JP2002208477A - Light emission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a pixel part from generating cracks by relaxing thermal stress. SOLUTION: On the upper layer of a thin film transistor used for an active matrix light emitting device, the third insulation layer made of silicon nitride or silicon nitric oxide is formed together with a positive electrode, an organic compound layer, and a negative electrode containing alkali metal between the fourth insulation layer, made of carbon as a main component and the third insulation layer. The light emitting element is formed between reverse tapered shaped separation walls made of insulation material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminous body capable of obtaining luminescence (electroluminescence) generated by applying an electric field, and a luminous device using the luminous body. In particular, the present invention relates to a light emitting device using an organic compound as a light emitter. Electroluminescence includes fluorescence and phosphorescence, and the present invention relates to a light-emitting device using light emission by one or both of them.

[0002]

2. Description of the Related Art A display device using a liquid crystal uses a backlight or a front light as a typical form, and is a mechanism for displaying an image by the light. 2. Description of the Related Art Liquid crystal display devices have been employed as image display means in various electronic devices, but have drawbacks due to a structure such as a narrow viewing angle. On the other hand, a display device using a luminous body capable of obtaining electroluminescence has attracted attention as a next-generation display device because of its wide viewing angle and excellent visibility.

A light emitting device using an organic compound as a light emitting body (hereinafter referred to as an organic light emitting device) has a structure in which a hole injection layer, a hole transport layer, and a light emitting layer formed of an organic compound are provided between a cathode and an anode. , An electron transport layer, an electron injection layer, and the like. Here, the hole injection layer and the hole transport layer are distinguished from each other, but they are the same in that the hole transport property (hole mobility) is a particularly important property. For convenience, the hole injection layer is a layer in contact with the anode, and the layer in contact with the light emitting layer is called a hole transport layer. The layer in contact with the cathode is called an electron injection layer, and the layer in contact with the light emitting layer is called an electron transport layer.
The light emitting layer may also serve as an electron transport layer, and is also called a light emitting electron transport layer. A light emitting element formed by combining these layers exhibits rectification characteristics and has a structure similar to a diode.

The light-emitting mechanism is such that electrons injected from a cathode and holes injected from an anode recombine in a layer (light-emitting layer) composed of a light-emitting body to form an exciton, and the exciton is in a ground state. It is considered as a phenomenon that emits light when returning to.
The excited state includes light emission from a singlet state (fluorescence) and light emission from a triplet state (phosphorescence). Brightness is thousands to tens of thousands cd
/ M ² , it is considered that application to a display device or the like is possible in principle. However, on the other hand, there are various deterioration phenomena, which remain as problems that hinder practical use.

[0005] Factors that cause deterioration of a luminous body or an organic light-emitting element made of an organic compound include (1) chemical deterioration of the organic compound (via an excited state), (2) melting of the organic compound due to heat generation during driving, (3) breakdown due to macro defects (4) deterioration of electrode or electrode / organic layer interface, (5)
There have been considered five types of degradation due to instability in the amorphous structure of the organic compound.

The above (1) to (3) are deteriorated by driving the organic light emitting device. Heat generation is inevitably generated by converting current in the element into Joule heat. If the melting point or glass transition temperature of the organic compound is low, it is considered that the organic compound is melted. In addition, the presence of pinholes and scratches causes the electric field to concentrate on those portions, causing dielectric breakdown. (4) and (5) deteriorate even when stored at room temperature. (4) is known as a dark spot and is caused by oxidation of the cathode and reaction with moisture. In (5), all organic compounds used in the organic light-emitting device are amorphous materials, and it is thought that there are few compounds that can be stored stably for a long period of time, change over time, or generate heat to stably store the amorphous structure. .

Although the dark spot has been considerably suppressed by the improvement of the sealing technique, the actual deterioration is caused by a combination of the above-mentioned factors, and it is difficult to uniformly understand the deterioration. A typical sealing technique is known as a method of sealing an organic light emitting element formed on a substrate with a sealing material and providing a desiccant in the space. However, it is considered that the phenomenon that, when a constant voltage is continuously applied, the emission luminance decreases with a decrease in the current flowing through the organic light emitting element is caused by the physical properties of the organic compound.

As organic compounds for forming an organic light emitting device, both low molecular weight organic compounds and high molecular weight organic compounds are known. One example of the low molecular weight organic compound is α-NPD (4,4′-bis- [N- (naphthyl) -N-phenyl-amino], which is a copper phthalocyanine (CuPc) aromatic amine-based material as a hole injection layer. Biphenyl) and MTDATA (4,4 ', 4 "-
Tris (N-3-methylphenyl-N-phenyl-amino) triphenylamine) and tris-8-quinolinolato aluminum complex (Alq ₃ ) as a light emitting layer are known.
As polymer organic light emitting materials, polyaniline, polythiophene derivatives (PEDOT) and the like are known.

[0009] From the viewpoint of the variety of materials, it is said that low molecular weight organic compounds produced by vapor deposition have much greater diversity than high molecular weight organic materials. However, in any case, organic compounds made of purely basic structural units are rare, and heterogeneous bonds and impurities are mixed in during the production process, and various additives such as pigments may be added. . Further, these materials include materials that are deteriorated by moisture, materials that are easily oxidized, and the like. Moisture and oxygen can be easily mixed in from the atmosphere, and care must be taken when handling.

[0010]

When an organic compound undergoes photodegradation, the chemical bond becomes a double bond and a structure containing oxygen (-
OH, -OOH,> C = O, -COOH, etc.). Therefore, when an organic compound is placed in an atmosphere containing oxygen, or when oxygen or H
_When 2O is contained as an impurity, it is considered that the bonding state changes and deterioration is promoted.

In the field of semiconductor technology, in a semiconductor device having a semiconductor junction such as a diode, impurities caused by oxygen form localized levels in a forbidden band,
It is known that this causes a reduction in junction leak and carrier lifetime, and significantly lowers the characteristics of a semiconductor device.

The oxygen molecule is a unique molecule in a ground state triplet state because the highest occupied level (HOMO) of the molecular orbital is degenerate. Normally, a triplet to singlet excitation process is hard to occur because of a forbidden transition (spin forbidden), so that a singlet state oxygen molecule is not generated. However, when the triplet-like excited state of molecules of higher energy state than the singlet state to the ambient oxygen molecules ⁽³ M *) is present, by happens energy transfer as described below, the oxygen molecules in the singlet state The reaction that takes place can be guided.

[0013]

(Equation 1)

It is said that 75% of the excited states of the molecules in the light emitting layer of the organic light emitting device are in a triplet state. Therefore, when oxygen molecules are mixed in the organic light emitting device,
The energy transfer of Equation 1 can generate a singlet state oxygen molecule. Since an oxygen molecule in a singlet excited state has an ionic (charge is biased) property, it is conceivable that the oxygen molecule may react with a charge bias generated in an organic compound.

For example, bathocuproin (hereinafter, BCP)
), The carbon directly bonded to the conjugated ring is positively charged because the methyl group is electron donating. As shown in the following chemical formula 1, singlet oxygen having ionic properties may react with positively charged oxygen molecules to form carboxylic acid and hydrogen as shown in the following chemical formula 2. As a result, the electron transportability is expected to decrease.

[0016]

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[0017]

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Based on these considerations, the present inventor has found that in organic light-emitting devices and organic light-emitting devices using the same, impurities such as oxygen and H ₂ O contained in the organic compounds cause various problems such as a decrease in luminance. Has been found to be an impurity that causes the degradation of

In an organic light-emitting device having a layer made of an organic compound between a cathode and an anode, and a light-emitting device constituted by using the organic light-emitting device, deterioration of the electrode material such as decrease in luminance and dark spots is prevented. It is necessary to reduce the resulting oxygen concentration.

A preferable application example using an organic light emitting element is a light emitting device of an active matrix drive system in which a pixel portion is formed by the organic light emitting element. Each pixel is provided with a thin film transistor (hereinafter, referred to as TFT) as an active element. However, it is known that a TFT formed using a semiconductor film varies in characteristic values such as a threshold voltage due to contamination of an alkali metal. The present invention relates to an organic light emitting device and a TFT using an alkali metal having a small work function for a cathode.
A suitable structure for forming a pixel portion by combining the above is required.

An active matrix driving type light-emitting device in which a pixel portion is formed by combining an organic light-emitting element and a TFT is formed by appropriately combining a semiconductor material containing silicon as a main component, an inorganic insulating material containing silicon as a component, or an organic insulating material. It is composed. Since the external quantum efficiency of the organic light emitting device is still less than 50%, most of the injected carriers are converted into heat and heat the light emitting device. As a result, thermal stress is applied to the light emitting element, and thermal stress acts on each of the layers forming the pixels. If the force is large, cracks occur.

In view of the above problems, it is an object of the present invention to prevent deterioration of a light emitting device due to chemical and physical factors and improve reliability.

[0023]

According to the present invention, in order to prevent the deterioration of the light emitting device, it is desirable to reduce oxygen and impurities including oxygen such as H ₂ O contained in the organic compound forming the organic light emitting element. Features. Of course, oxygen, hydrogen, and the like are included as constituent elements of the organic compound. However, in the present invention, the impurity for the organic compound refers to an exogenous impurity that is not included in the original molecular structure. Such impurities are considered to be present in the organic compound as atoms, molecules, free radicals, and oligomers.

Further, according to the present invention, in a light emitting device driven by an active matrix, a structure is provided for preventing alkali metal such as sodium, potassium or the like from contaminating the TFT and preventing fluctuation of threshold voltage.

The present invention removes such impurities to form a layer made of an organic compound used for forming an organic light emitting device such as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. The concentration of the impurity contained is 5 × 10 ¹⁹ / cm ³ or less at the average concentration, preferably 1 × 10 ¹⁹ / cm ³ or less.
Reduce to ¹⁹ / cm ³ or less. In particular, it is required to reduce the oxygen concentration in the light emitting layer and its vicinity.

When the organic light-emitting device emits light at a luminance of 1000 Cd / cm ² , it can be converted into 10 ¹⁶ photons / photon.
It corresponds to the amount of release of sec · cm ² . Assuming that the quantum efficiency of the organic light emitting device is 1%, the required current density is 100 m
A / cm ² is required. According to an empirical rule based on a semiconductor element such as a solar cell or a photodiode using an amorphous semiconductor, in order to obtain good characteristics in an element in which such a current flows, it is necessary to reduce the defect level density to 10 ¹⁶ / Cm ³
It must be: In order to realize that value, the concentration of the vicious impurity element that forms the defect level is set to 5 as described above.
It is necessary to reduce the density to not more than × 10 ¹⁹ / cm ³ , preferably not more than 1 × 10 ¹⁹ / cm ³ .

In order to reduce impurities in an organic compound for forming an organic light emitting device, a manufacturing apparatus for forming the same has the following configuration.

In a vapor deposition apparatus for forming a layer made of a low molecular weight organic compound, the inner wall surface of the reaction chamber is mirror-polished by electrolytic polishing to reduce the amount of gas released. The material of the reaction chamber is stainless steel or aluminum. For the purpose of preventing gas release from the inner wall, a baking process is performed by providing a heater outside the reaction chamber. Outgassing can be considerably reduced by the baking process, but it is preferable to conversely cool with a refrigerant during vapor deposition. The exhaust system uses a turbo molecular pump and a dry pump to prevent reverse diffusion of oil vapor from the exhaust system. Further, a cryopump may be provided to remove the remaining H ₂ O.

Although the evaporation source is basically a resistance heating type, a Knudsen cell may be used. The material for vapor deposition is carried in from a load-lock type exchange room attached to the reaction chamber. Thus,
Minimize the opening of the reaction chamber to the atmosphere when mounting the deposition material.
The evaporation source is mainly an organic material, but sublimation purification is performed inside the reaction chamber before vapor deposition. In addition, a zone refining method (zone refining) may be applied.

In the pretreatment of the substrate to be introduced into the reaction chamber, a gas release process by heating or a plasma process using argon is performed to reduce impurities released from the substrate as much as possible. In a light emitting device driven by an active matrix, TFTs are formed in advance on a substrate on which an organic light emitting element is formed. When an insulating layer using an organic resin material or the like is appropriately used as a component of the substrate, it is necessary to reduce gas emission from the member. Further, nitrogen gas or argon gas introduced into the reaction chamber is purified at a supply port.

On the other hand, when a layer composed of a high molecular weight organic compound is formed, the degree of polymerization cannot be completely controlled, so that the molecular weight may vary and the melting point may not be determined uniquely. In that case, a dialysis method or a high performance liquid chromatography method is suitable. In particular, in the dialysis method, the electrodialysis method is suitable for efficiently removing ionic impurities.

In the active matrix driving method in which a pixel portion is formed by the organic light emitting element thus formed and each pixel of the pixel is controlled by an active element, as one form of the structure, a semiconductor film and a gate insulating film are formed on a substrate. A TFT having a gate electrode is formed, and an organic light emitting element is formed thereover. A typical example of a substrate to be used is a glass substrate, and barium borosilicate glass and aluminoborosilicate glass contain a trace amount of an alkali metal. The semiconductor film is covered with silicon nitride or silicon oxynitride in order to prevent contamination by an alkali metal from the lower glass substrate and the upper organic light emitting element.

On the other hand, an organic light emitting element desirably formed on a flattened surface is formed on a flattening film made of an organic resin material such as polyimide or acrylic. However, such an organic resin material has hygroscopicity. An organic light emitting element that is degraded by oxygen or H ₂ O is covered with silicon nitride, silicon oxynitride, or diamond-like carbon (DLC) having gas barrier properties.

FIG. 12 is a diagram for explaining the concept of the active matrix driving type light emitting device of the present invention. As components of the light emitting device 1200, a TFT 1201 and an organic light emitting element 1202 are formed on the same substrate. T
The components of the FT 1201 are a semiconductor film, a gate insulating film, a gate electrode, and the like, and include silicon, hydrogen,
Examples include oxygen, nitrogen, and other metals that form a gate electrode. On the other hand, the organic light emitting element 1202 contains an alkali metal such as lithium as an element in addition to carbon as a main constituent of the organic compound material.

The lower side of the TFT 1201 (glass substrate 12
On the 03 side), silicon nitride or silicon oxynitride 1205 is formed as a blocking layer. On the opposite upper layer side, silicon oxynitride 1206 is formed as a protective film. On the other hand, below the organic light emitting element 1202, silicon nitride or silicon oxynitride 1207 is formed as a protective film. In addition, as the protective film, aluminum oxide, aluminum nitride, aluminum oxynitride, or the like can be used. A particularly suitable protective film is a silicon nitride film formed by a sputtering method. A DLC film 1208 is formed as a protective film on the upper layer side.

An organic resin interlayer insulating film 1204 is formed and integrated between the TFT and the organic light emitting element. Alkali metals such as sodium which the TFT 1201 dislikes most are blocked by silicon nitride or silicon oxynitride 1205 or silicon oxynitride 1206. on the other hand,
Since the organic light emitting device 1202 dislikes oxygen and H ₂ O most,
In order to block this, a silicon nitride or silicon oxynitride 1207 and a DLC film 1208 are formed.
Further, they also have a function of keeping the alkali metal element of the organic light-emitting element 1202 from outside.

In the light emitting device constituted by combining the TFT and the organic light emitting element in this manner, an insulating film having a blocking property against oxygen and H ₂ O is skillfully combined in order to satisfy the contradictory properties against impurity contamination. Form.

Based on the above components, a light emitting element having an anode, an organic compound layer, and a cathode containing an alkali metal is formed between partition layers made of an insulating material. The partition layer has a shape in which an upper portion protrudes in a direction parallel to the substrate (a so-called overhang shape), and has a structure in which the organic compound layer of the organic light-emitting element and the cathode layer are not in contact with each other.

The purification of the organic compound material for forming the light-emitting element and the prevention of impurities from being mixed during film formation and the high purity of the organic compound layer can prevent a decrease in luminance and a deterioration of the cathode layer. Further, by providing an inorganic insulating layer made of silicon nitride or silicon oxynitride between the light emitting element and the TFT, the alkali metal element forming the cathode layer can be TF
Diffusion into the semiconductor film constituting T can be prevented. In the light-emitting element, the partition layer has an overhang shape, and the organic compound layer and the cathode layer of the organic light-emitting element have a structure in which the cathode layer is not in contact with the light-emitting element. Physical damage can be prevented from occurring. Then, by such an operation, the reliability of the light emitting device can be improved.

[0040] In this specification, the term "light-emitting device" refers to any device using the light-emitting body. A module in which a TAB (Tape Automated Bonding) tape or a TCP (Tape Carrier Package) is attached to an element having a layer containing the luminous body between an anode and a cathode (hereinafter referred to as a light-emitting element); a TAB tape or a TCP A module in which a printed wiring board is provided first, or a module in which an IC is mounted on a substrate on which a light-emitting element is formed by a COG (Chip On Glass) method are all included in the category of the light-emitting device.

The oxygen concentration as an impurity element in the present specification refers to the lowest concentration measured by secondary ion mass spectrometry (SIMS).

[0042]

[Embodiment 1] An example of an organic light emitting element manufacturing apparatus capable of reducing the concentration of impurities such as oxygen and H ₂ O contained in an organic compound will be described with reference to FIG. FIG. 1 shows an apparatus for forming and sealing a layer made of an organic compound and a cathode. The transfer chamber 101 is connected to a load chamber 104, a pretreatment chamber 105, an intermediate chamber 106, and film formation chambers 107 to 109 via gates 100a to 100f. The pretreatment chamber 105 is provided for the purpose of gas release treatment and surface modification of a substrate to be treated, and is capable of performing heat treatment in a vacuum and plasma treatment using an inert gas.

The film forming chambers 107 and 108 are processing chambers for forming a film mainly composed of a low-molecular organic compound by a vapor deposition method, and the film forming chamber 109 forms a cathode containing an alkali metal by a vapor deposition method. It is a processing room for. Material exchange chambers 112 to 114 for loading an evaporation source with an evaporation material are connected to the film forming chambers 107 to 109 via gates 100h to 100j. The material exchange chambers 112 to 114 are used for filling a deposition material without opening the film formation chambers 107 to 109 to the atmosphere.

First, the substrate 103 on which a film is to be deposited is mounted in the load chamber 104 and moved to the pretreatment chamber and each reaction chamber by the transfer mechanism (A) 102 in the transfer chamber 101. Load chamber 104, transfer chamber 101, pretreatment chamber 105, intermediate chamber 106, film formation chambers 107 to 109, material exchange chambers 112 to 1
Numeral 14 is maintained in a reduced pressure state by an exhaust means. The evacuation unit evacuates from about atmospheric pressure to about 1 Pa with an oil-free dry pump, and evacuates any pressure higher than that with a magnetically levitated turbo-molecular pump or composite molecular pump.
A cryopump may be provided in the reaction chamber to remove H ₂ O. Thus, reverse diffusion of the oil vapor from the exhaust means is prevented.

The inner wall surfaces of these evacuated rooms are mirror-finished by electrolytic polishing to reduce the surface area and prevent gas emission. The material is stainless steel or aluminum. For the purpose of reducing gas emission from the inner wall, it is desirable to perform baking by providing a heater outside the reaction chamber. Outgassing can be significantly reduced by baking. Further, in order to prevent impurity contamination due to gas release, it is preferable to use a cooling medium during vapor deposition. Thus, a degree of vacuum up to 1 × 10 ⁻⁶ Pa is realized.

The intermediate chamber 106 is connected to a coating chamber 110 provided with a spinner 111 via a gate 110g. The coating chamber 110 is a processing chamber for forming a film of an organic compound mainly composed of a polymer material by spin coating, and this processing is performed at atmospheric pressure. Therefore, unloading and loading of the substrate are performed through the intermediate chamber 106, and are performed by adjusting the pressure to the same level as the room on which the substrate moves. The high molecular organic material to be supplied to the coating chamber is supplied after being purified by a dialysis method, an electrodialysis method, or a high-performance liquid chromatograph. Purification is performed at the feed port.

In the pretreatment of the substrate to be introduced into the reaction chamber, a gas release treatment by heating and a surface treatment by argon plasma are performed in the pretreatment chamber 105 to minimize impurities released from the substrate. Especially when an interlayer insulating film or a pattern made of an organic resin material is formed on the substrate,
Since H ₂ O and the like stored by the organic resin material are released under reduced pressure, the inside of the reaction chamber is contaminated. For that purpose, the substrate is heated in the pretreatment chamber 105 to perform a gas release process, or a plasma process is performed to densify the surface, thereby reducing the amount of gas release. Here, nitrogen gas or argon gas introduced into the reaction chamber is purified by a purifying means using a getter material.

Although the vapor deposition method is of a resistance heating type, a Knudsen cell may be used to control the temperature with high accuracy and to control the amount of evaporation. The material for vapor deposition is introduced from a dedicated material exchange chamber attached to the reaction chamber. Thus, opening of the reaction chamber to the atmosphere is minimized. By opening the film forming chamber to the atmosphere, various gases including H ₂ O are adsorbed on the inner wall, and these gases are released again by evacuating. The time required for the release of the adsorbed gas to stop and the degree of vacuum to stabilize to an equilibrium value is several tens to
It takes hundreds of hours. For this purpose, the wall of the film forming chamber is baked to reduce the time. However, since repeatedly opening to the atmosphere is not an efficient method, it is desirable to provide a dedicated material exchange chamber as shown in FIG.
The evaporation source is mainly an organic material, but sublimation purification is performed inside the reaction chamber before vapor deposition. Further, a zone purification method may be applied.

On the other hand, the sealing chamber 115 divided by the load chamber 104 is subjected to processing for sealing the substrate completed up to the formation of the cathode with a sealing material without exposing the substrate to the atmosphere. When the sealing material is fixed with an ultraviolet curing resin, the ultraviolet irradiation mechanism 11 is used.
6 is used. A transfer mechanism (B) 118 is provided in the delivery chamber 117, and the substrate that has been sealed in the sealing chamber 115 is stored.

FIG. 2 is a diagram illustrating a detailed configuration of the transfer chamber 101, the pretreatment chamber 105, and the film formation chamber 107. Transfer room 1
01 is provided with a transport means 102, and a composite molecular pump 207a and a dry pump 208a as exhaust means. The pretreatment chamber 105 and the film formation chamber 107 are each provided with a gate 1
00b and 100d. The pretreatment chamber 105 is provided with a high-frequency electrode 201 to which a high-frequency power supply 216 is connected, and the substrate 103 is provided with substrate heating means 104a, 104
b is held by the opposed electrode provided. Impurities such as moisture adsorbed on the substrate 103 are reduced to 50 by the substrate and heating means.
It can be desorbed by heating in a vacuum to about 120 ° C. The gas introduction means connected to the pretreatment chamber 105 includes a cylinder 216a, a flow controller 216b, and a purifier 203 using a getter material or the like.

The surface treatment using plasma is performed by purifying an inert gas such as helium, argon, krypton, or neon, or a mixed gas of inert gas and hydrogen by a purifier 203, and applying a high-frequency power to the plasma-treated atmosphere. The exposure is performed by exposing the substrate to the substrate. The purity of the gas used is C
Each of the concentrations of H ₄ , CO, CO ₂ , H ₂ O and O ₂ is 2p
pm or less, preferably 1 ppm or less.

The evacuation is performed by a magnetically levitated compound molecular pump 207b and a dry pump 208b. The pressure in the pretreatment chamber 105 during the surface treatment is controlled by controlling the exhaust speed by a control valve provided in the exhaust means.

The film forming chamber 107 includes an evaporation source 211 and an adsorption plate 21.
2, a shutter 218 and a shadow mask 217 are provided. The substrate 103 is provided on the shadow mask 217. The shutter 218 is opened and closed to open during vapor deposition. The temperatures of the evaporation source 211 and the adsorption plate 212 are controlled, and are connected to the heating means 213c and 213d, respectively. The exhaust system is a turbo molecular pump 207c and a dry pump 208c.
To remove residual moisture in the film formation chamber. The reaction chamber is baked by the heating means 215a and 215b to reduce the amount of gas released from the inner wall of the film formation chamber. Baking process is 5
While the reaction chamber is heated to about 0 to 120 ° C., vacuum evacuation is performed by an evacuation system connected to a tarp molecular pump or a cryopump. Thereafter, the reaction chamber is cooled to room temperature or about the temperature of liquid nitrogen by a refrigerant to obtain 1 × 10 ⁻⁶ P
It is possible to evacuate to about a.

Material exchange chamber 1 divided by gate 100h
12 is provided with evaporation sources 210 and 211, and the temperature is controlled by heating means 213a and 213b. For the exhaust system, a turbo molecular pump 207d and a dry pump 208d are used. The evaporation source 211 is movable between the material exchange chamber 112 and the film formation chamber 107, and is used as a means for purifying the supplied evaporation material.

Although there is no limitation on the method of purifying the material for vapor deposition, it is preferable to employ a sublimation purification method in order to carry out the treatment in a film forming apparatus on site. Of course, other zone refining methods may be used. 3 and 4 are diagrams illustrating a method of performing sublimation purification in the film forming apparatus described with reference to FIG.

Many organic compounds for forming an organic light-emitting device are easily deteriorated by oxygen or H ₂ O. In particular, low molecular organic compounds have a strong tendency. Therefore, even if it is initially sufficiently purified and highly purified, there is a possibility that oxygen or H ₂ O may be easily taken in by subsequent handling. As described above, oxygen taken into an organic compound is considered to be a malignant impurity that changes the bonding state of molecules. This causes a change with time of the organic light emitting element and causes deterioration of characteristics.

FIG. 3 is a diagram illustrating the concept of sublimation purification of an organic compound material. The organic compound originally intended is M2, and the vapor pressure under a certain constant pressure is between temperatures T1 and T2. Those having a vapor pressure of T1 or less are M1
And impurities such as H ₂ O correspond thereto. Also, T
M3 having a vapor pressure higher than 2 corresponds to impurities such as transition metals and organic metals.

As described above, M1, M2,
As shown in FIG. 4A, the material containing M3 is placed in the first evaporation source 210 and heated at a temperature lower than T2. The materials sublimated from the first evaporation source are M1 and M2. At this time, if the second evaporation source 211 is provided above and kept at a temperature lower than T1, it can be adsorbed there. Next, as shown in FIG. 4B, when the second evaporation source 211 is heated to the temperature of T1, M1 sublimates and is adsorbed on the adsorption plate 212. M1 and M3 are removed from the second evaporation source 211 and M2 and M3 are removed.
Remains. Thereafter, as shown in FIG.
11 is heated to a temperature of about T2 to form an organic compound layer on the substrate.

The sublimation purification step shown in FIG. 4 can be performed in the material exchange chamber 112 and the film formation chamber 107 of the film formation apparatus described with reference to FIG. Since the cleanliness of the inside of the film formation chamber is increased by mirror finish of the inner wall or exhaustion by a turbo molecular pump or a cryopump, the oxygen concentration in the organic compound deposited on the substrate is 5 × 10 ¹⁹ / cm ^3. Hereinafter, it can be preferably reduced to 1 × 10 ¹⁹ / cm ³ or less.

[Second Embodiment] The structure of an organic light-emitting element manufactured using the film forming apparatus described in the first embodiment is not limited. An organic light-emitting element is formed with an anode made of a light-transmitting conductive film, a cathode containing an alkali metal, and a layer made of an organic compound therebetween. The layer composed of an organic compound consists of one or more layers. Each layer has a hole injection layer, a hole transport layer,
It is referred to as a light emitting layer, an electron transport layer, an electron injection layer, or the like. These can be formed of either a low molecular weight organic compound material or a high molecular weight organic compound material, or a suitable combination of both.

For the hole injecting layer and the hole transporting layer, an organic compound material having excellent hole transporting properties is selected, and a phthalocyanine-based or aromatic amine-based material is typically used. Further, a metal complex having an excellent electron transporting property is used for the electron injection layer.

FIG. 5 shows an example of the structure of the organic light emitting device.
FIG. 5A illustrates an example of an organic light-emitting element using a low-molecular-weight organic compound, in which an anode 300 formed of indium tin oxide (ITO), a hole injection layer 301 formed of copper phthalocyanine (CuPc), and an aromatic compound are used. MT which is an amine material
Hole transport layer 30 formed of DATA and α-NPD
2, 303, an electron injection layer and a light emitting layer 30 formed of a tris-8-quinolinolato aluminum complex (Alq ₃ )
4. A cathode 305 made of ytterbium (Yb) is laminated. Alq ₃ enables light emission (fluorescence) from a singlet excited state.

In order to increase the luminance, it is preferable to use light emission (phosphorescence) from a triplet excited state. FIG. 5B shows an example of such an element structure. An anode 310 formed of ITO, a hole injection layer 311 formed of CuPc which is a phthalocyanine-based material, α which is an aromatic amine-based material
A light-emitting layer 313 using a carbazole-based CBP + Ir (ppy) ₃ on a hole transport layer 312 formed of -NPD.
Is formed. Further, a hole blocking layer 314 is formed using bathocuproine (BCP), and an electron injection layer 315 of Alq ₃ is formed.

Although the above two structures are examples using a low molecular weight organic compound, an organic light emitting device in which a high molecular weight organic compound and a low molecular weight organic compound are combined can be realized. FIG. 5C is an example of this, in which a hole injection layer 321 is formed using a polythiophene derivative of a high molecular weight organic compound (PEDOT), and a hole transport layer 322 formed of α-NPD is used.
Light emitting layer 323 of CBP + Ir (ppy) ₃ , BCP
, And an electron injection layer 325 made of Alq ₃ . By changing the hole injection layer to PEDOT, hole injection characteristics are improved, and luminous efficiency can be improved.

A carbazole-based CBP + I
r (ppy) ₃ is an organic compound capable of obtaining light emission (phosphorescence) from a triplet excited state. As the triplet compound, an organic compound described in the following paper is mentioned as a typical material. (1) T.Tsutsui, C.Adachi,
S. Saito, Photochemical Processes in Organized Mol
ecular Systems, ed.K. Honda, (Elsevier Sci. Pub., To
kyo, 1991) p.437. (2) MABaldo, DFO'Brien, Y.Yo
u, A. Shoustikov, S. Sibley, METhompson, SRForre
st, Nature 395 (1998) p. 151. This article discloses an organic compound represented by the following formula. (3) MABaldo,
S. Lamansky, PEBurrrows, METhompson, SRForre
st, Appl. Phys. Lett., 75 (1999) p. 4. (4) T. Tsutsui,
M.-J.Yang, M.Yahiro, K.Nakamura, T.Watanabe, T.ts
uji, Y.Fukuda, T.Wakimoto, S.Mayaguchi, Jpn.Appl.P
hys., 38 (12B) (1999) L1502.

In addition to the light-emitting materials described in the above paper, it is considered that light-emitting materials represented by the following molecular formulas (specifically, metal complexes or organic compounds) can be used. .

[0067]

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[0068]

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In the above molecular formula, M is 8 to 1 in the periodic table.
An element belonging to Group 0, Et, is an ethyl group. In the above paper, platinum and iridium are used. In addition, the present inventor considers that nickel, cobalt, or palladium is preferable in reducing the manufacturing cost of a display device because it is less expensive than platinum or iridium. In particular, nickel is considered to be preferable because of its high productivity because it easily forms a complex. In any case, light emission (phosphorescence) from the triplet excited state has higher luminous efficiency than light emission (fluorescence) from the singlet excited state, and an operating voltage (light emission from the organic light emitting element) is required to obtain the same light emission luminance. (The voltage required to perform this) can be reduced.

Phthalocyanine CuPc, aromatic amine α-NPD, MTDATA, carbazole C
BP and the like are all organic compounds containing no oxygen in the molecule. When oxygen or H ₂ O is mixed into such an organic compound, a change in the bonding state described with reference to Chemical Formulas 1 and 2 occurs, thereby deteriorating the hole transport property and the light emitting property. In forming such an organic compound layer, the film forming apparatus and the film forming method described in Embodiment 1 with reference to FIGS. As a result, the oxygen concentration in the light emitting element is reduced to 1 × 10 ¹⁹ / cm ³ or less, or
In an organic light emitting device having a phthalocyanine-based or aromatic amine-based hole injection layer or a hole transport layer, and a carbazole-based light-emitting layer, the oxygen concentration of the hole injection layer or the hole transport layer and the vicinity thereof is set to 1 × 10 ¹⁹ /. cm ³ or less.

[Embodiment 3] FIG. 6 is an example showing a structure of a light emitting device of an active matrix drive system. TFT
Are provided in various functional circuits in and around the pixel portion. T
FT is a material of a semiconductor film forming a channel formation region,
Although amorphous silicon or polycrystalline silicon can be selected, the present invention may employ either one.

The substrate 601 employs a glass substrate or an organic resin substrate. The organic resin material is lighter in weight than the glass material, and effectively acts to reduce the weight of the light emitting device itself. As a material that can be used for manufacturing a light-emitting device, an organic resin material such as polyimide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), or aramid can be used. It is desirable to use barium borosilicate glass or aluminoborosilicate glass, which is called an alkali-free glass, for the glass substrate. The thickness of the glass substrate is 0.
A thickness of 5 to 1.1 mm is adopted, but it is necessary to reduce the thickness for the purpose of weight reduction. Further, in order to further reduce the weight, it is desirable to use a material having a specific gravity as small as 2.37 g / cc.

In FIG. 6, an n-channel TFT 652 and a p-channel TFT 653 are formed in the drive circuit portion 650,
A state in which a switching TFT 654 and a current control TFT 655 are formed in the pixel portion 651 is shown.
These TFTs are made of silicon nitride or silicon oxynitride (Si
A semiconductor film 603 to 606, a gate insulating film 607, gate electrodes 608 to 611, and the like are formed over a first insulating layer 602 (shown by O _x N _y ).

A second insulating layer 618 made of silicon nitride or silicon oxynitride is formed on the gate electrode, and is used as a protective film. Further, a first interlayer insulating film 619 made of an organic resin material such as polyimide or acrylic is formed as a flattening film.

The circuit configuration of the drive circuit section 650 differs between the gate signal side drive circuit and the data signal side drive circuit, but is omitted here. Wirings 612 and 613 are connected to the n-channel TFT 652 and the p-channel TFT 653, and a shift register, a latch circuit, a buffer circuit, and the like are formed using these TFTs.

In the pixel portion 651, the data line 614 is connected to the source side of the switching TFT 654, and the drain side line 615 is connected to the gate electrode 611 of the current control TFT 655. The current control TFT 65
The source side of No. 5 is connected to the power supply wiring 617, and the electrode 616 on the drain side is connected to the anode of the light emitting element.

On these wirings, a second interlayer insulating film 627 made of an organic insulating material such as silicon nitride is formed. The organic resin material has a hygroscopic property and has a property of absorbing H ₂ O. When the H ₂ O is re-emitted, it supplies oxygen to the organic compound and causes deterioration of the organic light-emitting element. Therefore, in order to prevent occlusion and re-emission of H ₂ O, the H ₂ O is deposited on the second interlayer insulating film 627. Then, a third insulating film 620 made of silicon nitride or silicon oxynitride is formed. Alternatively, it is also possible to omit the second interlayer insulating film 627 and form this layer with only one layer of the third insulating film 620.

Further, as the third insulating film 620, aluminum oxide, aluminum nitride, aluminum oxynitride, or the like can be used. These can form a film by a sputtering method using aluminum oxide or aluminum nitride as a target.

The organic light-emitting element 656 is formed on the third insulating film 620, and is formed of a transparent conductive material such as ITO (indium tin oxide), an anode 621, a hole injection layer, a hole transport layer, a light-emitting layer, and the like. Compound layer 623 having MgA
and a cathode 624 formed using a material such as alkali metal or alkaline earth metal such as g or LiF. The detailed structure of the organic compound layer 623 is arbitrary, and an example is shown in FIG.

Since the organic compound layer 623 and the cathode 624 cannot be subjected to a wet process (etching with a chemical solution or washing with water), the organic compound layer 623 and the cathode 624 are formed of a photosensitive resin material on the organic insulating film 619 in accordance with the anode 621. Partition layer 62
2 is provided. The partition layer 622 is formed so as to cover an end of the anode 621. Specifically, the partition layer 622 is formed by applying a negative resist and having a thickness of about 1 to 2 μm after baking. Thereafter, exposure is performed by irradiating ultraviolet rays using a photomask provided with a predetermined pattern. When a negative resist material having poor transmittance is used, the rate of exposure in the thickness direction of the film changes, and when this is developed, the end of the pattern is formed into an inverted tapered shape as shown in FIG. Can be. Needless to say, such a partition layer can be formed using photosensitive polyimide or the like.

FIG. 8 is a detailed view of a portion where an organic light emitting device is formed. After the end portion of the partition layer 622 is formed in a reverse taper shape, an organic compound layer 623 and a cathode layer 624 are formed by an evaporation method, whereby the partition layer 62 in contact with the anode 621 is formed.
2 can be formed without wrapping around the bottom. Since the evaporation material from the evaporation source adheres to the substrate with directivity in the evaporation method, the organic compound layer is formed on the anode 621 in a state shown in FIG. 8 on the anode 621 due to a step between the top and bottom of the partition layer 622 having a reverse tapered shape. And a cathode layer.

FIG. 9 is a top view for explaining the structure of the pixel portion, and the sectional structure taken along line GG ′ corresponds to FIG. The anodes 621 are individually formed separately corresponding to the TFTs provided in each pixel. The partition layer 622 is formed in a stripe shape so as to cover an end of the anode 621 and over a plurality of pixels. An organic compound layer is formed by evaporation inside a region 690 surrounded by a dotted line. The organic compound layer is formed by a reverse tapered partition layer 622 as shown in FIG. The cathode 624 is formed in a similar manner, but is formed so as to be connected to a region outside the partition layer 622, that is, outside the pixel portion.

For the cathode 624, a material containing magnesium (Mg), lithium (Li) or calcium (Ca) having a small work function is used. Preferably, MgAg (M
An electrode made of a material obtained by mixing g and Ag at a ratio of Mg: Ag = 10: 1) may be used. In addition, MgAgAl, LiA
1, LiFAl, magnesium, a magnesium alloy or a magnesium compound can also be applied. Furthermore, a fourth insulating film 6 made of silicon nitride or a DLC film is further formed thereon.
25 is formed with a thickness of 2 to 30 nm, preferably 5 to 10 nm. The DLC film can be formed by a plasma CVD method, and can be formed to cover the end of the partition layer 622 with good coverage even at a temperature of 100 ° C. or lower. DLC
The internal stress of the film can be reduced by mixing a small amount of oxygen or nitrogen, and can be used as a protective film. The DLC film includes oxygen, CO,
It is known that gas barrier properties such as CO ₂ and H ₂ O are high. After forming the cathode 624, the fourth insulating film 625
It is desirable to form continuously without opening to the atmosphere. This is because the state of the interface between the cathode 624 and the organic compound layer 623 greatly affects the luminous efficiency of the organic light emitting device.

As described above, by forming the organic compound layer 623 and the cathode layer 624 without contacting the partition layer 622 to form an organic light-emitting device, it is possible to prevent cracks due to thermal stress. Further, the organic light emitting element is oxygen or H ₂
Since O is most hated, a silicon nitride or silicon oxynitride and a DLC film 625 are formed to block it. Further, they also have a function of keeping the alkali metal element of the organic light-emitting element from outside.

In FIG. 6, the switching TFT 654 has a multi-gate structure, and the current controlling TFT 655 has a low concentration drain (LDD) overlapping the gate electrode.
Is provided. Since a TFT using polycrystalline silicon exhibits a high operation speed, deterioration such as hot carrier injection is likely to occur. Therefore, as shown in FIG. 6, it is highly reliable to form a TFT having a different structure (a switching TFT having a sufficiently low off-state current and a current control TFT having a high resistance against hot carrier injection) in a pixel according to the function. And good image display is possible (high operating performance)
This is very effective in manufacturing a display device.

As shown in FIG. 6, the TFTs 654, 655
The first insulating film 602 is formed below the semiconductor film (on the side of the substrate 601) that forms the semiconductor device. On the opposite upper layer side, a second insulating film 618 is formed. On the other hand, a third insulating film 620 is formed below the organic light emitting element 656. A fourth insulating film 625 is formed on the upper layer side. An organic insulating film 619 is formed and integrated between the two. The alkali metal such as sodium, which is a killer impurity of the TFTs 654 and 655, may be the substrate 601 or the organic light emitting element 656 as a contamination source.
Blocking is performed by being surrounded by the insulating film 602 and the second insulating film 618. On the other hand, since the organic light-emitting element 656 most dislikes oxygen and H ₂ O, a third insulating film 620 and a fourth insulating film 625 are formed to block them. These also have a function of keeping the alkali metal element included in the organic light-emitting element 656 from outside.

In an organic light emitting device having a structure as shown in FIG. 6, an example of an efficient manufacturing method is to use a third insulating film 620,
Anode 621 made of a transparent conductive film represented by ITO
Of forming a continuous film by sputtering. A sputtering method is suitable for forming a dense silicon nitride film or a silicon oxynitride film without significantly damaging the surface of the organic insulating film 619.

As described above, the pixel portion is formed by combining the TFT and the organic light emitting device, and the light emitting device can be completed. In such a light-emitting device, a driver circuit can be formed over the same substrate using a TFT. As shown in FIG. 6 or 7, the semiconductor film, the gate insulating film, and the gate electrode, which are main components of the TFT, have their lower and upper layers surrounded by a blocking layer made of silicon nitride or silicon oxynitride and a protective film. Thereby, it has a structure for preventing contamination of alkali metals and organic substances. On the other hand, the organic light-emitting element is partially surrounded by a protective film made of silicon nitride or silicon oxynitride, and a gas barrier layer made of an insulating film containing silicon nitride or carbon as a main component. _It has a structure to prevent ₂ O from entering.

As described above, according to the present invention, a light emitting device can be completed without interfering with each other by combining elements having different characteristics with respect to impurities. Further, reliability can be improved by eliminating the influence of stress.

[Embodiment 4] In Embodiment 3, a top gate type TFT structure has been described. However, a bottom gate type or inverted stagger type TFT can of course be applied. FIG. 7 shows an inverted staggered TFT for the pixel portion 751.
Switching TFT 754, Current controlling TFT 755
Is formed. A gate electrode 702 and 703 formed of molybdenum, tantalum, or the like and a wiring 704 are provided over a substrate 701, and a first insulating film 705 functioning as a gate insulating film is formed thereover. The first insulating film 705 is formed with a thickness of 100 to 200 nm using silicon oxide, silicon nitride, or the like.

In the semiconductor films 706 and 707, a source or drain region and an LDD region are formed in addition to a channel forming region. Insulating films 708 and 709 are provided for forming these regions and protecting the channel formation region. The second insulating film 710 is formed using silicon nitride or silicon oxynitride, and is provided so that the semiconductor film is not contaminated with an alkali metal, an organic substance, or the like. Further, a first interlayer insulating film 711 made of an organic resin material such as polyimide is formed. Then, after forming a contact hole, the wiring 71 is formed.
3 to 716 are formed, and a second interlayer insulating film 719 is formed. Similarly, the second interlayer insulating film 719 is formed of an organic resin material such as polyimide. A third insulating film 712 made of silicon nitride or silicon oxide is formed thereon. Wiring 71
3 to 716 are formed on the third insulating film 712.

The anode 717 of the organic light emitting element 756 is formed on the third insulating film 712, and thereafter, the partition layer 718 is formed of polyimide. The surface of the partition layer 718 may be subjected to plasma pretreatment with argon for densification. Alternatively, as shown in FIG. 7, an insulating film 719 made of a silicon nitride film may be formed to perform a gas release prevention treatment. Organic compound layer 72
The configurations of the 0, the cathode 721, and the fourth insulating film are the same as those of the second embodiment. Thus, a light emitting device can be completed using an inverted staggered TFT.

Further, a driving circuit can be formed on the same substrate using an inverted staggered TFT. As shown in FIG. 7, a semiconductor film which is a main component of a TFT has a lower layer side and an upper layer side surrounded by a first insulating film made of silicon nitride or silicon oxynitride and a second insulating film, so that alkali metal or It has a structure to prevent organic contamination. On the other hand, the organic light emitting element partially includes an alkali metal and has a third insulating film 712.
The fourth insulating film 757 has a structure for preventing oxygen and H ₂ O from entering from the outside. As described above, even when an inverted staggered TFT is used, a technique is provided in which elements having different characteristics with respect to impurities are combined to form a light emitting device without mutual interference.

[Embodiment 5] A structure for sealing the organic light emitting device formed in Embodiment 3 or 4 is shown in the drawings. FIG.
Reference numeral 0 denotes a state in which the element substrate 401 on which the driver circuit 408 and the pixel portion 409 are formed using a TFT and the sealing substrate 402 are fixed with a sealant 405. An organic light emitting element 403 is formed in a sealing region between the element substrate 401 and the sealing substrate 402, and the desiccant 407 is
8 or in the vicinity where the sealing material 405 is formed. The organic light emitting element 403 is formed between the partition layers 412.

For the sealing substrate, an organic resin material such as polyimide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), or aramid is used. The thickness of the substrate is 30 ~
It is also possible to employ a material having a size of about 120 μm to provide flexibility. A DLC film (fourth insulating film) 408 is formed at the end as a gas barrier layer. However, the DLC film is not formed on the external input terminal 404. An epoxy adhesive is used for the sealing material. The DLC film 408 is formed along the sealing material 405 and the element substrate 401 and the sealing substrate 40.
Forming along the end of No. ₂ prevents H ₂ O from penetrating from this portion.

FIG. 11 is a diagram showing the appearance of such a display device. The direction in which an image is displayed differs depending on the configuration of the organic light-emitting element. Here, light is emitted upward to perform display. The structure illustrated in FIG. 11 is an element substrate 401 in which a driver circuit portion 408 and a pixel portion 409 are formed using TFTs.
And a sealing substrate 402 are attached with a sealant 405. A partition layer 412 is formed in the pixel portion 409. An input terminal 404 is provided at an end of the element substrate 401, and an FPC (Flexible Print Circuit) is connected at this portion. The input terminal 404 has a terminal for inputting an image data signal, various timing signals, and power from an external circuit.
They are provided at a pitch of μm. The wiring 410 is connected to a driving circuit portion. Also, if necessary,
IC chip 411 on which U, memory, etc. are formed is COG
It may be mounted on the element substrate 401 by a (Chip on Glass) method or the like.

[0097] A DLC film is formed at the end to prevent water vapor, oxygen, and the like from penetrating from the sealing portion to prevent the organic light emitting element from being deteriorated. When an organic resin material is used for the element substrate 401 and the sealing substrate 402, a DLC film may be formed on the entire surface except for the input terminal portion. When forming the DLC film, the input terminal portion may be covered in advance using a masking tape or a shadow mask.

As described above, Embodiment 3 or 4
The light emitting device can be formed by sealing the organic light emitting element formed by the above. Each of the TFT and the organic light emitting element is surrounded by an insulating film and has a structure in which impurities do not enter from the outside. Furthermore, it is bonded to the element substrate using a sealing material,
By covering the end with DLC, airtightness is improved, and deterioration of the light emitting device can be prevented.

[Embodiment 6] The present invention is applicable to display media used in various electronic devices. Such electronic devices include portable information terminals (electronic notebooks, mobile computers, mobile phones, etc.), video cameras, digital cameras, personal computers, television receivers, mobile phones, and the like. One example of these is shown in FIG.

FIG. 13A shows an example in which a television receiver is completed by applying the light emitting device of the present invention.
It is composed of a support base 3002, a display unit 3003, and the like. The present invention can be applied to the display portion 3003 to complete a television receiver.

FIG. 13B shows an example in which a video camera is completed by applying the light emitting device of the present invention.
Display unit 3012, voice input unit 3013, operation switch 3
014, a battery 3015, an image receiving unit 3016, and the like. The video camera can be completed by applying the light emitting device of the present invention to the display portion 3012.

FIG. 13C shows an example in which a notebook personal computer is completed by applying the light emitting device of the present invention. A main body 3021, a housing 3022, a display portion 3023,
It is composed of a keyboard 3024 and the like. By applying the light emitting device of the present invention to the display portion 3023, a notebook personal computer can be completed.

FIG. 13D shows an example in which a PDA (Personal Digital Assistant) is completed by applying the light emitting device of the present invention, and a main body 3031, a stylus 3032, and a display unit 3 are provided.
033, operation button 3034, external interface 3
035 and the like. The PDA can be completed by applying the light emitting device of the present invention to the display portion 3033.

FIG. 13E shows an example in which a sound reproducing apparatus is completed by applying the light emitting device of the present invention. Specifically, FIG.
42, operation switches 3043, 3044 and the like. By applying the display device of the present invention to the display portion 3042, a sound reproducing device can be completed.

FIG. 13F shows an example in which a digital camera is completed by applying the light emitting device of the present invention.
1. Display unit (A) 3052, eyepiece unit 3053, operation switch 3054, display unit (B) 3055, battery 3056
And the like. Display unit of the light emitting device of the present invention
A digital camera can be completed by applying to the (A) 3052 and the display portion (B) 3055.

FIG. 13G shows an example in which a light-emitting device of the present invention is applied to complete a mobile phone. A main body 3061, an audio output unit 3062, an audio input unit 3063, and a display unit 306 are shown.
4. It is composed of an operation switch 3065, an antenna 3066 and the like. By applying the light emitting device of the present invention to the display portion 3064, a mobile phone can be completed.

Note that the electronic device exemplified here is only an example, and is not limited to these applications.

[0108]

As described above, by using the present invention, it is possible to prevent the organic light emitting device from being deteriorated by stress. Further, according to the present invention, a semiconductor film, a gate insulating film, and a gate electrode, which are main components of a TFT, have their lower and upper layers surrounded by a first insulating layer and a second insulating layer made of silicon nitride or silicon oxynitride. Thereby, it has a structure for preventing contamination of alkali metals and organic substances. On the other hand, the organic light-emitting element is partially surrounded by an alkali metal and is surrounded by a third insulating layer made of silicon nitride or silicon oxynitride, and a fourth insulating layer made of an insulating film containing carbon as a main component. A structure for preventing H ₂ O from entering is realized. Then, elements having different characteristics with respect to impurities can be combined to complete a light-emitting device without mutual interference.

[Brief description of the drawings]

FIG. 1 illustrates a structure of a film forming apparatus of the present invention.

FIG. 2 illustrates a structure of a film forming apparatus of the present invention.

FIG. 3 illustrates a relationship between impurities contained in an organic compound material and a vapor pressure thereof.

FIG. 4 is a diagram illustrating a method for performing sublimation purification in a film forming apparatus.

FIG. 5 illustrates a structure of an organic light-emitting element.

FIG. 6 is a partial cross-sectional view illustrating a structure of an organic light emitting device including a pixel portion and a drive circuit portion.

FIG. 7 is a cross-sectional view illustrating a structure of a pixel portion of an organic light-emitting device.

FIG. 8 is a cross-sectional view illustrating a structure of a pixel portion of an organic light-emitting device.

FIG. 9 is a top view illustrating a structure of a pixel portion of an organic light-emitting device.

FIG. 10 is a cross-sectional view illustrating a structure of an organic light-emitting device.

FIG. 11 is a perspective view illustrating an appearance of an organic light emitting device.

FIG. 12 illustrates a concept of a light emitting device of the present invention.

FIG. 13 is a diagram illustrating an electronic device to which the light-emitting device of the present invention is applied.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H05B 33/22 H05B 33/22 Z F term (Reference) 3K007 AB11 AB18 BA06 BB05 BB07 CB01 DA01 DB03 EA00 EB00 5C094 AA31 AA33 AA38 AA43 BA03 BA27 CA19 DA09 DA13 EA04 EA05 EB02 FA02 FB01 FB02 FB12 FB14 FB15 FB20 GB10

Claims (6)

[Claims] 1. A first material comprising silicon nitride or silicon oxynitride.
Between the insulating layer and a second insulating layer made of silicon oxynitride,
A thin film transistor including a semiconductor layer containing silicon as a main component, a gate insulating film, and a gate electrode is formed. A third insulating layer made of silicon nitride or silicon oxynitride is formed on the thin film transistor, and carbon is used as a main component. A fourth insulating layer, an anode between the third insulating layer and the fourth insulating layer,
A light-emitting device in which a light-emitting element having an organic compound layer and a cathode containing an alkali metal is formed, and the light-emitting element is formed between partition layers made of an insulating material. 2. The method according to claim 1, wherein the first layer comprises silicon nitride or silicon oxynitride.
Between the insulating layer and a second insulating layer made of silicon oxynitride,
A thin film transistor having a semiconductor layer containing silicon as a main component, a gate insulating film, and a gate electrode is formed. A third insulating layer made of silicon nitride or silicon oxynitride is formed on the thin film transistor, and carbon is used as a main component. A fourth insulating layer, and an anode between the third insulating layer and the fourth insulating layer;
A light-emitting element having an organic compound layer and a cathode containing an alkali metal is formed. The light-emitting element is formed of an insulating material and has an upper portion formed between partition layers having a shape protruding in a direction parallel to the substrate. A light-emitting device characterized by the above-mentioned. 3. The method according to claim 1, wherein the first layer comprises silicon nitride or silicon oxynitride.
Between the insulating layer and a second insulating layer made of silicon oxynitride,
A thin film transistor including a semiconductor layer containing silicon as a main component, a gate insulating film, and a gate electrode is formed. A third insulating layer made of silicon nitride or silicon oxynitride is formed on the thin film transistor, and carbon is used as a main component. A light-emitting element having an anode, an organic compound layer, and a cathode containing an alkali metal is formed between the fourth insulating layer to be formed and the third insulating layer and between the fourth insulating layer and the light-emitting element. A light emitting device formed between partition layers made of an insulating material, wherein the organic compound layer and the cathode are provided without being in contact with the partition layers. 4. A method according to claim 1, wherein the first layer comprises silicon nitride or silicon oxynitride.
Between the insulating layer and a second insulating layer made of silicon oxynitride,
A thin film transistor including a semiconductor layer containing silicon as a main component, a gate insulating film, and a gate electrode is formed. A third insulating layer made of silicon nitride or silicon oxynitride is formed on the thin film transistor, and carbon is used as a main component. A light-emitting element having an anode, an organic compound layer, and a cathode containing an alkali metal is formed between the fourth insulating layer to be formed and the third insulating layer and between the fourth insulating layer and the light-emitting element. The organic compound layer and the cathode are provided without being in contact with the partition layer, and are formed between partition layers having an insulating material and having an upper portion protruding in a direction parallel to the substrate. Light emitting device. 5. The light emitting device according to claim 1, wherein the fourth insulating layer is a layer made of diamond-like carbon. 6. The light emitting device according to claim 1, wherein an organic resin layer is provided between the second insulating layer and the third insulating layer.