Photosensitive organic insulating material composition, insulating film, gate insulating film, transistor, electronic device, and method for manufacturing a transistor

Abstract

An objective of the present invention is to provide a photosensitive organic insulating composition having sufficient absorption, even of i-line radiation, as a photosensitive organic insulating composition that has little influence on device reliability and is capable of forming a gate insulating film for transistors. An objective of the present invention is also to provide a gate insulating film and a transistor.　A photosensitive organic insulating composition according to one embodiment of the present invention contains a chalcone compound and polyvinyl cinnamate.

Description

[Technical Field]

[0001] The present invention relates to a photosensitive organic insulating material composition, an insulating film, a gate insulating film, a transistor, an electronic device, and a method for manufacturing a transistor. [Background technology]

[0002] In organic electronics such as organic thin-film transistors (OTFTs), photosensitive materials that can be directly patterned are sometimes used as organic insulating film materials. For example, Non-Patent Document 1 discloses an OTFT using polyvinyl cinnamate (also called poly(vinyl cinnamate), hereafter sometimes referred to as PVCi), a photosensitive resin material, as a gate insulating film. However, PVCi has problems such as very little absorption of the i-line (wavelength 365 nm) when the light used for exposure is the i-line, requiring a very large exposure amount for curing when using an i-line monochromatic light source. Against this backdrop, there has been a need for a photosensitive organic insulating composition that maintains insulating properties comparable to PVCi, has high i-line absorption, and does not require a large exposure amount for curing even when using an i-line monochromatic light source. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Feng, L. et al. Unencapsulated Air-stable Organic Field Effect Transistor by All Solution Processes for Low Power Vapor Sensing. Sci. Rep. 6, 20671; doi: 10.1038 / srep20671 (2016). [Overview of the Initiative]

[0004] A first aspect of the present invention is a photosensitive organic insulating material composition comprising a chalcone compound and polyvinyl cinnamate. A second aspect of the present invention is an insulating film which is a photocured product of the photosensitive organic insulating material composition of the first aspect. A third aspect of the present invention is a gate insulating film which is a photocured product of the photosensitive organic insulating material composition of the first aspect. A fourth aspect of the present invention is a transistor having the gate insulating film of the third aspect. A fifth aspect of the present invention is an electronic device having a thin-film transistor according to the fourth aspect. A sixth aspect of the present invention is a method for manufacturing a gate insulating film, comprising the steps of: applying a photosensitive organic insulating material composition according to the first aspect to a substrate; and curing the photosensitive organic insulating material composition by exposure to form a gate insulating film. A seventh aspect of the present invention is a method for manufacturing a transistor, comprising the step of forming a gate insulating film by the method for manufacturing a gate insulating film according to the sixth aspect. [Brief explanation of the drawing]

[0005] [Figure 1] This diagram shows the cross-sectional shapes of organic thin-film transistors. (a): Bottom-gate, top-contact type organic thin-film transistor; (b): Bottom-gate, bottom-contact type organic thin-film transistor; (c): Top-gate, top-contact type organic thin-film transistor; (d): Top-gate, bottom-contact type organic thin-film transistor. [Figure 2] This is a schematic cross-sectional view showing the structure of a bottom-gate, bottom-contact type organic thin-film transistor, which is Example 1. [Figure 3] This is a schematic diagram of a Metal-Insulator-Metal structure fabricated to investigate the electrical properties of the organic insulating film obtained from the composition prepared in Example 1. [Figure 4] This figure shows the residual film ratio relative to the exposure amount for the insulating films obtained in Examples 1 and 6 and Comparative Example 1. [Figure 5] This figure shows the residual film ratio relative to the exposure amount for the insulating films obtained in Examples 1 and 6 and Comparative Example 1. This is an enlarged view of Figure 4. [Figure 6]This figure shows the leakage current between the upper and lower electrodes of the MIM structure shown in Figure 3 for Examples 1 and 6 and Comparative Example 1. [Figure 7] This figure shows the method for fabricating organic thin-film transistors in Examples 1 and 16. [Figure 8] This figure shows a microscopic image of the OTFT completed in Example 1. [Figure 9] This figure shows the transfer characteristics and bias stress test results of the fabricated OTFT. [Figure 10] This figure shows the results of the VTH shift amount for the fabricated OTFT. [Figure 11] This figure shows the residual film ratio relative to the exposure amount for the insulating film obtained in Example 16. [Figure 12] This figure shows the residual film ratio relative to the exposure amount for the insulating film obtained in Example 16. This is an enlarged view of Figure 11. [Figure 13] This figure shows the leakage current between the upper and lower electrodes of the MIM structure shown in Figure 3, in Example 16 and Comparative Example 1. [Figure 14] This figure shows a microscopic image of the OTFT completed in Example 16. [Figure 15] The transfer characteristics and bias stress test results of the OTFT fabricated in Example 16 are shown. [Figure 16] Comparative Example 1 shows the transfer characteristics and bias stress test results of the fabricated OTFT. [Modes for carrying out the invention]

[0006] (Photosensitive organic insulating material composition) The photosensitive organic insulating material composition of the present invention will be described in detail below using the first and second embodiments.

[0007] [First Embodiment] The photosensitive organic insulating material composition of the first embodiment comprises a chalcone compound and polyvinyl cinnamate (PVCi).

[0008] <Chalcone compounds> Chalcone compounds are chalcone derivatives such as (unsubstituted) chalcone and substituted chalcone. Examples of substituted chalcone include chalcones having one or more selected from the group consisting of substituents such as an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a polyoxyalkyl group having 1 to 5 carbon atoms, an alkylamino group having 1 to 5 carbon atoms, a thioalkyl group having 1 to 5 carbon atoms, a sulfonyl group having 1 to 5 carbon atoms, a nitro group, and a cyano group. Among them, chalcones having one or more selected from the group consisting of substituents such as an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, and a polyoxyalkyl group having 1 to 5 carbon atoms are preferred. The number of substituents is preferably 1 to 3, more preferably 1. The substitution position is preferably on the benzene ring on the alkene side of the unsaturated carbonyl, and more preferably substituted at the ortho and para positions. From the viewpoint of facilitating the photoreaction and increasing the i-line absorption, a chalcone substituted with one alkoxy group having 1 to 5 carbon atoms at the para position of the benzene ring on the alkene side of the unsaturated carbonyl is preferred, and an alkoxy group having 1 to 3 carbon atoms is more preferred. Specific examples of chalcone compounds include, for example, chalcone, methoxy chalcone, etc. Chalcone, 2-methoxy chalcone, and 4-methoxy chalcone are more preferred. 4-Methoxy chalcone (hereinafter, may simply be referred to as methoxy chalcone) is even more preferred. The chalcone compounds according to this embodiment may be used alone or in combination of two or more.

[0009] <Polyvinyl cinnamate (PVCi)> Polyvinyl cinnamate is also referred to as poly(vinyl cinnamate). For example, it can be obtained from Sigma-Aldrich Japan K.K.

[0010] <Solvent> The photosensitive organic insulating material composition of this embodiment may further contain a solvent. Examples of solvents include alcohol-based solvents, ester-based solvents, hydrocarbon-based aromatic solvents, amide-based solvents, ketone-based solvents, glycol ether-based solvents, and ether-based solvents. From the viewpoint of solubility and film-forming properties, ester-based and ketone-based solvents are preferred as the solvent, and among these, propylene glycol 1-monomethyl ether 2-acetate (PGMEA) and cyclopentanone are preferred.

[0011] <Other ingredients> To improve weather resistance and light resistance, known antioxidants, light stabilizers, and UV absorbers may be added. To improve adhesion, known adhesion promoters may be added. To improve leveling, surface wettability, or hydrophobicity, known surface modifiers may be added.

[0012] <Composition ratio of the composition> The photosensitive organic insulating material composition of this embodiment may contain the above-mentioned chalcone compounds and polyvinyl cinnamate in the following mass ratios. The ratio of the total mass of the chalcone compounds to the mass of polyvinyl cinnamate is 0.01 to 1, preferably 0.01 to 0.3, more preferably 0.03 to 0.3, and even more preferably 0.05 to 0.1. In the photosensitive organic insulating material composition of this embodiment, the total amount of chalcone compounds and polyvinyl cinnamate is preferably 10% to 30% by mass, and more preferably 10% to 15% by mass, based on 100% by mass of the total amount of the composition. In the photosensitive organic insulating material composition of this embodiment, the total amount of chalcone compounds is preferably 0.1% to 15% by mass, and more preferably 0.1% to 3% by mass, based on 100% by mass of the total amount of the composition.

[0013] <i-line sensitivity of the composition> The photosensitive organic insulating material composition of this embodiment preferably has an absorption spectrum peak in the wavelength range of 300 to 370 nm, more preferably in the wavelength range of 320 to 370 nm, even more preferably in the wavelength range of 340 to 370 nm, and most preferably has an absorption spectrum peak in the i-line (365 nm). Since the photosensitive organic insulating material composition of this embodiment also contains chalcone compounds in addition to polyvinyl cinnamate, the absorption in the i-line is greater compared to the case where only polyvinyl cinnamate is contained. As a result, when using an i-line exposure machine with the same light intensity, the time required for photocuring is shortened. Productivity can be greatly improved. The absorbance intensity of the i-line of the photosensitive organic insulating material composition of this embodiment can be adjusted by the type of chalcone compound, the content of the chalcone compound, and so on. For example, if the chalcone compound is unsubstituted chalcone, it is preferable that the content is 10% to 50% by mass in 100% by mass of the components (solids) of the photosensitive organic insulating material composition excluding the solvent. If the chalcone compound is methoxychalcone, it is preferable that the content is 5% to 25% by mass.

[0014] [Second Embodiment] The photosensitive organic insulating material composition of the second embodiment comprises a polymer having a chalcone skeleton.

[0015] <Polymers containing a chalcone skeleton> The chalcone skeleton in the polymer according to this embodiment is a structure derived from various chalcone compounds contained in the photosensitive organic insulating material composition of the first embodiment. The chalcone compounds in this embodiment have the same meaning as the chalcone compounds in the first embodiment, and their preferred examples are also the same. The chalcone skeleton in the polymer according to this embodiment is preferably a structure contained in a side chain linked to the main chain of the polymer. In this embodiment, the main chain of the polymer is preferably a vinyl polymer chain produced by a polymerization reaction of monomers having ethylenically unsaturated bonds. In this embodiment, the polymer having a chalcone skeleton preferably has a vinyl polymer main chain and side chains containing the chalcone skeleton.

[0016] The chalcone-containing polymer according to this embodiment may contain side chains that do not contain a chalcone skeleton, in addition to the vinyl polymer main chain and the side chains containing the chalcone skeleton. Preferably, the chalcone-containing polymer according to this embodiment contains no other side chains in addition to the vinyl polymer main chain and the side chains containing the chalcone skeleton.

[0017] In this embodiment, the polymer having a chalcone skeleton is preferably a monomer polymer or copolymer containing a substituted chalcone compound having an ethylenically unsaturated group. The substituted chalcone compound having an ethylenically unsaturated group is preferably at least one selected from the group consisting of chalcones having an ethylenically unsaturated group and chalcones having an ethylenically unsaturated group and a methoxy group. Specific examples of polymers having a chalcone skeleton according to this embodiment include, for example, polymers represented by the following formulas (1) to (3).

[0018] [ka] (In equation (1), n1 is an integer between 1 and 1000.)

[0019] [ka] (In equation (2), n² is an integer between 1 and 1000.)

[0020] [ka] (In equation (3), n3 is an integer between 1 and 1000.)

[0021] In this embodiment, the weight-average molecular weight of the polymer having a chalcone skeleton is preferably 5,000 to 100,000, more preferably 10,000 to 80,000, and even more preferably 20,000 to 50,000. Gel permeation chromatography (GPC) can be used to measure the weight-average molecular weight.

[0022] In this embodiment, the polymer having a chalcone skeleton preferably contains 20% to 97% by mass, and more preferably 50% to 80% by mass, of the chalcone skeleton (a structure derived from chalcone compounds, for example, the structure of compound 3 in the scheme below excluding the -OH group) per 100% by mass of the polymer.

[0023] <Method for producing polymers having a chalcone skeleton> The method for producing a polymer having a chalcone skeleton according to this embodiment will be described in detail below, using the polymer of formula (2) above as an example. The polymer production method according to this embodiment includes a step of synthesizing an ethylenically unsaturated compound having a chalcone skeleton, and a polymerization step of polymerizing the ethylenically unsaturated compound to form a vinyl polymer main chain.

[0024] The ethylenically unsaturated compounds having the chalcone skeleton described above can be produced by known methods of reacting a compound having a hydroxyl group and a chalcone skeleton with an acid chloride having an ethylenically unsaturated group in a solvent. For example, compound 3 can be synthesized by the method described in Non-Patent Document 2, as shown in Scheme 1 below. Another method involves reacting the resulting phenol derivative compound 3 (or 4'-hydroxy-4-methoxychalcone from Biosynth) with compound 4 to synthesize compound 5.

[0025] [ka]

[0026] (Non-patent document 2: X. Yang et.al. Synthesis of a series of novel dihydroartemisinin derivatives containing a substituted chalcone with greater cytotoxic effects in leukemia cells, Bioorganic & Medicinal Chemistry Letters, Volume 19, Issue 15, (2009), Pages 4385-4388.)

[0027] In polymerization steps for polymerizing ethylenically unsaturated compounds, for example, when radical copolymerizing an ethylenically unsaturated compound, known methods such as solution polymerization, emulsion polymerization, suspension polymerization, and bulk polymerization can be used for the radical copolymerization. The solvent used in solution polymerization is not limited in any way as long as it dissolves the above monomers and the polymer of the present invention. Examples include toluene, xylene, diethyl ether, tetrahydrofuran, 1,4-dioxane, dimethylformamide, dimethyl sulfoxide, etc., and these solvents can also be used in mixture form.

[0028] The polymerization temperature is selected depending on the initiator used, but is not particularly limited. The initiator is not particularly limited, but examples include azo-based initiators such as azoisobutyronitrile; and peroxide-based initiators such as benzoyl peroxide and di(t-butyl) peroxide. A specific example is 2,2'-azobis(isobutyronitrile) (AIBN). The reaction time is not limited and is set according to the half-life of the initiator used, but from an economic standpoint, 4 to 30 hours is preferred.

[0029] For example, as shown in Scheme 2 below, compound 6 is synthesized by polymerizing the compound 5 obtained above. The conditions for the synthesis reaction will be explained in detail in the examples. The evaluation results for compound 6 will also be explained in the examples.

[0030] [ka]

[0031] In the polymerization step described above, the ethylenically unsaturated monomer used as a raw material for the polymerization reaction may include not only ethylenically unsaturated compounds having a chalcone skeleton, such as compound 5 in scheme 2, but also ethylenically unsaturated compounds without a chalcone skeleton. When ethylenically unsaturated compounds without a chalcone skeleton are included, the side chains of the resulting polymer will include not only side chains having a chalcone skeleton but also side chains without a chalcone skeleton. In this case, the total mass of the ethylenically unsaturated compounds without a chalcone skeleton is preferably 0 to 50 parts by mass, more preferably 0 to 30 parts by mass, and even more preferably 0 parts by mass, relative to 100 parts by mass of the total mass of the ethylenically unsaturated compounds having a chalcone skeleton.

[0032] <Solvent> The photosensitive organic insulating material composition of this embodiment may further contain a solvent. Examples of solvents include alcohol-based, ester-based, and ketone-based solvents. Among these, propylene glycol 1-monomethyl ether 2-acetate (PGMEA) and cyclopentanone are preferred. Alternatively, the solvent used in the polymerization reaction may be used as is as part of the solvent in the composition.

[0033] <Other ingredients> To improve weather resistance and light resistance, known antioxidants, light stabilizers, and UV absorbers may be added. To improve adhesion, known adhesion promoters may be added. To improve leveling, surface wettability, or hydrophobicity, known surface modifiers may be added.

[0034] <Composition ratio of the composition> In the 100% by mass of the component (solid content) of the photosensitive organic insulating material composition of this embodiment, excluding the solvent, it is preferable that the polymer having the chalcone skeleton is 50% to 100% by mass, more preferably 75% to 100% by mass, and even more preferably 100% by mass. The chalcone compounds and polyvinyl cinnamate may also be included in the following mass ratios. In the photosensitive organic insulating material composition of this embodiment, the total amount of the polymer having the chalcone skeleton is preferably 10% to 30% by mass, and more preferably 10% to 15% by mass, based on 100% by mass of the total amount of the composition.

[0035] <i-line sensitivity of the composition> The photosensitive organic insulating material composition of this embodiment preferably has an absorption spectral peak in the wavelength range of 300 to 370 nm, more preferably in the wavelength range of 320 to 370 nm, even more preferably in the wavelength range of 340 to 370 nm, and most preferably has an absorption spectral peak in the i-line (365 nm). Since the photosensitive organic insulating material composition of this embodiment contains a polymer having a chalcone skeleton, the absorption in the i-line is greater compared to the case of the conventional technology containing only polyvinyl cinnamate. As a result, when using an i-line exposure machine with the same light intensity, the time required for photocuring is shortened. Productivity can be greatly improved. The i-line absorbance of the photosensitive organic insulating material composition of this embodiment can be adjusted by the type of chalcone compound used for the chalcone skeleton, the content of the chalcone skeleton in the polymer, and so on. For example, when the chalcone compound is methoxychalcone, i.e., when the polymer has a methoxychalcone skeleton, the content is preferably 50 to 90 parts by mass. If the i-line absorption is large, the deep curability decreases, resulting in reduced photocurability at thick films and reduced edge painting properties. The content can be arbitrarily adjusted to obtain excellent photocurability at the desired film thickness.

[0036] (Organic insulating film) An organic insulating film according to one embodiment of the present invention (hereinafter referred to as the organic insulating film of this embodiment) is obtained by forming one or more of the photosensitive organic insulating material compositions selected from the group consisting of the first and second embodiments described above (hereinafter sometimes referred to as the compositions according to this embodiment) on a substrate and then photocuring them (photocured product). The compositions according to this embodiment can be printed on various substrates. The organic solvent used is not limited in any way, as long as it dissolves the compounds contained in the composition and does not dissolve materials such as organic semiconductors used in the manufacture of devices such as organic thin-film transistors. Examples include aromatic hydrocarbon solvents such as cyclohexane, benzene, toluene, xylene, ethylbenzene, isopropylbenzene, N-hexylbenzene, tetralin, decalin, isopropylbenzene, and chlorobenzene; chlorinated aliphatic hydrocarbon compounds such as methylene chloride and 1,1,2-trichloroethylene; aliphatic cyclic ether compounds such as tetrahydrofuran, tetrahydropyran, and dioxane; ketone compounds such as methyl ethyl ketone, cyclopentanone, and cyclohexanone; ester compounds such as ethyl acetate, dimethyl phthalate, methyl salicylate, amyl acetate, and propylene glycol 1-monomethyl ether 2-acetate (PGMEA); alcohols such as n-butanol, ethanol, and iso-butanol; and 1-nitropropane, carbon disulfide, and limonene. These solvents can be mixed as needed. It is preferable that the organic solvent is the same as the organic solvent used for synthesis described above, and more preferably propylene glycol 1-monomethyl ether 2-acetate (PGMEA), cyclopentanone, etc.

[0037] There are no restrictions on the coating or printing method; for example, printing can be done using spin coating, drop casting, dip coating, doctor blade coating, pad printing, squeegee coating, roll coating, rod bar coating, air knife coating, wire bar coating, flow coating, gravure printing, flexographic printing, screen printing, inkjet printing, letterpress reverse printing, etc.

[0038] The composition according to this embodiment has photocrosslinking groups that have photodimerization reactivity, and radiation is preferably used for the photocrosslinking. Examples of radiation include ultraviolet and visible light with wavelengths of 245 to 450 nm. From the viewpoint of maximizing the effects of the present invention, the vicinity of the i-line is preferred, and an i-line monochromatic light source is more preferred. The radiation dose is appropriately changed depending on the composition of the polymer, but for example, 100 to 300 mJ / cm². 2 For example, to prevent a decrease in the degree of crosslinking and to improve economic efficiency by shortening the process time, a preferably 50-200 mJ / cm² is used. 2 The environment for irradiation with ultraviolet and visible light is not particularly limited and can be carried out in the atmosphere, in an inert gas, or under a constant flow of inert gas. If necessary, a photosensitizer can be added to the composition to promote the photocrosslinking reaction. There are no restrictions on the photosensitizer used, and examples include benzophenone compounds, anthraquinone compounds, thioxanthone compounds, and nitrophenyl compounds. In addition, two or more of these sensitizers can be used in combination as necessary. Furthermore, from the viewpoint of improving the electrical properties of the organic insulating film of this embodiment, it is preferable that the composition is substantially free of photosensitizers. Here, a photosensitizer is a substance that assists the photocrosslinking reaction process by transferring the energy it obtains from absorbing light to other substances. Examples include benzophenone compounds, anthraquinone compounds, thioxanthone compounds, and nitrophenyl compounds. The chalcone compounds contained in the photosensitive organic insulating material composition of the first embodiment described above are not photosensitizers because they themselves absorb light and participate in the photocrosslinking reaction. "Substantially absent" means that it contains only a small amount, so small that no photosensitizing effect is observed. For example, in the composition according to this embodiment, the amount is preferably in the range of 0% to 0.05% by mass, more preferably in the range of 0% to 0.01% by mass, even more preferably in the range of 0% to 0.05% by mass, and even more preferably 0% by mass.

[0039] Furthermore, the photosensitive organic insulating material composition used in the organic insulating film of this embodiment can be photocrosslinked efficiently in a short time. To achieve photocrosslinking more efficiently in a shorter time, for example, when using i-line light, it is preferable to limit the light irradiation time to 2 minutes or less. Moreover, since it is suitable for controlling the crosslinking time, for example, when using i-line light, it is even more preferable to limit the light irradiation time to 1 minute or less.

[0040] The organic insulating film of this embodiment can be suitably used as an insulating film for various devices such as organic thin-film transistors. In particular, the organic insulating film of this embodiment can be suitably used as a gate insulating film for organic thin-film transistors, as described later.

[0041] (Organic thin-film transistor)

[0042] The organic thin-film transistor of this embodiment may have any of the following device structures as shown in Figure 1: bottom-gate-top-contact type (A), bottom-gate-bottom-contact type (B), top-gate-top-contact type (C), and top-gate-bottom-contact type (D). The polymer of this embodiment is particularly applicable to devices of form (A) and (B). In the example, a device of form (B) was used. Here, 1 is the organic semiconductor layer, 2 is the substrate, 3 is the gate electrode, 4 is the gate insulating layer, 5 is the source electrode, and 6 is the drain electrode.

[0043] In the organic thin-film transistor, the substrate (substrate) that can be used is not particularly limited as long as sufficient flatness for fabricating the device can be ensured. Examples include inorganic material substrates such as glass, quartz, aluminum oxide, highly doped silicon, silicon oxide, tantalum dioxide, tantalum pentoxide, and indium tin oxide; plastics; metals such as gold, copper, chromium, titanium, and aluminum; ceramics; coated paper; and surface-coated nonwoven fabrics. Composite materials made of these materials or materials made by layering these materials may also be used. Furthermore, the surface of these materials can be coated to adjust the surface tension.

[0044] Examples of plastics that can be used as a base material include polyethylene terephthalate, polyethylene naphthalate, triacetylcellulose, polycarbonate, polymethyl acrylate, polymethyl methacrylate, polyvinyl chloride, polyethylene, ethylene-vinyl acetate copolymer, polymethylpentene-1, polypropylene, cyclic polyolefin, fluorinated cyclic polyolefin, polystyrene, polyimide, polyvinylphenol, polyvinyl alcohol, poly(diisopropyl fumarate), poly(diethyl fumarate), poly(diisopropyl maleate), polyethersulfone, polyphenylene sulfide, polyphenylene ether, polyester elastomer, polyurethane elastomer, polyolefin elastomer, polyamide elastomer, styrene block copolymer, etc. Furthermore, two or more of the above plastics can be used laminated to form a base material.

[0045] Examples of conductive materials that can be used as gate electrodes, source electrodes, or drain electrodes in this embodiment include gold, silver, aluminum, copper, titanium, platinum, chromium, polysilicon, silicide, indium tin oxide (ITO), and tin oxide. Multiple of these conductive materials can also be used in a laminated configuration.

[0046] Furthermore, in bottom-gate-top-contact type (A) elements and bottom-gate-bottom-contact type (B) elements, electrodes are formed on the organic semiconductor layer or on the gate insulating film. In this case, there are no particular restrictions on the method of forming the electrodes, and examples include vapor deposition, high-frequency sputtering, electron beam sputtering, etc. Methods such as solution spin coating, drop casting, dip coating, doctor blade, die coating, pad printing, roll coating, gravure printing, flexographic printing, screen printing, inkjet printing, and letterpress inversion printing can also be employed using an ink obtained by dissolving nanoparticles of the conductive material in water or an organic solvent. In addition, if necessary, a treatment to adsorb fluoroalkylthiols, fluoroallylthiols, etc., onto the electrodes may be performed.

[0047] There are no restrictions on the organic semiconductors that can be used in the organic thin-film transistor of this embodiment; either N-type or P-type organic semiconductors can be used, and it can also be used as a bipolar transistor combining N-type and P-type semiconductors. For example, polypyrroles, polythiophenes, polyanilines, polyallylamines, fluorenes, polycarbazoles, polyindoles, and poly(p-phenylenevinylenes) can be used. In addition, low molecular weight substances that are soluble in organic solvents can be used, such as polycyclic aromatic derivatives such as pentacene, phthalocyanine derivatives, perylene derivatives, tetrathiafulvalene derivatives, tetracyanoquinodimethane derivatives, fullerenes, and carbon nanotubes. Specifically, examples include condensates of 9,9-di-n-octylfluorene-2,7-di(ethylene boronate) and 5,5'-dibromo-2,2'-bithiophene.

[0048] In this embodiment, a preferred method for forming the organic semiconductor layer is to dissolve the organic semiconductor in an organic solvent and then coat or print it; however, there are no limitations as long as a thin film of the organic semiconductor layer can be formed. The solution concentration when printing the solution in which the organic semiconductor layer is dissolved in the organic solvent varies depending on the structure of the organic semiconductor and the solvent used, but from the viewpoint of forming a more uniform semiconductor layer and reducing the thickness of the layer, it is preferably 0.5 to 5% by weight. The organic solvent used in this process is not limited in any way as long as it dissolves the organic semiconductor at a certain concentration that allows for film formation. Examples include hexane, heptane, octane, decane, dodecane, tetradecane, decalin, indan, 1-methylnaphthalene, 2-ethylnaphthalene, 1,4-dimethylnaphthalene, dimethylnaphthalene isomer mixture, toluene, xylene, ethylbenzene, 1,2,4-trimethylbenzene, mesitylene, isopropylbenzene, pentylbenzene, hexylbenzene, tetralin, octylbenzene, cyclohexylbenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, trichlorobenzene, 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, γ-butyrolactone, 1,3-butylene glycol, ethylene glycol, benzyl alcohol, glycerin, cyclohexanol acetate, 3-methoxybutyl acetate, and ethylene glycoside. 1,6-Hexanediol diacetate, 1,3-Butylene glycol diacetate, 1,4-Butanediol diacetate, 1,6-Hexanediol diacetate, 1,6-Hexanediol diacetate, 1,3-Butylene glycol diacetate, 1,4-Butanediol diacetate, 1,6-Hexanediol diacetate, 1,3-Butylene glycol diacetate, 1,4-Butanediol diacetate, ethyl acetate, phenyl acetate, dipropylene glycol dimethyl ether, dipropylene glycol methyl-N-propyl ether, tetradecahydrophenanthrene, 1,2,3,4,5,6,7,8-Octahydrophenanthrene, Decahydro-2-Naphthol, 1,2,3,4-Tetrahydro-1-naphthol, α-Terpineol, Isophorone triacetine decahydro-2-naphthol, Dipropylene glycol dimethyl ether, 2,6-Dimethylanisole, 1,2-Dimethylanisole, 2,3-Dimethylanisole, 3,4-Dimethylanisole, 1-Benzothiophene, 3-Methylbenzothiophene, 1,2-Dichloroethane, 1,1,2,2-Tetrachloroethane, Chloroform, Dichloromethane, Tetrahydrofuran, 1,2-Dimethoxyethane, Dioxane, Cyclohexanone, Aceto Examples include methyl ethyl ketone, diethyl ketone, diisopropyl ketone, acetophenone, N,N-dimethylformamide, N-methyl-2-pyrrolidone, and limonene. However, to obtain a crystalline film with desirable properties, solvents with high dissolving power for organic semiconductors and a boiling point of 100°C or higher are suitable. Xylene, isopropylbenzene, anisole, cyclohexanone, mesitylene, 1,2-dichlorobenzene, 3,4-dimethylanisole, pentylbenzene, tetralin, cyclohexylbenzene, and decahydro-2-naphthol are preferred. Furthermore, mixed solvents obtained by mixing two or more of the aforementioned solvents in appropriate proportions can also be used.

[0049] Various organic and inorganic polymers or oligomers, or organic and inorganic nanoparticles, can be added to the organic semiconductor layer as needed, either as a solid or as a dispersion in water or an organic solvent. A polymer solution can then be applied to the polymer dielectric layer to form a protective film. Furthermore, various moisture-proof coatings, light-resistant coatings, etc., can be applied to this protective film as needed.

[0050] Examples of conductive materials that can be used as gate electrodes, source electrodes, or drain electrodes in the organic thin-film transistor of this embodiment include inorganic electrodes such as aluminum, gold, silver, copper, highly doped silicon, polysilicon, silicide, tin oxide, indium oxide, indium tin oxide, chromium, platinum, titanium, tantalum, graphene, and carbon nanotubes, or organic electrodes such as doped conductive polymers (e.g., PEDOT-PSS). Multiple layers of these conductive materials can also be used. Furthermore, to increase the carrier implantation efficiency, these electrodes can be surface-treated using a surface treatment agent. Examples of such surface treatment agents include benzenethiol and pentafluorobenzenethiol.

[0051] Furthermore, there are no particular limitations on the method of forming electrodes on the substrate, insulating layer, or organic semiconductor layer, and examples include vapor deposition, high-frequency sputtering, electron beam sputtering, etc. Methods such as solution spin coating, drop casting, dip coating, doctor blade, die coating, pad printing, roll coating, gravure printing, flexographic printing, screen printing, inkjet printing, and letterpress reverse printing can also be employed using an ink obtained by dissolving nanoparticles of the conductive material in water or an organic solvent.

[0052] The organic thin-film transistor of this embodiment can, for example, use an element in the form of a bottom gate-bottom contact type used in the embodiment. Figure 2 is a schematic cross-sectional view showing the structure of a bottom gate-bottom contact type organic thin-film transistor, which is an example of this embodiment. This organic thin-film transistor includes a substrate 2, a gate electrode 3 formed on the substrate 2, a gate insulating layer 4 formed on the gate electrode 3, a source electrode 5 and a drain electrode 6 formed on the gate insulating layer 4 with a channel portion in between, and an organic semiconductor layer 1 formed on the electrodes.

[0053] The organic thin-film transistor of this embodiment has a mobility of 0.20 cm, from the viewpoint of the practicality of organic thin-film transistor elements. 2 It is preferable that it is greater than or equal to / Vs.

[0054] In this embodiment, from the viewpoint of practicality for organic thin-film transistor elements, it is preferable that the threshold voltage of the organic thin-film transistor is -10.0V or higher and less than 0V.

[0055] The organic thin-film transistor of this embodiment has a leakage current density of 10, from the viewpoint of the practicality of the organic thin-film transistor element. -9 A / cm 2 The following is preferable:

[0056] (Electronic devices including organic thin-film transistors) The electronic device of this embodiment includes the organic thin-film transistor of this embodiment. Examples of the electronic device of this embodiment include organic electroluminescent elements, organic photoelectric conversion elements, and displays. [Examples]

[0057] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0058] The raw materials, apparatus, etc., used in the embodiments of the present invention will be described below.

[0059] (raw materials) Chalcone: Tokyo Chemical Industry Co., Ltd., Product Code C0071, Purity (Test Method): >98.0% (GC) Methoxychalcone: Tokyo Chemical Industry Co., Ltd., Product Code M1409, Purity (Test Method): >98.0% (GC) Polyvinyl cinnamate (PVCi): Sigma-Aldrich, Product Code 182648 Cyclopentanone: Fujifilm Wako Pure Chemical Industries, Ltd., Product Code 039-09716, Purity (Test Method): >95.0% (GC) PGMEA: Tokyo Chemical Industry Co., Ltd., Product Code P1171, Purity (Test Method): >98.0% (GC) Silicon wafer: Shonan Electronic Materials Research Institute, P-type resistivity less than 1 Ωcm Glass substrate: Shonan Electronic Materials Research Institute, soda lime Organic semiconductor layer raw material: 2-decyl-7-phenyl[1]benzothieno[3,2-b][1]benzothiophene, Tokyo Chemical Industry Co., Ltd., product code D5491, purity (test method): >99.5% (HPLC) Organic semiconductor layer doping material: Polystyrene, Sigma-Aldrich, product code 182427, average Mw ~280,000 (GPC)

[0060] (Device) Film deposition equipment: Spin coater (Mikasa Corporation, MS-A150) i-line exposure machine: Multilight (manufactured by Ushio Inc.) Photolithography Weight average molecular weight: GPC (manufactured by TOSO: GPC-8020) Residual film percentage: Stylus-type profiler (KLA-Tencor: P16) Electrical characteristic evaluation: Semiconductor parameter analyzer (Keithley Instruments: Model 4200A-SCS)

[0061] (Evaluation method) Average molecular weight: Calculated using GPC (TOSO: GPC-8020) Chalcone skeleton content: Calculated from the composition ratio of synthetic raw materials. Residual film percentage: The ratio of film thickness after exposure and development to film thickness before exposure. Leakage current: Obtained by current-voltage (IV) measurement of a metal-insulator-metal structure using a semiconductor parameter analyzer. Dielectric constant: Calculated from capacitance measurements of a metal-insulator-metal structure using a semiconductor parameter analyzer. Transfer characteristics: Obtained using a semiconductor parameter analyzer. Threshold voltage shift amount due to bias stress test: Obtained by a Negative Bias Stress (NBS) test in which a constant voltage (VGS = -20V) is applied between the source and gate. The application time was set to 1 second, 10 seconds, 100 seconds, and 1000 seconds, and the transfer characteristics were measured after each application time to calculate the difference in threshold voltage.

[0062] (Synthesis Example 1) "Synthesis of a compound having a hydroxyl group and a methoxychalcone skeleton (compound 3 in scheme 1 above)" Compound 3: <Substance name: 4'-hydroxy-4-methoxychalcone> Under Ar, 4-hydroxyacetophenone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 390g), p-anisaldehyde (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 390g), and methanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 5.5L) were mixed in a 20L four-necked flask. Then, while maintaining the internal temperature below 15°C in an ice bath, 2.7L of 50% NaOH aqueous solution was added dropwise over 60 minutes. After that, the ice bath was removed and the mixture was stirred at room temperature for 95 hours. 5.4L of distilled water was placed in a 90L container, and the reaction mixture was poured in. Then, approximately 35L of 1N HCl aqueous solution was added little by little. If the internal temperature was likely to exceed 30°C, ice was added to maintain it at around 25°C. The pH was adjusted to approximately 4, and the precipitated solid was separated by suction filtration. The solution was washed with a mixed solution of methanol and distilled water (2 / 1.3 L), and the resulting solid was dried under reduced pressure at 50°C for 24 hours to obtain 544.6 g of a pale yellow solid. Recrystallization was performed using ethanol to obtain 520.8 g of the target product, which is a pale yellow solid (yield 71%). The 1H-NMR measurement results for 4'-hydroxy-4-methoxychalcone are shown below. 1H-NMR(CDCl3)3.86(3H,s),5.52(1H,s),6.93(4H,m),7.41(1H,m),7.60(2H,m),7.81(1H,m),8.01(2H,m)

[0063] (Synthesis Example 2) "Synthesis of an ethylenically unsaturated compound having a methoxychalcone skeleton (compound 5 in scheme 1 above)" Compound 5: <Substance name: (E)-4-(3-(4-methoxyphenyl)acryloyl)phenyl methacrylate> 30.0 g of 4'-hydroxy-4-methoxychalcone and dry THF were added to a 2 L four-necked flask under argon and dissolved. 15.5 g of triethylamine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added, and the mixture was cooled with ice water. Then, 14.8 g of methacryloyl chloride (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added dropwise, and the mixture was stirred overnight. 600 mL of water was poured into the reactor, and the mixture was transferred to a separatory funnel and extracted with ethyl acetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 1.2 L). The ethyl acetate layer was then washed twice with 600 mL of 5% sodium bicarbonate solution and three times with 600 mL of water, and dried over anhydrous sodium sulfate. After removing the drying agent, the mixture was concentrated under reduced pressure (40°C / 20 mmHg) to obtain a pale yellow solid. 600 mL of ethanol was added to the resulting crude mixture, and the mixture was suspended and stirred for 30 minutes. The mixture was then filtered to obtain a white solid. By drying this under reduced pressure (40°C / <1mmHg), 30.1 g (79.2%) of the target product was obtained. The 1H-NMR measurement results for (E)-4-(3-(4-methoxyphenyl)acryloyl)phenyl methacrylate are shown below. 1H-NMR(CDCl3)2.09(3H,s),3.87(3H,s),5.81(1H,m),6.39(1H,m),6.93 (2H,d),7.26(2H,d),7.38(1H,m),7.63(2H,d),7.78(1H,m),8.08(2H,d)

[0064] (Synthesis Example 3) "Synthesis of polymers having a methoxychalcone skeleton (PMC: Poly(4-Methoxychalcone)) (compound represented by formula (2) above, compound 6 in scheme 2)" As shown in Scheme 2 above, compound 6 is synthesized by polymerizing compound 5 obtained in Synthesis Example 2. (E)-4-(3-(4-methoxyphenyl)acryloyl)phenyl methacrylate and degassed DMF were added to a 3L four-necked flask under argon and stirred. AIBN (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 3.82g) was then added, and the temperature was raised to 60°C and stirred for 21 hours. After cooling, the mixture was added dropwise to methanol (30 L). After stirring for 60 minutes, the mixture was filtered under reduced pressure, washed three times with methanol (2 L), and the resulting solid was dried under reduced pressure (50°C / <1 mmHg) to obtain 135 g of the target PMC. The 1H-NMR measurement results for PMC are shown below. 1H-NMR(CDCl3)1.57(3H,br),1.94(1H,br),3.75(3H,br),6.83(2H,br),7.31(6H,m,br),7.96(2H,br) The obtained compound 6 was evaluated for its weight-average molecular weight, chalcone skeleton content, and solid content, and the results are shown below. The evaluation method is described above. Weight average molecular weight: 44131 Chalcone skeleton content: 74 parts by mass

[0065] (Example 1) [Preparation of the composition] 3% by mass of chalcone and 10% by mass of polyvinyl cinnamate were dissolved in cyclopentanone to prepare the composition of this example.

[0066] [Fabrication and evaluation of organic insulating films] Figure 3 is a schematic diagram of a Metal-Insulator-Metal structure fabricated to investigate the electrical properties of the organic insulating film obtained from the composition prepared in this embodiment. The composition prepared in this embodiment was used to deposit a film on a silicon wafer by spin coating at 2000 rpm for 60 seconds. The film thickness before photolithography was 450 nm. Pre-baking was performed at 80°C for 20 minutes, and the organic insulating film was exposed at various i-line exposure levels and developed with PGMEA. Figures 4 and 5 (enlarged view of Figure 4) show the residual film ratio relative to the exposure level. As shown in Figure 5, 2400 mJ / cm 2 The residual film rate reached almost 1. Figure 6 shows the leakage current between the upper and lower electrodes of the MIM structure shown in Figure 3. Figure 6 shows that the organic insulating film of Example 1 has almost the same insulating properties as the organic insulating film of Comparative Example 1, which will be described later. Furthermore, the dielectric constant of the organic insulating film in Example 1 was also evaluated. Table 1 shows the evaluation results of the organic insulating film in Example 1.

[0067] [Manufacturing and evaluation of organic thin-film transistors] Figure 7 shows the method for fabricating an organic thin-film transistor according to this embodiment. Figure 2 is a schematic diagram of the layered structure of the fabricated organic thin-film transistor. First, the gate electrode was formed in the process shown in Figure 7(1). A 50 nm layer of aluminum (Al) was deposited on a soda-lime wafer, which is an insulating substrate, using a resistance-heating vacuum deposition method. Next, electrode processing was performed. First, a positive-type photoresist, Sumiresist PFI-34A (manufactured by Sumitomo Chemical), was spin-coated onto the surface of the Al layer at 1500 rpm for 45 seconds, and pre-baked at 105°C for 10 minutes to remove the solvent from the resist film. Next, the gate electrode pattern was exposed using a photomask with an i-line dose of 270 mJ / cm2, and post-exposure baking (PEB) was performed at 105°C for 10 minutes. After that, the resist in the exposed area was removed by immersion in tetramethylammonium hydroxide (TMAH) at room temperature (25°C) for 1 minute. After washing the substrate with pure water, it was dried by blowing N2 gas on it and post-baked at 105°C for 10 minutes. Next, the Al layer was processed. The substrate was immersed in a heated mixed acid aqueous solution (H3PO4:CH3COOH:HNO3:H2O = 10:1:1:2 by weight ratio) and the exposed Al was etched. The resist on the substrate was removed with acetone, washed with pure water, and then dried by blowing N2 gas onto it. Next, a gate insulating film was formed using the process shown in Figure 7(2). The composition obtained in this example was deposited by spin coating at 2000 rpm for 60 seconds, and pre-baked at 80°C for 20 minutes. Then, using a photomask, an i-line dose of 2400 mJ / cm² was applied. 2 It was cured using [method / technology]. Then, it was immersed in PGMEA as a developer at room temperature (25°C), leaving only the pad portion of the gate electrode open. After that, it was post-baked at 150°C for 1 hour. Next, the source / drain electrodes were formed in the process shown in Figure 7(3). A 50 nm thin layer of gold (Au) was deposited on the gate insulating film (layer) using a resistance heating vacuum deposition method. Then, electrode processing was performed. The resist process and etching process were carried out in the same manner as in Figure 7(1). Finally, the semiconductor layer was formed using the process shown in Figure 7(4). After UV treatment of the substrate on which the source / drain electrodes were fabricated, a thiol-based self-assembled monolayer (SAM) was formed on the Au electrode surface by immersion. Subsequently, a semiconductor solution prepared by dissolving 0.5 mass% organic semiconductor and 0.2 mass% polystyrene in xylene was heated to 150°C, and the film was deposited by spin coating at 1000 rpm for 30 seconds, followed by post-baking at 120°C for 5 minutes. Finally, the semiconductor layer was patterned by wiping each electrode pad. A microscopic image of the completed OTFT is shown in Figure 8. Figure 9 shows the transfer characteristics and bias stress test results of the fabricated OTFT (channel length L=50μm, channel width W=500μm). The transfer characteristics were acquired with a source / drain voltage Vds=-2V. For the bias stress test, a bias voltage Vg=-20V was applied between the source and gate, and the characteristic changes were acquired after 1 second, 10 seconds, 100 seconds, and 1000 seconds of application. Figure 10 shows the threshold voltage shift amount with respect to application time. In this embodiment, a threshold voltage shift of 0.5V was observed after 1000 seconds of application in the gate insulating film.

[0068] (Examples 2-15) [Preparation of the composition] The compositions of Examples 2 to 5 were prepared with the compositions shown in Tables 1 and 2.

[0069] [Fabrication and evaluation of organic insulating films] Organic insulating films were prepared and evaluated in the same manner as in Example 1, except that the compositions of Examples 2 to 15 were used instead of the composition of Example 1. The results are shown in Tables 1 and 2.

[0070] [Manufacturing and evaluation of organic thin-film transistors] Organic thin-film transistors were fabricated and evaluated in the same manner as in Example 1, except that the compositions of Examples 2 to 15 were used instead of the composition of Example 1. The results are shown in Tables 1 and 2.

[0071] (Example 16) [Preparation of the composition] The polymerized methoxychalcone film obtained in Synthesis Example 3 was dissolved in cyclopentanone at a concentration of 10% by mass to prepare the composition of this example.

[0072] [Fabrication and evaluation of organic insulating films] Figure 3 is a schematic diagram of a Metal-Insulator-Metal structure fabricated to investigate the electrical properties of the organic insulating film obtained from the composition prepared in this example. The composition prepared in this example was used to deposit a film on a silicon wafer by spin coating at 2000 rpm for 60 seconds. The film thickness before photolithography was 450 nm. Pre-baking was performed at 80°C for 20 minutes, and the organic insulating film was exposed at various i-line exposure levels and developed with cyclopentanone. Figures 11 and 12 (enlarged view of Figure 11) show the residual film ratio relative to the exposure level. As shown in Figure 12, 200 mJ / cm 2 The residual film rate reached almost 1. Figure 13 shows the leakage current between the upper and lower electrodes of the MIM structure shown in Figure 3. Figure 13 shows that the organic insulating film of Example 1 has almost the same insulating properties as the organic insulating film of Comparative Example 1, which will be described later. Furthermore, the dielectric constant of the organic insulating film in Example 16 was also evaluated. Table 2 shows the evaluation results of the organic insulating film in Example 16.

[0073] [Manufacturing and evaluation of organic thin-film transistors] Figure 7 shows the method for fabricating an organic thin-film transistor according to this embodiment. Figure 2 is a schematic diagram of the layered structure of the fabricated organic thin-film transistor. First, a gate electrode was formed in the process of Fig. 7(1). Aluminum (Al) was deposited in a thickness of 50 nm on a soda lime wafer, which is an insulating substrate, by a resistance heating type vacuum evaporation method. Next, electrode processing was performed. First, a strawberry resist PFI-34A (manufactured by Sumitomo Chemical Co., Ltd.), which is a positive photoresist, was spin-coated on the surface of the Al layer at 1500 rpm for 45 seconds, and pre-baked at 105 °C for 10 minutes to remove the solvent from the resist film. Next, using a photomask, the gate electrode pattern was exposed with an i-line dose of 270 mJ / cm2, and post-exposure bake (PEB) was performed at 105 °C for 10 minutes. Then, it was immersed in tetramethylammonium hydroxide (TMAH) at room temperature of 25 °C for 1 minute to remove the resist in the exposed area. After washing the substrate with pure water, it was dried by blowing N2 gas and post-baked at 105 °C for 10 minutes. Next, the Al layer was processed. The substrate was immersed in a heated mixed acid aqueous solution (H3PO4:CH3COOH:HNO3:H2O = 10:1:1:2 by weight ratio) to etch the exposed Al. The resist on the substrate was removed with acetone, washed with pure water, and dried by blowing N2 gas. Next, a gate insulating film was formed in the process of Fig. 7(2). The composition obtained in this example was spin-coated at 2000 rpm for 60 seconds and pre-baked at 80 °C for 20 minutes. Next, using a photomask, it was cured with an i-line dose of 2400 mJ / cm 2 . Then, it was immersed in cyclopentanone as a developer at room temperature of 25 °C to open only the pad portion of the gate electrode. Then, it was post-baked at 150 °C for 1 hour. Next, source / drain electrodes were formed in the process of Fig. 7(3). Gold (Au) was deposited in a thickness of 50 nm on the gate insulating film (layer) by a resistance heating type vacuum evaporation method. Next, electrode processing was performed. The resist process and the etching process were carried out in the same manner as in the process of Fig. 7(1). Finally, the semiconductor layer was formed using the process shown in Figure 7(4). After UV treatment of the substrate on which the source / drain electrodes were fabricated, a thiol-based self-assembled monolayer (SAM) was formed on the Au electrode surface by immersion. Subsequently, a semiconductor solution prepared by dissolving 0.5 mass% organic semiconductor and 0.2 mass% polystyrene in xylene was heated to 150°C, and the film was deposited by spin coating at 1000 rpm for 30 seconds, followed by post-baking at 120°C for 5 minutes. Finally, the semiconductor layer was patterned by wiping each electrode pad. A microscopic image of the completed OTFT is shown in Figure 13. Figure 15 shows the transfer characteristics and bias stress test results of the fabricated OTFT (channel length L=50μm, channel width W=500μm). The transfer characteristics were acquired with a source / drain voltage Vds=-2V. For the bias stress test, a bias voltage Vg=-20V was applied between the source and gate, and the characteristic changes were acquired after 1 second, 10 seconds, 100 seconds, and 1000 seconds of application. Figure 10 shows the threshold voltage shift amount with respect to application time. In this embodiment, a threshold voltage shift of 0.67V was observed after 1000 seconds of application in the gate insulating film.

[0074] (Comparative Example 1) PVCi was dissolved in cyclopentanone at a concentration of 10% by mass to prepare the composition for this comparative example.

[0075] [Fabrication and evaluation of organic insulating films] The composition of this comparative example was used instead of the composition of Example 1, and the resulting organic insulating film was developed with PGMEA. Except for these differences, the organic insulating film was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0076] [Manufacturing and evaluation of organic thin-film transistors] As Comparative Example 1, in the OTFT fabrication process of Example 1 described above, PVCi was used as the gate insulating film. PVCi was dissolved in cyclopentanone at a concentration of 10% by mass, and the film was deposited by spin coating at 2000 rpm for 60 seconds, followed by pre-baking at 80°C for 20 minutes. Next, it was thoroughly cured using a low-pressure mercury lamp with a photomask. After that, it was immersed in cyclopentanone at room temperature (25°C) to open only the gate electrode pad portion. Then, it was post-baked at 150°C for 1 hour. Figure 16 shows the transfer characteristics and bias stress test results of the fabricated OTFT (channel length L=50 μm, channel width W=500 μm). The transfer characteristics were acquired with a source / drain voltage Vds=-2V. For the bias stress test, a bias voltage Vg=-20V was applied between the source and gate, and the characteristic changes were acquired after 1 second, 10 seconds, 100 seconds, and 1000 seconds of application. Figure 9 shows the threshold voltage shift amount with respect to application time. For PVCi, a threshold voltage shift of 0.74V was observed after 1000 seconds of application.

[0077] [Table 1]

[0078] [Table 2]

[0079] The meanings of the symbols in the table are as follows: PVCi: Polyvinyl cinnamate CH: Calcon MC: Methoxychalcone PMC: Poly(4-methoxychalcone) CPN: Cyclopentanone PGMEA: Propylene glycol 1-monomethyl ether 2-acetate [Explanation of symbols]

[0080] 1, 11: Organic semiconductor layer 2, 12, 22: Circuit board 3, 13, 33: Gate 4, 14: Gate insulating layer 5, 15, 35: Source electrodes 6, 16, 36: Drain electrodes 22: Circuit board 23: Electrode 24: Insulating layer

Claims

1. Chalcone compounds and, Polyvinyl cinnamate and A photosensitive organic insulating material composition containing [the specified element].

2. The photosensitive organic insulating material composition according to claim 1, wherein the chalcone compound is at least one selected from the group consisting of chalcone and methoxychalcone.

3. The photosensitive organic insulating material composition according to claim 1 or 2, wherein the ratio of the total mass of the chalcone compounds to the mass of the polyvinyl cinnamate is 0.01 to 1.

4. The photosensitive organic insulating material composition according to claim 1 or 2, wherein the total amount of the chalcone compound and the polyvinyl cinnamate is 10% to 30% by mass, based on 100% by mass of the total amount of the photosensitive organic insulating material composition.

5. The photosensitive organic insulating material composition according to claim 1 or 2, wherein the total amount of the chalcone compounds is 0.1% to 15% by mass, based on 100% by mass of the total amount of the photosensitive organic insulating material composition.

6. A photosensitive organic insulating material composition according to claim 1 or 2, having an absorption spectrum peak in the wavelength range of 300 to 370 nm.

7. An insulating film which is a photocured product of the photosensitive organic insulating material composition according to claim 1 or 2.

8. A gate insulating film which is a photocured product of the photosensitive organic insulating material composition according to claim 1 or 2.

9. A transistor having the gate insulating film according to claim 8.

10. An electronic device having the transistor described in claim 9.

11. A step of applying the photosensitive organic insulating material composition according to claim 1 or 2 to a substrate, A method for producing a gate insulating film, comprising the step of curing the photosensitive organic insulating material composition by exposure to form a gate insulating film.

12. A method for manufacturing a transistor having a gate insulating film, A method for manufacturing a transistor, comprising the step of forming the gate insulating film by the method for manufacturing the gate insulating film described in claim 11.

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