TWI573194B - Insulation film for semiconductor and organic film transister using the same - Google Patents

Description

Insulating film for semiconductor and organic thin film transistor using same

The present invention relates to an insulating film for active energy ray-hardening semiconductor for an insulating film and a method for producing an organic thin film transistor using the same.

In recent years, in place of the tantalum film transistor manufactured in the previous niobium process, research and development of a printed organic transistor by a wet process, which is lightweight, flexible, and excellent in fastness and can be expected to be inexpensive, has been actively researched and developed. . The insulating film in the functional layer of the printed organic transistor is one of the most important constituent elements. As an insulating material which can be applied in a wet process and which has the same performance as an inorganic-containing insulating film used in the prior art process, a polysilsesquioxane compound which is an organic-inorganic hybrid material has been attracting attention.

It is known that a monomer containing a (meth) acrylonitrile group is mixed with a non-reactive polysesquioxane, and this is applied to a support, and an active energy ray is irradiated to form an insulating film (Patent Document) 1); or an active energy ray-curable composition comprising a sesquioxane having a (meth) acrylonitrile group, a methacrylate oligomer of (meth) acrylate, and a monofunctional (meth) acrylate (Patent Document 2). Also known as: package An active energy ray-curable composition of an acrylate containing a sesquioxane having a (meth) acrylonitrile group or tris(2-hydroxyethyl) isocyanurate (Non-Patent Document 1).

However, although the ink described in Patent Document 1 has an advantage of obtaining an insulating film at a low temperature for a short period of time, it is substantially active in a polysilsesquioxane which does not have crosslinkability by an active energy ray. When the energy ray-polymerizable (meth) acrylate-based compound is mixed, the insulating film obtained therefrom captures the poly-sesquioxane molecule in a dispersed manner in the polymer network structure of the active energy ray-polymerizable compound. It is an insulating film in a dispersed state.

The insulating film has the greatest influence on the characteristics of the thin film transistor (TFT), but the insulating film obtained by the ink of Patent Document 1 is due to the polysilsesquioxane molecule and the above polymer molecule. There is no covalent bond between them, so the excellent characteristics inherent in polysilsesquioxanes are not fully utilized. For example, there are inherent disadvantages in that only organic substances having poor field-effect mobility and ON/OFF ratio can be obtained. Thin film transistor.

The cured product of the composition described in Patent Document 2 has a covalent bond between the polysilsesquioxane molecule and the above polymer molecule, but does not mention any application in the insulating film for an organic semiconductor, and No surface repellency of the crosslinked cured product was found.

The cured product of the composition described in Non-Patent Document 1 cannot be used as an insulating film, and a polymer film of a difunctional (meth) acrylate having a cyclic structure is used as a premise for application to an organic thin film transistor. The field effect mobility and ON/OFF ratio are still not met.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2006-253510

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2008-38117

[Non-patent literature]

[Non-Patent Document 1] East Asia Synthetic Group Research Annual Report "Trend" (TREND) 2011 No. 14 Page 16 ~ Page 19

That is, the technical problem to be solved by the present invention is to provide an insulating film which is cured by an active energy ray, which can exhibit a high field-effect mobility, an ON/OFF ratio, and a small variation at a constant break. A threshold voltage (Vth) and an organic transistor that is excellent in practical performance.

The inventors of the present invention have intensively studied in view of the above-described practical application, and as a result, found that in a sesquioxane compound having active energy ray polymerity, a compound containing a specific active energy ray polymerizable double bond is used in combination, and these materials are used. A film having a water contact angle of 85° to 115° is formed by polymerization of an active energy ray to form a highly practical thin film transistor which has an organic film in addition to excellent film insulation and solvent resistance. The excellent field effect mobility and ON/OFF ratio of the gate insulating film for a thin film transistor are small, and the fluctuation of the threshold voltage (Vth) at the time of the normal break is small, and the characteristic stability is excellent, and the present invention has been completed.

That is, the present invention has the following constitution.

An insulating film for a semiconductor which hardens an active energy ray by an active energy ray The active energy ray-curable ink has a sesquioxane compound (A) having an active energy ray polymerizable group and a crosslinking promoting compound having two or more active energy ray polymerizable groups (B). The insulating film for a semiconductor is characterized in that the film thickness is in the range of 0.1 μm to 5 μm, and the surface of the film has a water contact angle of 85° to 115°; 2. The semiconductor insulation as described in 1. a film wherein the active energy ray-polymerizable group of the sesquioxane compound (A) having an active energy ray polymerizable group is a (meth) acrylonitrile group or an oxetanyl group; 3. such as 1. 2. The insulating film for a semiconductor, wherein the crosslinking promoting compound (B) having two or more active energy ray polymerizable groups is a compound having three to six (meth) acryl fluorenyl groups, or a cis-butene The insulating film for a semiconductor according to any one of claims 1 to 3, wherein the active energy ray-curable ink contains an active energy ray-polymerizable fluorine-based surfactant; 5. An organic film The insulating film for a semiconductor according to any one of 1. to 4.

The insulating film of the present invention can be used as a gate insulating film, an interlayer insulating film, a protective film, or the like of a thin film transistor. When the insulating film of the present invention is used as a gate insulating film of an organic transistor such as a TFT, it is possible to form a threshold voltage having excellent field-effect mobility and ON/OFF ratio and having a small off-time variation. High organic transistors.

In addition, the transistor of the present invention is provided by ultraviolet (UV), An active energy ray such as an electron beam (EB) or visible light is used to substantially use a cross-linked insulating film under conditions of no heating/heating time, so that there is no thermal damage to the film substrate or the like, and poly terephthalic acid can be used. An inexpensive film such as polyethylene terephthalate (PET) can easily form an organic TFT excellent in flexibility, high performance, and stability with a short production tact.

Hereinafter, the present invention will be described in detail.

The insulating film of the present invention is an insulating film for a semiconductor obtained by crosslinking and polymerizing an active energy ray-curable ink by an active energy ray-curable ink which has an active energy ray-polymerizable group of a sesquiterpene oxide compound ( A) and a crosslinking promoting compound (B) having two or more active energy ray polymerizable groups as an essential component, and the insulating film for a semiconductor is characterized in that a water contact angle of the surface of the film is 85 to 115 .

The sesquioxane is a trifunctional polyoxyalkylene represented by the unit composition formula (RSiO _3/2 )n, and it is well known that R is a methyl group and/or a phenyl group. Polyoxanes, so-called anthrones are represented by the unit composition formula R ₂ SiO, cerium oxide is also represented by SiO ₂ , and sesquioxanes are clearly distinguished from these, and sesquiterpene is present in The middle of anthrone and cerium oxide.

As the sesquiterpene oxide structure, a random structure, a completely cage structure, a ladder type structure, an incomplete cage type structure, and the like are known. Sesquiterpene alkoxylation The compound is not limited to these structures, and may be a single substance of these structures, a mixture of the compounds, or a compound having a structure in which a plurality of these structures are linked.

The sesquioxane compound (A) having an active energy ray polymerizable group used in the formation of the insulating film of the present invention may have a sesquiterpene oxide structure as a main skeleton, for example, an anthrone may be contained in the same molecule. structure. As the fluorenone structure, a dimethyloxane structure is preferable in terms of lowering the surface energy of the cured product and obtaining a liquid-repellent surface. Further, the sesquiterpene oxide compound is characterized by having a so-called active energy ray functional group which directly and indirectly forms a crosslinked structure by an active energy ray such as UV, EB or xenon light.

Examples of the functional group include, in addition to a (meth) acryl fluorenyl group, an oxetanyl group, an epoxy group, a thiol group, and a maleimide group, a methylene group or an ethylidene group. An alkyl group, an isocyanate group, a hydroxyl group, an alkoxyalkyl group, and the like. The sesquiterpoxy oxane compound having these functional groups can be used as a monomer, and can be a mixture of sesquiterpoxy oxane compounds having different functional groups, and can have different functional groups in the same molecule. Happening. Among them, a sesquioxane having a (meth) acrylonitrile group or an oxetanyl group as a functional group is preferred because it has excellent storage stability and excellent crosslinkability by irradiation with an active energy ray.

As the sesquioxane compound containing a (meth) acrylonitrile group, for example, the MAC grade of the SQ series of East Asia Synthetic Co., Ltd. or the AC grade can be used. The MAC grade is a sesquioxane compound containing a methacryl fluorenyl group, and specific examples thereof include MAC-SQ TM-100, MAC-SQ SI-20, and MAC-SQ HDM. The AC grade is a sesquiterpene oxide compound containing an acrylonitrile group, and specific examples thereof include AC-SQ TA-100 and AC-SQ SI-20.

Further, as the sesquioxane compound having an oxetanyl group as a functional group, for example, an OX grade of the SQ series of East Asia Synthetic Co., Ltd. can be used. Specifically, for example, OX-SQ SI-20, OX-SQ ME-20, OX-SQ HDX, or the like can be mentioned.

As a synthesis method of sesquiterpene oxide, a usual method can be used. For example, various methods such as Brown et al., J. Am. Chem. Soc., 1965, 87, 4313, or U.S. Patent No. 5,942,638 are mentioned.

The number average molecular weight of sesquiterpene oxide can be measured in terms of polystyrene measured by a gel permeation chromatography (GPC) method.

The analysis of the molecular structure of sesquiterpene oxide can be carried out by the following method: Nuclear Magnetic Resonance (NMR): Vogt et al., Inorgana. Chem. ), 189 (1963)), infrared absorption spectroscopy, X-ray structural analysis (Larsson et al., Alkiv Kemi, 16, 209 (1960)), mass spectrometry. Most of the sesquioxanes have a property of being soluble in a solvent, and the molecular weight by GPC can also be easily measured. Further, in the measurement method of the identification of the molecular structure, focusing on the hydrogen atoms ⁽¹ H) or silicon atom ⁽²⁹ Si) nuclear magnetic resonance spectroscopy (NMR method) is an extremely useful method. In particular, in the ²⁹ Si-NMR method, the number of oxygen atoms in the vicinity of the bond of the ruthenium atom can be quantified.

The mass ratio of sesquiterpene oxide in all the crosslinking components of the insulating film for a semiconductor of the present invention is preferably 30% to 80%, more preferably 40% to 70%. When the content of the sesquiterpene oxide structure is less than this range, the high frequency responsiveness of the insulating film is lowered and it is not preferable. Further, when the sesquiterpene oxide structure is more than the above range and the remaining crosslinking auxiliary component is 20% or less, the crosslinking density of the insulating film is insufficient, and the withstand voltage or solvent resistance of the film is lowered and the film is poor. .

The insulating film for a semiconductor of the present invention is characterized in that it is cross-linked and hardened by an active energy ray, but may be subjected to heat treatment such as pre-hardening or post-hardening if necessary. Further, the insulating film for a semiconductor of the present invention is a polymerized crosslinked film having a reaction rate of an active energy ray-polymerizable group of 85% or more, and is characterized by: toluene, xylene, chloroform, tetrahydrofuran (THF), acetone The solvent of an organic semiconductor such as a hydrocarbon such as mesitylene, chlorobenzene, dichlorobenzene, tetralin or anisole, or an aromatic or halogen-based organic semiconductor has substantial resistance. The reaction rate of the active energy ray polymerizable group can be easily confirmed by infrared (infrared, IR) measurement of the cured film.

The insulating film for a semiconductor of the present invention is characterized in that the active energy ray-curable ink is subjected to active energy ray polymerization, and the active energy ray-curable ink has a sesquioxane having an active energy ray-polymerizable group. The compound (A) and the crosslinking promoting compound (B) having two or more active energy ray polymerizable groups in the molecule are essential components.

In the sesquioxane compound (A) having an active energy ray polymerizable group, the crosslinking promoting compound (B) containing two or more active energy ray polymerizable groups in the molecule is mixed, and substantially only Hardened by active energy rays to form a strong crosslink The film structure of the semiconductor insulating film such as film formability and solvent resistance can be achieved.

Here, the active energy ray-polymerizable group of the crosslinking promoting compound (B) is characterized in that it has a so-called functional group which directly and indirectly forms a crosslinked structure by an active energy ray such as UV, EB or xenon light. Examples of the functional group include, in addition to a (meth) acryl fluorenyl group, an oxetanyl group, an epoxy group, a thiol group, and a maleimide group, a methylene group, an exoethyl group, and the like. A variety of alkyl, isocyanate, hydroxy, alkoxyalkyl and the like.

Whether or not the bifunctional or higher crosslinking promoting compound (B) having any one of the functional groups is used, and the reactivity with the active energy ray polymerizable group possessed by the sesquioxane compound used in the present invention, or the applied The type of the active energy ray or the like is appropriately selected.

When a sesquiterpoxy oxane compound (A) having a (meth) acrylonitrile group as a functional group is used, it is preferably used: (meth) acryl fluorenyl group, thiol group, maleic fluorene group The bifunctional or higher crosslinking of the amine group promotes the compound (B).

As the crosslinking promoting compound (B) having a (meth) acrylonitrile group, various epoxy acrylates, various urethane acrylates, various polyester acrylates, various polybutadienes can be used. Acrylates, various anthrone acrylates, and various amine resin acrylates and the like.

Examples of such a compound include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tetramethylene ether glycol di(meth)acrylate, and trimethylolpropane di ( Methyl) acrylate, trimethylolpropane or its alkylene oxide adduct (meth) acrylate having no cyclic structure and having three polymerizable double bonds, such as (meth) acrylate, tetrakis (meth) acrylate such as pentaerythritol or an alkylene oxide adduct thereof, etc. (meth) acrylate having a structure and containing four polymerizable double bonds, hexa (meth) acrylate such as dipentaerythritol or an alkylene oxide adduct thereof, having no cyclic structure and containing 6 polymerizable double bonds (meth) acrylate, acrylate of tris(2-hydroxyethyl) isocyanurate, such as an adduct of isophorone diisocyanate and hydroxyethyl (meth) acrylate (meth) acrylate having a structure and containing two or more polymerizable double bonds, a styrene compound such as styrene, α-methylstyrene or t-butyl styrene, such as methyl (meth) acrylate, (A) (meth)acrylate containing 2-ethylhexyl acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, benzyl (meth) acrylate, etc. a thiol-based compound, or a molecular weight such as polyether (meth) acrylate, polyester (meth) acrylate, poly(meth) acrylate urethane Over oligo (meth) acrylate of 1000.

A bifunctional or higher crosslinking promoting compound (B) having a thiol group as a functional group can be preferably used, for example, trimethylolethane tris(3-mercaptobutyrate) or trimethylolpropane tri 3-mercaptobutyrate), pentaerythritol tetrakis(3-mercaptobutyrate), 1,4 bis(3-mercaptobutoxy)butane, and the like.

When a sesquiterpene oxide compound having an oxetanyl group as a functional group is used in the formation of the insulating film of the present invention, a crosslinking promoting compound having an epoxy group or a vinyl ether group as a functional group can be preferably used. B). Examples of such a compound include bisphenol A type epoxy, bisphenol BA type epoxy, bisphenol F type epoxy, bisphenol AD type epoxy, phenol novolak type epoxy, and cresol novolac type ring. Oxygen, alicyclic Epoxy, fluorene-based epoxy, naphthalene-based epoxy, glycidyl ester compound, glycidylamine compound, heterocyclic epoxy, α-olefin epoxy, and the like. In particular, in terms of obtaining an excellent hardened film, an alicyclic epoxy compound can be preferably used.

As the alicyclic epoxy, for example, 3', 4'-epoxycyclohexanecarboxylic acid 3,4-epoxycyclohexylmethyl ester and its ε-caprolactone modified product, adipic acid can be preferably used. Bis-(3,4 epoxycyclohexylmethyl)ester, diepene limonene, and the like.

Further, it can be used in combination with these epoxy compounds: 1,4-bis{[(3-ether-3-oxetanyl)methoxymethyl]benzene, 3-ether-3-{[(3 An oxetane compound such as -ethyloxetane-3-yl)methoxy]methyl}oxetane, or diallyl phthalate, divinylethylene urea, A vinyl compound such as divinyl acetate or ethylene glycol, trimethylolpropane, various polyether polyols, various polyester polyols, and various caprolactone polyols.

Further, not only a compound having a single functional group having a cationic reactivity such as an epoxy group, an oxetanyl group or a vinyl group in one molecule but also a compound having a plurality of functional groups in the same molecule can be used. For example, a compound containing a vinyl ether group and an epoxy group in the same molecule, or a reactive compound containing a propylene ether group and an epoxy group, or the like can be used.

Further, if necessary, a reactive component having a radical crosslinking curing mechanism containing a (meth)acryl fluorenyl group and a cation crosslinking curing mechanism such as an oxetanyl group or an epoxy group may be mixed. The mixing can be obtained, for example, by mixing a compound containing an acrylonitrile group in a cationic hardening type composition containing an epoxy compound, an oxetane compound, a vinyl compound or the like as a reactive compound. A radically curable component, and a radical hardening initiator as needed. Examples of the propylene group-containing compound include a compound having a cationically polymerizable vinyl ether and a radically polymerizable acrylonitrile group in the same molecule, such as (meth)acrylic acid (vinyloxy) ether.

The sesquioxane compound containing a (meth) acrylonitrile group and/or an oxetanyl group of the present invention is used in combination with a maleimide compound as a crosslinking promoting compound (B). In particular, when a sesquioxane compound containing a (meth)acryl fluorenyl group is mixed with a maleimide compound, even when UV light is used as an active energy ray, the photopolymerization described later is not used in combination. As the initiator, an insulating film for a semiconductor which is crosslinked and hardened can be obtained. Meanwhile, the inventors of the present invention have found that when the present insulating film is applied to a gate insulating film of an organic transistor, the field effect mobility of the organic transistor is remarkably improved, and the present invention has been completed.

As such a maleimide compound (B), for example, 4,4'-diphenylmethanebis-synylene diimide, polyphenylmethane maleimide, and Phenyl bis-synylene diimide, bisphenol A diphenyl ether bis-s-butylene diimide, 4-methyl-1,3-phenylenebis-synylene diimide, 1, 6-bis-s-methyleneimine-(2,2,4-trimethyl)hexane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenyl Methane bis-butenylene diimide, maleic acid imide acrylate, and the like.

Among them, a maleimide compound represented by the formula (1) is preferably used.

Formula 1)

(In the formula, m and n each represent an integer of 1 to 5, respectively, but m+n is 6 or less.

R ₁₁ and R ₁₂ each independently represent a hydrocarbon bond selected from the group consisting of an alkylene group, a cycloalkylene group, and a cycloalkylalkylene group. G ₁ and G ₂ each independently represent an ester bond represented by -COO- or -OCO-. R ₂ represents at least one organic group selected from the group consisting of a linear alkyl group, a branched alkyl group, and a cycloalkyl group, which is selected from the group consisting of an ether bond and an ester bond. A (poly)ether linked chain or a (poly)ester linked chain having an average molecular weight of 100 to 100,000 linked by at least one bond.

More preferably, the maleimide compound represented by the formula (2) is used.

(wherein k represents an integer of 1 to 10, and n represents a value selected such that the number average molecular weight of the polyether chain is in the range of 100 to 100,000.)

The insulating film for a semiconductor of the present invention is characterized in that the surface of the film is liquid repellency. dial Liquidity can be replaced by the dynamic contact angle of water on the surface of the membrane. The insulating film of the present invention is characterized in that the dynamic contact angle of water on the surface of the film is from 85 to 115, more preferably from 90 to 110. By implementing such a liquid-repellent surface, when the insulating film of the present invention is applied to a gate insulating film of an organic transistor, excellent field-effect mobility and a high ON/OFF ratio can be formed, and a normally-off time can be formed. An organic transistor having a small variation in Vth and having stable electrical characteristics. The reason for this is considered to be that the surface of the present insulating film having a highly crosslinked sesquiterpene oxide structure and having high liquid repellency has an electrical property to be eliminated from the conductive channel formed at the interface between the insulating film and the semiconductor layer. The effect of the influence of water which causes adverse effects, and the formation of a molecular structure of an organic semiconductor suitable for exhibiting excellent crystal characteristics. Of course, this does not impose any limitation on the invention. If the dynamic contact angle of water of the film is more than 115°, it is difficult to uniformly form, for example, a semiconductor layer or the like formed on the film, which is not preferable.

The insulating film for a semiconductor of the present invention may contain various surface energy adjusting agents such as an anthrone-based surfactant and a fluorine-based surfactant in the film. By adding such a surface energy adjusting agent, the smoothness or liquid repellency of the film surface can be improved.

Among them, the fluorine-based surfactant is excellent in compatibility with an organic semiconductor, and is not only improved in film quality such as liquid repellency or surface smoothness, but also improved in electrical characteristics of the organic transistor.

A preferred fluorine-based surfactant is a linear perfluoroalkyl group, a perfluoroalkylene bond, or a perfluorooxyfluoroalkyl group or a perfluorooxyfluoroalkyl group in the molecule, and A nonionic fluorine-based surfactant having a fluoroalkyl chain length of C4 or more and less than 8.

Specifically, for example, (meth)acrylic acid containing a perfluoroalkyl group Copolymer or a copolymer of a perfluorooxyfluoroalkyl-containing (meth) acrylate with other copolymerizable monomers. Examples of the nonionic fluorine-based surfactant having a carbon chain length of C4 or more as a perfluoroalkyl group include MEGAFAC F-482, MEGAFAC F-470 (R-08), MEGAFAC F-472SF, and MEGAFAC R-30. MEGAFAC F-484, MEGAFAC F-486, MEGAFAC F-172D, MEGAFAC F178RM, MEGAFAC F555 (all of which are manufactured by Dainippon Ink and Chemicals, Inc.).

Among them, the active energy ray-polymerizable fluorine-based surfactant is preferably used. In the fluorine-based surfactant, a polymer film based on a copolymer of a fluorine-based surfactant having a polymerizable double bond is formed on the surface of the insulating film of the present invention on the surface of the insulating film of the present invention, so that a crystal can be formed and formed. The other constituent elements in contact with the insulating film, for example, are excellent in bleed resistance to the organic semiconductor layer, and have a transistor having stable electrical characteristics over time. Specific examples of the fluorine-based surfactant having a polymerizable double bond include MEGAFAC RS-75 and RS-72-K (all of which are manufactured by Dainippon Ink Co., Ltd.).

The surfactant is used in an amount of, for example, 100 parts by weight based on the total amount of the compound (A) and the compound (B), and may be used in an amount of from 0.01 part to 10 parts.

The active energy ray-curable compound ink forming the insulating film for a semiconductor of the present invention can be polymerized and cured by irradiation with an active energy ray to obtain an insulating polymer film. Here, as the active energy ray, in addition to ultraviolet rays and visible rays, high-activity energy rays such as electron beams and X-rays may be used.

When using UV or visible light for photohardening, add it as needed. A photopolymerization initiator for a polymer functional group.

In order to form the insulating film for an organic semiconductor of the present invention, a sesquioxane compound (A) having a (meth) acrylonitrile group as a functional group and/or a crosslinking promoting compound (B) is preferably used. A hydrogen abstraction type photopolymerization initiator and/or a disintegrating photopolymerization initiator.

Examples of the photopolymerization initiator include benzophenones, mischoketones, dibenzopyrans, thioxanthones, and anthraquinones. On the other hand, examples of the disintegrating photopolymerization initiator include benzoin ethers, 2,2-dialkoxy-2-phenylacetophenones, acetophenones, and mercaptodecyl esters. Classes, azo compounds, organic sulfur compounds, sulfhydryl phosphine oxides, diketones, and the like.

As a matter of course, a compound having a function as a photo-hydrogenation-type photopolymerization initiator in the same molecule and a compound exhibiting a function as a disintegrating photopolymerization initiator, for example, α-aminobenzene can be used. Ethyl ketones are used as photopolymerization initiators.

When a sesquiterpoxide compound (A) having an oxetanyl group or an epoxy group as a functional group and/or a crosslinking promoting compound (B) is used, a diarylsulfonium salt or a triarylsulfonium salt can be used. An aromatic diazonium salt, an iron arene complex, and the like. Among them, the diarylsulfonium salt is excellent in curability (hardening rate, hardening depth, and coating film adhesion), and can be cured not only by photocationic polymerization but also by thermal cationic polymerization. The counter anion in the case where the cationic polymerization initiator is an onium salt compound is preferably a hexafluoroantimonate anion, a hexafluorophosphate anion or a tetrakis(pentafluorophenyl)borate anion.

In addition, it can be added: phenothiazine derivatives, oxonone derivatives, thioxanthone A light sensitizer such as a derivative, an aminobenzoic acid derivative, a polycyclic aromatic compound such as ruthenium, phenanthrene or a ruthenium or a combination thereof, or a polyol compound which functions as a proton supply source can be added.

The amount of the photopolymerization initiator to be added may be 0.05% by mass or more and 6% by mass or less, and more preferably 0.2% by mass or more and 3% by mass or less based on the total amount of the active energy ray polymerizable compound.

The sesquioxane compound (A) and the crosslinking promoting compound (B) are dissolved and dissolved in a transparent state. When the viscosity is suitable for coating, an organic solvent may be used in combination as needed. Examples of such an organic solvent include pentane, hexane, heptane, octane, decane, dodecane, isopentane, isohexane, isooctane, cyclohexane, methylcyclohexane, and a ring. An aliphatic hydrocarbon-based organic solvent such as pentane, an aromatic hydrocarbon solvent such as benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, mesitylene, naphthalene, cyclohexylbenzene or diethylbenzene; Ester ester solvents such as methyl ester, formate ether, propyl formate, methyl acetate, acetate, isopropyl acetate, n-propyl acetate, isobutyl acetate, n-butyl acetate, methyl propionate, propionate, etc. Alcohol solvent such as methanol, ethanol, propanol, isopropanol, second butanol, third butanol, cyclohexanol or α-rosin, acetone, methyl ethyl ketone, methyl isobutyl ketone, ring a ketone solvent such as ketone, 2-hexanone, 2-heptanone, 2-octanone or tetrahydrofuran, a carbonate such as ethylene carbonate or propylene carbonate, diethylene glycol diethyl ether or diethylene glycol diethyl ether. , propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, diethylene glycol methyl ether acetate, Ethylene glycol ethyl ether acetate, diethylene glycol propyl ether acetate, diethylene glycol isopropyl ether acetate, diethylene glycol butyl ether acetate, diethylene glycol-third dibutyl ether acetate ester, Triethylene glycol methyl ether acetate, triethylene glycol diethyl ether acetate, triethylene glycol propyl ether acetate, triethylene glycol isopropyl ether acetate, triethylene glycol butyl ether acetate, a glycol ether solvent such as triethylene glycol-tert-butyl ether acetate, dipropylene glycol dimethyl ether or dipropylene glycol monobutyl ether, diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, dihexyl ether , ethyl vinyl ether, butyl vinyl ether, anisole, butyl phenyl ether, amyl phenyl ether, methoxy toluene, benzyl ether, diphenyl ether, dibenzyl ether, dioxane, furan, tetrahydrofuran, etc. The ether solvent, a guanamine solvent such as N,N-dimethylformamide, N,N-dimethylacetamide or N-methylpyrrolidone is not particularly limited. Further, these may be used alone or in combination of two or more.

The present invention further provides a thin film transistor characterized in that the gate insulating film of the thin film transistor is a sesquioxane compound (A) and a crosslinking promoting compound (B) by irradiating the active energy ray of the present invention. Crosslinked polymeric copolymer.

Examples of the substrate of the thin film transistor include germanium, glass, metal, and synthetic resin. However, in terms of light weight and excellent flexibility, the thickness is preferably 50 μm to 500 μm, preferably 80 μm. 300 μm synthetic resin film or sheet. Examples of such a synthetic resin film or sheet include polyester, polycarbonate, and polycondensation such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). A film or sheet of quinonemine, polyamine, polyolefin, polyphenylene ether, polyphenylene sulfide, or the like.

As a coating method for forming the gate insulating film of the present invention, for example, plate printing, gravure printing, gravure printing, flexographic printing, screen printing, reverse printing, roll coating, gravure coating, and slit can be used. Slot coating, bar coating, spin coating, and the like. When the insulating film is used as the gate insulating film, the coating film thickness may be adjusted so that the film thickness after curing is 0.1 μm to 2 μm, and the cured film thickness is preferably 0.3 μm to 2.0 μm. According to the present invention, a gate insulating film having excellent insulating properties, film quality, and excellent crystal characteristics can be realized by the film. In addition, when the insulating film is used as the protective film or the smoothing film of the TFT, the coating film thickness may be adjusted so that the film thickness after curing is 2 μm to 5 μm.

When the ink coating film of the present invention formed on a substrate is polymerized and crosslinked by irradiation with an active energy ray, various light sources that emit the above-described active energy ray can be used. In addition to the electron beam, examples of the ultraviolet light include a high pressure mercury lamp, an ultrahigh pressure mercury lamp, an ultraviolet fluorescent lamp, a germicidal lamp, a carbon arc lamp, a xenon lamp, a metal halide lamp, an ozone-free UV lamp, and a light emitting device. Diode, LED) and so on. Moreover, the xenon lamp can be used as a flash lamp to utilize light in its entire wavelength region. Active energy ray irradiation may also be carried out under an inert gas such as nitrogen or a rare gas as needed.

As the active energy ray, the electron beam can easily increase the crosslinking density of the insulating film, and is preferable.

The amount of ultraviolet irradiation is not particularly limited as long as it forms a colored film which is free from damage or yellowing of the support itself, and is preferably 30 mJ/cm ² to 1000 mJ/cm ² . The electron beam irradiation amount is also not particularly limited, but is preferably 10 kGy to 200 kGy, more preferably 10 kGy to 100 kGy.

As the thin film transistor, various layer constitutions are known. However, by using the insulating film of the present invention, a thin film transistor having a desired layer structure can be easily obtained regardless of the layer configuration. As a specific thin film transistor structure, for example, not only List: Bottom Gate Bottom Contact (BGBC) structure, Bottom Gate Top Contact (BGTC), TopGate Top Contact (TGTC) or top gate contact (Top Gate Bottom Contact, TGBC) A lateral transistor of the structure, and various vertical organic thin film transistors are exemplified.

In the method of producing the thin film transistor of the present invention, the insulating film of the present invention is not particularly limited as long as it is included in the constituent elements of the transistor, but it is preferable to improve not only the productivity of the organic thin film transistor but also the productivity of the organic thin film transistor. The insulating film and all the layers are continuously formed by the printing step.

In order to obtain a thin film transistor by printing, in addition to the active energy ray-curable compound ink described above, a semiconductor ink, a conductive ink, and an ink for forming a protective film as needed may be specifically used.

As a coating and printing method for forming a thin film transistor using these inks, for example, plate printing, gravure printing, gravure printing, flexographic printing, screen printing, reverse printing, roll coating, gravure coating can be used. Cloth, slit coating, bar coating, spin coating, and the like.

Further, as a method of modifying the transistor functional layer of these ink films formed by printing, a modification method suitable for the characteristics of the ink to be used and the formation of various thin film transistor structures can be selected. As a modification method of the conductive ink or the semiconductor ink, for example, oven heating drying, calcination, electron beam calcination, plasma calcination, high-frequency electromagnetic wave calcination, photocalcination using a xenon lamp or the like can be applied.

As a semiconductor material contained in the above semiconductor ink, it can be applied Machine, inorganic semiconductor materials. As the organic semiconductor material, for example, a low molecular organic semiconductor can be preferably used: a phthalocyanine derivative, a porphyrin derivative, a naphthyltetracarboxylic acid diimine derivative, a fullerene derivative, pentacene, and pentacene Isopropyl decyl (TIPS) pentacene, fluorinated pentacene and other derivatives, polytetracyclic aromatic compounds such as fluorinated tetraphenyl, benzalkonium, tetracene, anthracene, phenanthrene, coronene and the like Derivatives, oligothiophenes and derivatives thereof, thiazole derivatives, and various low molecular semiconductors such as thiophene, phenylene, vinyl, etc., such as benzothienobenzothiophene, TIPS pentacene, various One or more of the soluble acene-based compounds such as a pentabenzene precursor and these copolymers.

Further, as the polymer compound, a polythiophene-based polymer such as polythiophene, poly(3-hexylthiophene) (P3HT) or PQT-12, or a thiophene-thienothiophene copolymer such as B10TTT, PB12TTT or PB14TTT can be preferably used. An anthracene-based polymer such as F8T2, a phenylacetylene-based polymer such as phenylacetylene, or an arylamine-based polymer such as polytriarylamine.

In addition, in addition to these organic semiconductor materials, solution-soluble Si semiconductor precursors which can be modified into inorganic semiconductors by heat treatment or active energy ray irradiation such as EB or Xe flash lamps, and oxidation of IGZO, YGZO, ZnO, etc. can be applied. Precursors of semiconductors, etc.

The solvent which can be applied to the inkization of the organic and inorganic semiconductor materials can dissolve the semiconductor material by heating at a normal temperature or a slight temperature, and has a moderate volatility, and an organic semiconductor film can be formed after the solvent is volatilized, for example, Use: toluene, xylene, chloroform, chlorobenzene, cyclohexylbenzene, tetralin, N-methyl-2-pyrrolidine Organic solvents such as ketone, dimethyl hydrazine, isophorone, cyclobutyl hydrazine, tetrahydrofuran, mesitylene, anisole, benzonitrile, pentylbenzene, γ-butyrolactone, acetone, methyl ethyl ketone .

Further, in order to improve the characteristics of these inks, inorganic fine particles such as cerium oxide, titanium oxide, and zirconium oxide, or a polymer such as polystyrene or polymethyl methacrylate, or an anthrone or fluorine may be added to these solutions. It is a surface energy conditioner such as a surfactant. In particular, the fluorine-based surfactant in the crystalline semiconductor solution can not only improve the effect of improving the ink characteristics, but also can improve the characteristics of the semiconductor film formed by drying the ink, for example, the field-effect mobility, and the like. It can be preferably used.

As the conductive ink, for example, the following components may be contained as a conductive component in a suitable solvent: metal such as gold, silver, copper, nickel, zinc, aluminum, calcium, magnesium, iron, platinum, palladium, tin, chromium, or lead. An alloy of these metals such as particles, silver/palladium, or a thermally decomposable metal compound which forms a conductive metal by thermal differentiation at a relatively low temperature such as silver oxide, organic silver or organic gold, zinc oxide (ZnO), indium tin oxide (Indium Tin) Conductive metal oxide particles such as Oxide or ITO); and conductive polymers such as polyethylene dioxythiophene/polystyrene sulfonate (PSS) and polyaniline.

In particular, in order to form a conductive film having high conductivity at a lower temperature and for a shorter period of time, it is preferred to use an ink containing silver particles having a nano-average particle diameter and copper particles.

In the active energy ray-curable ink for an insulating film of the present invention, other insulating materials may be contained as needed. As such an insulating material, for example, it is applicable: Epoxy resin, polyimide resin, polyvinylpyrrolidone resin, polyvinyl alcohol resin, acrylonitrile resin, methacrylic resin, polyamide resin, polyvinylphenol resin, phenol resin, polyamine A quinone imine resin, a fluororesin, a melamine resin, a urethane resin, a polyester resin, an alkyd resin, or the like. In addition, these may be used singly or in combination of two or more kinds, and may be added as needed: low relative dielectric constant such as high relative dielectric constant particles such as alumina fine particles, cerium oxide fine particles, and cerium oxide fine particles or hollow cerium oxide fine particles. Body composition such as particles. The solvent to be used in the insulating ink is not limited, and an organic solvent as described above can be used. Further, an anthrone-based and fluorine-based various surfactants may be added to the insulating ink as needed.

In addition, the protective film ink that forms the protective film may be formed into a film excellent in barrier properties against light, oxygen, water, ions, or the like, by being subjected to a modification treatment by heating, light, electron beam, or the like. For example, a resin which forms an organic film such as a polyacrylonitrile-based resin, a polyvinyl alcohol-based resin, a nylon-based resin, a methacrylic resin, a polyvinylidene chloride-based resin, a fluorine-based resin, or an epoxy resin can be used. A decane compound, a decazane compound, an alkoxylated magnesium compound, an alkane oxide compound, or an alkoxylated oxime compound which forms an inorganic film by hydrolysis and, if necessary, heat treatment. The solvent to be used in the protective film ink is not limited, and an organic solvent as described above can be used. Further, an anthrone-based or fluorine-based surfactant may be added to the protective film ink as needed.

[Examples]

In order to explain the present embodiment in more detail, the examples and comparative examples are shown below, but these examples specifically show the description of the present embodiment and the obtained therefrom. The effects and the like are not limited to the embodiment. Further, each of the properties in the following examples and comparative examples was measured by the following method.

<Preparation of active energy ray-curable ink for insulating film of organic thin film transistor>

The insulating film of the organic thin film transistor is prepared by mixing and mixing an active energy ray-curable ink as in the following blending table.

In addition, the official names of the abbreviations in the above tables are as follows.

AC-SQ SI-20: a sesquioxane group represented by a unit composition formula (RSiO _3/2 )n having a (meth) acrylonitrile group as a functional group manufactured by East Asia Synthetic Co., Ltd., and a unit composition formula R ₂ Copolymerized compound of polyoxyalkylene represented by SiO

QX-SQ SI-20: a sesquioxane group represented by a unit composition formula (RSiO _3/2 )n having an oxetanyl group as a functional group manufactured by East Asia Synthetic Co., Ltd., and a unit composition formula R ₂ SiO Copolymerized compound of polyoxyalkylene shown

AC-SQ TA100: a sesquioxane compound represented by a unit composition formula (RSiO _3/2 )n having a (meth)acryl fluorenyl group as a functional group manufactured by Toagosei Co., Ltd.

OX-SQ-TX100: a sesquioxane compound represented by the unit composition formula (RSiO _3/2 )n of oxetanyl ketone manufactured by Toagosei Co., Ltd.

Bis-m-butylene diimide compound: formula (3)

(in equation (3), k=1, n=3)

M4004: Miramer 4004 (Ethylene Oxide, EO modified pentaerythritol tetraacrylate) manufactured by Toyo Chemical Co., Ltd.

EDG: diethylene glycol monomethyl ether

PGMAc: propylene glycol monomethyl ether acetate

TMP: Trimethylolpropane

Celloxide 2021P: 3,'4'-epoxycyclohexenecarboxylic acid 3,4-epoxycyclohexenyl methyl ester manufactured by Daicel Co., Ltd.

Karenz MT PE1: pentaerythritol tetrakis(3-mercaptobutyrate)

CPI-100P: Photocationic polymerization initiator manufactured by San-Apro Co., Ltd.

F-555: Surfactant made from Dainippon Ink

RS-72-K: Polymeric fluorine-based surfactant manufactured by Dainippon Ink Co., Ltd.

The dynamic contact angles of the water on the surface of the film of Examples 1 to 8 and Comparative Examples 1 to 3 were measured by hardening on a glass plate by a spin coater. The insulating ink before curing is applied to a thickness of 1 μm, and the solvent is dried and removed. When the polymerization is cured by electron beam irradiation, the irradiation is performed at 55 KGy, and when the polymerization is hardened by ultraviolet irradiation, high pressure is used. The Hg lamp was irradiated so as to be 260 mJ, and after the coating film was cured, the automatic contact angle meter DSA100 manufactured by KURUSS was used to drip on the produced hardened coating film at 30 μL/min. Water was added to measure the dynamic contact angle of the water droplets with the coating film.

The evaluation of the solvent resistance of the cured film was carried out by immersing acetone on a cotton swab and rubbing the same portion (length of about 10 mm) of the surface of the above-mentioned cured coating film until 25 reciprocations, and visually evaluating the occurrence of damage and traces. The evaluation was performed by setting the film having no damage trace in 25 reciprocations to ○, and the film having the damage trace within 25 times as ×.

Using the active energy ray-curable ink prepared in each of the above Examples and Comparative Examples, an element for measuring a transistor characteristic having a bottom gate bottom contact (BGBC) structure was produced in the following manner, and field-effect mobility was measured (cm). ² /Vs), ON/OFF ratio and threshold voltage (Vth). The results are shown in Tables 3 and 4.

(1) Formation of Gate Electrode: A Cr film is formed by sputtering on an alkali-free glass, and is etched into a desired pattern to form a gate electrode.

(2) Formation of gate insulating layer: The active energy ray-curable ink of each of the examples and the comparative examples described in Tables 1 and 2 was used as an insulating ink, and was applied to the above-described gate electrode by spin coating. On the glass substrate, after drying the solvent, the electron polymerization is hardened by ultraviolet light irradiation (UV) at a temperature of 60 KGy, and the ink is cured by active energy ray irradiation at 260 mJ. And an organic gate insulating layer having a film thickness of about 1 μm was formed.

(3) Formation of source and drain electrodes: a metal mask is used on the previously formed gate insulating layer, and a source including gold having a channel length of 20 μm and a channel width of 1 mm is formed by vacuum evaporation. Polar electrode pattern.

(4) An organic semiconductor ink is prepared by adding a surfactant prepared by Dainippon Ink Co., Ltd. to a 0.2% by mass solution of chloroform/xylene = 1/1 of polyhexylthiophene (P3HT) at a mass ratio of 0.01% by mass. . After the prepared organic semiconductor ink is formed on a smooth polydimethyl siloxane (PDMS) rubber by a bar coater, the active electrode and the ruthenium prepared before the coating film is pressed together The insulating layer of the electrode electrode was transferred onto the insulating layer, and a P3HT semiconductor layer having a film thickness of about 50 nm was formed on the insulating layer to form a BGBC type transistor. Next, the gate insulating film across the Cr gate electrode across the substrate is cut by a cutter knife in such a manner that the fabricated transistor elements are separated one by one on the respective independent Cr gate electrodes. And a semiconductor film to form separate unit members for measuring characteristics.

(5) The produced element was heat-treated at 150 ° C for about 10 minutes in a glove box, and the electrical characteristics of the element were measured using a semiconductor parameter measuring device (Kiithley's 4200). The method determines the field effect mobility, ON/OFF, and threshold voltage (Vth).

[Industrial availability]

The insulating film of the present invention can be used as a gate insulating film, an interlayer insulating film, a protective film, or the like of a thin film transistor. When the insulating film of the present invention is used as a gate insulating film of an organic transistor such as a TFT, a highly practical thin film transistor having high field-effect mobility and ON/OFF ratio, which is normally broken, can be formed. The fluctuation of the threshold voltage (Vth) is small, and the characteristic stability is excellent. Further, in the organic thin film transistor of the present invention, the use of the present invention exhibits high-performance crystal characteristics which are formed under conditions of no heating/heating time by an active energy ray such as UV, EB or visible light. Since the insulating film is contacted, the film substrate or the like on which the transistor is formed is not thermally damaged, and an inexpensive TFT such as PET can be used to form a flexible and highly reliable organic TFT by printing.

Claims (5)

An insulating film for a semiconductor obtained by cross-linking an active energy ray-curable ink by an active energy ray-curable ink, wherein the active energy ray-curable ink has a sesquioxane compound (A) having an active energy ray polymerizable group, And the crosslinking promoting compound (B) having two or more active energy ray polymerizable groups as an essential component, and the insulating film for a semiconductor is characterized in that the film thickness is in the range of 0.1 μm to 5 μm, and the water contact angle of the surface of the film It is 85°~115°. The insulating film for a semiconductor according to the first aspect of the invention, wherein the active energy ray-polymerizable group of the sesquioxane compound (A) having an active energy ray-polymerizable group is a (meth) acrylonitrile group, Or oxetanyl. The insulating film for a semiconductor according to the first or second aspect of the invention, wherein the crosslinking promoting compound (B) having two or more active energy ray polymerizable groups has three to six (methyl) groups. A propylene sulfhydryl compound or a maleimide compound. The insulating film for a semiconductor according to the first or second aspect of the invention, wherein the active energy ray-curable ink contains an active energy ray-polymerizable fluorine-based surfactant. An organic thin film transistor using the insulating film for a semiconductor according to any one of claims 1 to 4.