WO2007026586A1 - Organic thin-film semiconductor device and method for manufacturing same - Google Patents

Abstract

Disclosed is an organic thin-film semiconductor device comprising an auxiliary electrode arranged on a substrate, an insulating layer arranged on the auxiliary electrode, a first electrode arranged on the insulating layer, an organic semiconductor layer which is in contact with the first electrode and composed of a carrier-transporting organic semiconductor material, and a second electrode supported by the organic semiconductor layer. The organic semiconductor layer is formed through a liquidation/solidification process of the organic semiconductor material. A light-emitting layer may be formed between the organic semiconductor layer and the second electrode.

Description

 Specification '

'Organic thin film semiconductor device and manufacturing method thereof

Background of the Invention

1. Field of Invention.

 The present invention relates to an organic thin film semiconductor element using a compound having a carrier (hole or electron) transport property and having a semiconductor layer made of such a compound, and a method for producing the same. 2. Explanation of related technology

 2. Description of the Related Art Light emitting devices that emit light by applying an electric field, for example, light emitting devices that utilize electroluminescence (hereinafter simply referred to as EL) due to recombination of carriers (holes or electrons) in a substance are known. For example, an EL display device equipped with a display panel using an injection type organic EL element using an organic compound material has been developed. The organic EL element includes a red EL element having a structure emitting red light, a green EL element having a structure emitting green light, and a blue EL element having a structure emitting blue light. A color display device can be realized by arranging three organic EL elements that emit red, blue, and green RGB in a single pixel emission unit and arranging multiple pixels in a matrix on the panel. . As a display panel driving method using such a color display device, a passive matrix driving type and an active matrix driving type are known. ACT

The active matrix drive type EL display device has advantages such as lower power consumption and less crosstalk between pixels compared to the passive matrix type display device, especially large screen display devices and high definition display devices. Suitable for '' On the display panel of the active matrix drive type EL display device, the anode power line, the cathode power line, the scanning line responsible for horizontal scanning, and the data lines arranged across the scanning lines are arranged in a grid pattern. Is formed. RGB subpixels are formed at each RGB intersection of the scan line and data line.

For each subpixel, the scan line is connected to the gate of a field effect transistor (FET) for selecting the scan line, the data line is connected to the drain, and the source is connected to the source. The gate of the light emitting drive FET is connected. A drive voltage is applied to the source of the light emission drive F E T through an anode power line, and the anode end of the EL element is connected to the drain D of the light emission drive F E T. A capacitor is connected between the gate and source of the light emission drive FET. Furthermore, a ground potential is applied to the cathode end of the EL element via the cathode power supply line. .

 Conventional φ organic light-emitting devices, represented by organic EL devices, are basically active devices that exhibit diode characteristics, and most of them are manufactured by passive matrix drive5. In the passive matrix driving method, line-sequential driving requires instantaneously high brightness, and the limit number of scanning lines is limited, so it is difficult to obtain a high-definition display device.

 Organic EL display devices using TFTs using polysilicon, etc. are being studied. However, the process temperature is high, the manufacturing cost per unit area is high, and it is not suitable for large screens. There were disadvantages such as the aperture ratio was lowered and the organic EL had to emit light with high brightness because it was necessary to arrange two or more transistors and capacitors.

Therefore, the auxiliary electrode, the insulating layer ', the anode, the organic functional layer including the light emitting layer, and the cathode are sequentially arranged on the substrate. 2002-343578 Proposed in the news. In the light emitting device having such a configuration, an auxiliary electrode, an insulating layer, and an anode are sequentially provided on a substrate, an organic functional layer is formed by a vapor deposition method, and a cathode is provided. However, when the organic functional layer is formed by the vapor deposition method, the anode is completely covered by the organic functional layer because the vapor deposition material flow is blocked by the anode depending on the angle between the vapor source and the vapor deposition surface. There is a possibility that a portion not covered with the coating or a portion where the organic functional layer is thin is formed. When such a portion is formed, an electric field and current injection are concentrated on the portion, and a short circuit and a current leakage occur, thereby destroying the light emitting element or causing a light emitting failure. In addition, there is a problem that the hole injection efficiency from the anode to the organic functional layer is lowered.

 Further, even in the case of an organic thin film transistor having no light emitting layer in the organic functional layer and similar to the above-described element structure, the uniformity of the electric field, the leakage current, and the like can be problems. , Summary of Invention '.

 · An object of the present invention is to provide a means for solving various problems mentioned above as an example.

 '' The organic thin film semiconductor device according to the first aspect of the present invention includes an auxiliary electrode provided on a substrate, an insulating layer provided on the auxiliary electrode, and an insulating layer provided on the insulating layer. A first electrode; an organic semiconductor layer made of a carrier-transporting organic semiconductor material in contact with the first electrode; and a second electrode supported by the organic semiconductor layer, the organic semiconductor layer comprising: The organic semiconductor material is formed by fluidization solidification treatment.

The method for producing an organic thin film semiconductor device according to the second aspect of the present invention comprises a step of providing an auxiliary electrode on a substrate, a step of providing an insulating layer on the auxiliary electrode, and a first electrode on the insulating layer. And a carrier transporting organic semiconductor material in contact with the first electrode. A step of providing an organic semiconductor layer comprising: and a step of forming a second electrode supported by the organic semiconductor layer, wherein the step of providing the organic semiconductor layer comprises using a dry process method. The method includes a step of forming a thin film made of an organic semiconductor material, and a fluidization treatment step of the organic semiconductor material of the thin film.

5 Brief description of the drawings

 FIG. 1 is a partial cross-sectional view of an organic EL device according to the present invention.

 FIG. 2 is a partial sectional view of a modification of the organic EL device according to the present invention.

 FIG. 3 is a partial sectional view of a modification of the organic EL device according to the present invention.

 FIG. 4 is a partial sectional view of a modification of the organic EL device according to the present invention.

FIG. 5 is a conceptual diagram for explaining the energy level of the organic EL device according to the present invention. FIG. 6 is a partial plan view of the organic EL device according to the present invention.

 FIG. 7 is an equivalent circuit diagram showing a sub-pixel light emitting part of the organic EL device according to the present invention. FIG. 8 is a partial sectional view for explaining a part of the manufacturing process of the organic EL device according to the present invention. '

 FIG. 9 is a partial cross-sectional view for explaining the continuation of the step shown in FIG. 8 among the steps of manufacturing the organic EL device according to the present invention.

 FIG. 10 is a partial cross-sectional view for explaining the continuation of the process shown in FIG. 9 in the manufacturing process of the organic EL device according to the present invention.

FIG. 11 is a partial sectional view of an organic thin film transistor according to the present invention.

 Detailed Description of the Invention

 Hereinafter, as an example of the organic thin film semiconductor device according to the present invention, an organic EL device including a light emitting layer will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, the organic EL element 1 includes five auxiliary electrodes 3 provided on a substrate 2. Substrate 2 materials include glass, quartz, polystyrene, etc. 'Not only translucent materials such as tic materials, but also non-transparent materials such as silicone A 1, thermosetting resins such as phenolic resins, thermoplastic resins such as polystrength Ponate, etc. can be used. Absent. '

An insulating layer 4 is provided on the auxiliary electrode 3. Insulating layer 4, S I_〇 _2, S i ₃ N

Although the 5 ₄ may be made of various insulating materials Ru representative of E, especially high have an inorganic oxide film of the dielectric constant is preferable. Examples of inorganic oxides include silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, barium zirconate titanate, lead zirconate titanate, and lead lanthanum titanate. Strontium titanate, barium titanate, magnesium barium fluoride, bismuth titanate, strontium bismuth titanate, strontium bismuth tantalate, bismuth tantalate niobate, yttrium trioxide, and the like. Among them, preferred are silicon oxide, aluminum oxide, tantalum oxide, and titanium oxide. Inorganic nitrides such as silicon nitride and aluminum nitride can also be suitably used. As the organic compound film 5, polyimide, polyamide, polyester, polyacrylate, photo-radical polymerization system, photo-curing resin of photothion polymerization system, or a copolymer containing acrylonitrile component, polyvinyl phenol, polyvinyl alcohol Nopolac resin and cyanoethyl pullulan, a polymer, a phosphazene compound containing an elastomer, and the like can also be used. .

0 An anode 5 is provided on the insulating layer 4, and the anode 5 serves as a first electrode. The anode 5 has a smaller area than the cathode 8 described later. That is, the area of the surface of the cathode 5 facing the cathode 8 is smaller than the area of the surface of the cathode 8 facing the anode 5. In addition, the anode 5 may be formed in a comb shape, a saddle shape, or a lattice shape. The anode 5 is in contact with the organic semiconductor layer 6 made of a carrier transporting organic semiconductor material. The organic semiconductor layer 6 is composed of a hole injection layer, a hole transport layer, or a combination thereof. '

 The hole injection layer has a function of facilitating the injection of holes from the anode 5. As a material used for the hole injection layer, a porphyrin derivative typified by copper phthalocyanine (CuP c), polyacene typified by betacene, and a polymer arylamine called burstamine typified by m-TDATA are used. be able to. In addition, a layer in which the conductivity is increased by mixing a porphyrin derivative, a triphenylamine derivative, or the like with Lewis acid tetrafluorotetracyanoquinodimethane (F4-TCNQ) can be used for the hole injection layer. At this time, the mixing ratio is preferably 5 to 95% by weight. In the polymer system, polymer materials such as polyaniline (PAN I), polythiophene derivative (PEDOT), and poly (3-hexylthiophene) (P 3HT) can be used. The IE hole injection layer may be a mixed layer of these materials or a laminated layer. The hole transport rod has a function of stably transporting holes from the anode 5. Materials used for the hole transport layer include triphenyldiamine derivatives, styrylamine derivatives, amine derivatives having an aromatic condensed ring, carbazole derivatives, polymer materials such as polyvinyl carbazol and its derivatives, polythiophene, etc. Can be mentioned. Two or more of these compounds may be used in combination. Further, in general, it is preferable to use an organic semiconductor material having a higher ionization potential IP than the hole injection layer for the hole transport layer.

The organic semiconductor layer 6 made of the material as described above is formed by a fluidization treatment process of the organic semiconductor material. Here, fluidized solidification treatment refers to organic semiconductor by heating a thin film made of an organic semiconductor material to a temperature higher than the glass transition temperature of the organic semiconductor material or by exposing the thin film made of an organic semiconductor material to a vapor atmosphere of a solvent. Flow material ■ To solidify after moving. By causing the organic semiconductor material to flow, the anode 5 is completely covered with the organic semiconductor layer 6. In particular, the step between the -top portion of the anode 5 and the surface of the insulator layer is covered by the organic semiconductor layer 6, and the step coverage characteristic of the organic semiconductor layer 6, so-called step coverage, is good.

5 In the case where the organic semiconductor layer 6 is composed of a hole injection layer and a hole transport layer, at least the hole injection layer is solidified after flowing the organic semiconductor material constituting the hole injection layer. Preferably it is formed.

 A light emitting layer 7 is provided above the organic semiconductor layer 6. That is, the light emitting layer 7 is supported by the organic semiconductor layer 6. The light emitting layer 7 contains 0 fluorescent material or phosphorescent material which is a compound having a light emitting function. Examples of such a fluorescent substance include at least one compound selected from compounds such as those disclosed in JP-A 63-264692, such as quinacridone, J levrene, and styryl dyes. . Examples of phosphorescent substances include App 1. Phy s. Let t., Vol. 5, Volume 5, Item 4, Organic Iridium Complex as in 1 '999, and Organic Platinum Complex. '

 A cathode 8 is provided above the light emitting layer 7, and the cathode 8 serves as a second electrode.

The cathode 8, the anode 5 and the auxiliary electrode 3 include Ti, Al, Li: A1, Cu, Ni, Ag, Mg: Ag, A, u, Pt, Pd, Ir, Examples include metals such as Cr, Mo, W, and Ta0 or alloys thereof. Alternatively, a conductive polymer such as polyaniline or PE DT: PSS can be used. Alternatively, the transparent conductive thin film oxides, such as tin-doped indium oxide (I TO), zinc oxide doped Injiu beam (I ZO), indium oxide (I n ₂ 〇 _3), zinc oxide (ZnO), tin oxide (S n0 ₂ However, the present invention is not limited to this. The thickness of each electrode is preferably about 30 to 500 nm. Cathode 8 and auxiliary In particular, a range of 50 to 300 nm is suitable for the electrode 3. For the anode, a metal having a high work function that can easily inject pores into the organic semiconductor layer 6, such as A u, P t, and P d −, is preferable. The thickness of the cathode 8 is particularly preferably in the range of about 30 to 200 nm.

 These electrodes are preferably produced by vacuum deposition or sputtering.

5 When a voltage is applied between the auxiliary electrode 3 and the cathode 8 in the organic EL device 1 having the above-described configuration so that the voltage is applied in the same direction as the voltage applied between the anode 5 and the cathode 8. In addition, the light emitting layer 7 'emits light. In the organic EL element 1 having such a configuration, the organic semiconductor layer 6 is formed by fluidizing and solidifying the material constituting the layer, whereby the step coverage of the organic semiconductor layer 6 is improved. As a result, the anode 5 is completely covered by the organic semiconductor layer 6 and the contact area between the organic semiconductor layer 6 and the anode 5 is increased, and carrier injection efficiency from the anode 5 to the organic semiconductor layer 6 is increased. Will improve. That is, the electric field and current injection are dispersed, and the amount of carrier injection increases.

 Also, pinholes in the thin film of the organic semiconductor material produced by the vapor deposition method are filled by the fluidized solidification treatment of the material, thereby reducing leakage and short circuit. In addition, the organic EL device 1. having the above-described structure is a passive device and can be manufactured without greatly changing the organic EL manufacturing process.

 The organic EL device of the above-described embodiment shown in FIG. 1 has a configuration of auxiliary electrode Z insulating layer / anode / hole injection layer / light emitting layer / cathode, but is not limited to this. An electron injection layer, an electron transport layer, or a combination thereof may be arbitrarily used between the light emitting layer and the cathode. For example, as shown in FIG. 2, an electron transport layer 9 and an electron injection layer 10 may be provided between the light emitting layer 7 and the cathode 8.

In the electron injection layer 10 and / or the electron transport layer 9, 8-quinolinols such as tris (8-quinolinolato) alminium (A l Q ₃ ) is used as an organic metal complex having a derivative as a ligand. Quinoline derivatives, oxadiazole derivatives, perylene derivatives, Pyridine derivatives, pyrimidine derivatives, quinoxaline derivatives, diphenylquinone derivatives, nitro-substituted fluorene derivatives, and the like can be used. The electron injection layer 10 and / or the electron transport layer 9 may also serve as the light emitting layer 7. In such a case, it is preferable to use tris (8-quinolinolato) aluminum or the like. When the electron injection layer 10 and the electron transport layer 9 are produced, it is preferable to form a film so that a compound having a large electron affinity value is disposed on the cathode 8 side.

 In the above embodiment, although the first electrode is described as the anode and the second electrode is described as the cathode, the structure after the insulating layer is reversed, that is, the first electrode is the negative electrode, and the second electrode is the second electrode. The electrode may be an anode. In such a configuration, the organic semiconductor layer may be an electron injection layer, an electron transport layer, or a combination thereof. For example, as shown in FIG. 3, a configuration of auxiliary electrode 3 / insulating layer 4 / cathode 8 electron injection layer 10 Z light emitting layer 7 / anode 5 may be used.

Although not shown, a hole lock layer and an electron block layer may be arbitrarily used between the first electrode and the second electrode. In the organic EL element, a carrier regulating layer may be provided between the organic semiconductor layer and the anode. For example, as shown in FIG. 4, the organic EL element 1 has a carrier regulating layer BF between the organic semiconductor body layer 6 and the anode 5 and sandwiched between the anode 5 and the cathode 8. Also good. The carrier restricting layer BF functions as a barrier for carrier movement from the anode 5 to the organic semiconductor layer 6. By providing the carrier restricting layer BF, it becomes difficult for current to flow through the carrier restricting layer BF. The material of the carrier restriction layer BF is selected based on the condition of its ionization potential, that is, the value of the work function (or ionization potential) between the work function of the contact electrode and the ionization potential of the organic semiconductor layer. This is because a larger energy barrier is better to inhibit carrier movement. As shown in Fig. 5, the work function W f 1 ¾ of the anode 5 made of metal and the work function W f 2 of the carrier restriction layer BF are the energy measured from the vacuum level (0 e V) to each Fermi level. is there. The energy measured from the vacuum level of the organic semiconductor layer 6 to the highest occupied molecular orbital (HOMO) level at the top of the valence band. The insulator affinity Ea is the energy measured from the vacuum level (VACU UM LEVEL) at the reference energy level of 0 eV to the lowest unoccupied molecular orbital (LUMO) level at the bottom of the conduction band. :

 Therefore, as a material of the carrier regulation layer BF, specifically, a hole injection material (organic semiconductor layer 6) having an ionization potential I p 1 (e V) and an anode having a work function 1 (e V) are used. When 5 and a carrier regulation layer BF having a work function Wf 2 (e V) are laminated, it is preferable that I p 1 and Wf 2 have a relationship of I pl> Wf 2. .

At this time, I p 1 and Wf 1 are preferably I p 1 and Wf 1. However, I p 1 ≥ Wf 1 is acceptable, and the difference between I p 1 and Wf 1 is within 0.5 eV. Good. For example, a metal having a low work function that hardly injects holes into the organic semiconductor layer 6 such as A1, Mg, A′g, Ta, and Cr is preferable as the carrier regulation layer BF. The total film thickness of the anode 5 and the carrier regulating layer BF is suitably in the range of about 30 to 200 nm. By providing such a carrier regulating layer BF, a carrier path to be injected into the organic semiconductor layer 6 such as a hole injection layer is defined. In the case of the configuration shown in FIG. 4, that is, when the carrier restricting layer BF is sandwiched between the anode 5 and the cathode 8, carriers (holes) are not covered by the carrier restricting layer BF. It is injected from the part (side of anode 5). Here, since the side portion of the anode 5 is completely covered by the organic semiconductor layer 6, the carrier injection efficiency is improved. In addition, the organic semiconductor layer 6 has good step coverage, and the electric field is concentrated. Since the thin portion of the organic semiconductor layer 6 is not formed in the carrier passage injected from the side surface of the anode 5, mass injection of carriers can be realized. 'Note that the anode 5 serving as the first electrode has a smaller area than the cathode 8 serving as the second electrode, and defines a pattern for carriers passing through the organic semiconductor layer 6. Yes. For example, as shown in FIG. 6, the anode 5 serving as the first electrode and the carrier restricting layer BF have a comb-like shape or a bowl-like shape, and have a smaller area than the cathode 8 serving as the second electrode. It is good also as having. The shapes of the anode 5 and the carrier regulation layer BF may be a lattice shape. Further, if at least one of the anode 5 and the carrier regulation layer BF has a lattice shape, a comb shape, or a comb shape, the anode 5 has an area smaller than the anode 8 and passes through the organic semiconductor layer 6. A pattern can be defined for the carrier to perform.

 • In the above embodiment, an example of an organic EL element is shown. However, a plurality of organic EL elements may be used for a pixel of a display device. Specifically, the active drive type display device according to the present invention can be realized by manufacturing at least one organic transistor, a necessary element such as a capacitor, and a pixel electrode on a common substrate. As an example, the structure when applied to a display device will be described below.

FIG. 7 shows an equivalent circuit diagram showing the light emitting portion of the subpixel of the organic EL display panel. Each of the light emitting portions 10 0 1 formed on the substrate is composed of a switching organic TFT element 11 1 of a selection transistor, a capacitor 12 2 for holding a data voltage, and an organic EL element 13. . By arranging this configuration in the vicinity of each intersection of the scanning line SL, the power supply line Vcc L, and the data line DL, a light emitting portion of the pixel can be realized. In this embodiment, the effect of omitting the driving transistor can be obtained, but it goes without saying that the present invention can also be applied when two or more driving organic TFT elements are provided. -. The gate electrode G of the switching organic TFT element 11 is connected to the scanning line SL to which the address signal is supplied, and the source electrode S ′ of the switching organic TFT element 11 is the data line to which the data signal is supplied. Connected to DL. The drain electrode D of the switching organic TFT element 11 is connected to one terminal of the auxiliary electrode 3 of the organic EL element 13 and the capacitor 5 capacitor 12. The anode 5 of the organic EL element 13 is connected to the power supply line Vc c L, and the other side of the capacity line 12 is connected to the capacity line V cap. The cathode 8 of the organic EL element 13 is connected to the common electrode 14. The power supply line Vc c L and the common electrode 14 are respectively connected to voltage sources (not shown) that supply power to each.

The light emitting units 101 having such a configuration are arranged in a matrix, and an active matrix type organic EL display panel can be formed. The organic EL element of the above embodiment can also be applied to a substrate of a passive matrix type panel in which a TFT element or the like is arranged around the panel screen. Next, a method for manufacturing the organic EL element having the above configuration will be described.

5 ′ As shown in FIG. 8 (a), first, the auxiliary electrode 3 is formed on the substrate 2. The auxiliary electrode 3 may be formed by, for example, a film forming method using a dry process and a patterning process using a photoresist. More specifically, for example, after forming a thin film made of ITO by sputtering, a photoresist is applied by a spin coat. This photoresist is patterned by exposure and development using an optical mask, and the ITO film without the photoresist pattern is removed from the photoresist by milling, and finally the photoresist is dissolved using a stripping solution. The auxiliary electrode 3 may be formed by such a procedure.

Next, as shown in FIG. 8B, an insulating layer 4 is formed on the auxiliary electrode 3. For the formation of the insulating layer 4, a film forming method by a dry process or a film forming method by a Wetz process can be used. When the insulating layer 4 is made of an organic compound film, 'A deposition process by wet process may be used. For example, the insulating layer 4 can be formed by a spin coating method using a polyvinyl phenol polymer 1 O wt% propylene glycol monomethyl ether acetate (PGMEA) solution. In this case, after removing a portion of the polymer film that does not require an edge, such as an end on the auxiliary electrode 3, by wiping it with cotton containing PGMEA, Baking is performed using heating means. On the insulating layer 4, an anode 5 serving as a first electrode is formed as shown in FIG. The anode 5 may be formed using a dry process such as a vapor deposition method. For example, the anode 5 may be formed by depositing gold by a vacuum deposition method using a metal mask.

 After the anode 5 is formed, an organic semiconductor layer made of a carrier transporting organic semiconductor material is formed so as to be in contact with the anode 5. For the formation of the organic semiconductor layer, a deposition method such as a vapor deposition method, a sputtering method, or a CVD method can be used. When the film formation method by the dry process is used, the thin film 6 a made of organic semiconductor material has an uncovered area or a thin part (Fig. 9 (a)) in the stepped part such as the side of the 5 anode 5 Is done. This is considered to be due to the formation of a portion where the organic semiconductor material cannot be adhered, for example, by the vapor deposition material flow being blocked by the anode 5 according to the angle between the vapor deposition material source and the vapor deposition surface. In other words, it is considered that the anode 5 serves as a shielding portion 0 for the material flow depending on the incident angle of the material flow of the vapor deposition material from the vapor deposition material source toward the vapor deposition surface. In addition, when the end of the anode 5 is substantially parallel to the vapor deposition material flow, it is considered that the vapor deposition material is difficult to adhere to the end.

After the thin film 6a is produced, as shown in FIG. 9 (b), the organic semiconductor material of the thin film is fluidized and solidified to produce the organic semiconductor layer 6. The flow of the organic semiconductor material of the thin film is performed, for example, by heating the thin film above the glass transition temperature of the organic semiconductor material. -. By heating above the glass transition temperature, the thin film transitions from a crystalline state to an amorphous state and becomes fluid. Fluidized organic semiconductor • Material can move to the stepped part of the anode 5 by gravity and surface tension. The heating is performed using a heating means such as a hot plate or a halide lamp. It is also possible to completely melt the organic semiconductor material by setting the heating temperature to a temperature higher than the melting point. After flowing the organic semiconductor material, it cools and solidifies. As a result, as shown in FIG. 9B, the stepped portion is covered with the organic semiconductor material, and defects such as pinholes existing in the thin film are filled. Note that the method of causing the organic semiconductor material of the thin film formed by the dry process to flow is not limited to heating, for example, by exposing the thin film to a vapor of a solvent in which the organic semiconductor material is soluble. Done. The exposure to solvent vapor may be performed, for example, by inserting the entire substrate into a chamber full of solvent vapor. The solvent vapor can be obtained by heating the solvent to volatilize it or by using a spraying device. The thin film is placed in a solvent vapor atmosphere and fluidized, and then solidified by removing from the atmosphere. In some cases, it is preferable to remove the solvent contained in the organic semiconductor layer 6 by heating in order to volatilize it.

When the organic semiconductor layer 6 is a single layer including only a hole injection layer or a hole transport layer, a thin film of an organic semiconductor material constituting the hole injection layer or the hole transport layer is formed by a dry film formation method. Then, the organic semiconductor layer 6 is formed by heating or using solvent vapor to cause the organic semiconductor material to flow and solidify. In the case where the organic semiconductor layer 6 is composed of a plurality of layers of a hole injection layer and a hole transport layer, at least the hole injection layer is formed by fluidized solidification processing of the organic semiconductor material constituting the hole injection layer. Is preferred. In such a case, the organic semiconductor layer 6 is obtained by fluidizing and solidifying a thin film made of an organic semiconductor material in which the 5 hole injection layer has hole injection properties. It is most preferable that the hole transport layer is formed by fluid solidification treatment of a thin film made of an organic semiconductor material having hole transportability. 'After the organic semiconductor layer 6 is fabricated, the light emitting layer 7 is formed by using a dry process such as a vapor deposition method as shown in FIG.

5 On the light emitting layer 7 ′, the cathode 8 is formed as shown in FIG. 10 (b). A dry process such as vapor deposition is used to form the cathode 8. The cathode 8 is formed, and the organic EL element 1 is formed.

 As described above, in the step of forming the organic semiconductor layer 6, after forming a thin film made of the organic semiconductor material, it is subjected to 0 heat treatment or solvent vapor at a temperature equal to or higher than the glass transition temperature (T. g) of the organic semiconductor material. By dissolving the organic semiconductor material in this atmosphere, the contact between the anode 5 as the first electrode and the organic semiconductor layer 6 becomes good. That is, the contact area between the anode 5 and the organic semiconductor layer 6 is increased, and a good anode-organic semiconductor layer interface can be formed.

 In particular, since the contact between the anode 5 and the organic semiconductor layer 6 in the portion of the anode 5 that does not face the cathode 8 of the anode 5 such as the side portion of the anode 5 is good, an element that injects current from that portion. The carrier injection efficiency can be increased.

 Also, the step coverage of the organic semiconductor layer 6 is improved. As a result, the carrier injection efficiency from the anode 5 to the organic semiconductor layer 6 is improved.

 In addition, when a thin film of organic semiconductor material is formed using the CVD method and sputtering method, it is difficult to form a portion that is not formed or a portion that is thin compared to the evaporation method, and it is difficult for short circuits and leaks to occur. . As a result of the solidification treatment of the organic semiconductor material, the step coverage of the organic semiconductor layer 6 is improved, so that the carrier injection efficiency is improved.

In order to provide the electron transport layer 9 and / or the 5 electron injection layer 10 between the light emitting layer 7 and the cathode 8, if necessary, a film forming method such as a vapor deposition method after the light emitting layer 7 is formed. A thin film forming step of providing the electron transport layer 9 and Z or the electron injection layer 10 using the above may be performed.

 In addition, the organic EL device having the structure shown in FIG. 3, that is, the first electrode is the 'cathode 8', the second electrode is the anode 5, and the organic semiconductor layer 6 is the electron injection layer 10 and the electron transport layer 9 or In the case of manufacturing an organic EL element that is a combination of these, among the above-described manufacturing methods, almost the same process can be adopted up to the process of forming the insulator layer. After the insulating layer 4 is fabricated, the cathode 8 is formed using a dry process such as a vacuum deposition method using a metal mask. After the cathode 8 is formed, an organic semiconductor layer 6 made of a carrier transporting organic semiconductor material is formed in contact with the cathode 8. The organic semiconductor layer 6 is formed by forming a thin film made of an organic semiconductor material using a film forming method using a dry process such as an evaporation method, and subjecting the thin film organic semiconductor material to fluidization solidification treatment. Done. As described above, the organic semiconductor material is flowed and solidified by heating or using vapor. After the organic semiconductor layer 6 is formed, the light emitting layer 7 and the anode 5 are sequentially formed. Both layers are formed using a dry process such as vapor deposition. If necessary, a thin film forming step using a film forming method such as a vapor deposition method is performed to provide a hole transport layer and / or a hole injection layer between the light emitting layer 7 and the anode 5. Also good.

When the carrier regulating layer BF is provided between the first electrode and the organic semiconductor layer 6 as in the organic EL element shown in Fig. 4, the organic semiconductor layer 6 is formed after the first electrode is formed. Before being formed, the carrier regulating layer BF is formed using a dry process such as a vapor deposition method. When the first electrode is the anode 5 and made of gold, an aluminum film is formed by vacuum deposition using a metal mask having the same opening pattern as the mask used when the anode 5 is manufactured. The regulation layer BF may be produced. In the above embodiment, the organic EL element in which the light emitting layer is provided between the first electrode and the second electrode is described. However, the organic thin film semiconductor element of the present invention is It is not limited to a light emitting device, but may be an organic thin film transistor having a vertical MQS structure. The organic thin film transistor has substantially the same configuration as the organic EL element described above except that a light emitting layer is not provided between the first electrode and the second electrode.

 For example, as shown in 0 1 1, the organic thin film transistor 15 includes an auxiliary electrode provided on the substrate and serving as the gate electrode 1 ′ 6, and an insulating layer 4 provided on the gate electrode 16. A first electrode which is provided on the insulating layer 4 and serves as the source electrode 17; an organic semiconductor layer 6 which is in contact with the source electrode 17 and is made of a carrier-transporting organic semiconductor material; and an organic semiconductor layer A second electrode provided on 6 and serving as a drain electrode 18. The organic semiconductor layer 6 is formed by fluidizing and solidifying the organic semiconductor material. As such an organic semiconductor material, for example, 4,4′bis [N— (1 naphthyl) 1 N-phenylamino] —biphenyl (so-called N P B) can be used. , An auxiliary electrode provided on the substrate, an insulating layer provided on the auxiliary electrode, a first electrode provided on the insulating layer, and a carrier transport property in contact with the first electrode An organic semiconductor layer made of the organic semiconductor material, and a second electrode supported by the organic semiconductor layer, and the organic semiconductor layer is formed by fluidizing and solidifying the organic semiconductor material. According to the organic thin film semiconductor device of the present invention, the first electrode is completely covered with the organic semiconductor layer, and no defects such as pinholes are generated in the organic semiconductor layer. Occurrence can be prevented.

A step of providing an auxiliary electrode on the substrate; a step of providing an insulating layer on the auxiliary electrode; a step of providing a first electrode on the insulating layer; an organic material comprising a carrier transporting organic semiconductor material in contact with the first electrode; A step of providing a semiconductor layer and a step of forming a second electrode supported by the organic semiconductor layer. According to the method for producing an organic thin film semiconductor element of the present invention, the method includes a step of forming a thin film made of the organic semiconductor material using a process method and a fluidization treatment step of the organic semiconductor material of the thin film. Since the first electrode is completely covered with the organic semiconductor layer, the contact area between the organic semiconductor layer and the first electrode is increased, and the efficiency of carrier injection from the first electrode to the organic semiconductor layer can be improved. This application is based on Japanese Patent Application No. 2005-251409, and includes the disclosure content of the publication by using the publication.

Claims

The scope of the claims ' '1. An auxiliary electrode provided on the substrate, an insulating layer provided on the auxiliary electrode, a first electrode provided on the insulating layer, and in contact with the first electrode An organic semiconductor layer made of a carrier-transporting organic semiconductor material, and a second electrode supported by the organic semiconductor layer, and the organic semiconductor layer is formed by a fluidization solidification process of the organic semiconductor material. An organic thin film semiconductor element characterized by the above. 2. The area of the surface of the first electrode facing the second electrode is smaller than the area of the surface of the second electrode facing the first electrode. 1. The organic thin film semiconductor device according to 1. 3. The organic thin film semiconductor device according to claim 1, wherein a light emitting layer is provided between the organic semiconductor layer and the second electrode. 4. The first electrode according to claim 3, wherein the first electrode is an anode, the second electrode is a cathode, and the organic semiconductor layer is a hole injection layer, a hole transport layer, or a combination thereof. Organic thin film semiconductor element. 5. The organic thin film according to claim 3, wherein the first electrode is a cathode, the second electrode is an anode, and the organic semiconductor layer is an electron injection layer, an electron transport layer, or a combination thereof. Semiconductor element. ■ 6. Including a carrier restricting layer inserted in contact between the first electrode and the organic semiconductor layer. 2. The organic thin film semiconductor device according to claim 1, wherein 7. The organic thin film semiconductor device according to claim 6, wherein the first electrode defines a pattern for carriers passing through the organic semiconductor layer. 8. The organic thin film semiconductor device according to claim 6, wherein the carrier regulating layer is sandwiched between the first electrode and the second electrode. 9. A step of providing an auxiliary electrode on a substrate, a step of providing an insulating layer on the auxiliary electrode, a step of providing a first electrode on the insulating layer, and a carrier transporting organic semiconductor in contact with the first electrode A step of providing an organic semiconductor layer made of a material and a step of forming a second electrode that can be supported by the organic semiconductor layer. The step of providing the organic semiconductor layer includes the step of forming the organic semiconductor layer using a dry process method. A method of manufacturing an organic thin film semiconductor element, comprising: forming a thin film made of a material; and fluidizing and solidifying the organic semiconductor material of the thin film. 10. The method of manufacturing an organic thin film semiconductor device according to claim 9, wherein the dry process method is any one of an evaporation method, a CVD method, and a sputtering method. 11. The process for producing an organic thin film semiconductor device according to claim 9, wherein the fluidization treatment step includes a step of heating above the glass transition temperature of the organic semiconductor material. 10. The method of manufacturing an organic thin film semiconductor element according to claim 9, wherein the fluidized solidification treatment step includes a step of exposing the thin film to vapor of a solution in which the organic semiconductor material is soluble. ' '\ ¾¾  10. The method of claim 9, further comprising a step of forming a light emitting layer supported by the organic semiconductor layer after the step of providing the semiconductor layer and before the step of providing the second electrode. Manufacturing method of the organic thin film semiconductor element.