manner so as to cover them. Here, the gate insulating film 3b in addition to the characteristics of transistors as used for controlling the functions of an insulating film, a film or as a surface treatment as a source 4 and drain electrode 4 for forming the electrode of the function of the lower layer film.

Furthermore, in the Figure 4 example, on the base plate 1 is formed with a semiconductor layer 5, in order to cover the semiconductor layer 5 and substrate 1 is arranged between the two sides of the active electrode 4 and drain 4. Moreover, the gate insulating film 3 in the semiconductor layer 5 and source 4 and drain electrode 4 is formed, on the gate insulating film 3 is provided with a grid 2.

As a thin-film transistor of the present invention the electrode material used in the (gate, source, drain), may enumerate for example, gold, silver, copper, aluminum, calcium and other metal, carbon black, fullerene, carbon nanotube, and other inorganic material, and polythiophene, polyaniline, polypyrrole, polyfluorenes and their derivatives, such as organic π conjugated polymer.

These electrode material can use 1 kind of, however, to improve the field effect of the thin-film transistor migration, the on/off ratio, or in order to control the threshold voltage, also a plurality of materials can be combined to be used. Furthermore, gate, source, drain can be respectively using different electrode material.

As electrode forming method, using a vacuum evaporation method, a sputtering method is a general method, in order to simplify the manufacturing method, can also be the use of spraying, printing, ink jet coating method such as to a method of forming an electrode. Furthermore, in recent years, also raised the gate by ultraviolet radiation to the surface of the insulating film formed by local changes in the fine electrode pattern-coating method, the method also can be used. As the electrode material can be coated, with the nano metal particles, such as organic π conjugated polymer.

When the electrode-forming coating in use, as the nano metal ink, organic π conjugated polymer solvent, from the present invention relates to the destruction of the gate insulation film of (mixed) proceeding less, preferably water, various alcohols.

Furthermore, the electrode material from the viewpoint of excellent solubleness, N, N-dimethyl formamide, N, N-dimethyl acetamide, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-methyl caprolactam, dimethyl sulfoxide, such as four embodiments it is also preferred if the polar solvent, the polar solvent is preferably the present invention relates to the destruction of the gate insulating film is used in the range of.

Thin-film transistor of the present invention included in the use of material of the semiconductor layer, as long as they can in the present invention on the gate insulating film, the above-mentioned electrode and the above-mentioned plastic substrate can be formed on, there is no particular limitation, as a specific example, can enumerate pentacene, low poly-thiophene derivatives, phthalocyanine derivatives, organic low-molecular material, poly-thiophene derivatives, polystyrene support derivatives, π conjugated polymer such as polyfluorenes derivatives, InGaZnO series, InGaO series, is ZnGaO, InZnO series, ZnO, SnO₂ oxide semiconductor.

These semiconductor material film-forming method can use a sputtering method, the vacuum evaporation coating method, ink jet method, a spraying method, and the like. Because the ink jet method, such as spraying coating law is simple and convenient, can reduce the manufacturing cost, therefore, is particularly preferred.

As to the coating method is of a semiconductor material, can be enumerated solvent solubility is high, is easy to obtain the uniform thin film of the π conjugated polymer.

In the film-forming time, as the solvent of the π conjugated polymer, as long as they can be dissolved or uniformly dispersed, and the gate insulating film of this invention (mixing and other) damage can be less, there is no particular limitation, can be instantiated b toluene, three paradichlorbenzene, three toluene and the like.

Embodiment

The following list represents detailed example that the implementation of the invention, but the invention is not limited to these embodiments.

[Number-average molecular weight and the determination of the weight average molecular weight]

In this embodiment, obtained by the polymerization of the P-1 molecular weight by GPC (gel permeation chromatography at room temperature) device to determine, as a polystyrene conversion value of the average molecular weight and computation number weight average molecular weight.

GPC apparatus: JASCO society system (  Ver. 1.50 JASCO-BORWIN)

Column: Shodex Xinhua systems (804,805 series)

Column temperature: 40 the [...]

Eluent: tetrahydrofuran

Flow velocity: 1.0 ml/minute

Standard curve plotting using standard sample to: standard polystyrene (210,000, 70, 600, 28,600, 10,900, 3, 000, 1,300)

Furthermore, in this embodiment, obtained by the polymerization of the P-2 molecular weight by GPC (gel permeation chromatography at room temperature) device to determine, as the polyethylene glycol, polyethylene oxide conversion value of the average molecular weight and computation number weight average molecular weight.

GPC apparatus: Shodex society system (strain) (GPC-101)

Column: Shodex society system (KD803, KD805 series)

Column temperature is: the 50 [...]

Eluant: N, N-dimethyl formamide (as an additive, lithium bromide-hydrate (LiBr·H₂ O) to 30 long and fine hair Morocco /L, phosphoric acid · anhydrous crystalline (ortho-phosphoric acid) to 30 long and fine hair Morocco /L, tetrahydrofuran (THF) to 10 ml/L)

Flow velocity: 1.0 ml/minute

Standard curve plotting using standard sample to: standard polyethylene oxide (molecular weight of about 900,000, 150, 000,100,000, 30,000), and, a [...] a [...] Xinhua the system gathers glycol (molecular weight of about 12,000, 4, 000, 1,000)

[Determination of film thickness]

Film thickness is determined by the following method: cutting knife for a part of the release film, the use of full automatic fine form measuring instrument (ET4000A, (strain) Kosaka research Institute society system) determination strength is in the 13  N, scanning velocity is 0.05 mm/ under second determine its section difference.

[Thin-film crystal affective gate insulating film forming composition used in the synthesis of polymer]

< gathers the precedent aodirenc 1:P-1>

The monoolefin propyl two glycidyl isocyanurate 90g, monoethylenically propyl isocyanurate 54.4g and benzyl triethyl ammonium chloride 3.66g added to the cyclohexanone 222g in, the mixture is heated to 125 the [...] , while at the same time flowing through the nitrogen gas in the mixture, while stirring 4 hours. Furthermore, the resulting reaction solution is dropped in methanol solvent, filtering out the separated precipitate, P-1 so as to obtain the reaction product (white powder).

To the resulting reaction product P-1 to GPC analysis, results in a standard polystyrene conversion to (Mw) weight average molecular weight of 21,500.

Furthermore, P-1 reaction product having the following formula (13) of the structure unit shown.

< compared with gathers the precedent aodirenc 1:P-2>

The phenylenediamine 4.86g, 4-hexadecyl propoxycyclohexyl -1, 3-diaminobenzene 1.74g dissolved in N-methyl pyrrolidone (hereinafter referred to as NMP) 122.5g in, then adding 3, 4-dicarboxy -1, 2, 3, 4-tetrahydro-1-naphthalene succinic acid dianhyride 15.01g, the stirring at room temperature for 10 hours the polymerization reaction to proceed. The resulting polyamic acid solution with NMP diluted to 8 weight %. In the solution 50g as imidization catalyst in second grade acid anhydride 10.8g, pyridine 5.0g, in 50 the reaction under [...] 3 hours, thereby obtaining the polyimide solution. The solution is added to a large amount of methanol in, filtering out the resulting white precipitate of, drying, thereby obtaining white polyimide powder. Through¹ H-NMR the polyimide powder confirmed 90% is imidized.

Furthermore, the resulting polyimide number average molecular weight (Mn) and weight average molecular weight of the (Mw) Mn=18,000, Mw=54,000.

< embodiment 1: composition modulation A >

The gathers the precedent 1 P-1 obtained (white powder) 20g dissolved in γ-butyrolactone (hereinafter referred to as GBL) 107g, cyclohexanone 47g and propylene glycol monomethyl ether 19g (hereinafter referred to as the PGME) in the mixed solvent, then adding the above-mentioned type (10) blocked isocyanate shown 8g, surfactant R-300.84g, so as to obtain the solid content 14% A weight of the composition.

< compared with example aodirenc 1: composition modulation B >

The gathers the precedent 1 P-1 obtained (white powder) 10g dissolved in GBL75g and double c glycol single butyl ether 15g (hereinafter referred to as the DPM) in the mixed solvent, thereby obtaining B the composition.

< compared with example aodirenc 2: composition modulation C >

The comparison alloy precedent 1 P-2 obtained (white powder) 10g dissolved in GBL75g and DPM15g in the mixed solvent, thereby obtaining C the composition.

[Solvent resistance]

< embodiment 2: using the composition of the solvent resistance of the film A >

With for the 0.2   m hole in the injector of the filter of the glass substrate with ITO (2.5 cm × 2.5 cm, thickness 0.7 mm) dropping on embodiment 1 composition of the modulation A, coating by spin coating. Furthermore, in the atmosphere, for the 80 the electric heating board [...] heat treatment of 5 minutes, the organic solvent is volatilized. Furthermore, for the 180 [...] baking a platen 30 minutes, thereby obtaining membrane thick approximately 400 nm of the gate insulating film.

Next, each membrane of the glass substrate in propylene glycol monomethyl ether acetate, respectively (hereinafter referred to as PGMEA), PGME, dipping in acetone solvent of 1 minute, and then, through the glass substrate of the film 150 the heating on a platen [...] 1 minutes to dry the same. Impregnated before and after the measuring film thickness (residual film ratio), evaluation of solvent resistance, as a result of the composition of the formed A any solvent not only the residual film ratio of 99% or more, excellent solvent resistance.

< compared with example aodirenc 3: using the composition of the solvent resistance of the film B >

With the embodiment 2 of the same steps to obtain B of the composition of the gate insulating film is formed. Furthermore, with the embodiment 2 of the same steps to evaluate the solvent resistance. Forming a film made from the composition in PGMEA B, PGME, acetone dissolved in the solvent. In other words, the composition form B of the gate insulating film exhibits no tolerance manufacturing process of the organic transistor.

[Production of insulating film, the insulating film of the electrical characteristic evaluation and light fastness]

< embodiment 3: using the composition of the insulating film characteristics A >

With 0.2 the hole   m the of the filter of the glass substrate with ITO (2.5 cm × 2.5 cm, thickness 0.7 mm) dropping on embodiment 1 composition of the modulation A, coating by spin coating. Furthermore, in the atmosphere 80 the electric heating board [...] heat treatment of 5 minutes, the organic solvent is volatilized. Then use the 180 [...] baking a platen 30 minutes, thereby obtaining membrane thick approximately 400 nm of the gate insulating film.

Next, using a vacuum vapor deposition apparatus in the above-mentioned insulating film is laminated on the 1.0-2.0 mm, film thickness 100 nm of aluminum electrode, thereby manufacturing the upper limit of the insulating film to the insulating quality of electrodes are provided on the sample for evaluation. Furthermore, vacuum deposition conditions are at this time, room temperature, vacuum 1 × 10^-3 Pa the following, aluminum vapor deposition speed 0.4 nm/sec the following.

In the sample in the atmosphere for 1 hour, then in the air measuring the current-voltage characteristic. Set up the voltage from 0V to 60V each gear 2V, each shelf holding time is 3 seconds, while applying a voltage to the aluminum electrode side, is comprised of electric field 1MV/cm the current value of the resistivity of the obtained. The result shows that, of the composition the resistivity of the insulating film formed A for 1 × 10¹⁶ Ωcm, has as an insulating film for electronic device required 10¹⁵ Ωcm the resistivity of the above, display excellent characteristic. Furthermore, the gate insulation film of relative dielectric constant of 3.5.

< embodiment 4:A using the composition of the insulating film of the light fastness >

Use and embodiment 3 the same steps to obtain A of the composition of the gate insulating film is formed. Next, in order to high-pressure mercury lamp as the light source, through a wavelength 254 nm light in the vicinity of the band-pass filter to the gate insulating film to 10J/cm² irradiating ultraviolet ray.

Furthermore, in the calculation of the exposure of the grid is on the insulating film, in a luminometer (society system OAI, MODEL306) is provided at a wavelength of 253.7 nm Deep having a peak sensitivity at probe for   UV illumination intensity of ultraviolet radiation is measured, the illumination intensity of the resulting 45-50mW/cm².

Next, use and embodiment 3 the same steps with 10J/cm² irradiating the ultraviolet ray on the substrate of the insulating film of the laminated aluminum electrode, thereby manufacturing a sample for evaluation of light fastness.

In the sample in the atmosphere for 1 hour, then in the air measuring the current-voltage characteristic. Set up the voltage from 0V to 60V each gear 2V, each shelf holding time is 3 seconds, while applying a voltage to the aluminum electrode side, is comprised of electric field 1MV/cm the current value of the resistivity of the obtained. To 10J/cm² of the ultraviolet ray irradiation to the electrical resistivity of the insulating film for 7 × 10¹⁵ Ωcm, A of the composition formed in the insulating film of the ultraviolet radiation and the less the variation of the resistance, has high light resistance.

< compared with example aodirenc 4: using the composition of the insulating film characteristics C >

Use and embodiment 3 the same steps to the evaluation of the composition form C the insulating quality of the gate insulating film. The results shown in table 1. C of the composition of the insulating film formed of electrical resistivity as the 8 × 10¹⁵ Ωcm, the gate insulation film of relative dielectric constant of 3.3.

< compared with example aodirenc 5: using the composition for the light resistance of an insulating film C >

Use and embodiment 4 the same steps to evaluate C of the composition forming the gate insulation film of the light fastness. The results shown in table 1. C of the composition formed through the insulating film of the ultraviolet irradiation to the resistance value is reduced to 1 × 10¹⁵ cm, result of light.

Table 1-ultraviolet irradiation before and after the change of the volume resistivity of the

[Organic transistor manufacturing and the electrical characteristics of the transistor]

<embodiments aodirenc 5>

With 0.2 the hole   m the of the filter of the glass substrate with ITO (2.5 cm × 2.5 cm, thickness 0.7 mm) dropping on embodiment 1 composition of the modulation A, heat treatment (pre-drying) 5 minutes, the organic solvent is volatilized. Then use the 180 [...] baking a platen 30 minutes, thereby obtaining membrane thick approximately 400 nm of the gate insulating film.

The gate insulation film the electrostatic capacity of the for C 7.7 × 10^-9 (F/cm²).

Next, in the above-mentioned gate insulating film is formed on the semiconductor layer.

First of all, the poly (3-hexyl) thiophene (hereinafter referred to as P3HT) to 2 mass % concentration of in dissolved in xylene, modulation P3HT coating solution, under the nitrogen atmosphere, the coating the coating liquid by using the spin coating method in the above-mentioned gate insulating film. Furthermore, in order to make the solvent is completely volatilized, in the vacuum state 105 the heating treatment under [...] 60 minutes, forming the semiconductor layer.

Furthermore, in the above-mentioned semiconductor layer, the semiconductor layer using vacuum vapor deposition device (P3HT film) laminated on jin Yue 80 nm, forming channel long L is the 90  m, channel width W to 2 mm source · drain, thereby completing the organic transistor. Furthermore, Figure 2 shown in the organic thin-film transistor of the embodiment of the profiles 5 of the corresponding organic transistor.

Furthermore, at this moment the vacuum vapor deposition of the electrode is the condition of, the room temperature, vacuum 1 × 10^-3 Pa the following, the gold deposition speed 0.1 nm/sec the following.

According to the above-mentioned method of the evaluation of the organic transistor electrical characteristics of the vacuum in the drain of the characteristics of the current and grid voltage.

Specifically, the source drain voltage · (VD) is -40V, + 30V (VG) from the gate voltage of -40V to each gear 2V change, the voltage keeps 1 seconds until the current sufficiently stable recording the value of the measured value of the drain current. Furthermore, when measuring HP4156C using a semiconductor parameter analyzer ([...] · [...] (strain) systems).

Such measuring the drain current of the characteristic with respect to the gate voltage (V_G-I_D characteristic) is, when the when the gate voltage is a negative value, a significant increase in drain current, P3HT as p-type semiconductor work. The results shown in Figure 5.

Generally speaking, the drain current of the saturated state I_D can be expressed by the following formula. In other words, the mobility μ of the organic semiconductor can be made of when the in order to drain current I_D the square root of the absolute value of the axis of ordinates, the grid voltage V_G to carry out slope of the plan of the drawing is obtained.

I_D =WCμ (V_G-V_T)²/2L

In the formula, W is the width of the channel of the transistor, is L ditch Daoist priest of the transistor, is C the electrostatic capacity of the gate insulating film, V_T is the threshold voltage of the transistor, μ is the mobility. When the to is calculated on the basis of this formula P3HT migration rate, μ, of the results of the 2 × 10^-3 cm²/Vs. Furthermore, the threshold voltage + 3V, the ratio of the compressor open state of the state (open/pentacene) for 10³ order of magnitude. Furthermore, the hysteresis have not observed. Furthermore, stop all of the evaluation of the organic transistor is carried out in vacuum.

Next, the organic transistor is exposed in the atmosphere 1 minutes, with the above-mentioned same drain current and to evaluate the characteristics of the gate voltage. The results shown in Figure 5. The drain current value to the high-current side mobile, open/pentacene · lag no change, to obtain a good characteristic.

In other words, the composition obtained A of the gate insulating film as the organic crystal tube can be suitable for a gate insulating film.

The results of the above summarized shown in table 2.

[Table 2]

It can be seen from the above, the invention of the thin film crystal tube composition for forming a gate insulating film as the gate insulating film with the desired solvent resistance, insulation property and light resistance, and also excellent characteristic of the FET.

Note the Figure mark

1: base plate

2: grid

3 (3a, 3b): gate insulating film

4: source electrode, drain electrode

5: semiconductor layer