JP4046512B2 - Method for manufacturing light-emitting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a light-emitting device including a light-emitting element having a layer made of an organic compound (hereinafter referred to as an organic compound layer). In particular, the present invention relates to the organic compound and a method for stabilizing a light-emitting element containing the organic compound in a light emitter.
[0002]
[Prior art]
A light-emitting element (organic light-emitting element) in which an organic compound layer is interposed between a pair of electrodes has been attracting attention as a next-generation display device because of its wide viewing angle and excellent visibility. The light emitting mechanism of the organic light emitting device is excited by recombination of holes injected from one anode of a pair of electrodes and electrons injected from the other cathode in a light emitting organic compound layer (light emitting layer). It is considered as a phenomenon in which light is emitted when excitons return to the ground state. This light emission is called electroluminescence. Electroluminescence includes fluorescence and phosphorescence, and these include emission from a singlet state (fluorescence) in an excited state and emission from a triplet state (phosphorescence). Luminance by light emission is thousands to tens of thousands cd / m ² Therefore, it is considered that it can be applied to a display device or the like in principle. However, on the other hand, various deterioration phenomena exist and remain as problems that impede practical use.
[0003]
Although various configurations of the organic compound layer have been devised, the organic compound layer has a structure in which a hole injecting and transporting layer on the anode side, an electron injecting and transporting layer on the cathode side, a light emitting layer, and the like are appropriately combined. The hole injecting and transporting layer or the electron injecting and transporting layer is a material in which the efficiency of injecting holes or electrons from the electrode and the transportability (mobility) are particularly important characteristics. It is also said that there is a luminescent electron injecting and transporting layer that also has both.
[0004]
As organic compounds forming these layers, both low molecular organic compounds and high molecular organic compounds are known. An example of a low molecular weight organic compound is α-NPD (4,4′-bis- [N- (naphthyl) -N-phenyl-amino) which is a copper phthalocyanine (CuPc) aromatic amine material as a hole injection transport layer. ] Biphenyl), MTDATA (4,4 ', 4 "-tris (N-3-methylphenyl-N-phenyl-amino) triphenylamine), tris-8- as an electron injecting and transporting layer or a luminescent electron injecting and transporting layer Quinolinolato aluminum complex (Alq _Three ) Etc. are known. As the polymer organic light emitting material, polyaniline, polythiophene derivative (PEDOT) and the like are known.
[0005]
By the way, the organic light emitting element is known to have a deterioration phenomenon in which the light emission luminance is lower than that in the initial stage when light is emitted for a certain period. The presence of moisture has been pointed out as one of the causes of such deterioration. Moisture that has entered the organic light-emitting element reacts with the cathode and the organic compound in particular, causing chemical structural changes and peeling of the cathode or the organic compound layer, thereby causing irreversible deterioration.
[0006]
As measures for preventing such deterioration, as disclosed in Japanese Patent Application Laid-Open No. 2001-35659, a device such as disposing a desiccant-containing layer that adsorbs moisture on the inner surface of the cap that seals the organic light emitting element is provided. Is made.
[0007]
[Problems to be solved by the invention]
However, the sealing structure has been devised so that moisture entering from the outside can be adsorbed by the desiccant provided in the sealing cap, and even if the influence is eliminated, the deterioration of the organic light emitting device cannot be completely eliminated. .
[0008]
Therefore, the present inventor speculated that the organic compound layer formed of an amorphous material has a structure-induced instability as a cause of deterioration, which causes deterioration of the organic light emitting device. In general, it is known that organic molecules have a planar shape or a shape close to that, and relatively long molecules have a laminated structure extending in the c-axis (molecular long axis) direction. The problem caused by the structure here relates to the short-range order, and targets unbonded hands, fluctuations in the molecular structure or intermolecular bonds, and the like.
[0009]
In the first place, when a semiconductor or insulator film is formed by vacuum deposition, it is difficult to form a dense film, particularly when the substrate heating temperature is low. It can be easily assumed that this is the same for organic compound materials. Assuming that the dangling bonds formed in organic compounds are active, it is considered possible that they can bind to and react with moisture and other impurities, causing irreversible degradation. .
[0010]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique relating to an organic compound and a method for stabilizing a light-emitting element containing the organic compound in a light-emitting body.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, the present invention is to inactivate the dangling bonds present in the organic compound layer by terminating with hydrogen or a halogen element such as fluorine. That is, hydrogen or a halogen element is added to the organic compound layer so that the hydrogen or halogen element acts on the dangling bonds. In addition, as another effect to be considered, a hydrogen atom or a hydrogen molecule is inserted between molecules, and an effect of stabilizing the molecular structure or intermolecular bond is exhibited.
[0012]
Hydrogen or halogen elements are diffused into organic compounds by plasma treatment (diffusion from the gas phase) supplied from a glow discharge plasma of a gas containing the hydrogen or halogen elements using a coating containing hydrogen or halogen elements as a source (solid state). Diffusion from the phase) can be applied. Alternatively, the ions may be implanted by being accelerated by an electric field by an ion implantation method or an ion doping method. Furthermore, as another method, the organic light emitting element may be diffused by heating or generating heat in an atmosphere containing hydrogen or a halogen element.
[0013]
The plasma treatment is a method in which hydrogen or a gas containing a halogen element such as fluorine, chlorine, bromine, or iodine is turned into plasma, and generated radicals or ions are added to the organic compound layer. In order to add hydrogen or a halogen element by plasma treatment, there is a method performed after forming an organic compound layer and before forming an electrode to be a cathode or an anode. Another method is performed after an electrode to be a cathode or an anode is formed on the organic compound layer. In this case, when the metal is contained in the electrode material, such as nickel, which has a catalytic action for generating hydrogen from hydrogen molecules, a large number of atomic hydrogen is generated, and the effect can be increased.
[0014]
When a coating containing hydrogen or a halogen element such as fluorine, chlorine, bromine or iodine is used as a supply source, an amorphous carbon (aC: H) film or amorphous silicon that is hydrogenated or halogenated as the coating An (a-Si) film, a diamond-like carbon (DLC) film, an amorphous silicon nitride film, or the like can be used. These films are formed in contact with the organic light-emitting element, and thereafter, hydrogen in the film is released by heating, and can be added to the organic compound layer. As a heating method, it is appropriate to use a heating means such as an electric heater. However, as another method, the organic light emitting element can be self-heated by energizing and emitting light, thereby releasing hydrogen. When these films are formed by the plasma CVD method, hydrogen or halogen is supplied into the plasma, so that they can be added to the film at the time of formation.
[0015]
Amorphous carbon (a-C: H) film and diamond-like carbon (DLC) film are used as hydrocarbon-based gases. _Four , C ₂ H ₂ , C ₆ H ₆ Etc. are used as raw materials, and AC or DC power is applied to dissociate the gas to form plasma. In the case of forming an amorphous silicon (a-Si) film, SiH is used as a hydride or fluoride gas of silicon. _Four , Si ₂ H ₆ SiF or the like is used as a raw material gas. SiH when an amorphous silicon nitride film is used _Four , NH _Three , N ₂ Etc. are used as the raw material gas. These source gases may be mixed with hydrogen or halogen.
[0016]
In addition, H ₂ Or NH _Three Atmosphere or H ₂ Or NH _Three The organic light-emitting element may be heated or energized in an inert gas containing hydrogen to cause self-heating, and the added hydrogen or halogen element may be more actively reacted with dangling bonds.
[0017]
Further, when sealing the organic light emitting device, the sealed atmosphere is H ₂ Or NH _Three You may use the gas containing.
[0018]
As described above, the structure of the present invention is such that after forming an organic light-emitting element having a pair of electrodes, at least one of which is translucent, and a layer made of an organic compound material sandwiched between these electrodes, hydrogen or a halogen element is added. Hydrogen or a halogen element is added to the layer made of the organic compound material by exposing the organic light emitting element to the plasma contained therein.
[0019]
After forming one electrode and a layer made of an organic compound material, the layer made of the organic compound material is exposed to a plasma containing hydrogen or a halogen element to add hydrogen or a halogen element to the layer made of the organic compound material, and then The other electrode opposite to one electrode is formed.
[0020]
In another configuration, after forming an organic light-emitting element having a pair of electrodes, at least one of which is translucent, and a layer made of an organic compound material sandwiched between the electrodes, in an atmosphere containing hydrogen or a halogen element The organic light emitting element is heated or self-heated to add hydrogen or a halogen element to the layer made of the organic compound material.
[0021]
In another configuration, after forming an organic light-emitting element having a pair of electrodes, at least one of which is translucent, and a layer made of an organic compound material sandwiched between the electrodes, a hydride of carbon, a fluoride of carbon A protective film containing hydrogen or a halogen element is formed on the organic light emitting device by plasma CVD using one or more selected from silicon hydride and silicon fluoride as a source gas, and the organic light emitting device is heated or By self-heating, hydrogen or a halogen element contained in the protective film is added to a layer made of an organic compound material.
[0022]
In another structure, an organic light-emitting element having a pair of electrodes, at least one of which is light-transmitting, and a layer made of an organic compound material sandwiched between these electrodes is formed, and organic light emission is performed in plasma containing hydrogen or a halogen element. After exposing the device, a protective film containing hydrogen or a halogen element by plasma CVD using one or more kinds selected from carbon hydride, carbon fluoride, silicon hydride, silicon fluoride as a source gas Is formed on the organic light emitting element, and the organic light emitting element is heated or self-heated to add hydrogen or a halogen element contained in the protective film to the layer made of the organic compound material.
[0023]
The protective film is formed of diamond-like carbon, amorphous carbon, amorphous silicon, or amorphous silicon nitride. After forming the protective film, a passivation film made of a silicon nitride film is formed on the protective film by high-frequency sputtering using silicon as a target and nitrogen as a sputtering gas.
[0024]
In this way, the hydrogen or halogen element supplied to the organic compound layer can be inactivated by diffusing to a place where there is an active dangling bond and terminating the bond.
[0025]
FIG. 7 is a schematic diagram for explaining the behavior of the holes injected from the anode and the electrons injected from the cathode into the organic light emitting device using band diagrams. Types of defects formed in the organic compound layer include interface states, recombination centers, and trap centers. In FIG. 7A, (a) is a recombination process through an interface state, (b) is a recombination process through a recombination center, and (c) is an electron and hole trapped in a capture center. The process of recombination through a recombination center is shown.
[0026]
It is considered that electrons and holes recombine and disappear through these defects without contributing to light emission. The recombination may be radiant or non-radiative, and it is considered that new defects are generated by energy released as phonons.
[0027]
In the stabilization treatment in the present invention, defects in these organic compounds are compensated by hydrogen or a halogen element. When defects are compensated for by the stabilization treatment, the mobility of the injected electrons and holes is improved as shown in FIG. 7B, and the probability of singlet excitation or triplet excitation due to these carrier recombination is increased. The luminance can be improved. In addition, there is no negative cycle for promoting deterioration such as multiplication of defect generation, so that deterioration of luminance can be suppressed and reliability can be improved.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings. 1A and 1B illustrate the structure of a pixel portion of a light emitting device of the present invention. The light-emitting device shown here includes an organic light-emitting element having a pair of electrodes, at least one of which is translucent, and at least one organic compound material sandwiched between the electrodes, and the organic light-emitting element. A driving thin film transistor (TFT) is provided.
[0029]
The structure of the pixel portion shown in FIG. 1A is a form (downward emission type) in which light emitted from the organic light emitting element 32 is emitted to the translucent substrate 10 side. The organic light emitting device includes an anode 20 formed of a light-transmitting conductive film such as indium tin oxide (ITO), zinc oxide (ZnO), and indium zinc oxide (IZO), an organic compound layer 22, CsF, BaF, CaF, MgAg, The cathode 23 is formed using a conductive material containing an alkali metal or alkaline earth metal such as AlLi.
[0030]
When the organic compound layer 21 is formed of a low molecular organic compound, a hole injection transport layer formed of copper phthalocyanine (CuPc) and MTDATA and α-NPD which are aromatic amine materials, Tris-8-quinolino Latoaluminum complex (Alq _Three Can be formed by laminating the electron injection layer and the light-emitting layer formed in (1). Alq _Three Enables light emission (fluorescence) from a singlet excited state.
[0031]
In order to increase luminance, it is preferable to use light emission (phosphorescence) from a triplet excited state. In this case, a carbazole-based CBP + Ir (ppy) is formed on the hole injection transport layer formed of CuPc, which is a phthalocyanine-based material, and α-NPD, which is an aromatic amine-based material, as the organic compound layer 21. _Three Is used to form a light emitting layer, and bathocuproin (BCP) is used to form a hole blocking layer, Alq _Three It is also possible to have a structure in which the electron injection / transport layer is stacked.
[0032]
The above two structures are examples using a low molecular weight organic compound, but an organic light emitting device combining a high molecular weight organic compound and a low molecular weight organic compound can also be realized. For example, from the anode side as the organic compound layer 21, a hole injection transport layer by a polythiophene derivative (PEDOT) of a high molecular organic compound, a hole injection transport layer by α-NPD, CBP + Ir (ppy) _Three Light emitting layer, BCP hole blocking layer, Alq _Three An electron injecting and transporting layer may be laminated. By changing the hole injection layer to PEDOT, the hole injection characteristics can be improved and the light emission efficiency can be improved.
[0033]
In any case, light emission from the triplet excited state (phosphorescence) has higher emission efficiency than light emission from the singlet excited state (fluorescence), and the operating voltage (light emission from the organic light emitting element) can be obtained with the same light emission luminance. The voltage required for making it low) can be lowered.
[0034]
The TFT is preferably formed of a crystalline semiconductor film, and includes an active layer 12, a gate insulating film 13, and a gate electrode 14 that form a source and drain region in addition to a channel region as components, and the first inorganic insulating film 15 includes A protective film for the TFT is formed of silicon nitride or silicon oxynitride. Further, an organic insulating film 16 is formed of a material such as polyimide or acrylic for planarization, and the second inorganic insulating film 17 is formed of a silicon nitride film formed by a high frequency sputtering method. The organic light emitting element 32 is formed thereon. The wirings 17 and 18 are in contact with source or drain regions formed in the active layer 12 through contact holes that penetrate the second inorganic insulating film 17, the organic insulating film 16, and the first inorganic insulating film 15.
[0035]
The partition wall layer 21 is formed of an organic material, covers the end of the anode 20, and has an inclined surface of about 35 to 60 degrees.
[0036]
Stabilization treatment of the organic light emitting element, that is, addition of hydrogen or halogen element to the organic compound layer is performed by plasma treatment after forming the organic compound layer 22, method by plasma treatment after forming the cathode 23, cathode After forming 23, plasma treatment is performed to further form a protective film 23 containing hydrogen or halogen, and after forming the cathode 23, a protective film 23 containing hydrogen or halogen is used. The method of effectively releasing hydrogen or halogen from the protective film 23 and adding it to the organic compound layer includes a heat treatment at a temperature below the crystallization temperature of the organic compound material and a heat treatment of 50 to 200 ° C. Can be done. Energization is performed by applying direct current, alternating current, or pulse voltage.
[0037]
FIG. 8 shows an example of a pulse waveform to be applied. When intermittently applied while gradually increasing the forward voltage as shown in FIG. 8 (A), current flows concentratedly in the defective portion, and locally. It is possible to prevent the element from being heated to a high temperature to such an extent that the element is destroyed. FIG. 8B shows an example in which a reverse voltage is applied in addition to the pattern of FIG. The application of the reverse voltage is an effective treatment that prevents the ionic impurities in the organic light emitting element from segregating to one side and has a synergistic effect to improve the reliability of the element.
[0038]
The passivation film 25 formed on the uppermost layer is a high frequency sputtering method, using silicon as a target, and a silicon nitride film manufactured by a sputtering method is applied. The film forming conditions may be selected as appropriate, but particularly preferably, sputtering is performed by applying high frequency power using nitrogen or a mixed gas of nitrogen and argon as the sputtering gas. The substrate temperature is set to room temperature and the heating means may not be used. The dense silicon nitride film thus formed has a blocking effect that prevents moisture and oxygen from entering from the outside and prevents hydrogen or halogen from being diffused into the gas phase from the protective film.
[0039]
FIG. 1B shows a pixel portion in a form (upward emission type) in which light emitted from the organic light emitting element 33 is emitted to the side opposite to the substrate 10. The configuration of the TFT and the like below the organic light emitting element 33 is the same as that shown in FIG. It is connected to the cathode 26 which is one electrode of the organic light emitting element 33 connected to the wiring 18. The organic compound layer 27 is formed from the cathode side in the order of an electron injecting and transporting layer, a light emitting layer, and a hole injecting and transporting layer. A thin translucent metal layer 28 is provided between the anode 29 formed on the upper layer side. As the anode 29, a light-transmitting conductive film such as indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), or the like is formed by resistance heating evaporation. The metal layer 28 prevents the organic compound layer 27 from being damaged and the device characteristics from being deteriorated when the anode 29 is formed.
[0040]
The protective film 24, the passivation film 25, and the stabilization process that are formed thereafter are formed in the same manner as in FIG.
[0041]
Next, details of a manufacturing method of the light-emitting device of the present invention will be described. 3 to 5 show a method for manufacturing an organic light-emitting element and a stabilization process in the order of steps.
[0042]
In FIG. 3A, after the anode 301 and the partition layer 302 are formed, an organic compound layer 303 and a cathode 304 formed by stacking a hole injecting and transporting layer, a light emitting layer, and an electron injecting and transporting layer are formed. In FIG. 3B, a protective film 305 containing hydrogen or halogen is formed over the cathode 304 by a plasma CVD method at room temperature or by heating to about 50 to 200 ° C. When this protective film 305 is formed of a DLC film, as a hydrocarbon-based gas, CH _Four , C ₂ H ₂ , C ₆ H ₆ A mixed gas of hydrogen and hydrogen is used. A DLC film is a diamond-bonded SP as a carbon-carbon bond in a short-range order. ^Three Although it has a bond, macroscopically it is a graphite bond (SP ² It has an amorphous structure with a mixture of bonds. The composition of the DLC film is 95 to 70 atomic% for carbon and 5 to 30 atomic% for hydrogen, and is very hard and excellent in insulation. Such a DLC film is also characterized by low gas permeability such as water vapor and oxygen. Further, it is known to have a hardness of 15 to 25 GPa as measured by a micro hardness meter. Further, an amorphous carbon film may be formed without using DLC.
[0043]
The passivation film 306 is formed using a silicon nitride film formed by a high frequency sputtering method.
[0044]
In the stabilization treatment illustrated in FIG. 3C, an organic light-emitting element or a substrate on which the organic light-emitting element is formed is held in an inert gas, and heat treatment is performed at or below the crystallization temperature of the organic compound material. Although a specific heating temperature varies depending on the organic compound material to be used, it is performed at about 50 to 200 ° C. for about 10 to 120 minutes. By this heat treatment, hydrogen or halogen contained in the protective film 305 is released and can be added to the organic compound layer 303.
[0045]
As another method, the same effect can be obtained even if the organic light emitting element is subjected to an energization process to cause self-heating. When the energization process is performed, the defective portion where the current flows intensively is locally heated, so that the reaction of hydrogen or halogen element is particularly activated there.
[0046]
Hydrogen or halogen added to the organic compound layer 303 is inactivated by terminating dangling bonds existing in the organic compound layer. This reduces the rate of recombination via the recombination center, or from the capture center to the recombination via the recombination center, and the carrier recombination via the interface state. Such recombination of carriers is accompanied by phonon emission, which is considered to be a factor that promotes deterioration of the organic light-emitting device due to repeated bond breaking and recombination center generation. You can do it.
[0047]
The stabilization treatment shown in FIG. 4 is a method of introducing hydrogen or a halogen element from the gas phase by plasma treatment.
[0048]
4A, an anode 301, a partition layer 302, and an organic compound layer 303 are formed as in FIG. 3A. Thereafter, in this state, the stabilization process is continuously performed without exposure to the atmosphere. The stabilization treatment performed in FIG. 4B uses glow discharge plasma, and a gas containing hydrogen or halogen is turned into plasma and radicals or ions are added to the organic compound layer. In order to perform more effectively, it is desirable to heat the substrate to about 50 to 200 ° C.
[0049]
Further, an ion implantation method or an ion doping method may be applied as a method using ions.
[0050]
After that, the cathode 304, the protective film 305, and the passivation film 306 shown in FIG. 4C are formed. Further, stabilization processing may be performed as shown in FIG. This plasma treatment may be performed after the cathode 304 is formed. At this time, if a catalyst for generating hydrogen radicals such as nickel is added to the cathode material, the effect of hydrogenation can be further enhanced.
[0051]
FIG. 5 shows an example applied to a top emission type light emitting device. FIG. 5A shows a two-layer structure of an aluminum layer 312 and an alkali metal or alkaline earth metal layer 322 such as CaF or MgAg as an electrode on the cathode side. The alkali metal or alkaline earth metal layer 322 is formed after the partition layer 302 is formed, and has a thickness of 1 to 3 nm. An organic compound layer 303 is formed thereon in the order of, for example, an electron injecting and transporting layer, a light emitting layer, and a hole injecting and transporting layer.
[0052]
A thin translucent metal layer 323 is provided between the anode 324 formed on the upper layer side. For the anode 324, a light-transmitting conductive film such as indium tin oxide (ITO), zinc oxide (ZnO), or indium zinc oxide (IZO) is formed by resistance heating evaporation. The metal layer 323 prevents damage to the organic compound layer 303 and deterioration of device characteristics when forming the anode 324.
[0053]
Thereafter, in FIG. 5B, a protective insulating film 305 and a passivation film 306 containing hydrogen or halogen are formed in the same manner. Further, stabilization processing is performed as shown in FIG.
[0054]
A cross-sectional view of the light-emitting device illustrated in FIG. 6 illustrates the structure of the pixel portion 401, the driver circuit portion 402, and the input terminal portion 403. In the organic light emitting device, individual electrodes 451 and 452 formed as anodes or cathodes and a partition layer 460 covering the end portions are formed, and the organic compound layer 461, the cathode 462, and the protective film 463 are formed between the plurality of individual electrodes. It is formed regularly. Of course, the organic compound layer 461 is formed in this manner when emitting light in a single color, but in the case of R, G, B color display, it is formed according to each color. It ’s fine.
[0055]
The organic light emitting elements 441 and 442 are hermetically sealed by a sealing material 471 and a sealing material 470 for fixing the sealing material 471. This sealed space is filled with a gas such as nitrogen and hydrogen or nitrogen and ammonia. In this state, the organic light emitting element is energized and turned on to generate heat. Accordingly, a part of hydrogen in the sealed space diffuses into the organic compound layer and can be stabilized.
[0056]
An example of a manufacturing apparatus for manufacturing such a light emitting device is shown in FIG. In the apparatus shown here, formation of an organic compound layer, formation of a cathode, formation of a protective film and a passivation film, plasma treatment, and sealing can be performed without being continuously exposed to the atmosphere.
[0057]
2, 100a to 100k and 100m to 100u are gates, 101 and 119 are delivery chambers, 102, 104a, 107, 108, 111 and 114 are transfer chambers, 105, 106R, 106B, 106G, 109, 110, 112, Reference numeral 113 denotes a film formation chamber, 103 denotes a pretreatment chamber, 117a and 117b denote sealing substrate loading chambers, 115 denotes a dispenser chamber, 116 denotes a sealing chamber, 118 denotes an ultraviolet irradiation chamber, and 120 denotes a substrate reversing chamber.
[0058]
Hereinafter, a procedure for carrying a substrate provided with TFTs in advance into the manufacturing apparatus shown in FIG. 2 and forming the laminated structure shown in FIG. 5 will be described.
[0059]
First, a substrate provided with a TFT and a cathode is set in the delivery chamber 101. Next, it is transferred to a transfer chamber 102 connected to the delivery chamber 101. In advance, it is preferable to bring the atmosphere to atmospheric pressure by introducing an inert gas after evacuation so that moisture and oxygen do not exist in the transfer chamber as much as possible.
[0060]
The transfer chamber 102 is connected to an evacuation chamber that evacuates the transfer chamber. As the vacuum evacuation processing chamber, a magnetic levitation type turbo molecular pump, a cryopump, or a dry pump is provided. As a result, the ultimate vacuum in the transfer chamber is reduced to 10 ^-Five -10 ^-6 Pa can be set, and the back diffusion of impurities from the pump side and the exhaust system can be controlled. In order to prevent impurities from being introduced into the apparatus, an inert gas such as nitrogen or a rare gas is used as the introduced gas. These gases introduced into the apparatus are those purified by a gas purifier before being introduced into the apparatus. Therefore, it is necessary to provide a gas purifier so that the gas is introduced into the film forming apparatus after being highly purified. Thereby, oxygen, water, and other impurities contained in the gas can be removed in advance, so that these impurities can be prevented from being introduced into the apparatus.
[0061]
Further, in order to remove moisture and other gases contained in the substrate, it is preferable to perform annealing for deaeration in a vacuum, and the substrate is transferred to a pretreatment chamber 103 connected to the transfer chamber 102, where annealing is performed. Just do it. Further, if it is necessary to clean the surface of the cathode, it may be transferred to a pretreatment chamber 103 connected to the transfer chamber 102 and cleaned there.
[0062]
A poly (ethylenedioxythiophene) / poly (styrene sulfonic acid) aqueous solution (REDOT / PSS) may be formed on the entire surface of the cathode as a hole injection / transport layer. The manufacturing apparatus of FIG. 2 is provided with a film forming chamber 105 for forming an organic compound layer made of a polymer. In the case of forming by a spin coating method, an ink jet method, or a spray method, the substrate is set with the deposition surface of the substrate facing upward at atmospheric pressure. A substrate is appropriately reversed in a substrate reversing chamber 120 provided between the film forming chamber 105 and the transfer chamber 102. In addition, after film formation using an aqueous solution, it is preferably transferred to the pretreatment chamber 103 where heat treatment is performed in a vacuum to vaporize moisture.
[0063]
Next, after the substrate 104c is transferred from the transfer chamber 102 to the transfer chamber 104 without being exposed to the atmosphere, the substrate 104c is transferred to the film formation chamber 106R by the transfer mechanism 104b, and an organic compound layer that emits red light is appropriately formed on the cathode 200. To do. Here, an example of forming by vapor deposition is shown. In the film formation chamber 106R, the substrate inversion chamber 120 is set with the film formation surface of the substrate facing downward. Note that the film formation chamber is preferably evacuated before the substrate is carried in.
[0064]
For example, the degree of vacuum is 1 × 10 ^-2 Pa or less, preferably 10 ^-Four -10 ^-6 Deposition is performed in the film forming chamber 106R evacuated to Pa. At the time of vapor deposition, the organic compound is vaporized in advance by resistance heating, and is scattered in the direction of the substrate by opening a shutter (not shown) at the time of vapor deposition. The vaporized organic compound is scattered upward and deposited on the substrate through an opening (not shown) provided in a metal mask (not shown). Note that the temperature of the substrate (T ₁ ) Is 50 to 200 ° C, preferably 65 to 150 ° C.
[0065]
When forming a pixel for color display, three types of organic compound layers are formed. This may be formed by sequentially forming the film in each of the film formation chambers 106G and 106B after forming the film in the film formation chamber 106R.
[0066]
After a desired organic compound layer is formed on the cathode, the substrate is transferred from the transfer chamber 104 to the transfer chamber 107 without being exposed to the atmosphere, and then further transferred from the transfer chamber 107 to the transfer chamber 108 without being exposed to the atmosphere. Transport the substrate to
[0067]
At this stage, the substrate may be transferred to the plasma treatment chamber, a non-deposition gas containing hydrogen or a halogen element may be introduced, and plasma treatment may be performed to add hydrogen or halogen to the organic compound layer.
[0068]
The anode is formed by a transfer mechanism installed in the transfer chamber 108 and transferred to the film formation chamber 110, a thin metal layer is formed on the organic compound layer, and then transferred to the film formation chamber 109 to transmit light. A conductive film is formed, and an anode composed of a thin metal layer and a light-transmitting conductive film is appropriately formed. Here, the film formation chamber 110 is a vapor deposition apparatus provided with Mg and Ag as a vapor deposition source, and the film formation chamber 109 is a sputtering apparatus having at least a target made of a transparent conductive material.
[0069]
Next, the film 203 is transferred to the film formation chamber 113 by a transfer mechanism installed in the transfer chamber 108, and the film 203 containing hydrogen is formed in a temperature range that the organic compound layer can withstand. Here, a plasma CVD apparatus is provided in the film formation chamber 113, and the reaction gas used for film formation is hydrogen gas and a hydrocarbon-based gas (for example, CH _Four , C ₂ H ₂ , C ₆ H ₆ Etc.) to form a DLC film containing hydrogen. Note that there is no particular limitation as long as a means for generating hydrogen radicals is provided, and when the DLC film containing hydrogen is formed, defects in the organic compound layer are terminated with hydrogen by plasma hydrogen.
[0070]
Next, the film is transferred from the transfer chamber 108 to the film formation chamber 109 without being exposed to the air, and a passivation is formed over the protective film containing hydrogen or halogen. Here, a sputtering apparatus provided with a target made of silicon or a target made of silicon nitride in the film formation chamber 109 is used. The silicon nitride film can be formed by setting the film formation chamber atmosphere to a nitrogen atmosphere or an atmosphere containing nitrogen and argon.
[0071]
Through the above steps, the organic light emitting device can be covered with the stacked structure shown in FIG. 5, that is, the passivation film and the protective film containing hydrogen or halogen on the substrate.
[0072]
Next, the substrate on which the organic light emitting element is formed is transferred from the transfer chamber 108 to the transfer chamber 111 without being exposed to the atmosphere, and further transferred from the transfer chamber 111 to the transfer chamber 114. The substrate on which the organic light emitting element is formed is transferred from the transfer chamber 114 to the sealing chamber 116. Note that a sealing substrate provided with a sealant is preferably prepared in the sealing chamber 116.
[0073]
The sealing material is set to the sealing material load chambers 117a and 117b from the outside. In order to remove impurities such as moisture, it is preferable to perform annealing in advance in vacuum, for example, annealing in the sealing material load chambers 117a and 117b. In the case of forming a sealing material on the sealing substrate, after the transfer chamber 108 is set to atmospheric pressure, the sealing substrate is transferred from the sealing substrate load chamber to the dispenser chamber 115, and the substrate provided with the light emitting element. And a sealing material on which the sealing material is formed is transported to the sealing chamber 116.
[0074]
Next, in order to deaerate the substrate on which the organic light emitting element is provided, after annealing in a vacuum or an inert atmosphere, a sealing substrate on which a sealing material is provided and a substrate on which the organic light emitting element is formed are provided. to paste together. The sealed space is filled with an inert gas such as nitrogen or helium, or a gas obtained by mixing the inert gas with hydrogen or ammonia. Note that, here, an example in which the sealing material is formed on the sealing substrate is shown; however, there is no particular limitation, and the sealing material may be formed on the substrate on which the light emitting element is formed.
[0075]
Next, the pair of bonded substrates is transferred from the transfer chamber 114 to the ultraviolet irradiation chamber 118. Next, the sealing material is cured by irradiating UV light in the ultraviolet irradiation chamber 118. In addition, although ultraviolet curable resin was used here as a sealing material, if it is an adhesive material, it will not specifically limit. Next, the transfer chamber 114 is transferred to the delivery chamber 119 and taken out.
[0076]
As described above, by using the manufacturing apparatus illustrated in FIG. 2, it is not necessary to expose the light-emitting element to the outside air until the light-emitting element is completely enclosed in the sealed space, so that a highly reliable light-emitting device can be manufactured. In the transfer chambers 102 and 114, vacuum and atmospheric pressure are repeated, but the transfer chambers 104a and 108 are always kept in vacuum. Note that an in-line film forming apparatus may be used.
[0077]
As described above, a light emitting device can be formed by sealing an organic light emitting element. Thereafter, more preferably, stabilization treatment may be performed to diffuse hydrogen or halogen into the organic compound layer. Hydrogen or halogen supplied to the organic compound layer diffuses to a place where there is an active dangling bond and can be deactivated by terminating the bond.
[0078]
【The invention's effect】
As described above, hydrogen or halogen element is added to inactivate dangling bonds present in the organic compound layer, thereby suppressing deterioration in luminance of the organic light emitting element and obtaining a highly reliable light emitting device. be able to.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view illustrating a configuration of a pixel portion and a structure of an organic light emitting element formed in the pixel portion in a light emitting device of the present invention.
FIG. 2 is a diagram showing an example of a structure of a manufacturing apparatus suitable for manufacturing a light-emitting device of the present invention.
FIG. 3 is a longitudinal sectional view showing a method for manufacturing an organic light-emitting element in the present invention.
FIG. 4 is a longitudinal sectional view showing a method for manufacturing an organic light-emitting element in the present invention.
FIG. 5 is a longitudinal sectional view showing a method for manufacturing an organic light-emitting element in the present invention.
FIG. 6 is a longitudinal sectional view illustrating the structure of a light-emitting device of the present invention.
FIG. 7 is a band diagram for explaining a difference in characteristics of an organic light-emitting element depending on the presence or absence of stabilization treatment.
FIG. 8 is a schematic diagram for explaining an AC voltage applied in a stabilization process.

Claims (5)

After forming the organic light emitting element having at least one of an organic compound material sandwiched between a pair of electrodes and these electrodes are light-transmitting layer, amorphous carbon containing Ha androgenic element by the flop plasma CVD film, a protective film made of either amorphous silicon film and the amorphous silicon nitride film is formed on the organic light-emitting device, by heating or self-heating of the organic light emitting device, Ruha androgenic elements to contain said protective film Is added to the layer made of the organic compound material. An organic light-emitting device having a pair of electrodes at least one of which is light-transmitting and a layer made of an organic compound material sandwiched between these electrodes is formed, and the organic light-emitting device is exposed to plasma containing hydrogen or a halogen element after the amorphous carbon film containing the Ha androgenic element by the flop plasma CVD, the protective film made of either amorphous silicon film and the amorphous silicon nitride film is formed on the organic light-emitting device, heating the organic light emitting device or by self-heating, a method for manufacturing a light emitting device characterized by adding Ruha androgenic element to contain the protective film in the layer composed of the organic compound material. After forming the organic light emitting element having at least one of an organic compound material sandwiched between a pair of electrodes and these electrodes are light-transmitting layer, amorphous carbon containing Ha androgenic element by the flop plasma CVD A protective film made of any one of a film, an amorphous silicon film and an amorphous silicon nitride film is formed on the organic light emitting device, and silicon nitride is formed on the protective film by a high frequency sputtering method using silicon as a target and nitrogen as a sputtering gas. forming a passivation film made of a film, it said by heating or self-heating the organic light-emitting element, a light-emitting device characterized by adding Ruha androgenic element to contain the protective film in the layer composed of the organic compound material Manufacturing method. An organic light-emitting device having a pair of electrodes at least one of which is light-transmitting and a layer made of an organic compound material sandwiched between these electrodes is formed, and the organic light-emitting device is exposed to plasma containing hydrogen or a halogen element after the amorphous carbon film containing the Ha androgenic element by the flop plasma CVD, the protective film made of either amorphous silicon film and the amorphous silicon nitride film is formed on the organic light-emitting device, high-frequency sputtering on the protective layer by law, a silicon as a target, the nitrogen as a sputtering gas to form a passivation film made of a silicon nitride film, by heating or self-heating of the organic light emitting device, wherein the Ruha androgenic element to contain said protective film A method for manufacturing a light-emitting device, which is added to a layer made of an organic compound material. 5. The self-heating of the organic light emitting device according to claim 1, wherein the organic light emitting device is intermittently applied while gradually increasing a forward voltage, or gradually applied to the organic light emitting device. A method for manufacturing a light-emitting device, wherein a forward voltage and a reverse voltage that are increased alternately are applied alternately.

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