WO2006104069A1

WO2006104069A1 - Gate insulating film, organic transistor, method for manufacturing organic el display, and display

Info

Publication number: WO2006104069A1
Application number: PCT/JP2006/306074
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: JPWO2006104069A1; JP4914828B2

Abstract

Disclosed are a method for manufacturing an organic transistor comprising a gate insulating film of higher quality, 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 organic TFT (50) is characterized in that the gate insulating film (54) is obtained by thermosetting a mixture containing a melamine derivative and a mixed polymer represented by the chemical formula below wherein a cyanoethyl group and a hydroxyl group coexist.

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

Organic thin film transistors (hereinafter also referred to as organic TFTs (Thin Film Transistors)) are used in various applications. For example, organic TFTs have been studied as a 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 such as 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 high dielectric constant gate insulating film by printing technology, the selection of a coating film that becomes a gate insulating film after solidification becomes a problem. As the coating film, since the binder resin alone generally does not tend to have a high relative dielectric constant, a coating film containing a high relative dielectric constant material having a higher relative dielectric constant than that of the binder resin is employed. Patent Document 1 listed below includes a method of simply dispersing metal oxide particles having a high relative dielectric constant in a binder resin. It is.

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] Therefore, it is conceivable to use a polymer having a cyano group having a high relative dielectric constant alone or in a mixture with other polymers.

However, when a polymer having a cyanoethyl group is used alone, an etching solvent or a coating type organic semiconductor used in a transistor manufacturing process such as photolithography or etching is used. May have a problem with solvent resistance.

[0014] When a polymer having a cyanoethyl group is mixed with another curable polymer, the solvent resistance is improved, but phase separation with poor compatibility may occur. In some cases, a high-quality gate insulating film cannot be provided.

[0015] The present invention has been made in view of the above problems, and a method for producing a higher quality gate insulating film, a method for producing a higher performance organic transistor, a method for producing an organic EL display device, a display, The main purpose is to provide.

Means for solving the problem

The invention according to claim 1 is a method for manufacturing a gate insulating film in an organic transistor, which is formed by thermosetting a mixture containing a mixed polymer in which cyanoethyl groups and hydroxyl groups are mixed and a melamine derivative. Including the step of:

The invention described in claim 3 is a method for manufacturing an organic transistor including a gate insulating film, and the gate insulating film is manufactured by the method for manufacturing a gate insulating film according to claim 1 or 2. The manufacturing method of the organic transistor which becomes.

[0018] The invention of claim 4 is an organic EL element comprising at least an anode, an organic light emitting layer, and a cathode. A method of manufacturing an organic EL display device including an element and an organic transistor that drives the organic EL element, wherein the organic transistor is manufactured by the method of manufacturing an organic transistor according to claim 3. To do.

The invention described in claim 5 is a display including the organic transistor manufactured by the method for manufacturing an organic transistor according to claim 3.

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. Explanation of symbols

[0021] 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

[0022] "Improved gate insulating film manufacturing process"

The inventor mixed a polymer having a cyanoethyl group with another polymer. The gate insulating film to be fabricated was examined. As described above, cyanobacterized resin may cause phase separation with poor compatibility with the solvent, and may lead to deterioration of the gate insulating film. In addition, polymers having cyanoethyl groups may be affected by solvents that have poor solvent resistance, such as etching solvents or coating organic semiconductors, leading to deterioration of the gate insulating film.

The present inventor has come to consider using a crosslinking reaction in order to improve the compatibility of cyanobacterized resin. For example, polybutane alcohol (PVA: chemical formula (1) below), polybutanol (PVP: chemical formula (2) below), polyphenol alcohol and! /, Tuna resin are melamine derivatives (chemical formula (3) below: One example is melamine (formaldehyde resin), which is crosslinked by heat and thermally cured, so that the compatibility with these resins is good. However, since it is difficult to secure a sufficient dielectric constant with a resin such as polybutanol or polyphenol alcohol, it is conceivable to use a polymer having a cyano group instead.

[0023] [Chemical 1]

[0024] [Chemical 2]

[0025] [Chemical 3]

(3) However, as described above, the melamine derivative crosslinks with polyphenolphenol resin and the melamine derivative has a cyanoamine group and has a cyanoamine group. The cross-linking reaction does not occur.

[0026] This is considered by the present inventor as an example. In polybuluenol and polystyrene, hydroxyl groups are involved in the crosslinking reaction between the melamine derivative and the cross-linking reaction because the only difference is the presence or absence of hydroxyl groups. Thus, it is considered that a cyanoethyl pullulan or polystyrene having a cyanoethyl group does not cause a crosslinking reaction with a melamine derivative because it does not have a hydroxyl group.

[0027] In view of the above, as a result of intensive studies, the present inventor has found that a part of the hydroxyl group is partially a cyanoethyl group for a polymer having a hydroxyl group, and a polymer having a cyanoethyl group is a part of the cyanoethyl group. It was found that using a mixed polymer in which a cyanoethyl group and a hydroxyl group are mixed (hereinafter also referred to simply as a mixed polymer) by using a partial hydroxyl group as a part, and utilizing both advantages of a cyanoethyl group and a hydroxyl group, The present invention has been reached.

[0028] That is, the high relative permittivity 匕 by the cyanoethyl group is measured, and the hydroxyl group promotes the crosslinking reaction with the melamine derivative while ensuring the high relative permittivity, so that the solvent resistance and compatibility are improved. I found it. Furthermore, particularly when the gate insulating film has a relative dielectric constant of 7 to 40, the dielectric constant can be secured, and the reasons such as prevention of hysteresis and stabilization of electrical properties are also suitable.

As a result, a higher quality gate insulating film can be provided, and 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 can be found. did it.

[0030] "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 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 noor film 12, and the organic TFT 50. 100 and the organic TFT 50 have a protective film 20 that also protects the erosion power of external force.

[0032] <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.

[0033] <Barrier film>

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

[0034] 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 included, moisture is contained. This is preferable because it improves the noria property from erosion due to oxygen and oxygen. As the inorganic film, for example, a nitride film, an oxide film, a carbon film, a silicon film, or the like can be employed. 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.

[0036] 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, chlorotrifluoroethylene, dichlorodifluoroethylene, etc.), metal alkoxides (CHOM, CHOM, etc.),

3 2 5

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

[0037] 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, and 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

[0038] <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.

[0039] The anode 14 may be a transparent electrode such as ITO (Indium tin oxide) 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.

[0040] 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.

[0041] The organic solid layer 16 is formed from the anode 14 side from the hole injection layer 162 / hole transport layer 164 / light emitting layer 16 6 / electron transport layer 168.

The hole injection layer 162 is a layer that is provided between the anode 14 and the light emitting layer 166 and promotes the 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 the 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.

[0044] The hole transport layer 164 is a layer that is provided between the hole injection layer 162 and the light emitting layer 166 and promotes hole transport, and has a function of appropriately transporting holes to the light emitting layer 166. .

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.

[0046] The light-emitting layer 166 is a layer that recombines the transported holes and the transported electrons, which will be described later, 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.

[0047] For example, in the phosphorescent device, when electrons and holes are injected from the cathode 18 and the anode 14 respectively into the phosphorescent light emitting layer 166 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 the emission color of the host material and the emission color of the dopant material are different. Additive light 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.

[0048] The electron transport layer 168 is provided between the cathode 18 and the light emitting layer 166, and has a function of promoting 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, LiO (two

(2) Lithium oxide) and other thin films (eg 0.5 nm) can be used.

[0050] Each layer constituting the organic solid layer 16 is usually made of an organic substance, and may be made of a low-molecular organic substance or a high-molecular organic substance. 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.

[0051] 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 includes a hole injection layer 162, a hole transport layer 166, a light emitting layer 166, and an 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.

[0053] For example, depending on the characteristics of the organic material to be adopted, 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 is provided between the light emitting layer 166 and the electron transport layer 168 in the organic solid layer 16. You may choose. 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.

[0055] For the cathode 18, in order to improve the electron injection into the organic solid layer 16, a material having a small work function or electron affinity may be selected. 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.

[0056] <Organic transistor (organic TFT)>

FIG. 5 shows an enlarged view of the vicinity of 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.

The gate electrode 52 may be any metal that can be anodized as the 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.

[0058] In the method of manufacturing the gate electrode 52, the wiring pattern of the gate electrode 52 is formed on the substrate 10. Any general method may be used. 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.

[0059] The gate insulating film 54 has a hydroxyl group partially including a cyanoethyl group, and a polymer having a cyanoethyl group partially includes a cyanoethyl group. For example, a mixed solution of a mixed polymer in which a cyanoethyl group and a hydroxyl group are mixed (hereinafter also simply referred to as a mixed polymer) and a melamine derivative is applied and thermally cured.

[0060] The mixed polymer is not particularly limited as long as it has a partially cyanoethyl group and a partially hydroxyl group. Also, the mixed polymer does not prevent the inclusion of groups other than cyanoethyl and hydroxyl groups! / ,.

[0061] For example, as the polymer constituting the gate insulating film 54, polybutanol and polyvinyl alcohol, starch and derivatives thereof, ethyl cellulose, methoxycellulose, hydrogenated chichenenoresenorelose, canoleboxymethylenole Examples thereof include cellulose derivatives such as senorelose, methinoresenellose, and ethinoresululose, pullulan, sorbitol, phenoxy resin, polyphenol resin, and the like, in which a cyanoethyl group is partially added.

[0062] For example, polyphenolic resin is obtained by reacting phenols and aldehydes in a ratio of 1 to 3 moles of aldehydes to 1 mole of phenolic hydroxyl group under a basic catalyst or an acidic catalyst. It is done.

[0063] Examples of phenols include phenol, cresol, xylenol, octylphenol, phenol-phenol, bisphenol A, bisphenol S, and bisphenol F. Aldehydes include formaldehyde, paraformaldehyde, glyoxal, Trioquizal etc. are mentioned.

[0064] If necessary, those modified with a modifying agent that promotes plasticization such as paratoluene sulfonamide, tung oil, phosphate esters, glycols, etc. can be applied. Examples of basic catalysts include sodium and potassium. Alkali metals, magnesium, calcium and other alkaline earth metals oxides and hydroxides, triethylamine, triethanolamine and other metals Examples of the acidic catalyst include paratoluenesulfonic acid and hydrochloric acid.

[0065] The melamine derivative is not particularly limited as long as it has good compatibility with the polymer and can be dissolved in the same solvent as the partially cyanethylated polymer. As the melamine derivative, there is a force using a methylated polymer formaldehyde copolymer, and as the melamine derivative, there are methylolated, acrylated, butylated and isobutylated polymelamine formaldehyde copolymer. For example, triazines and formaldehydes such as methylolated melamine resin, methylolated melamine-phenol cocondensed resin, methylolated melamine-urea cocondensed resin, and methylolated melamine-epoxy cocondensed resin can be used together. A synthetic resin obtained by condensation can be used.

[0066] Although the gate insulating film 54 is formed of the above mixed polymer, it does not prevent mixing of other polymers such as thermoplastic resin and thermosetting resin or metal oxide particles. Yes. These can be appropriately selected and used in combination with the mixed polymer.

[0067] It is preferable that the other polymer mixed here has a high relative dielectric constant. For example, organic polymer or oligomer materials having a high dielectric constant include, for example, cyanoethyl cellulose (dielectric constant 16), cyanoethyl hydroxyethyl cellulose (dielectric constant 18), cyanoethyl hydroxypropyl. Cellulose (dielectric constant 14), cyanoethyldihydroxypropylcellulose (dielectric constant 23), cyanoethyl amylose (dielectric constant 17), cyanoethyl starch (dielectric constant 17), cyanoethyldihydroxypropyl starch (ratio) Dielectric constant 18), cyanoethyl pullulan (relative dielectric constant 18), cyanoethyl dalicidol pullulan (dielectric constant 20), cyanopolyvinyl alcohol (dielectric constant 20), cyanoethyl polyhydroxymethylene (dielectric) 10), cyanoethyl sucrose (dielectric constant 25), cyanoethyl sorbitol (dielectric constant 40), etc. Ethyl group-containing polymer or oligomer 1. Polyvinylidene fluoride (dielectric constant 11), vinylidene fluoride-trifluoroethylene copolymer (55/45: dielectric constant 18, 75/25: dielectric constant) Vinylidene polymers such as 10) are listed.

[0068] Furthermore, it is preferable to mix a thermosetting resin. Thermosetting resins include polyurethane, phenol resin, melamine resin, urea resin, unsaturated polyester resin, diallyl cover. Examples thereof include rate resin, silicon resin, and epoxy resin. For example, bisphenol-A type epoxy resin, bisphenol-F type epoxy resin, bisphenol-AD type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, cycloaliphatic epoxy resin Glycidyl ester-based resins, glycidylamine-based epoxy resins, heterocyclic epoxy resins, urethane-modified epoxy resins, brominated bisphenol mono-A type epoxy resins, and the like.

[0069] The metal oxide particles can be appropriately selected and used. For example, 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, MgTiO, BaZrO

2 5 2 2 3 3 3 3 3

, PbZrO, SrZrO, CaZrO, LaTiO, LaZrO, BiTiO, LaPbTiO, Y 2 O, etc.

3 3 3 3 3 3 3 2 3 or solid solutions thereof, more specifically barium strontium titanate, strontium titanate, barium titanate, belly titanate, calcium titanate, magnesium titanate, zirconate Barium titanate, lead zirconate titanate, lead zirconate

, Barium zirconate, strontium zirconate and calcium zirconate. In addition, composite oxide particles such as lead lanthanum zirconate titanate, lead lanthanum titanate, bismuth titanate, lanthanum titanate, barium magnesium fluoride, etc.

And metal oxide particles such as titanium dioxide, tantalum pentoxide, and yttrium trioxide. Only one kind of these metal oxide particles may be used, or a plurality of kinds may be used in combination.

[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

Organic conductive materials containing conjugated polymer compounds such as polyarines, polythiophenes, and polypyrroles may also be used.

[0071] The source electrode 58 and the drain electrode 60 may be manufactured by a general method. Spatter Examples of such a method include an etching method and a CVD method, 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. 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, thiathiazole , Nitrogen-containing cyclic compound derivatives such as triazole, hydrazine derivatives, triphenylamine derivatives, triphenylmethane derivatives, stilbenes, quinone compound derivatives such as anthraquinone diphenoquinone, anthracene, bilene, The structure of polycyclic aromatic compound derivatives such as enanthrene and coronene was used in the main chain of polymers such as polyethylene chains, polysiloxane chains, polyether chains, polyester chains, polyamide chains, and polyimide chains. Attached in a pendant form as a side chain, or an aromatic conjugated polymer such as polyparaphenylene, an aliphatic conjugated polymer such as polyacetylene, a heterocyclic conjugate of polypinol or polythiophene ratio Polymers, heteroatom-conjugated polymers such as polyarylenes and polyphenylene sulfide, and conjugates such as poly (phenylene vinylene), poly (anilenylene vinylene), and poly (cellene vinylene) A carbon-based conjugated polymer such as a composite conjugated polymer having a structure in which structural units of the conductive 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 Organic compounds such as polymers obtained by heat-treating perylenes such as polyacrylamide, ladder-type polymers obtained by heat-treating polyethylene derivatives having a cyano group such as polyacrylo-tolyl, and mouth-bumite. Using inter-forced composite material A little.

[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 noria 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.

2 3 4

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. In addition, the film stress of the inorganic film can be relaxed There is also a role to play.

[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 (region of about several nm) between the organic semiconductor 56 and the gate insulating film 54. When holes are generated and a voltage is applied between the source electrode 58 and the drain electrode 60, the holes 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. In this way, switching can be performed using the non-conduction state (the switch is off) and the conduction 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 noria film 12, and the substrate 10 in order, and the light emission can be visually recognized.

[0086] In the case where A1 is used for the cathode 18, the interface between the cathode layer 18 and the electron transport layer 168 becomes a reflection surface, and is reflected at this interface, proceeds to the anode 14 side, and passes through the substrate 10. And injected outside. Therefore, the organic EL element with the above configuration is used as a display. When it is adopted, 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.

A high-performance organic TFT can be fabricated using the gate insulating film of this embodiment. Therefore, an organic EL display device having a high-performance organic TFT can be provided. Here, photolithography is more suitable for providing a gate insulating film, an organic TFT, and an organic EL display device if a polymer polymer such as a polymer solvent having high solvent resistance for etching, heat treatment and other processes is used. is there.

[0090] 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.

[0091] "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 the organic EL element 100 and the organic TFT 50 are manufactured 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, keep the organic EL element 100 and the organic TFT50 to cover the surface. The protective film 20 is formed to manufacture the organic EL display device PI.

[Method of forming gate insulating film]

An example of a method for manufacturing the gate insulating film 54 of the organic TFT 50 will be described.

[0093] (Production of mixed polymer)

The mixed polymer may be a ready-made one, but may be produced. The method for producing the mixed polymer is not particularly limited. For example, the polymer having a hydroxyl group can be produced by a cyano-ethylation reaction (Michael addition reaction, etc.) using nitrile nitrile. The amount of acryl-tolyl added here is limited so that all the hydroxyl groups of the polymer having a hydroxyl group are not cyanoethylated.

[0094] As an example, the mixed polymer is represented by the following chemical formulas (4) and (5). The mixed polymer represented by the chemical formula (4) is a mixed polymer in which the hydroxyl group of the polybutyl alcohol represented by the chemical formula (1) is substituted with a cyanoethyl group. The mixed polymer represented by the chemical formula (5) is a mixed polymer in which the polybutanol represented by the chemical formula (2) is substituted with a cyanoethyl group.

[0095] [Chemical 4]

( Five )

(Preparation of gate insulating film) The mixed polymer represented by the above chemical formulas (4), (5), etc., and the melamine derivative represented by the above chemical formula (3), etc. are liquefied, mixed and stirred to prepare a coating solution as a mixture containing them. The liquefaction method of the mixed polymer and melamine derivative includes a method of liquefying the mixture of the mixed polymer and melamine derivative itself (solvent-free coating solution), and a method of using a solvent that dissolves the mixture separately from the mixture.

[0097] The solvent is not particularly limited as long as it is appropriately selected and used. For example, acetonitrile, DMF (N, N-dimethylformamide), acetonitrile, and the like are used.

[0098] 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.

[0099] 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.

[0100] As shown in FIG. 6, the coating solution 32 thus prepared is applied to the surface of the barrier film 12 on the substrate 10 on which the gate electrode surface and the gate electrode are formed.

[0101] The coating method of the coating liquid is not particularly limited as long as it is appropriately selected and used, but is not limited to inkjet, gravure coating, gravure reverse coating, comma coating, die coating, lip coating, cast coating, ronore coating, Air knife coat, Mayer coat, Extrusion coat, Offset, UV curing offset, Flexo, Stencil, Silk, Curtain Flow coat, Wire coat-Reno cloth coat-Gravure coat, Kiss coat, Blay Various printing methods such as coating, smooth coating, spray coating, pouring coating and brush coating can be applied.

[0102] Next, as shown in FIG. 7, a desired portion 34 where the gate insulating film 54 is formed is heated. By this heating, the cross-linking reaction between the mixed polymer and the melamine derivative proceeds. By this crosslinking reaction, a three-dimensional crosslinked structure of the mixed polymer and the melamine derivative is formed and cured. In this manner, the desired portion 34 where the gate insulating film 54 is formed is thermally cured by heating.

[0103] After thermosetting, as shown in FIG. 8, the desired portion 34 where the gate insulating film 54 is to be formed is thermally cured, and then the portion of the coating solution is washed with a solvent by an etching process such as oxygen-reactive ion etching, and then flowed. The portion 34 that has been removed, solidified, washed, and forced to flow becomes the gate insulating film 54, and the gate insulating film 54 is formed.

[0104] 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), 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 veratole, toluene, and phenetole, and other materials include diethylene glycol monomethylenoatenore, diethyleneglycolenomonochinenoreatenore, and diethyleneglycolenomonoenoate. Examples also include butyl ether, diethylene glycol dimethyl ether, tetralin, methyl isobutyl ketone, dimethylacetamide, N-methyl-2-pyrrolidone, and dimethylformamide.

[0105] 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.

[0106] The gate insulating film in the present embodiment is such that a polymer having a hydroxyl group partially has a cyanoethyl group, or a polymer having a cyanoethyl group partially has a cyanoethyl group. A mixture containing a mixed polymer containing cyanoethyl groups and hydroxyl groups and a melamine derivative, such as a hydroxyl group, is heat-cured and a crosslinked film is used, which makes the gate insulation highly compatible with high dielectric constant. A membrane can be provided. A high-performance organic TFT can be manufactured using the gate insulating film of this embodiment. Therefore, an organic EL display device having a high-performance organic TFT can be provided. In this case, if photolithography is used for etching, heat treatment, and so on, a polymer polymer with high solvent resistance to the process is used to provide a gate insulating film, organic TFT, organic EL display device and display. Is preferred.

Claims

The scope of the claims

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

A method for producing a gate insulating film, comprising a step of thermally curing a mixture containing a mixed polymer containing a cyanoethyl group and a hydroxyl group and a melamine derivative.

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

The method for manufacturing a gate insulating film, wherein the gate insulating film has a relative dielectric constant of 7 to 40.

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

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.

[4] 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,

4. The method for manufacturing an organic EL display device, wherein the organic transistor is manufactured by the method for manufacturing an organic transistor according to claim 3.

[5] A display including the organic transistor manufactured by the method for manufacturing an organic transistor according to claim 3.