WO2006104068A1

WO2006104068A1 - Gate insulating film, organic transistor, method for manufacturing organic el display, and display

Info

Publication number: WO2006104068A1
Application number: PCT/JP2006/306073
Authority: WO
Inventors: Satoru Ohta
Original assignee: Pioneer Corporation
Priority date: 2005-03-28
Filing date: 2006-03-27
Publication date: 2006-10-05
Also published as: JP2008140786A

Abstract

Disclosed are a method for producing a gate insulating film of higher quality, a method for manufacturing an organic transistor comprising such a gate insulating film, a method for manufacturing an organic EL display, and a display. Specifically disclosed is an organic TFT (50) composed of a gate electrode (52), a gate insulating film (54), an organic semiconductor layer (56), a source electrode (58) and a drain electrode (60). The gate insulating film (54) is produced by applying a coating film (32), which is a material for forming the gate insulating film (54) and contains metal oxide particles (30) and a binder resin, and pressing the surface of the coating film (32) with a mold surface (42).

Description

Specification

Gate insulating film, organic transistor, organic EL display device manufacturing method, display

Technical field

The present invention relates to a method for manufacturing a gate insulating film, a method for manufacturing an organic transistor, a method for manufacturing an organic EL display device, and a display.

Background art

[0002] Organic transistors (hereinafter also referred to as organic TFTs (Thin Film Transistors)) are used in various applications. For example, organic TFTs are used as means for driving organic EL elements in organic EL display devices.

[0003] An organic EL device includes an electrode and an organic solid layer having at least a light-emitting layer between the electrodes, and injects electrons and holes into the light-emitting layer in the organic solid layer from both the electrode caps. It is an element that causes light emission in the organic light emitting layer, and can emit light with high brightness. In addition, since it uses the luminescence of organic compounds, it has a feature that it has a wide selection range of luminescent colors, and is expected as a light source and organic EL display device. In particular, the organic EL display device is generally expected as a flat panel display having a wide field of view, high contrast, high speed response and visibility, thin and light, and low power consumption.

[0004] An organic EL display device includes a pixel composed of an organic EL element including at least an anode, an organic light emitting layer, and a cathode, and an organic transistor that lights and controls the organic EL element. In organic EL display devices, a passive matrix system in which organic EL elements arranged in a matrix are driven externally by stripe-shaped scanning electrodes and data electrodes (signal electrodes) orthogonal to each other, and switching elements that also have organic transistor power for each pixel. And an active matrix system that includes a memory element and lights an organic EL element.

[0005] The active matrix method using organic transistors is generally superior to the active matrix method in which organic EL elements are driven by TFTs as compared to the V and passive matrix methods as the number of pixels increases. This is because the organic EL element of each pixel is lit only during the period when the scanning electrode is selected and the number of pixels increases. While the average luminance tends to decrease as the lighting period of the organic EL element becomes shorter, the active matrix method has a switching element and a memory element consisting of TFTs for each pixel, so the lighting of the organic EL element This is because the state is maintained, operation is possible with high brightness, high efficiency and long life, and there is a tendency to be advantageous for high definition and large display.

[0006] FIG. 1 shows an organic EL display device PA according to the background art. The organic EL display device PA covers the substrate 10, the barrier film 12 formed on the substrate 10, the organic EL element 100 and the organic TFT 50 formed on the barrier film 12, and the organic EL element 100 and the organic TFT 50. And a protective film (passivation film) 20.

In the organic TFT 50, the source electrode 58 and the drain electrode 60 are provided separately from each other, the organic semiconductor layer 56 is interposed between the source electrode 58 and the drain electrode 60, and the source is interposed via the gate insulating film 54. In this structure, the electrode 58, the drain electrode 60, and the gate electrode 52 disposed to face the organic semiconductor layer 56 are provided.

[0008] The performance of the organic TFT itself is often about the same as that of an amorphous silicon TFT! However, the performance of the organic TFT is about the on-Zoff ratio as long as the liquid crystal is used as an electrophoretic drive element. If there is a certain amount, low current drive is possible, so there are many problems such as ensuring insulation in the gate insulating film!

On the other hand, in order to drive an organic EL element, which is a self-luminous element, by an active matrix method, a transistor capable of supplying a large current is required to emit light. For this reason, a high dielectric constant material such as TaO is used as the gate insulating film, and it is induced.

twenty five

The development of organic TFTs that can supply large currents from many carriers is progressing! /

[0010] On the other hand, since there are various advantages, a method of forming a gate insulating film by a printing technique in which a coating liquid is applied to the surface of a material to be coated and solidified to form a gate insulating film has been studied. Yes. In order to form a gate dielectric film having a high relative dielectric constant by printing technology, the selection of a coating solution that becomes a gate dielectric film after solidification becomes a problem. As the coating liquid, since there is a general tendency that a high relative dielectric constant cannot be secured only with a binder resin, a coating liquid containing a high relative dielectric constant material having a higher relative dielectric constant than that of the binder resin is employed. . Patent Document 1 below discloses a method of simply dispersing metal oxide particles having a high relative dielectric constant in a binder resin. Can be mentioned.

Patent Document 1: Japanese Patent Laid-Open No. 2002-110999

Disclosure of the invention

Problems to be solved by the invention

[0011] However, when the gate insulating film is formed with a coating solution in which the metal oxide particles are simply dispersed in the binder resin as in Patent Document 1 described above, the metal oxide particles contained therein May cause problems. For example, metal oxide particles protruding from the surface of the gate insulating film may cause the surface of the gate insulating film to become rough and cause the performance of the organic TFT to deteriorate.

[0012] The present invention has been made in view of the above problems, and includes a method for producing a higher quality gate insulating film, a method for producing a high performance organic transistor, a method for producing an organic EL display device, and a display. The main purpose is to provide.

Means for solving the problem

[0013] The invention according to claim 1 is a method for producing a gate insulating film in an organic transistor, comprising metal oxide particles and a binder resin, which is a constituent material of the gate insulating film It includes an application step of applying a liquid and a surface pressing step of pressing the surface of the applied coating film.

[0014] The invention according to claim 6 is a method of manufacturing an organic transistor including a gate insulating film, and the gate insulating film is manufactured from the gate insulating film according to any one of claims 1 to 5. It is manufactured by a manufacturing method.

[0015] The invention described in claim 7 is a method of manufacturing an organic EL display device including an organic EL element including at least an anode, an organic light emitting layer, and a cathode, and an organic transistor for driving the organic EL element, The organic transistor is manufactured by the method for manufacturing an organic transistor according to claim 6.

The invention according to claim 8 is a display including the organic transistor manufactured by the method for manufacturing an organic transistor according to claim 6.

Brief Description of Drawings FIG. 1 is a schematic cross-sectional view of an organic EL display device in the prior art.

FIG. 2 is a schematic cross-sectional view of an organic TFT in the prior art.

FIG. 3 is a schematic cross-sectional view of an organic EL display device in the present embodiment.

FIG. 4 is a schematic enlarged view of the vicinity of the organic EL element of the organic EL display device in the present embodiment.

FIG. 5 is a schematic enlarged view of the vicinity of the organic TFT of the organic EL display device in the present embodiment.

FIG. 6 is a schematic explanatory view of a method for manufacturing a gate insulating film in the present embodiment.

FIG. 7 is a schematic explanatory view of a method for manufacturing a gate insulating film in the present embodiment.

FIG. 8 is a schematic explanatory view of a method for manufacturing a gate insulating film in the present embodiment.

FIG. 9 is a schematic explanatory view of a method for manufacturing a gate insulating film in the present embodiment.

FIG. 10 is a schematic explanatory view of a method for manufacturing a gate insulating film in the present embodiment.

FIG. 11 is a schematic explanatory view of a method for manufacturing a gate insulating film in the present embodiment. Explanation of symbols

[0018] 10 substrates

16 Organic solid layer

18 Cathode

20 Protective film

50 organic TFT

54 Gate insulation film

100 organic EL elements

PI, PA OLED display

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] "Improved gate insulating film manufacturing process"

The present inventor has improved the gate insulating film formed by applying a coating liquid in which metal oxide particles are dispersed in a binder resin in an organic TFT to make it a higher quality gate insulating film. .

[0020] As a result, the present inventor considered as an example that metal oxide grains in the binder resin In the gate insulating film formed by applying the coating liquid in which the particles are dispersed, the increase in the roughness of the surface of the gate insulating film due to the metal oxide particles is found to be a factor causing the performance deterioration. It came to. In other words, it can be seen that when the roughness increasing force S on the surface of the gate insulating film due to the metal oxide particles occurs, the rough surface is formed and the charge mobility is reduced compared to the flat surface. It started.

FIG. 2 shows an organic TFT 50 having a gate insulating film 54 formed by applying a coating liquid in which metal oxide particles 30 are dispersed in a binder resin. Hereinafter, the same reference numerals denote the same members, and the description thereof is omitted. Over the interface 40 between the gate insulating film 54 and the organic semiconductor layer 56, the metal oxide particles 30 protrude toward the organic semiconductor layer 56, the source electrode 58, and the drain electrode 60, and the metal oxide particles 30 It can be seen that 40 is roughened.

[0022] As a result of intensive studies on a method for preventing the interface 40 from being roughened by the metal oxide particles 30, the inventor has applied the coated film containing the metal oxide particles 30. It was found that the metal oxide particles 30 can be prevented from protruding from the interface 40 to the organic semiconductor layer 56 side by pressing the surface with an imprinting method or the like. As a result, it was possible to provide a higher-quality gate insulating film, and to find a high-performance organic transistor including the gate insulating film and a method for manufacturing an organic EL display device including the organic transistor and a display.

[0023] "Organic EL display device"

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present embodiment is only one form for carrying out the present invention, and the present invention is not limited to the present embodiment.

FIG. 3 shows a schematic cross-sectional view of the organic EL display device P 1 according to the present embodiment. The organic EL display device P1 covers the film substrate 10, the barrier film 12 formed on the substrate 10, the organic EL element 100 and the organic TFT 50 formed on the noria film 12, and the organic TFT 50. And a protective film 20 that protects the organic TFT 50 from the erosion power of external force.

[0025] <Substrate> The substrate 10 may be formed by appropriately selecting the constituent materials. For example, as the resin, thermoplastic resin, thermosetting resin, polycarbonate, polymethyl methacrylate, polyarylate, polyether sulfone, polysulfone, polyethylene terephthalate polyester, polypropylene, cellophane, polycarbonate, cellulose acetate, polyethylene, Poly (vinyl chloride), polystyrene, polyamide, polyimide, poly (vinyl chloride), polyvinyl alcohol, saponified ethylene butyl acetate copolymer, fluorine resin, salt rubber, ionomer, ethylene / acrylic acid copolymer Various substrates can be used as ethylene / acrylic acid ester copolymers. Further, a glass substrate or a glass / plastic bonded substrate may be used instead of a substrate mainly composed of resin, and an alkali barrier film or a gas noria film may be coated on the substrate surface. In addition, in the case of a top emission type in which light is emitted from the opposite side to these transparent substrates, the substrate 10 is not necessarily transparent.

[0026] <Barrier film>

The noria film 12 does not necessarily have to be formed. However, the formation of the noria film 12 is preferable because it can protect the erosion force from moisture or oxygen from the substrate side. When the barrier film 12 is formed, the material can be appropriately selected and used.

[0027] The noria film 12 may have a multilayer structure, a single layer structure, an inorganic film, or an organic film, but if an inorganic film is contained, moisture is contained. It is preferable because noria property from erosion due to oxygen and oxygen is improved.

[0028] As the inorganic film, for example, a nitride film, an oxide film, a carbon film, a silicon film, or the like can be used. More specifically, a silicon nitride film, a silicon oxide film, a silicon oxide film, or the like can be used. Examples include nitride films, diamond-like carbon (DLC) films, and amorphous carbon films. That is, nitrides such as SiN, A1N, and GaN, oxides such as SiO, Al 2 O, Ta 2 O, ZnO, and GeO

2 3 2 5

Oxynitrides such as SiON, carbonitrides such as SiCN, metal fluorine compounds, metal films, and the like.

[0029] Examples of the organic film include a furan film, a pyrrole film, a thiophene film, or a polyparaxylene film, an epoxy resin, an acrylic resin, a polyparaxylene, a fluorine-based molecule (perfluoroolefin, perfluoroolefin ether, tetrafluoroethylene). Fluoroethylene, chlorotrifanololethylene , Dichlorodifluoroethylene, etc.), metal alkoxides (CH OM, CH OM, etc.),

3 2 5

Polymerized films such as lyimide precursors and perylene compounds can be used.

[0030] The noria film 12 has a laminated structure having two or more kinds of material forces, an inorganic protective film, a silane coupling layer, a laminated structure made of a resin sealing film, a barrier layer made of an inorganic material cover, an organic material cover. Laminated structure that also has cover layer strength, Si-CXHY or other metal or compound of semiconductor and organic material, laminated structure of inorganic material, structure in which inorganic film and organic film are laminated alternately, Si on Si layer Examples thereof include a laminated structure such as a structure in which O or SiN is laminated.

2 3 4

[0031] <Organic EL device>

FIG. 4 shows an enlarged view of the vicinity of the organic EL element 100 of the organic EL display device P1. The organic EL element 100 is configured by laminating the barrier film 12 side force from the anode 14Z organic solid layer 16Z cathode 18 as well.

As the anode 14, a transparent electrode such as ITO (Indium tin oxide) may be used as long as it uses a layer having an energy level at which holes can be easily injected. In the case of the top emission type, a general electrode may be used instead of the transparent electrode.

[0033] A transparent conductive material such as ITO is formed to a thickness of, for example, 150 nm by sputtering or the like. Instead of ITO, an oxide zinc (ZnO) film, IZO (indium-zinc alloy) gold, copper iodide, or the like can be used instead.

The organic solid layer 16 includes a hole injection layer 162 / a hole transport layer 164 / a light emitting layer 166 / an electron transport layer 168 from the anode 14 side.

The hole injection layer 162 is a layer that is provided between the anode 14 and the light emitting layer 166 and promotes injection of holes from the anode 14. With the hole injection layer 162, the driving voltage of the organic EL element 100 can be lowered. Also, it plays a role such as stabilizing hole injection and extending the life of the element, and covering irregular surfaces such as protrusions formed on the surface of the anode 14 to reduce element defects. May be responsible for

The material of the hole injection layer 162 may be appropriately selected so that its ionization energy is between the work function of the anode 14 and the ion energy of the light emitting layer 166. For example, triphenylamine tetramer (TPTE), copper phthalocyanine, etc. can be used. [0037] The hole transport layer 164 is a layer provided between the hole injection layer 162 and the light emitting layer 166 to promote hole transport, and has a function of appropriately transporting holes to the light emitting layer 166. .

[0038] The material of the hole transport layer 164 may be appropriately selected so that the ionization energy is between the hole injection layer 162 and the light emitting layer 166. For example, TPD (a triphenylamine derivative) can be employed.

[0039] The light-emitting layer 166 is a layer that recombines the transported holes and the below-described transported electrons to emit fluorescence or phosphorescence. The material of the light-emitting layer 166 may be selected as appropriate so as to satisfy the properties corresponding to the above light-emitting modes. For example, tris (8-quinolinolato) aluminum complex (Alq), bis (benzoquinolinolato) beryllium complex (Be Bq), tri (dibenzoylmethyl) phenantorporin europium complex (Eu (DBM) 3 (Phen n )), Ditoluyl birubbe (DTVBi), poly (p-phenolene), and π-conjugated polymers such as polyalkylthiophene. For example, an aluminum quinolinol complex (Alq3) can be used to emit green light.

[0040] For example, in a phosphorescent device, when electrons and holes are injected into the phosphorescent layer 166 from the cathode 18 and the anode 14, respectively, and recombined there, the recombination energy is doped through the host material. When supplied to the material, this dopant emits phosphorescence. Here, under conditions where the injection current density is low, this phosphorescent organic EL device can emit red light due to the dopant. In addition, under conditions where the injection current density is high, the host material according to the present invention having a light emitting function also emits light, and an additive color of the emission color of the host material and the emission color of the dopant material is obtained. For example, when a compound that emits light blue is used, the dopant emits red light. Therefore, in this organic EL element, white light in which light blue and red are synthesized can be emitted to the outside.

[0041] The electron transport layer 168 is provided between the cathode 18 and the light emitting layer 166, and has a function of accelerating the injection of electrons from the cathode 18, and lowers the driving voltage of the organic EL element 100. In addition, the electron injection may be stabilized to extend the life of the device, the adhesion between the cathode 18 and the light emitting layer 166 may be enhanced, or the uniformity of the light emitting surface may be improved to reduce device defects.

The material of the electron transport layer 168 may be appropriately selected so as to be between the work function of the cathode 18 and the electron affinity of the light emitting layer 166. For example, the electron transport layer 168 is LiF (LiF (Thium), Li 0 (lithium oxide) and other thin films (for example, 0.5 nm) can be employed.

2

[0043] Each layer constituting the organic solid layer 16 is usually made of an organic material, and may be made of a low molecular weight organic material or a high molecular weight organic material. Organic functional layers with low molecular organic power are generally produced by dry processes (vacuum processes) such as vapor deposition. Organic functional layers made of high molecular organic materials are generally spin-coated, blade-coated, dipped, sprayed, and printed. Each can be formed by a wet process.

[0044] As an organic material used for each layer constituting the organic solid layer 16, for example, as a polymer material, PEDOT, polyarine, polyparaphenylene-biylene derivative, polythiophene derivative, polyparaphenylene derivative, polyalkylphenol, And polyacetylene derivatives.

In the present embodiment, the organic solid layer 16 is composed of the hole injection layer 162, the hole transport layer 164, the light emitting layer 166, and the electron transport layer 168, but is limited to this configuration. The light emitting layer 166 may be included at least, and it is not necessary.

[0046] For example, depending on the characteristics of the organic material used, etc., in addition to the single layer structure of the light emitting layer, the hole transport layer Z light emitting layer, the light emitting layer Z electron transport layer, etc., two layer structure, hole transport Layer Z light-emitting layer Z Three-layer structure of Z electron transport layer, and multilayer structure including a charge (hole, electron) injection layer, etc. can also be used.

Further, a hole blocking layer may be provided between the light emitting layer 166 and the electron transport layer 168 in the organic solid layer 16. Holes may pass through the light emitting layer 166 and reach the cathode 18. For example, when Alq3 or the like is used for the electron transport layer 168, when Alq3 emits light when holes flow into the electron transport layer or the holes cannot be trapped in the light emitting layer, the light emission efficiency is low. There is a possibility of lowering. Therefore, a hole blocking layer may be provided to prevent holes from flowing out from the light emitting layer 166 to the electron transporting layer 168.

For the cathode 18, a material having a small work function or electron affinity may be selected in order to improve the electron injection into the organic solid layer 16. For example, an alloy type (mixed metal) such as an Mg: Ag alloy or an Al: Li alloy can be suitably used. The cathode 18 can be formed by vacuum deposition of a metal material such as A1 or MgAg to a thickness of 150 nm, for example. [0049] <Organic transistor (organic TFT)>

FIG. 5 shows an enlarged view around the organic TFT 50 of the organic EL display device P1. The organic TFT 50 has a gate electrode 52 formed on the barrier film 12 from the side of the NOR film 12 and a gate insulating film 54 formed so as to cover the surface of the gate electrode 52. An organic semiconductor layer 56 is formed on the gate insulating film 54, a source electrode 58 is formed on the left edge side, and a drain electrode 60 is formed on the right edge side. Here, the drain electrode 60 is electrically connected to the anode 14 of the organic EL element 100. That is, in the organic TFT 50, the source electrode 58 and the drain electrode 60 are provided separately from each other, the organic semiconductor layer 56 is interposed between the source electrode 58 and the drain electrode 60, and the source electrode is interposed through the gate insulating film 54. 58, a drain electrode 60, and a gate electrode 52 arranged to face the organic semiconductor layer 56.

[0050] The gate electrode 52 may be any metal that can be anodized as a gate electrode material. A single substance such as Al, Mg, Ti, Nb, Zr, or an alloy thereof may be used, but the material is not limited thereto. No. The gate electrode only needs to have sufficient conductivity.For example, Pt, Au, W, Ru, Ir, Al, Sc, Ti, V, Mn, Fe, Co, Ni, Zn, Ga, Y, Zr, Nb, Mo, Tc, Rh, Pd, Ag, Cd, Ln, Sn, Ta, Re, Os, Tl, Pb, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho , Er, Tm, Yb, Lu, etc. In addition, organic conductive materials containing conjugated polymer compounds such as metal oxide particles such as ΙΤΟ and 、, polyaniline, polythiophene, and polypyrrole may be used.

The manufacturing method of the gate electrode 52 may be any general method for forming the wiring pattern of the gate electrode 52 on the substrate 10. Power that can be used for sputtering, CVD, etc. There is no particular limitation and an appropriate one may be used. For example, general thin film forming methods such as vacuum deposition, ion plating, sol-gel method, spin coating method, spray method, and CVD are also possible.

[0052] As will be described later, the gate insulating film 54 is formed by applying a coating liquid in which metal oxide particles are dispersed in a binder resin.

[0053] As the Noinder resin, a resin component serving as a binder of the coating solution can be appropriately selected and used, and is not particularly limited, but is not limited to olefin-based resin, acrylic resin, cellulose. Series, melamine series, polyester series, polyamide series, acrylic series For example, a resin such as a thermoplastic elastomer such as a resin, a styrene-based resin, a polyamide, an ethylene vinyl acetate copolymer, a vinyl chloride-acetic acid copolymer, or a styrene-butadiene rubber can be used. For example, a mixture of polyvinyl phenol and methylated melamine formaldehyde copolymer, polymethyl metatalylate, or insulating property may be used. Other examples include polyethylene, polyvinyl chloride, polyvinylidene fluoride, polycarbonate, polyphenylene sulfide, polyether ether ketone, polyether sulfone, polyimide, phenol novolac, polyamide, benzocyclobutene, polychloropyrene, polyester, Polyoxymethylene, polysulfone, epoxy resin, polybulal alcohol, etc., polyacrylate, etc. can be used.

[0054] It is preferable to select a suitable binder resin for solidifying the coating liquid. That is, based on the curing method of the coating solution, there are a photocuring method, a thermosetting method, an electron beam curing method, a cooling method, a drying method, etc., and it is preferable to select a binder resin suitable for these. .

[0055] When the photocuring method is used, it can be appropriately selected and used as the photocurable resin. For example, a preferred example is the use of ultraviolet curable resin as the main component.

[0056] When the electron beam curing method is used, the electron beam curable resin can be appropriately selected and used. The electron beam curing method is a method in which a coating solution is irradiated with an electron beam and cured. A preferred example is the use of electron beam curable resin as the main component.

[0057] These electron beam curable resins and photocurable resin resins have an energy quantum capable of polymerizing and cross-linking molecules of electromagnetic waves or charged particle beams, light such as ultraviolet rays, and ionizing radiation such as electron beams. A resin that can be cured by the above, and a composition obtained by appropriately mixing a polymer, an oligomer, and Z or a monomer having a polymerizable unsaturated bond or an epoxy group in the molecule is used. Examples of these compositions include urethane acrylate, polyester acrylate, epoxy acrylate, and other silicone silicates, polyester resins, unsaturated polyester resins, epoxy resins, phenol resins, and polyurethanes. Examples thereof include system fats.

[0058] When the thermosetting method is used, the thermosetting resin can be appropriately selected and used. . The thermosetting method is a method in which a coating solution is heated to be cured. A preferred example is the use of thermosetting resin as the main component.

[0059] Examples of thermosetting resins include polyurethane, phenol resin, melamine resin, urea resin, unsaturated polyester resin, diallyl phthalate resin, silicon resin, epoxy resin, and the like. Can do. For example, as an example of epoxy resin, bisphenol A type A epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, cyclic aliphatic Examples include epoxy resins, glycidyl ester resins, glycidylamine epoxy resins, heterocyclic epoxy resins, urethane-modified epoxy resins, brominated bisphenol-A type epoxy resins.

[0060] When the cooling method is used, a resin that is cured by cooling can be appropriately selected and used. The cooling method is a method in which the coating liquid is cooled and cured. The cooling method uses cooling heat such as the use of vaporization heat generated by blowing air or a decrease in ambient temperature, and naturally cools over time regardless of the cooling method. Both methods are included.

[0061] A preferred example is the use of thermoplastic resin as the main component. Examples of thermoplastic resin include polyethylene, polypropylene, polyisoprene, polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polybutadiene, styrene resin, impact polystyrene, acrylonitrile-styrene resin (AS resin), acrylonitrile. — Butadiene styrene resin (ABS resin), methyl methacrylate-butadiene styrene resin (MBS resin), methyl methacrylate / acrylonitrile / butadiene / styrene resin (MABS resin), acrylonitrile / acrylic rubber / styrene resin (AAS resin), poly (meth) acrylate, polycarbonate, modified polyphenylene ether (PPE), polyamide, polyphenylene sulfide, polyimide, polyether ether ketone, polysulfone, poly Over DOO, polyether ketone, polyether nitrile, polyether Chio polyether sulfone, polyether sulfone, Poribe lens imidazole, polycarbodiimide, polyamideimide, polyetherimide, liquid crystal polymers, composite plastics and the like.

[0062] When the drying method is used, it is possible to appropriately select and use a resin that is easily cured by drying. The drying method is a method for volatilizing volatile components in the coating solution, such as heating. It includes both a method of drying by means of applying volatile energy and a method of natural drying over time regardless of the heating means. A coating solution using a volatile solvent is preferred.

[0063] The binder resin is preferably a resin having a high relative dielectric constant. Examples of the organic polymer or oligomer material having a high relative dielectric constant include, for example, cyanoethyl cellulose (dielectric constant 16), cyanoethyl hydroxyethyl cellulose (dielectric constant 18), cyanoethyl hydroxypropyl cellulose (ratio). Dielectric constant 14), cyanoethyldihydroxypropylcellulose (dielectric constant 23), cyanoethyl amylose (dielectric constant 17), cyanoethyl starch (dielectric constant 17), cyanoethyldihydroxypropyl starch (dielectric constant 18) ), Cyanoethyl pullulan (dielectric constant 18), cyanoethyl dalicidol pullulan (dielectric constant 20), cyanopolybutyl alcohol (dielectric constant 20), cyanopolypolyhydroxymethylene (dielectric constant 10) ), Cyano sucrose (dielectric constant 25), cyanoethyl sorbitol (dielectric constant 40), etc. Containing polymer or oligomer, poly vinylidene (dielectric constant 11), fluorinated vinylidene-trifluoroethylene copolymer (55/45: relative dielectric constant 18, 75/25: relative dielectric constant 10) And the like.

[0064] The metal oxide particles contained in the coating solution are not particularly limited, and may be appropriately selected and used.

[0065] The metal oxide contained in the metal oxide particles can be appropriately selected and used, and is not particularly limited. For example, Ta O, TiO, ZrO, BaTiO, PbTiO, CaTiO, MgTi

2 5 2 2 3 3 3

O, BaZrO, PbZrO, SrZrO, CaZrO, LaTiO, LaZrO, BiTiO, LaPbTiO

3 3 3 3 3 3 3 3

, Yo, etc., or solid solutions thereof, more specifically barium strontium titanate

3 2 3

, Strontium titanate, barium titanate, lead titanate, calcium titanate, magnesium titanate, barium zirconate titanate, lead zirconate titanate, lead zirconate, barium zirconate, strontium zirconate, zirconate Calcium is mentioned. In addition, composite oxide particles such as lead lanthanum zirconate titanate, lead lanthanum titanate, bismuth titanate, lanthanum titanate, and barium magnesium fluoride, titanium dioxide, ditantalum pentoxide, yttrium trioxide, etc. Metal oxide particles. These metal oxide particles may be used alone or in combination. You can use any combination.

[0066] As the relative dielectric constant of metal oxide particles, the higher the relative dielectric constant such as TiO, the better

2

Physically, those having a relative dielectric constant of 10 or more are suitable. In this application, the relative permittivity is obtained by the relative permittivity measuring method according to ί and ISC6481.

[0067] The shape of the metal oxide particles is not particularly limited, and may be any shape such as an elliptical shape, a scale shape, a needle shape, a spherical shape, a flat plate shape, a needle shape, and an indefinite shape. In addition, when the average value of the major axis and the minor axis is taken as the particle size of the metal oxide particles, it is desirable to use an average particle size of 500 nm or less, and further, an average particle size of lOOnm or less. It is more desirable to use When the average particle size force is larger than OOnm, the dispersion of metal oxide particles in the gate insulating film 54 is not uniform, and as a result, the relative dielectric constant of the gate insulating film 54 is uniform, The surface smoothness of the film 54 may be impaired. The smaller the average particle size of the particles, the better the smoothness of the gate insulating film 54 and the uniformity of the relative dielectric constant. The rate may decrease. Therefore, it is desirable to use high relative dielectric constant inorganic compound particles having an average particle size of 5 nm or more. If you select and use as appropriate.

[0068] The metal oxide particles blended in the coating liquid is preferably 2 to 8 parts by weight with respect to 100 parts by weight of the coating liquid.

[0069] It is preferable that the gate insulating film 54 is in direct contact with the surface of the gate electrode 52. For example, another layer such as a channel generation semiconductor layer is formed between the gate insulating film 54 and the gate electrode 52. May be. The gate insulating film 54 may be in contact with the surface of at least one of the organic semiconductor layer 56, the source electrode 58, and the drain electrode 60, preferably the organic semiconductor layer 56.

[0070] The source electrode 58 and the drain electrode 60 may be made of a simple substance such as Al, Mg, Ti, Nb, Zr, or an alloy thereof, but is not limited thereto. The gate electrode only needs to have sufficient conductivity.For example, Pt ゝ Au, W, Ru, Ir, Al, Sc ゝ Ti, V, Mn, Fe ゝ Co, Ni ゝ Zn, Ga, Y, Zr, Nb, Mo, Tc, Rh, Pd, Ag, Cd, Ln, Sn, Ta, Re, Os, Tl, Pb, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, A single metal such as Er, Tm, Yb, or Lu, or a laminate or a compound thereof may be used. Also, metal oxide particles such as ιτο, ΙΖΟ

Conjugated polymer compounds such as polya-phosphorus, polythiophenes and polypyrroles Organic conductive materials may be used.

[0071] The source electrode 58 and the drain electrode 60 may be manufactured by a general method. A sputtering method, a CVD method, and the like can be mentioned, but an appropriate method may be used as long as it is not particularly limited. For example, general thin film forming methods such as vacuum deposition, ion plating, sol-gel method, spray method, spin coating method, CVD, lift-off, etc. are also possible.

[0072] The organic semiconductor 56 is not particularly limited as long as it is an organic material exhibiting semiconductor characteristics such as pentacene. For example, phthalocyanine derivatives, naphthalocyanine derivatives, azo compound derivatives, perylene derivatives, indigo Derivatives, quinacridone derivatives, polycyclic quinone derivatives such as anthraquinones, cyanine derivatives, fullerene derivatives, or indole, carbazole, oxazole, inoxazole, thiazole, imidazole, pyrazole, oxadiazole, pyrazoline Nitrogen-containing cyclic compound derivatives such as thiothiazole and triazole, hydrazine derivatives, triphenylamine derivatives, triphenylmethane derivatives, stilbenes, quinone compound derivatives such as anthraquinone diphenoquinone, anthracene, and bire Polycyclic aromatic compound derivatives such as polyethylene, phenanthrene, coronene, etc., whose structure is used in the main chain of polymers such as polyethylene chain, polysiloxane chain, polyether chain, polyester chain, polyamide chain, polyimide chain, etc. Or an aromatic conjugated polymer such as polyparaphenylene, an aliphatic conjugated polymer such as polyacetylene, or a heterocyclic having a polypinol or polythiophene ratio. Conjugated polymers, heteroatom-conjugated polymers such as polyarines and polyphenylene sulfide, poly (phenylene vinylene), poly (anilenylene vinylene), poly (cellene vinylene), etc. A carbon-based conjugated polymer such as a composite conjugated polymer having a structure in which structural units of the conjugated polymer are alternately bonded is used. Also, oligosilanes such as disila-lene carbon-based conjugated polymer structures such as polysilanes, disila-lenarylene polymers, (disila-lene) etylene polymers, and (disila-diylene) ethylene polymers. Polymers in which carbon and conjugated structures are alternately linked are used. In addition, polymer chains composed of inorganic elements such as phosphorus and nitrogen may be used, and polymers with aromatic ligands of polymer chains such as phthalocyanate polysiloxane, perylene tetracarboxylic acid Polyacrylo-, a polymer fused with perylenes such as Use ladder-type polymers obtained by heat-treating polyethylene derivatives having a cyano group such as tolyl, and composite materials in which organic compounds are inter-activated in the mouth bskite.

[0073] As a method for forming the organic semiconductor 56, a force such as a sputtering method or a CVD method may be used. An appropriate method may be used without being particularly limited. For example, general thin film forming methods such as vacuum deposition, ion plating, sol-gel method, spray method, spin coating method, and CVD are also possible.

[0074] <Protective film>

The protective film 20 does not necessarily need to be formed, but it is preferable because it can protect the erosion power due to moisture, oxygen, and the like. The protective film 20 may have a multilayer structure, a single-layer structure, an inorganic film, or an organic film, but if an inorganic film is included, the protective film 20 is caused by moisture or oxygen. This is preferable because the noriness from erosion is improved.

As the inorganic film, for example, a nitride film, an oxide film, a carbon film, a silicon film, or the like can be used. More specifically, a silicon nitride film, a silicon oxide film, a silicon oxide film, or the like can be used. Examples include nitride films, diamond-like carbon (DLC) films, and amorphous carbon films. That is, nitrides such as SiN, A1N, and GaN, oxides such as SiO, Al 2 O, Ta 2 O, ZnO, and GeO

2 3 2 5

[0076] Examples of the organic film include a furan film, a pyrrole film, a thiophene film, or a polyparaxylene film, an epoxy resin, an acrylic resin, a polyparaxylene, a fluorine-based molecule (perfluoroolefin, perfluoronole ether, tetrafluoroethylene). Fluoroethylene, chlorotrifluoroethylene, dichlorodifluoroethylene, etc.), metal alkoxides (CHOM, CHOM, etc.),

3 2 5

[0077] The protective film 20 has a laminated structure composed of two or more kinds of substances, an inorganic protective film, a silane coupling layer, a laminated structure composed of a resin sealing film, a barrier layer composed of an inorganic material cover, an organic material cover. Laminated structure that also has cover layer strength, Si-CXHY or other metal or compound of semiconductor and organic material, laminated structure of inorganic material, structure in which inorganic film and organic film are laminated alternately, Si on Si layer Examples thereof include a laminated structure such as a structure in which O or SiN is laminated. The nolia film 12 and the protective film 20 fill the surface irregularities of the pinhole formed by the organic film formed on the inorganic film and flatten the surface. It may also play a role in relieving the film stress of the inorganic film.

[0079] A method for manufacturing the protective film 20 includes a sputtering method, a CVD method, and the like, but is not particularly limited, and an appropriate one may be used as appropriate. For example, general thin film forming methods such as vacuum deposition, ion plating, sol-gel method, spray method, spin coating method, and CVD are also possible.

[0080] <Light emitting mode of organic EL display device>

The light emission mode of the organic EL display device P1 will be described.

When a voltage is applied between the gate electrode 52 and the source electrode 58, holes are generated at the interface 40 (region of about several nm) between the organic semiconductor 56 and the gate insulating film 54. After a hole is generated, when a voltage is applied between the source electrode 58 and the drain electrode 60, the hole can be transported. On the other hand, holes are not transported unless a voltage is applied between the gate electrode 52 and the source electrode 58. Thus, switching can be performed using the non-conducting state (the switch is off) and the conducting state (the switch is on).

Holes (holes) are supplied from the source electrode 58 to the drain electrode 60 through the gate insulating film 54. Holes are transferred to the anode 14 of the organic EL element 100 through the drain electrode 60.

In the organic EL element 100, holes are transported from the anode 14 to the hole injection layer 162 in the organic solid layer 16. The transported holes are injected into the hole transport layer 164. The holes injected into the hole transport layer 164 are transported to the light emitting layer 166.

Further, in the organic EL element 100, electrons are transported from the cathode 18 to the electron transport layer 168 in the organic solid layer 16. The transported electrons are transported to the light emitting layer 166.

[0085] The transported holes and electrons recombine in the light emitting layer 166. During recombination, EL emits light due to the energy generated. This light emission is led out to the outside through the hole transport layer 164, the hole injection layer 162, the anode 14, the noor film 12, and the substrate 10 in order, and the light emission can be visually recognized.

[0086] When A1 is used for the cathode 18, the interface between the cathode layer 18 and the electron transport layer 168 is used. Becomes a reflection surface, is reflected at this interface, proceeds to the anode 14 side, passes through the substrate 10, and is emitted to the outside. Therefore, when the organic EL element having the above configuration is used for a display or the like, the substrate 10 side becomes the display observation surface.

[0087] For example, when an organic EL panel is intended to realize a full-color display, for example, a method of manufacturing organic EL elements that emit RGB colors by painting (painting method), a white-colored monochromatic light-emitting organic A combination of an EL element and a color filter (color filter method), a combination of a single color emission organic EL element such as blue light emission or white emission and a color conversion layer (color conversion method), a single color organic EL element In addition, a method (photo bleaching method) for realizing a plurality of light emission by irradiating the organic light emitting layer with an electromagnetic wave or the like can be mentioned, but it is not particularly limited.

[0088] In the organic EL display device P1 of the present embodiment, the organic EL element 100 is driven by the high-performance organic TFT including the high-quality gate insulating film 54, so that a higher-performance organic EL display device is provided. Can be provided.

In the above embodiment, an organic EL display device including an organic EL element and an organic TFT used in the organic EL display apparatus are shown. However, the present invention is not limited to this, and an organic transistor that drives other than the organic EL element may be used. This embodiment is applicable. That is, in the above embodiment, the organic EL element may be replaced with a driving element driven by another organic transistor, or the driving element such as the organic EL element may be omitted and the organic transistor alone may be used. Such an organic transistor can be applied to a display in general, for example, a liquid crystal display, an electrophoretic display, an electronic paper, and a toner display.

[0090] "Method for manufacturing organic EL display device"

A method for manufacturing the organic EL display device P1 shown in FIG. 2 will be described. A barrier film 12 is formed on the substrate 10, and an organic EL element and an organic TFT 50 are produced on the noria film 12. The drain electrode 60 of the organic TFT 50 and the anode 14 of the organic EL element 100 are fabricated so as to be in electrical contact with each other. Next, the protective film 20 is formed so as to cover the surfaces of the organic EL element 100 and the organic TFT 50, and the organic EL display device P1 is manufactured.

[0091] "Method for forming gate insulating film"

An example of a method for manufacturing the gate insulating film 54 of the organic TFT 50 will be described. Binder The oil is liquefied, the metal oxide 30 is put into the liquid binder resin and stirred, and the metal oxide 30 is dispersed in the solution to prepare the coating liquid 32.

[0092] The liquid method of the binder resin of the coating liquid 32 includes a method of liquefying the binder resin itself (solvent-free type coating liquid), and a method of using a solvent that dissolves the binder resin in addition to the binder resin. Can be mentioned.

[0093] The solvent is not particularly limited as long as it is appropriately selected and used. For example, acetonitrile is used.

[0094] As the solvent of the aqueous coating solution, a water-soluble organic solvent such as water or alcohol can be used. As the water, ordinary industrial water can be used. In addition to water, it can be prepared by using lower alcohols such as methanol, ethanol, isopropyl alcohol, N-propyl alcohol, glycols and esters thereof as water-soluble organic solvents that are equivalent to water and alcohol. . The lower alcohol, glycols and esters thereof are preferably contained in a proportion of about 5 to 20% by weight. These solvents such as lower alcohols, glycols and esters thereof are used for the purpose of improving the fluidity of ink, improving the wetness of the substrate sheet as the substrate, and adjusting the drying property. The type, amount used, etc. are determined according to the purpose.

[0095] The solvent of the solvent-based coating solution is not particularly limited. A water-insoluble organic solvent such as ether, ethylene glycol monomethinoreethenole, or a mixed solvent thereof is used.

As shown in FIG. 6, the prepared coating solution 32 is applied to the surface of the gate electrode 52 and the surface of the substrate 12 on which the gate electrode 52 is formed (application process).

[0097] The coating method of the coating liquid 32 is not particularly limited as long as it is appropriately selected and used. Ink jet, gravure coat, gravure reverse coat, comma coat, die coat, lip coat, cast coat , Ronole coat, Air knife coat, Mayer coat, Extrusion coat, Offset, UV curable offset, Flexo, Stencil, Silk, Power Ten-flow cord Wire no coat, Reno squirt coat, Gravure coat, Kiss cord Various printing methods such as blade coating, smooth coating, spray coating, pouring coating and brush coating can be applied.

[0098] After applying the coating liquid 32, as shown in FIG. 7, a mold 45 for surface flattening is prepared. The surface of the prepared coating film 32 (the coating state after coating of the coating solution is also expressed as “coating film”) and the surface is flat! /, The mold surface 42 comes to the position. Adjust the position of mode 45 as follows.

[0099] The mold 45 is not particularly limited as long as it is appropriately selected and used. For example, the mold surface may be a force metal using a mold made of Si, a metal oxide, diamond, or the like. For example, if light such as quartz and sapphire, especially ultraviolet light, is suitable, it can be readily irradiated with light, especially ultraviolet rays, when the curing process described below is performed by photocuring using a photocurable resin. It is.

[0100] The mold surface 42 is not particularly limited as long as the surface of the coating film 32 can be pressed, but it is preferable to have a shape corresponding to the interface of the gate insulating film 54. Further, the surface shape is not limited to being flat and may have surface irregularities that are not fine, but the flatter the surface, the better.

Next, the mold surface 42 is pushed down into the coating film 32 to obtain the state shown in FIG. In the state of FIG. 8, the surface of the coating film 32 is pressed by the mold surface 42 (surface pressing step). By the surface pressing step, the metal oxide 30 protruding on the surface (interface 40) of the coating film 32 is moved into the coating film 32. Due to this movement, the surface force of the coating film 32 can also prevent the metal oxide 30 from protruding and prevent the metal oxide 30 from protruding at the interface.

In this embodiment, the surface pressing step is performed when the coating film is in a liquid state, but the present invention is not limited to this. When the coating film is in a liquid state, the surface pressing step can be performed both in a solid state.

[0103] For example, even if it is in a solid state in the state of FIG. 6, it is sufficient that the surface is liquid before it is pressed by the mold surface 42. The metal oxide 30 that has been thermally melted by the surface 42 and protruded to the interface 40 can be moved into the coating film 32.

[0104] Next, while maintaining the state of FIG. 8, as shown in FIG. 4 is solidified (solidification step).

[0105] The solidification step is preferably, but not limited to, solidifying the entire desired portion 34 where the gate insulating film 54 is formed. As long as at least the surface of the pressed coating film is solidified, the surface force of the coating film 32 can also prevent the metal oxide 30 from protruding, and the metal oxide 30 from protruding at the interface.

[0106] This solidification is not particularly limited, but by a curing method combining at least one of a photocuring method such as an ultraviolet curing method, a heat curing method, an electron beam curing method, a cooling method, and a drying method. It is preferable from the viewpoint of solidifying when solidified.

[0107] For example, as a source of ultraviolet rays, an ultra-high pressure mercury lamp, a high-pressure mercury lamp, a low-pressure mercury lamp, a carbon arc, a black light lamp, a metal halide lamp, or the like can be used. The electron beam source is a Cockloft Walton type, a bandegraph type, a resonant transformer type, an insulated core transformer type, or an electron beam accelerator such as a linear type, a dynamitron type, a high frequency, etc. It can be irradiated with an electron beam.

[0108] The solidification step is not an essential step. In the surface pressing step, protrusion of the metal oxide 30 at the interface 40 can be prevented, and the solidification step can more suitably prevent such protrusion.

[0109] After solidification, the mold 45 is pulled up to the state shown in FIG.

[0110] After the state shown in FIG. 10 is reached, the coating film 32 is removed by washing with a solvent, flowing, or the like by an etching process such as oxygen-reactive ion etching (removal process), solidified and washed! The portion 34 that was not flown becomes the gate insulating film 54 shown in FIG. 11, and the gate insulating film 54 is formed.

[0111] An etching solvent may be appropriately selected and used. Aromatic organic solvents (such as alcohol and toluene), alcohol-based organic solvents (butanol, etc.), ester-based organic solvents (such as butyl acetate), and ether-based organic solvents (such as tetrahydrofuran) that are good solvents for silicone ladder polymers ) And ketone organic solvents (such as methyl isobutyl ketone). Specific examples include aromatic organic solvents such as veratol, toluene, and phenetole, and other materials include diethylene glycol monomethylenoatenore, diethyleneglycolenomonotenenoreatenore, and diethyleneglycolenomonoenoate. Examples also include butyl ether, diethylene glycol dimethyl ether, tetralin, methyl isobutyl ketone, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethylformamide.

[0112] After the gate insulating film 54 is formed, the organic semiconductor layer 56, the source electrode 58, and the drain electrode 60 are formed by photolithography or the like to form the organic TFT 50.

[0113] In the organic TFT according to the present embodiment, the particles are dispersed in this way, the relative permittivity is large, and the metal oxide particles that cause the surface roughness to deteriorate are prevented from protruding to the surface. It is possible to provide high-performance organic TFTs with high charge mobility because they have a gate insulating film that stops!

[0114] If the pressing step and the solidifying step are performed, the gate insulating film of the organic TFT can be more easily patterned.

Claims

The scope of the claims

[1] A method of manufacturing a gate insulating film in an organic transistor,

A coating step that includes a metal oxide particle and a binder resin, and a coating solution that is a constituent material of the gate insulating film;

A surface pressing step of pressing the surface of the applied coating film.

[2] A method for manufacturing a gate insulating film according to claim 1,

A method for producing a gate insulating film, comprising at least a solidifying step of solidifying the surface of the pressed coating film.

[3] The method for producing a gate insulating film according to claim 2,

The solidification is a method for manufacturing a gate insulating film which is solidified by at least one of a photocuring method, a heat curing method, an electron beam curing method, a cooling method, and a drying method.

[4] The method for manufacturing a gate insulating film according to any one of claims 1 to 3,

A method for manufacturing a gate insulating film, comprising: a removing step of removing a non-solidified coating film after the solidification.

[5] The method for manufacturing a gate insulating film according to any one of claims 1 to 4,

A method for producing a gate insulating film, wherein the metal oxide particles have a relative dielectric constant of 10 or more.

[6] A method of manufacturing an organic transistor including a gate insulating film,

6. The method for manufacturing an organic transistor, wherein the gate insulating film is manufactured by the method for manufacturing a gate insulating film according to claim 1.

[7] A method of manufacturing an organic EL display device including an organic EL element including at least an anode, an organic light emitting layer, and a cathode, and an organic transistor that drives the organic EL element,

7. The method of manufacturing an organic EL display device, wherein the organic transistor is manufactured by the method of manufacturing an organic transistor according to claim 6.

[8] A display including the organic transistor manufactured by the method for manufacturing an organic transistor according to [6].