JP4558277B2 - Method for manufacturing light emitting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor device, and more particularly to a light emitting device having an organic light emitting element formed over a substrate having an insulating surface and a method for manufacturing the same. The present invention also relates to an organic light emitting module in which an IC including a controller is mounted on an organic light emitting panel. In this specification, the organic light emitting panel and the organic light emitting module are collectively referred to as a light emitting device.
[0002]
[Prior art]
In recent years, research on a light-emitting device having an organic light-emitting element as a self-luminous element has been activated, and in particular, a light-emitting device using an organic material as an EL material has attracted attention. This light emitting device is also called an organic EL display or an organic light emitting diode.
[0003]
Note that the organic light-emitting element includes a layer containing an organic compound (hereinafter, referred to as an EL layer) from which luminescence generated by applying an electric field is obtained, an anode, and a cathode. Luminescence in an organic compound includes light emission (fluorescence) when returning from the singlet excited state to the ground state and light emission (phosphorescence) when returning from the triplet excited state to the ground state. The light-emitting device manufactured by the film formation method can be applied to either light emission.
[0004]
Unlike the liquid crystal display device, the light-emitting device is a self-luminous type and has a feature that there is no problem of viewing angle. That is, as a display used outdoors, it is more suitable than a liquid crystal display, and use in various forms has been proposed.
[0005]
An organic light emitting element has a structure in which an EL layer is sandwiched between a pair of electrodes, and the EL layer usually has a laminated structure. Typically, a laminated structure of “hole transport layer / light emitting layer / electron transport layer” can be given. This structure has very high luminous efficiency, and most of the light emitting devices that are currently under research and development employ this structure.
[0006]
In addition, a hole injection layer / a hole transport layer / a light emitting layer / an electron transport layer, or a hole injection layer / a hole transport layer / a light emitting layer / an electron transport layer / an electron injection layer are sequentially laminated on the anode. Good structure. You may dope a fluorescent pigment | dye etc. with respect to a light emitting layer. These layers may all be formed using a low molecular weight material, or may be formed using a high molecular weight material.
[0007]
Note that in this specification, all layers provided between a cathode and an anode are collectively referred to as an EL layer. Therefore, the above-described hole injection layer, hole transport layer, light emitting layer, electron transport layer, and electron injection layer are all included in the EL layer.
[0008]
In this specification, a light-emitting element formed of a cathode, an EL layer, and an anode is referred to as an organic light-emitting element, and this includes an EL layer between two types of stripe-shaped electrodes provided so as to be orthogonal to each other. There are two types: a method of forming an EL layer (simple matrix method), and a method of forming an EL layer between a pixel electrode connected to a TFT and arranged in a matrix and a counter electrode (active matrix method).
[0009]
Known typical vapor deposition methods include a resistance heating method in which a resistance heating body is placed around a container containing a vapor deposition material and heated indirectly by heating to evaporate the vapor deposition material, and an electron beam is vapor deposited. And an electron gun vapor deposition method (also referred to as an EB vapor deposition method) for irradiating and evaporating. Other vapor deposition methods include forming a container (contains the vapor deposition material) with metal, heating it by direct energization, and evaporating the vapor deposition material, or using a light transmissive material such as quartz (contains the vapor deposition material) ) And evaporating the vapor deposition material by radiant heating with an infrared lamp.
[0010]
In addition, an evaporation material made of an organic compound is decomposed due to its energy being too high when irradiated with an electron beam, and therefore other evaporation methods are often used. On the other hand, in general, when a metal thin film that is an inorganic substance having a relatively high melting point is deposited as a cathode or an anode of a light emitting element, an electron gun vapor deposition method that easily stabilizes the film formation rate is often used.
[0011]
[Problems to be solved by the invention]
In the present invention, an EL layer is connected between a first electrode (cathode or anode) and a second electrode (anode or cathode) connected to a TFT formed on an insulating surface and arranged in a matrix. An object of the present invention is to complete a light-emitting device having excellent TFT characteristics in a light-emitting device that is formed (active matrix method). Specifically, it is an object to complete a light-emitting device without deteriorating TFT characteristics in a process after forming a TFT (particularly, an EL layer forming process, a counter electrode forming process, a pixel electrode forming process, etc.). .
[0012]
Note that the TFT is an essential element for realizing an active matrix light-emitting device. In addition, in realizing a light-emitting device of an active matrix system, in a light-emitting device using an organic light-emitting element, amorphous silicon having a low field-effect mobility is used in order to control a current flowing through the organic light-emitting element by a TFT. It is difficult to realize with the TFT used, and it is desirable to employ a semiconductor film having a crystal structure, typically a TFT using polysilicon, as a TFT connected to the organic light emitting element.
[0013]
Even if an excellent TFT can be formed in the manufacturing process of a light-emitting device having an organic light-emitting element, if the impurities are mixed in the process after the TFT is formed or the TFT itself is damaged, the light-emitting device This also leads to a decrease in the characteristics itself, and also reduces the reliability and yield. In particular, a TFT having an active layer of a semiconductor film (typically a polysilicon film) having a crystal structure formed over a substrate having an insulating surface such as a glass substrate, a quartz substrate, or a plastic substrate has a high driving capability (on-current). , I _on ) On the other hand, it is very sensitive and affected by various factors, and its characteristics are likely to change.
[0014]
Therefore, in an active matrix light emitting device, there is a possibility that a difference may occur between the TFT characteristics measured at the stage of manufacturing up to the TFT and the TFT characteristics measured after the organic light emitting element is formed on the TFT.
[0015]
In an active matrix light-emitting device, at least a TFT that functions as a switching element and a TFT that supplies current to the organic light-emitting element are provided in each pixel. A TFT functioning as a switching element has a low off-current (I _off However, a TFT that supplies current to an organic light emitting device has a high driving capability (on-current, I _on ) And the hot carrier effect to prevent deterioration and to improve reliability. The TFT of the data line side driving circuit also has a high driving capability (ON current, I _on ) And the hot carrier effect to prevent deterioration and to improve reliability.
[0016]
In addition, the TFT that supplies current to the organic light emitting device has high driving capability (on-current, I _on It is desirable that the TFT characteristics other than () are also excellent. For example, as the TFT threshold (Vth) is closer to 0, driving with a lower driving voltage is possible, and power consumption can be reduced. Since the stress applied to the TFT is reduced, the reliability is improved. Further, the closer the S value (subthreshold coefficient) of the TFT is to the ideal value (60 mV / decade), the higher the speed of operation becomes possible, and the response speed for moving image display and the like improves.
[0017]
That is, an object of the present invention is to manufacture a light emitting device having excellent TFT characteristics (on current, off current, Vth, S value, etc.) in an active matrix light emitting device.
[0018]
In addition, the EL material is very easily deteriorated, and is easily oxidized and deteriorated in the presence of oxygen or water. Therefore, a photolithography process cannot be performed after the film formation, and in order to form a pattern, it is necessary to separate the film at the same time as the film formation with a mask having an opening (hereinafter referred to as an evaporation mask). Therefore, most of the sublimated organic EL material is attached to the inner wall of the film forming chamber or the deposition shield (a protective plate for preventing the deposition material from adhering to the inner wall of the film forming chamber).
[0019]
Further, in the conventional vapor deposition apparatus, in order to increase the uniformity of the film thickness, the distance between the substrate and the vapor deposition source is widened, and the apparatus itself is enlarged. In addition, since the distance between the substrate and the vapor deposition source is wide, the film formation rate is slow, and the time required for exhausting the film formation chamber is also long and throughput is reduced.
[0020]
In addition, in the conventional vapor deposition apparatus, the utilization efficiency of the expensive EL material is extremely low at about 1% or less, and the manufacturing cost of the light emitting device is very expensive.
[0021]
Another object of the present invention is to provide a vapor deposition apparatus that improves the utilization efficiency of the EL material, is excellent in uniformity, and has a high throughput.
[0022]
[Means for Solving the Problems]
In a method for manufacturing a simple matrix light-emitting device, since a TFT is not formed, an evaporation method using an electron gun is often used for a metal layer serving as a cathode or an anode of a light-emitting element. However, when the metal layer is formed on the EL layer by an evaporation method using an electron gun, there is a problem that the EL layer is damaged by the incidence of secondary electrons, reflected electrons, or X-rays. For the problem of secondary electrons and reflected electrons, a shielding plate is placed between the evaporation source and the substrate to isolate the electron gun from the substrate, and the incidence of electrons is suppressed by a magnetic field provided near the substrate. There have been proposed a method, a method of suppressing the incidence of electrons by applying a negative potential to the substrate, and a method of attracting electrons by arranging a conductive plate that applies a positive potential voltage in the vicinity of the evaporation source. By these methods, it becomes possible to solve the above problems, damage to the EL layer is reduced, and a metal layer can be formed on the EL layer by an electron gun evaporation method.
[0023]
In the active matrix light-emitting device, since the TFT is disposed below the EL layer, the present inventors have no problem in adopting an electron gun vapor deposition method as a method for forming a metal layer on the EL layer. I was expecting.
[0024]
However, TFTs are very sensitive to ionized evaporation particles generated by an electron gun, secondary electrons, reflected electrons, X-rays, etc., and when an electron gun deposition method is used, damage to the EL layer is not caused. Although it was hardly seen, it was found that the TFT was severely damaged.
[0025]
FIG. 13 shows the result of measuring the TFT characteristics after forming the cathode using the electron gun vapor deposition method. FIG. 13A shows the electrical characteristics of the p-channel TFT in the pixel portion, and FIG. 13B shows the electrical characteristics of the p-channel TFT in the driver circuit (driver circuit). In FIG. 13A, the TFT is connected to the cathode through the EL layer. In FIG. 13B, the cathode is disposed above the TFT and overlaps, but the cathode and the TFT are Not connected. FIG. 14A shows electrical characteristics of a p-channel TFT in a driver circuit (driver circuit) in a portion not overlapping with the cathode. FIG. 14B shows the electrical characteristics of the p-channel TFT in the pixel portion measured before forming the EL layer.
[0026]
Compared with FIG. 14B, the TFT characteristics of FIG. 13A change, and Vth is negatively shifted. Furthermore, the S value has also deteriorated. Also in FIG. 13B, Vth is negatively shifted and the S value is also deteriorated. On the other hand, FIG. 14A, which is a characteristic of a TFT in which a cathode is not formed above the TFT, hardly changes.
[0027]
In addition, when a film is formed by vapor deposition using an electron gun on a substrate partially covered with lead foil (substrate on which TFT is provided), the characteristics of the TFT covered with lead foil change. From this, it can be inferred that X-rays contribute to the change in TFT characteristics.
[0028]
As described above, the vapor deposition method using the electron gun has an advantage that an inorganic material having a high melting point can be deposited, but has a disadvantage that the characteristics of the TFT, particularly, the S value of the p-channel TFT is lowered. Have.
[0029]
Therefore, the present invention is to form a layer containing an organic compound (EL layer) and a metal layer (cathode or anode) by using a resistance heating method that has the least effect on a TFT in an active matrix light-emitting device. Features.
[0030]
In addition, EL materials that form layers containing organic compounds (EL layers) are broadly classified into low molecular (monomer) materials and high molecular (polymer) materials. Of these, low molecular materials are mainly used. The film is formed by vapor deposition. Further, an inorganic material (such as silicon) may be included in the EL layer.
[0031]
The structure of the present invention relating to a method for manufacturing a light-emitting device disclosed in this specification is as follows.
A method for manufacturing a light emitting device, comprising: a light emitting element having a cathode, a layer containing an organic compound in contact with the cathode; an anode in contact with the layer containing the organic compound; and a TFT connected to the light emitting element.
In the method for manufacturing a light-emitting device, the layer containing the organic compound and the cathode made of a metal material are formed by an evaporation method in which an evaporation material is heated by resistance heating.
[0032]
FIG. 1 shows the result of measuring the TFT characteristics after forming the cathode using the resistance heating method. FIG. 1A shows the electrical characteristics of the p-channel TFT in the pixel portion, and FIG. 1B shows the electrical characteristics of the p-channel TFT in the driver circuit (driver circuit). In FIG. 1A, the TFT is connected to the cathode through the EL layer. In FIG. 1B, the cathode is disposed above the TFT and overlaps, but the cathode and the TFT are Not connected. FIG. 2A shows electrical characteristics of the p-channel TFT in a driver circuit (driver circuit) in a portion not overlapping with the cathode. FIG. 2B shows electrical characteristics of the p-channel TFT in the pixel portion measured before forming the EL layer.
[0033]
As shown in FIG. 1, when the cathode is formed using the resistance heating method, the TFT characteristics hardly change as compared with FIG.
[0034]
The cathode may have a laminated structure of two or more layers. For example, when the cathode has a two-layer structure, the first layer of the cathode in contact with the EL layer may be formed by resistance heating, and the second layer in contact with the first layer of the cathode may be formed by electron gun evaporation. In this case, the first layer formed by the resistance heating method functions as a blocking layer, and damage to the TFT can be prevented. In addition, by providing a first layer formed by resistance heating, local concentration of electric charges can be prevented and electrical damage can be diffused during vapor deposition by the second layer electron gun vapor deposition method. .
[0035]
Another structure of the present invention relating to a method for manufacturing a light-emitting device disclosed in this specification is a light-emitting element including a cathode, a layer containing an organic compound in contact with the cathode, and an anode in contact with the layer containing the organic compound. And a method of manufacturing a light emitting device having a TFT connected to the light emitting element,
By a vapor deposition method in which a vapor deposition material is heated by resistance heating, a layer containing the organic compound and a lower layer of the cathode in contact with the layer containing the organic compound are formed.
A method for manufacturing a light-emitting device, characterized in that an upper layer of the cathode is formed by an evaporation method in which an evaporation material made of a metal material is heated with an electron gun.
[0036]
In addition, a configuration obtained by the above manufacturing method is also one aspect of the present invention.
A light-emitting device having a cathode, a light-emitting element having a layer containing an organic compound in contact with the cathode, an anode in contact with the layer containing the organic compound, and a TFT connected to the light-emitting element,
The cathode is a stack of a layer formed by a vapor deposition method in which a vapor deposition material made of a metal material is heated by resistance heating and a layer formed by a vapor deposition method in which the vapor deposition material made of a metal material is heated by an electron gun. It is.
[0037]
In the above structure, the evaporation material including the metal material is a material having a low work function, typically an alloy material including a metal element belonging to Group 1 or Group 2 of the periodic table.
[0038]
In the present invention, a layer containing an organic compound may be formed on the cathode, and an anode may be formed on the layer containing the organic compound.
A light-emitting device having a cathode, a light-emitting element having a layer containing an organic compound in contact with the cathode, an anode in contact with the layer containing the organic compound, and a TFT connected to the light-emitting element,
The anode is a laminate of a layer formed by a vapor deposition method for heating a vapor deposition material made of a metal material by resistance heating and a layer formed by a vapor deposition method for heating the vapor deposition material made of a metal material by an electron gun. It is.
[0039]
In the above structure, the vapor deposition material made of the metal material is a conductive material containing one or more elements selected from materials having a high work function, typically Pt, Cr, W, Ni, Zn, Sn, and In. It is characterized by being a sexual material.
[0040]
In addition, when the main process where impurities such as oxygen and water may be mixed into the EL material or metal material to be deposited is mentioned, the process of setting the EL material or metal material in the deposition apparatus before the deposition, Processes can be considered.
[0041]
Usually, the container for storing the EL material is placed in a brown glass bottle and closed with a plastic lid (cap). It is also conceivable that the container for storing the EL material is insufficiently sealed.
[0042]
Conventionally, when a film is formed by a vapor deposition method, a predetermined amount of evaporating material placed in a container (glass bottle) is taken out, and a container (typical) placed at a position facing a film formation in a vapor deposition apparatus. However, there is a risk that impurities may be mixed in this transfer operation. That is, oxygen, water, and other impurities that are one of the causes of deterioration of the organic light emitting element may be mixed.
[0043]
When transferring from a glass bottle to a container, for example, it is conceivable to carry out by a human hand in a pretreatment chamber provided with a glove or the like in a vapor deposition apparatus. However, when the pretreatment chamber is equipped with a glove, it cannot be evacuated and work is performed at atmospheric pressure, and it is difficult to reduce moisture and oxygen in the pretreatment chamber as much as possible even in a nitrogen atmosphere. Met. Although it is conceivable to use a robot, since the evaporation material is in the form of powder, it is difficult to produce a robot that can be transferred. Therefore, it has been difficult to fully automate the process from the process of forming the EL layer on the lower electrode to the process of forming the upper electrode, and to make a consistent closed system capable of avoiding contamination with impurities.
[0044]
Therefore, the present invention does not use a conventional container as a container for storing the EL material, typically a brown glass bottle, but directly stores the EL material or the metal material in a container to be installed in the vapor deposition apparatus. It is a manufacturing system that performs vapor deposition after transportation, and realizes prevention of impurities from being mixed into a high-purity vapor deposition material. Further, when directly storing the evaporation material of the EL material, the obtained evaporation material may not be stored separately, but sublimation purification may be directly performed on a container to be installed in the evaporation apparatus. The present invention makes it possible to cope with further ultra-high purity of the vapor deposition material in the future. Alternatively, the metal material may be directly stored in a container to be installed in the vapor deposition apparatus, and vapor deposition may be performed using a heating resistance.
[0045]
The operation of directly storing the vapor deposition material in the container installed in the vapor deposition apparatus is preferably requested by a light emitting device manufacturer using the vapor deposition apparatus to a material manufacturer that produces or sells the vapor deposition material.
[0046]
Also, no matter how high-purity EL material is provided by the material manufacturer, as long as there is a conventional transfer work at the light-emitting device manufacturer, there is a risk of contamination, and the purity of the EL material cannot be maintained, There was a limit in purity. According to the present invention, the light emitting device manufacturer and the material manufacturer cooperate to reduce the contamination of impurities, thereby maintaining the extremely high purity EL material obtained by the material manufacturer, and performing vapor deposition at the light emitting device manufacturer without reducing the purity as it is. be able to.
[0047]
The configuration of the invention disclosed in this specification is as follows.
A first container containing an organic material, an inorganic material, or a metal material is sealed with a second container;
A substrate is placed in a manufacturing apparatus having an evacuation means, the second container is introduced, the first container is taken out from the second container and placed, and then the first container is resisted. An operation method of a manufacturing apparatus, characterized in that vapor deposition is performed on the substrate by heating.
[0048]
In the above structure, the first container is characterized in that an organic material is sublimated and purified on an inner wall. In the above structure, the metal material is a conductive material that serves as a cathode or an anode of a light-emitting element. In the above structure, the inorganic material is a material (CaF) that becomes a cathode buffer layer of a light-emitting element. ₂ , MgF ₂ , BaF ₂ Etc.).
[0049]
Further, the conventional vapor deposition apparatus using the resistance heating method has a drawback that the film formation rate tends to become unstable as compared with the vapor deposition method using an electron gun.
[0050]
In view of this, the present invention provides a vapor deposition apparatus that improves the utilization efficiency of the vapor deposition material, is excellent in uniformity, and has a high throughput. Therefore, the utilization efficiency and throughput of the vapor deposition material are remarkably improved. By reducing the distance d between the substrate and the evaporation source, the size of the film formation chamber can be reduced. By reducing the size of the film formation chamber, the time required for evacuation can be shortened by reducing the volume of the film formation chamber, and the total amount of impurities present in the film formation chamber can be reduced. Etc.) to prevent mixing.
[0051]
In the operation method of the manufacturing apparatus, the distance between the substrate and the container is set to 20 cm or less, and vapor deposition is performed on the substrate.
[0052]
In addition, a mechanism for rotating the substrate and a mechanism for moving the vapor deposition source are provided in the film formation chamber, and by rotating the substrate and moving the vapor deposition source simultaneously during vapor deposition, excellent film thickness uniformity is achieved. The film formation is performed.
[0053]
In the operation method of the manufacturing apparatus, when performing the vapor deposition, the substrate is rotated and the first container is moved.
[0054]
The configuration of the invention disclosed in this specification is as follows.
A first step of storing a vapor deposition material made of an organic material or a metal material in a container;
A second step of disposing a substrate in the vapor deposition apparatus and installing the container so as to face the substrate;
And a third step of heating the container installed in the vapor deposition apparatus by resistance heating and performing vapor deposition on the substrate with a distance between the substrate and the container being 20 cm or less. This is a method for manufacturing a light-emitting device.
[0055]
In the above structure, the first step of storing a vapor deposition material made of an organic material or a metal material in the container is performed by a material manufacturer.
[0056]
Further, in the above structure, when the vapor deposition is performed, the substrate is rotated and the container is moved. Moreover, in the said structure, when accommodating an organic material, you may sublimate and refine directly in the said container.
[0057]
In the above configuration, the substrate includes a TFT and a first electrode connected to the TFT,
In the third step, a layer containing an organic compound made of an organic material is formed in contact with the first electrode by a resistance heating method, and a layer made of a metal material is formed in contact with the layer containing the organic compound by a resistance heating method. Forming a second electrode;
A light-emitting element including the first electrode, the layer containing the organic compound, and the second electrode is manufactured.
[0058]
In the light emitting device of the present invention, the screen display driving method is not particularly limited, and for example, a dot sequential driving method, a line sequential driving method, a surface sequential driving method, or the like may be used. Typically, a line sequential driving method is used, and a time-division gray scale driving method or an area gray scale driving method may be used as appropriate. The video signal input to the source line of the light-emitting device may be an analog signal or a digital signal, and a drive circuit or the like may be designed in accordance with the video signal as appropriate.
[0059]
In the light-emitting device of the present invention, the pixel structure is not particularly limited, and a storage capacitor or a memory (SRAM, DRAM, or the like) may be formed in one pixel. Further, a structure in which a plurality of (two or three or more) TFTs and various circuits (such as a current mirror circuit) are incorporated in one pixel may be employed.
[0060]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0061]
(Embodiment 1)
Here, a manufacturing process of an active matrix light-emitting device having a pixel portion and a driver circuit over the same substrate and including an organic light-emitting element will be described with reference to FIGS.
[0062]
First, as shown in FIG. 3A, a thin film transistor (hereinafter referred to as TFT) 12 is formed over a substrate 11 having an insulating surface by a known manufacturing process. The pixel portion 10a is provided with an n-channel TFT and a p-channel TFT. Here, a p-channel TFT for supplying current to the organic light emitting element is illustrated. The TFT for supplying current to the organic light emitting element may be an n-channel TFT or a p-channel TFT. In addition, an n-channel TFT, a p-channel TFT, a CMOS circuit in which these are complementarily combined, and the like are formed in the driver circuit 10b provided around the pixel portion. Here, transparent oxide conductive films (ITO (indium tin oxide alloy), indium oxide zinc oxide alloy (In ₂ O _Three An example is shown in which the anode 13 made of —ZnO), zinc oxide (ZnO), etc. is formed in a matrix, and then a wiring connected to the active layer of the TFT is formed. Next, an insulating film 14 made of an inorganic insulating material or an organic insulating material that covers the end portion of the anode 13 is formed.
[0063]
Next, as shown in FIG. 3B, a layer containing an organic compound (EL layer) that forms the organic light-emitting element is formed.
[0064]
First, as a pretreatment anode 1 3 is cleaned. As the cleaning of the anode surface, ultraviolet irradiation in a vacuum or oxygen plasma treatment is performed to clean the anode surface. In addition, the oxidation treatment may be performed by irradiating ultraviolet rays in an atmosphere containing oxygen while heating at 100 to 120 ° C., and is effective when the anode is an oxide such as ITO. The heat treatment may be performed at a heating temperature of 50 ° C. or higher, preferably 65 to 150 ° C. that the substrate can withstand in vacuum, and is formed on the substrate by impurities such as oxygen and moisture attached to the substrate. Impurities such as oxygen and moisture in the deposited film are removed. In particular, since the EL material is easily deteriorated by impurities such as oxygen and water, it is effective to heat in vacuum before vapor deposition.
[0065]
Next, the film is transported to a film formation chamber equipped with an evaporation source without being exposed to the atmosphere, and a hole transport layer, a hole injection layer, a light emitting layer, or the like, which is one layer containing an organic compound, is formed on the anode 13. A layer is formed as appropriate. Here, vapor deposition is performed by heating the vapor deposition source by resistance heating, and the hole injection layer 15, the light emitting layer (R) 16, the light emitting layer (G) 17, and the light emitting layer (B) 18 are formed. The light emitting layer (R) is a light emitting layer that emits red light, the light emitting layer (G) is a light emitting layer that emits green light, and the light emitting layer (B) is a light emitting layer that emits blue light.
[0066]
Next, the cathode 19 is evaporated by heating the evaporation source by resistance heating. By forming the cathode 19 by resistance heating, an organic light emitting device can be completed without changing the electrical characteristics of the TFT. In the pixel portion, even if FIG. 1A showing the TFT characteristics after the cathode formation by the resistance heating method is compared with FIG. 2B showing the TFT characteristics before the EL layer formation, there is almost no change in the characteristics. Absent. As shown in FIG. 1A, the Vths measured for any three TFTs are −0.44 (V), −0.51 (V), and −1.59 V, and the S value is 0.214 (V / dec), 0.287 (V / dec), and 0.26 (V / dec).
[0067]
As a material used for the cathode 19, it is preferable to use a metal having a small work function (typically, a metal element belonging to Group 1 or 2 of the periodic table) or an alloy containing these metals. The smaller the work function is, the better the light emission efficiency is. Therefore, among them, the material used for the cathode is preferably an alloy material containing Li (lithium), which is one of alkali metals. Note that the cathode also functions as a wiring common to all the pixels, and has a terminal electrode in the input terminal portion via the connection wiring. Therefore, as shown in FIG. 3B, some TFTs may overlap with the cathode 19 in the driver circuit. The result of measuring the TFT characteristics superimposed on the cathode 19 is shown in FIG.
[0068]
When the cathode is formed not by the resistance heating method but by vapor deposition using an electron gun, the electrical characteristics of not only the TFT in the pixel portion but also the TFT superimposed on the cathode in the drive circuit are changed. FIG. 13 and FIG. 14 show electrical characteristics of a TFT in which a cathode is formed by an evaporation method using an electron gun. As shown in FIG. 13A, Vths obtained by measuring arbitrary three TFTs in the pixel portion are −7.69 (V), −7.07 (V), and −7.15 V, The S values were 0.541 (V / dec), 0.559 (V / dec), and 0.566 (V / dec).
[0069]
Next, the organic light-emitting element is completely blocked from the outside by enclosing with a protective film, a sealing substrate, or a sealing can, and a substance that promotes deterioration due to oxidation of the EL layer such as moisture or oxygen enters from the outside. It is preferable to prevent this. A desiccant may be installed.
[0070]
Next, an FPC (flexible printed circuit) is attached to each electrode of the input / output terminal portion with an anisotropic conductive material. The anisotropic conductive material is composed of resin and conductive particles having a diameter of several tens to several hundreds μm whose surface is plated with Au or the like, and is formed on each electrode and FPC of the input / output terminal portion by the conductive particles. Electrical connection with wiring.
[0071]
If necessary, an optical film such as a circularly polarizing plate composed of a polarizing plate and a retardation plate may be provided, or an IC chip or the like may be mounted.
[0072]
Through the above steps, a module type active matrix light emitting device to which an FPC is connected is completed.
[0073]
The cathode may have a laminated structure of two or more layers. Here, an example in which the cathode has a two-layer structure, the first layer of the cathode in contact with the EL layer is formed by a resistance heating method, and the second layer is formed in contact with the first layer of the cathode by the electron gun evaporation method is shown in FIG. Show. Note that a detailed description of the same steps as those in FIG. 3 is omitted here for the sake of brevity.
[0074]
As in FIG. 3A, a TFT 22, an anode 23, and an insulating film 24 are formed over a substrate 21 having an insulating surface. (Fig. 4 (A))
[0075]
Next, the hole injection layer 25, the light emitting layer (R) 26, the light emitting layer (G) 27, and the light emitting layer (B) 28 are formed by resistance heating as in FIG. Next, a cathode (lower layer) 29a is formed by a resistance heating method. (FIG. 4 (B)) The film thickness of the cathode (lower layer) 29a may be appropriately set within a range in which the TFT is not damaged during the subsequent vapor deposition by the electron gun vapor deposition method.
[0076]
Next, as shown in FIG. 4C, a cathode (upper layer) 29b is formed by electron gun vapor deposition. Here, an example in which the same material is deposited as the cathodes 29a and 29b is shown, but different materials may be used.
[0077]
When the cathode has a laminated structure as described above, the first layer formed by the resistance heating method functions as a blocking layer, and damage to the TFT can be prevented. In addition, by providing a first layer formed by resistance heating, local concentration of electric charges can be prevented and electrical damage can be diffused during vapor deposition by the second layer electron gun vapor deposition method. .
[0078]
The subsequent steps are the same as the manufacturing method of the module type active matrix light-emitting device, and thus are omitted here.
[0079]
In this example, the anode is a transparent conductive film, and the anode, the layer containing the organic compound, and the cathode are stacked in this order. However, the present invention is not limited to this stacked structure, and includes the cathode and the organic compound. Layers and anodes may be stacked in this order, or the anode may be a metal layer, and the anode, a layer containing an organic compound, and a light-transmitting cathode may be stacked in this order, and an organic light emitting element is formed on the TFT In this case, a cathode or an anode made of a metal layer is deposited by a resistance heating method.
[0080]
Although the example of the top gate type TFT is shown here as the TFT structure, the present invention can be applied regardless of the TFT structure. For example, a bottom gate type (reverse stagger type) TFT or a forward stagger type TFT is applicable. It is possible to apply to.
[0081]
(Embodiment 2)
Here, the vapor deposition apparatus shown in FIG. 5 will be described. 5A is a cross-sectional view, and FIG. 5B is a top view.
[0082]
In FIG. 5, 51 is a film formation chamber, 52 is a substrate holder, 53 is a substrate, 54 is a vapor deposition mask, 55 is a vapor deposition shield (vapor deposition shutter), 57 is a vapor deposition source holder, 58 is a vapor deposition material, and 59 is a vapor deposition material that has evaporated. 59.
[0083]
The degree of vacuum is 5 × 10 ^-3 Torr (0.665 Pa) or less, preferably 10 ^-Four -10 ^-6 Deposition is performed in the film forming chamber 51 evacuated to Pa. At the time of vapor deposition, the vapor deposition material is evaporated (vaporized) in advance by resistance heating, and is scattered toward the substrate 53 when a shutter (not shown) is opened at the time of vapor deposition. The evaporated evaporation material 59 scatters upward and is selectively deposited on the substrate 53 through the opening provided in the deposition mask 54.
[0084]
In the vapor deposition apparatus, the vapor deposition source holder includes a crucible, a heater disposed on the outside of the crucible via a heat equalizing member, a heat insulating layer provided on the outside of the heater, and an outer cylinder storing these. The cooling pipe is turned to the outside of the outer cylinder, and a shutter device that opens and closes the opening of the outer cylinder including the opening of the crucible. In this specification, the crucible is a cylindrical container having a relatively large opening formed of a material such as a sintered body of BN, a composite sintered body of BN and AlN, quartz, or graphite. It can withstand high temperature, high pressure and reduced pressure.
[0085]
The evaporation source holder 5 7 It is preferable that the resistance heating provided in the apparatus be controlled so that the film formation rate can be controlled by a microcomputer.
[0086]
In the vapor deposition apparatus shown in FIG. 5, during vapor deposition, the distance d between the substrate 53 and the vapor deposition source holder 57 is typically 20 cm or less, preferably 5 cm to 15 cm, and the utilization efficiency and throughput of the vapor deposition material are markedly increased. It has been improved.
[0087]
Further, the substrate holder 52 is provided with a mechanism for rotating the substrate 53. Further, the evaporation source holder 57 is provided with a mechanism capable of moving in the film forming chamber 51 in the X direction or the Y direction while maintaining the horizontal state.
[0088]
The vapor deposition apparatus shown in FIG. 5 is characterized by performing film formation with excellent film thickness uniformity by simultaneously rotating the substrate 53 and moving the vapor deposition source holder 57 during vapor deposition.
[0089]
In the conventional vapor deposition apparatus using the resistance heating method, the film formation rate is likely to be unstable as compared with the vapor deposition method using the electron gun, but the vapor deposition apparatus shown in FIG. In addition, the vapor deposition apparatus has excellent throughput.
[0090]
Further, a vapor deposition shutter may be provided on the movable vapor deposition source holder 57. Moreover, the organic compound with which one vapor deposition source holder is equipped does not necessarily need to be one, and plural may be sufficient.
[0091]
Further, since the distance d between the substrate 53 and the vapor deposition source holder 57 is typically reduced to 20 cm or less, preferably 5 cm to 15 cm, the vapor deposition mask 54 may be heated. Therefore, the vapor deposition mask 54 is a metal material having a low coefficient of thermal expansion that is not easily deformed by heat (for example, a high melting point metal such as tungsten, tantalum, chromium, nickel or molybdenum or an alloy containing these elements, a material such as stainless steel, inconel, or hastelloy). ) It is desirable to use Moreover, in order to cool the vapor deposition mask to be heated, a mechanism for circulating a cooling medium (cooling water, cooling gas) through the vapor deposition mask may be provided.
[0092]
The vapor deposition mask 54 is used when a vapor deposition film is selectively formed, and is not particularly necessary when a vapor deposition film is formed on the entire surface.
[0093]
Further, the substrate holder 52 includes a permanent magnet, a vapor deposition mask made of metal is fixed by a magnetic force, and a substrate 53 sandwiched therebetween is also fixed. Here, an example in which the vapor deposition mask is in close contact with the substrate 53 is shown, but a substrate holder or vapor deposition mask holder that is fixed with a certain distance may be provided as appropriate.
[0094]
In addition, the film formation chamber is connected to an evacuation treatment chamber that evacuates the film formation 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.
[0095]
In addition, plasma generation means is provided in the film formation chamber 51, and plasma is generated in the film formation chamber in a state where the substrate is not disposed, thereby vaporizing the deposit attached to the film formation chamber wall, the deposition shield, or the vapor deposition mask. Then, cleaning may be performed by exhausting the film formation chamber to the outside. Thus, it is possible to clean the film formation chamber without touching the atmosphere during maintenance. In the cleaning, the vaporized organic compound can be recovered by an exhaust system (vacuum pump) and reused.
[0096]
This embodiment mode can be freely combined with Embodiment Mode 1. If the vapor deposition apparatus shown in FIG. 5 is used, uniformity within the substrate surface can be improved, and a layer containing an organic compound and a cathode or an anode made of a metal layer can be formed by a resistance heating method.
[0097]
(Embodiment 3)
FIG. 6 is an explanatory diagram of the manufacturing system of the present invention.
[0098]
In FIG. 6, 61a is a first container (crucible), and 61b is a second container for isolating the first container from the atmosphere and preventing it from contamination. Reference numeral 62 denotes a powdered EL material purified to a high purity. Reference numeral 63 denotes a vacuum chamber, 64 is a heating means, 65 is an object to be deposited, and 66 is a deposited film. In addition, 68 is a material manufacturer, a manufacturer (typically a raw material handling company) that produces and refines organic compound materials that are vapor deposition materials, 69 is a light emitting device manufacturer having a vapor deposition device, A manufacturer of light emitting devices (typically a production factory).
[0099]
The flow of the manufacturing system of the present invention will be described below.
[0100]
First, an order 60 is made from the light emitting device manufacturer 69 to the material manufacturer 68. The material manufacturer 68 prepares the first container and the second container according to the order 60. Then, the material maker purifies or stores the ultra-high purity EL material 62 in the first container 61a while paying sufficient attention to the mixing of impurities (oxygen, moisture, etc.) in the clean room environment. Thereafter, the material maker 68 preferably seals the first container 61a with the second container 61b so that excessive impurities do not adhere to the inside or outside of the first container in the clean room environment. When sealing, the inside of the second container 61b is preferably filled with vacuum or an inert gas. It is preferable to clean the first container 61a and the second container 61b before purifying or storing the ultra-high purity EL material 62.
[0101]
In the present invention, the first container 61a is installed in the chamber as it is when vapor deposition is performed later. In addition, the second container 61b may be a packaging film having a barrier property that blocks the mixing of oxygen and moisture, but in order to enable automatic removal, a cylindrical or box-like strong light-shielding property is provided. It is preferable to use a container having
[0102]
Next, the first container 61a is conveyed 67 from the material maker 68 to the light emitting device maker 69 in a state where the first container 61a is still sealed in the second container 61b.
[0103]
Next, the first container 61a is introduced into the processing chamber 63 capable of being evacuated while being sealed in the second container 61b. The processing chamber 63 is a vapor deposition chamber in which a heating unit 64 and a substrate holder (not shown) are installed. Thereafter, the inside of the processing chamber 63 is evacuated to a clean state in which oxygen and moisture are reduced as much as possible. Then, the first container 61a is taken out from the second container 61b, and the heating means 64 is supplied without breaking the vacuum. A vapor deposition source can be prepared by installing. Note that an evaporation target (here, a substrate) 65 is provided so as to face the first container 61a.
[0104]
Next, the vapor deposition material 66 can be formed on the surface of the deposition target 65 provided opposite to the vapor deposition source by applying heat to the vapor deposition material by a heating means 64 such as resistance heating.
The vapor deposition film 66 thus obtained does not contain impurities, and when a light emitting element is completed using the vapor deposition film 66, high reliability and high luminance can be realized.
[0105]
In this way, the first container 61a is introduced into the vapor deposition chamber 63 without being exposed to the atmosphere, and vapor deposition can be performed while maintaining the purity at the stage where the vapor deposition material 62 is stored by the material manufacturer. In addition, by storing the EL material 62 directly in the first container 61a by the material manufacturer, only a necessary amount can be provided to the light emitting device manufacturer, and a relatively expensive EL material can be used efficiently.
[0106]
In the conventional vapor deposition method by resistance heating, there is a method of increasing the use efficiency as shown below, for example, because the use efficiency of the material is low. After the first deposition with a new EL material in the crucible during the maintenance of the deposition apparatus, a residue remains without being deposited. Then, the next time vapor deposition is performed, the EL material is newly replenished on the residue and vapor deposition is performed, and the subsequent vapor deposition can increase the use efficiency by repeating the above replenishment until maintenance is performed. In the method, residues can cause contamination. Further, since replenishment is performed by an operator, oxygen or moisture may be mixed into the vapor deposition material and the purity may be lowered. Also, crucibles deposited several times are discarded during maintenance. In order to prevent contamination of impurities, a new EL material may be put into the crucible every time vapor deposition is performed, and the crucible may be abandoned every time vapor deposition is performed, but the manufacturing cost increases.
[0107]
Conventionally, the glass bottle storing the vapor deposition material can be eliminated, and further, the operation of transferring from the glass bottle to the crucible by the above-described manufacturing system can be eliminated, and contamination with impurities can be prevented. In addition, throughput is improved.
[0108]
According to the present invention, it is possible to realize a manufacturing system that is fully automated to improve throughput, and to realize a consistent closed system that can avoid contamination of the vapor deposition material 62 purified by the material manufacturer 68. .
[0109]
In the above description, the EL material has been described as an example. However, in the present invention, a metal layer serving as a cathode or an anode can also be deposited by resistance heating. If the cathode is formed by a resistance heating method, an organic light emitting element can be formed without changing the electrical characteristics (on current, off current, Vth, S value, etc.) of the TFT 12.
[0110]
Similarly, the metal material may be stored in advance in the first container, and the first container may be directly introduced into the vapor deposition apparatus and evaporated by resistance heating to form a vapor deposition film. .
[0111]
Further, this embodiment mode can be freely combined with Embodiment Mode 1 or Embodiment Mode 2. If the vapor deposition apparatus described in Embodiment 2 is used, a metal layer serving as a cathode or an anode can be formed with high uniformity even by a resistance heating method.
[0112]
(Embodiment 4)
In the first embodiment, an example in which top gate type TFTs (specifically, planar type TFTs) are manufactured as the TFTs 12 and 22 is shown. However, in this embodiment, a TFT 72 is used instead of the TFTs 12 and 22. The TFT 72 used in this embodiment is a bottom gate TFT (specifically, an inverted staggered TFT) and may be formed by a known manufacturing process.
[0113]
First, as shown in FIG. 7A, a bottom gate TFT 72 is formed over a substrate 71 having an insulating surface by a known manufacturing process. Here, after forming the TFT, the anode 73 made of a metal layer (a conductive material containing one or more elements selected from Pt, Cr, W, Ni, Zn, Sn, and In) is formed in a matrix. An example is shown.
[0114]
Next, an insulating film 74 made of an inorganic insulating material or an organic insulating material that covers the end portion of the anode 73 is formed.
[0115]
Next, as illustrated in FIG. 7B, a layer containing an organic compound (EL layer) for forming an EL element is formed. The film is transported to a film formation chamber equipped with a vapor deposition source, and a hole transport layer, a hole injection layer, a light emitting layer, or the like, which is one layer containing an organic compound, is appropriately stacked on the anode 73. Here, vapor deposition is performed by heating a vapor deposition source by resistance heating, and a hole injection layer 75, a light emitting layer (R) 76, a light emitting layer (G) 77, and a light emitting layer (B) 78 are formed.
[0116]
Next, the lower layer cathode 79a is vapor-deposited by heating the vapor deposition source by resistance heating. By forming the cathode 79 by a resistance heating method, an organic light emitting device can be completed without changing the electrical characteristics of the TFT. The cathode 79a as the lower layer is a very thin metal film (an alloy such as MgAg, MgIn, AlLi, CaN, or a film formed by co-evaporation with an element belonging to Group 1 or 2 of the periodic table and aluminum), or It is preferable to use a laminate of them.
[0117]
Next, the upper layer cathode 79b is formed. (FIG. 7C) The cathode 79b as the upper layer is formed of a transparent oxide conductive film (ITO (indium tin oxide alloy), indium oxide zinc oxide alloy (In ₂ O _Three -ZnO), zinc oxide (ZnO) or the like may be used. 7C is a case where light is emitted in a direction indicated by an arrow in the drawing (when light emission is allowed to pass through the cathode), it is preferable to use a light-transmitting conductive material as the cathode.
[0118]
The subsequent steps are the same as the manufacturing method of the module type active matrix light-emitting device described in Embodiment Mode 1, and thus are omitted here.
[0119]
Further, this embodiment mode can be freely combined with Embodiment Mode 1, Embodiment Mode 2, or Embodiment Mode 3.
[0120]
The present invention having the above-described configuration will be described in more detail with the following examples.
[0121]
(Example)
[Example 1]
In this embodiment, FIG. 8 shows an example of a multi-chamber manufacturing apparatus in which the production up to the upper electrode is fully automated.
[0122]
8, 100a to 100k, 100m to 100p, 100r to 100u are gates, 101 is a preparation chamber, 119 is an extraction chamber, 102, 104a, 108, 114 and 118 are transfer chambers, 105, 107 and 111 are delivery chambers, 106R, 106B, 106G, 109, 110, 112, 113 are film forming chambers, 103 is a pretreatment chamber, 117 is a sealing substrate loading chamber, 115 is a dispenser chamber, 116 is a sealing chamber, 120a and 120b are cassette chambers, Reference numeral 121 denotes a tray mounting stage.
[0123]
Hereinafter, a procedure in which the substrate on which the TFT 12 and the anode 13 are provided in advance is carried into the manufacturing apparatus shown in FIG. 8 to form the laminated structure shown in FIG.
[0124]
First, a substrate provided with the TFT 12 and the anode 13 is set in the cassette chamber 120a or the cassette chamber 120b. When the substrate is a large substrate (for example, 300 mm × 360 mm), it is set in the cassette chamber 120b, and when it is a normal substrate (for example, 127 mm × 127 mm), it is transferred to the tray mounting stage 121 and the tray (for example, 300 mm) Several boards are mounted on (360 mm).
[0125]
Next, the substrate is transferred from the transfer chamber 118 provided with the substrate transfer mechanism to the preparation chamber 101.
[0126]
The charging chamber 101 is connected to a vacuum evacuation treatment chamber, and after evacuating, it is preferable to introduce an inert gas to an atmospheric pressure. Next, the material is transferred to a transfer chamber 102 connected to the preparation chamber 101. In advance, the vacuum is maintained by evacuation so that moisture and oxygen do not exist in the transfer chamber as much as possible.
[0127]
Further, the transfer chamber 102 is connected to an evacuation processing 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.
[0128]
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 anode, it may be transferred to a pretreatment chamber 103 connected to the transfer chamber 102 and cleaned there.
[0129]
Further, a layer containing an organic compound made of a polymer may be formed on the entire surface on the anode.
The film formation chamber 112 is a film formation chamber for forming a layer containing an organic compound made of a polymer. In the present embodiment, an example in which a poly (ethylenedioxythiophene) / poly (styrenesulfonic acid) aqueous solution (PEDOT / PSS) acting as the hole injection layer 15 is formed on the entire surface is shown. In the case where a layer containing an organic compound is formed in the film formation chamber 112 by a spin coat method, an ink jet method, or a spray method, the film formation surface of the substrate is set upward at atmospheric pressure. In this embodiment, the delivery chamber 105 is provided with a substrate reversing mechanism, and the substrate is reversed appropriately. After film formation using an aqueous solution, it is preferable that the film be transferred to the pretreatment chamber 103 where heat treatment is performed in a vacuum to vaporize moisture. In addition, although the example which forms the hole injection layer 15 which consists of a polymer was shown in the present Example, the hole injection layer which consists of a low molecular organic material may be formed by vapor deposition by a resistance heating method, and a hole is formed. The injection layer 15 is not necessarily provided.
[0130]
Next, after the substrate 104c is transferred from the transfer chamber 102 to the delivery chamber 105 without being exposed to the atmosphere, the substrate 104c is transferred to the transfer chamber 104, and is transferred to the film formation chamber 106R by the transfer mechanism 104b. An EL layer 16 that emits red light is appropriately formed. Here, it is formed by vapor deposition using resistance heating. The film formation chamber 106R is set with the film formation surface of the substrate facing downward in the delivery chamber 105. Note that the film formation chamber is preferably evacuated before the substrate is carried in.
[0131]
For example, the degree of vacuum is 5 × 10 ^-3 Torr (0.665 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.
[0132]
In this embodiment, a crucible in which a vapor deposition material is stored in advance by a material manufacturer is set in the film forming chambers 106R, 106B, 106G, and 110. The setting is preferably performed without exposure to the atmosphere. When the material is transferred from the material manufacturer, the crucible is preferably introduced into the film formation chamber while being sealed in the second container. Desirably, a chamber having a vacuum evacuation unit is provided connected to the film formation chamber 106R, where the crucible is taken out from the second container in a vacuum or an inert gas atmosphere, and the crucible is installed in the film formation chamber. By doing so, the crucible and the EL material housed in the crucible can be prevented from contamination.
[0133]
Here, in order to obtain full color, after the film formation in the film formation chamber 106R, the film formation is performed in each of the film formation chambers 106G and 106B, and the layer 16 containing an organic compound that emits red, green, and blue light. To 18 are appropriately formed.
[0134]
After obtaining the hole injection layer 15 and the desired EL layers 16 to 18 on the anode 13, the substrate is transferred from the transfer chamber 104 a to the delivery chamber 107 without being exposed to the atmosphere, and is further exposed to the atmosphere. Without transferring, the substrate is transferred from the delivery chamber 107 to the transfer chamber 108.
[0135]
Next, the film is transferred to the film forming chamber 110 by a transfer mechanism installed in the transfer chamber 108, and the cathode 19 made of a metal layer is appropriately formed by an evaporation method using resistance heating. Here, the film formation chamber 110 is a vapor deposition apparatus that includes Li and Al as a vapor deposition source and performs vapor deposition by resistance heating.
[0136]
Through the above process, the light-emitting element having the stacked structure illustrated in FIG.
[0137]
Next, the film is transferred from the transfer chamber 108 to the deposition chamber 113 without being exposed to the air, and a protective film formed of a silicon nitride film or a silicon nitride oxide film is formed. Here, a sputtering apparatus provided with a target made of silicon, a target made of silicon oxide, or a target made of silicon nitride in the film formation chamber 113 is used. For example, a silicon nitride film can be formed by using a target made of silicon and setting a film formation chamber atmosphere to a nitrogen atmosphere or an atmosphere containing nitrogen and argon.
[0138]
Next, the substrate over which the light-emitting element is formed is transferred from the transfer chamber 108 to the delivery chamber 111 without being exposed to the atmosphere, and further transferred from the delivery chamber 111 to the transfer chamber 114.
[0139]
Next, the substrate over which the 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.
[0140]
The sealing substrate is set in the sealing substrate load chamber 117a from the outside. In order to remove impurities such as moisture, it is preferable to perform annealing in a vacuum in advance, for example, annealing in the sealing substrate load chamber 117. When a sealing material is formed on the sealing substrate, the transfer chamber 108 is set to atmospheric pressure, and then the sealing substrate is transferred from the sealing substrate load chamber to the dispenser chamber 115 to provide a light emitting element. And a sealing substrate on which the sealing material is formed is transported to the sealing chamber 116.
[0141]
Next, in order to deaerate the substrate provided with the light-emitting element, after annealing in a vacuum or an inert atmosphere, the sealing substrate provided with the sealant and the substrate on which the light-emitting element is formed are attached to each other . The sealed space is filled with hydrogen or an inert gas. Note that here, an example in which the sealing material is formed over the sealing substrate is described; however, there is no particular limitation, and the sealing material may be formed over the substrate over which the light-emitting element is formed.
[0142]
Next, the pair of bonded substrates is irradiated with UV light by an ultraviolet irradiation mechanism provided in the sealing chamber 116 to cure the sealing material. In addition, although ultraviolet curable resin was used here as a sealing material, if it is an adhesive material, it will not specifically limit.
[0143]
Next, the pair of bonded substrates is transferred from the sealing chamber 116 to the transfer chamber 114 and then transferred from the transfer chamber 114 to the take-out chamber 119 and taken out.
[0144]
As described above, by using the manufacturing apparatus illustrated in FIG. 8, it is not necessary to expose the light-emitting element to the outside until the light-emitting element is completely enclosed in the sealed space, so that a highly reliable light-emitting device can be manufactured. Moreover, since the crucible in which the vapor deposition material is stored in advance may be installed, the installation of the vapor deposition material can be automated. Note that in the transfer chamber 114, vacuum and a nitrogen atmosphere at atmospheric pressure are repeated, but it is desirable that the transfer chambers 102, 104a, and 108 are always kept in vacuum.
[0145]
Note that an in-line film deposition apparatus can also be used.
[0146]
Hereinafter, a procedure for carrying a substrate on which a TFT and an anode are provided in advance into the manufacturing apparatus shown in FIG. 8 and forming a laminated structure shown in FIG.
[0147]
First, as in the case of forming the stacked structure of FIG. 3A, a substrate provided with a TFT and an anode 73 is set in the cassette chamber 120a or the cassette chamber 120b.
[0148]
Next, the substrate is transferred from the transfer chamber 118 provided with the substrate transfer mechanism to the preparation chamber 101. Next, the material is transferred to a transfer chamber 102 connected to the preparation chamber 101.
[0149]
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 anode, it may be transferred to a pretreatment chamber 103 connected to the transfer chamber 102 and cleaned there.
[0150]
Further, a layer containing an organic compound made of a polymer may be formed on the entire surface on the anode.
The film formation chamber 112 is a film formation chamber for forming a layer containing an organic compound made of a polymer. For example, a poly (ethylenedioxythiophene) / poly (styrenesulfonic acid) aqueous solution (PEDOT / PSS) that acts as the hole injection layer 75 may be formed on the entire surface. In the case where a layer containing an organic compound is formed in the film formation chamber 112 by a spin coat method, an ink jet method, or a spray method, the film formation surface of the substrate is set upward at atmospheric pressure. The delivery chamber 105 is provided with a substrate reversing mechanism, and reverses the front and back of the substrate as appropriate. In addition, after film formation using the solution, it is preferable that the solvent component is vaporized by being transferred to the pretreatment chamber 103 where heat treatment is performed in vacuum.
[0151]
Next, after the substrate 104c is transferred from the transfer chamber 102 to the delivery chamber 105 without being exposed to the atmosphere, the substrate 104c is transferred to the transfer chamber 104, and is transferred to the film formation chamber 106R by the transfer mechanism 104b. The EL layer 16 that emits red light is appropriately formed. Here, it is formed by vapor deposition using resistance heating.
[0152]
Here, in order to obtain full color, after the film formation in the film formation chamber 106R, the film formation is sequentially performed in each of the film formation chambers 106G and 106B, and the layer 76 containing an organic compound that emits red, green, and blue light emission. -78 are formed appropriately.
[0153]
After obtaining the hole injection layer 75 and the desired EL layers 76 to 78 on the anode 13, the substrate is then transferred from the transfer chamber 104 a to the delivery chamber 107 without being exposed to the atmosphere, and is further exposed to the atmosphere. Without transferring, the substrate is transferred from the delivery chamber 107 to the transfer chamber 108.
[0154]
Next, the film is transferred to the film forming chamber 110 by a transfer mechanism installed in the transfer chamber 108, and is formed into a very thin inorganic film (an alloy such as MgAg, MgIn, AlLi, CaN, or the first or second group of the periodic table). A cathode (lower layer) 79a made of a film formed by co-evaporation with an element belonging to aluminum is formed by vapor deposition using resistance heating. After the cathode (lower layer) 79a made of a thin metal layer is formed, it is transported to the film forming chamber 109 and is formed by a transparent conductive film (ITO (indium tin oxide alloy), indium oxide zinc oxide alloy (In ₂ O _Three (ZnO), zinc oxide (ZnO), or the like) is formed, and cathodes 79a and 79b made of a laminate of a thin metal layer and a transparent conductive film are appropriately formed. Note that a thin metal layer functions as a cathode of the light-emitting element, but in this specification, a stacked film of a thin metal layer and a transparent conductive film is referred to as a cathode.
[0155]
Through the above process, the light-emitting element having the stacked structure illustrated in FIG. 7C is formed. The light-emitting element having the stacked structure illustrated in FIG. 7C has a light-emitting direction indicated by an arrow in the drawing, and is opposite to the light-emitting element in FIG.
[0156]
The subsequent steps are the same as the manufacturing procedure of the light-emitting device having the stacked structure shown in FIG.
[0157]
As described above, if the manufacturing apparatus shown in FIG. 8 is used, the stacked structure shown in FIGS. 3B and 7C can be formed separately.
[0158]
This embodiment can be freely combined with any of Embodiment Modes 1 to 4.
[0159]
[Example 2]
FIG. 9 is an external view of the top view of the EL module. A substrate 405 (also referred to as a TFT substrate) provided with an infinite number of TFTs includes a pixel portion 400 on which display is performed, drive circuits 401a and 401b for driving each pixel in the pixel portion, and a cathode provided on the EL layer. A connection portion for connecting the lead wiring and a terminal portion 402 for attaching an FPC for connection to an external circuit are provided. Further, the substrate is sealed with a substrate 406 for sealing the organic light emitting element and a sealing material 404.
[0160]
Note that the cross section of the pixel portion in FIG. 9 is not particularly limited; here, the cross-sectional view in FIG. 3B is used as an example, and a protective film or a sealing substrate is bonded to the cross-sectional structure in FIG. After the sealing step.
[0161]
An insulating film is provided on the substrate, and a pixel portion and a drive circuit are formed above the insulating film. The pixel portion includes a plurality of pixels including a current control TFT and a pixel electrode electrically connected to its drain. It is formed by. The driver circuit is formed using a CMOS circuit in which an n-channel TFT and a p-channel TFT are combined.
[0162]
These TFTs may be formed by the following steps.
[0163]
First, on a heat resistant glass substrate (first substrate) having a thickness of 0.7 mm, a plasma CVD method is used to form a lower layer of a base insulating film. _Four , NH _Three , N ₂ A silicon oxynitride film made of O (composition ratio Si = 32%, O = 27%, N = 24%, H = 17%) is formed to 50 nm (preferably 10 to 200 nm). Next, after cleaning the surface with ozone water, the oxide film on the surface is removed with dilute hydrofluoric acid (1/100 dilution). Next, as an upper layer of the base insulating film, a film formation temperature of 400 ° C. and a source gas SiH are formed by plasma CVD. _Four , N ₂ A silicon oxynitride film made of O (composition ratio Si = 32%, O = 59%, N = 7%, H = 2%) is laminated to a thickness of 100 nm (preferably 50 to 200 nm), and Deposition temperature 300 ° C., deposition gas SiH by plasma CVD method without opening to the atmosphere _Four A semiconductor film having an amorphous structure (here, an amorphous silicon film) was formed to a thickness of 54 nm (preferably 25 to 80 nm).
[0164]
Although the base insulating film is shown as a two-layer structure in this embodiment, it may be formed as a single layer film of an insulating film containing silicon as a main component or a structure in which two or more layers are stacked. The material of the semiconductor film is not limited, but preferably silicon or silicon germanium (Si _1-X Ge _X (X = 0.0001 to 0.02)) An alloy or the like may be used and may be formed by a known means (such as sputtering, LPCVD, or plasma CVD). The plasma CVD apparatus may be a single wafer type apparatus or a batch type apparatus. Alternatively, the base insulating film and the semiconductor film may be successively formed without being exposed to the air in the same film formation chamber.
[0165]
Next, after cleaning the surface of the semiconductor film having an amorphous structure, an extremely thin oxide film of about 2 nm is formed on the surface with ozone water. Next, a small amount of impurity element (boron or phosphorus) is doped in order to control the threshold value of the TFT. Here, diborane (B ₂ H ₆ ) Using a plasma-excited ion doping method without mass separation, a doping condition of an acceleration voltage of 15 kV, a gas obtained by diluting diborane to 1% with hydrogen at a flow rate of 30 sccm, and a dose of 2 × 10 ¹² / Cm ² Then, boron was added to the amorphous silicon film.
[0166]
Next, a nickel acetate salt solution containing 10 ppm of nickel in terms of weight was applied with a spinner. Instead of coating, a method of spreading nickel element over the entire surface by sputtering may be used.
[0167]
Next, heat treatment is performed for crystallization, so that a semiconductor film having a crystal structure is formed.
For this heat treatment, heat treatment in an electric furnace or irradiation with strong light may be used. In the case of performing heat treatment in an electric furnace, it may be performed at 500 ° C. to 650 ° C. for 4 to 24 hours. Here, after heat treatment for dehydrogenation (500 ° C., 1 hour), heat treatment for crystallization (550 ° C., 4 hours) was performed to obtain a silicon film having a crystal structure. Although crystallization is performed here using heat treatment using a furnace, crystallization may be performed using a lamp annealing apparatus capable of crystallization in a short time. Although a crystallization technique using nickel as a metal element for promoting crystallization of silicon is used here, other known crystallization techniques such as a solid phase growth method and a laser crystallization method may be used.
[0168]
Next, after removing the oxide film on the surface of the silicon film having a crystal structure with dilute hydrofluoric acid or the like, irradiation with laser light (XeCl: wavelength 308 nm) for increasing the crystallization rate and repairing defects left in the crystal grains In the air or in an oxygen atmosphere. As the laser light, excimer laser light having a wavelength of 400 nm or less, and second harmonic and third harmonic of a YAG laser are used. Here, pulse laser light having a repetition frequency of about 10 to 1000 Hz is used, and the laser light is 100 to 500 mJ / cm in an optical system. ² And the surface of the silicon film may be scanned by irradiating with an overlap rate of 90 to 95%. Here, repetition frequency 30Hz, energy density 470mJ / cm ² The laser irradiation was performed in the atmosphere. Note that since the reaction is performed in the air or in an oxygen atmosphere, an oxide film is formed on the surface by laser light irradiation. Although an example using a pulsed laser is shown here, a continuous wave laser may be used, and in order to obtain a crystal with a large grain size when crystallizing an amorphous semiconductor film, continuous wave is possible. It is preferable to use a solid-state laser and apply the second to fourth harmonics of the fundamental wave. Typically, Nd: YVO _Four A second harmonic (532 nm) or a third harmonic (355 nm) of a laser (fundamental wave 1064 nm) may be applied. When a continuous wave laser is used, a continuous wave YVO with an output of 10 W is used. _Four Laser light emitted from the laser is converted into a harmonic by a non-linear optical element. Also, YVO in the resonator _Four There is also a method of emitting harmonics by inserting a crystal and a nonlinear optical element. Preferably, the laser beam is shaped into a rectangular or elliptical shape on the irradiation surface by an optical system, and the object to be processed is irradiated. The energy density at this time is 0.01 to 100 MW / cm. ² Degree (preferably 0.1-10 MW / cm ² )is required. Then, irradiation may be performed by moving the semiconductor film relative to the laser light at a speed of about 10 to 2000 cm / s.
[0169]
Here, a technique of irradiating laser light after performing thermal crystallization using nickel as a metal element for promoting crystallization of silicon is used. However, a continuous wave laser (YVO) is used without adding nickel. _Four The amorphous silicon film may be crystallized by the second harmonic of the laser.
[0170]
Next, the oxide film formed by laser light irradiation is removed with dilute hydrofluoric acid, and then the surface is treated with ozone water for 120 seconds to form a barrier layer made of oxide films having a total thickness of 1 to 5 nm. Here, the barrier layer is formed using ozone water, but the surface of the semiconductor film having a crystal structure is oxidized by a method of oxidizing the surface of the semiconductor film having a crystal structure by irradiation with ultraviolet light in an oxygen atmosphere or the oxygen plasma treatment. The barrier layer may be formed by depositing an oxide film of about 1 to 10 nm by a method, plasma CVD method, sputtering method or vapor deposition method. In this specification, a barrier layer refers to a layer that has a film quality or a film thickness that allows a metal element to pass in a gettering step and that serves as an etching stopper in a step of removing a layer that becomes a gettering site.
[0171]
Next, an amorphous silicon film containing an argon element serving as a gettering site is formed with a thickness of 50 nm to 400 nm, here 150 nm, over the barrier layer by a sputtering method. The film forming conditions here were a film forming pressure of 0.3 Pa, a gas (Ar) flow rate of 50 (sccm), a film forming power of 3 kW, and a substrate temperature of 150 ° C. Note that the atomic concentration of the argon element contained in the amorphous silicon film under the above conditions is 3 × 10 ²⁰ / Cm ^Three ~ 6 × 10 ²⁰ / Cm ^Three The atomic concentration of oxygen is 1 × 10 ¹⁹ / Cm ^Three ~ 3x10 ¹⁹ / Cm ^Three It is. After that, heat treatment was performed at 550 ° C. for 4 hours using an electric furnace, and gettering was performed to reduce the nickel concentration in the semiconductor film having a crystal structure.
A lamp annealing apparatus may be used instead of the electric furnace.
[0172]
Next, the amorphous silicon film containing an argon element as a gettering site is selectively removed using the barrier layer as an etching stopper, and then the barrier layer is selectively removed with dilute hydrofluoric acid. Note that during gettering, nickel tends to move to a region with a high oxygen concentration, and thus it is desirable to remove the barrier layer made of an oxide film after gettering.
[0173]
Next, after forming a thin oxide film with ozone water on the surface of the obtained silicon film having a crystal structure (also called a polysilicon film), a mask made of resist is formed and etched into a desired shape to form islands. A separated semiconductor layer is formed. After the semiconductor layer is formed, the resist mask is removed.
[0174]
Next, the oxide film is removed with an etchant containing hydrofluoric acid, and at the same time, the surface of the silicon film is washed, and then an insulating film containing silicon as a main component and serving as a gate insulating film is formed. Here, a silicon oxynitride film (composition ratio: Si = 32%, O = 59%, N = 7%, H = 2%) with a thickness of 115 nm is formed by plasma CVD.
[0175]
Next, a first conductive film with a thickness of 20 to 100 nm and a second conductive film with a thickness of 100 to 400 nm are stacked over the gate insulating film. In this embodiment, a tantalum nitride film having a thickness of 50 nm and a tungsten film having a thickness of 370 nm are sequentially stacked on the gate insulating film, and patterning is performed in the following procedure to form each gate electrode and each wiring.
[0176]
The conductive material for forming the first conductive film and the second conductive film is an element selected from Ta, W, Ti, Mo, Al, and Cu, or an alloy material or a compound material containing the element as a main component. Form. Alternatively, a semiconductor film typified by a polycrystalline silicon film doped with an impurity element such as phosphorus, or an AgPdCu alloy may be used as the first conductive film and the second conductive film. Further, the present invention is not limited to the two-layer structure. For example, a three-layer structure in which a 50 nm-thickness tungsten film, a 500 nm-thickness aluminum and silicon alloy (Al-Si) film, and a 30 nm-thickness titanium nitride film are sequentially stacked. Also good. In the case of a three-layer structure, tungsten nitride may be used instead of tungsten of the first conductive film, or aluminum instead of the aluminum and silicon alloy (Al-Si) film of the second conductive film. A titanium alloy film (Al—Ti) may be used, or a titanium film may be used instead of the titanium nitride film of the third conductive film. Moreover, a single layer structure may be sufficient.
[0177]
An ICP (Inductively Coupled Plasma) etching method may be used for the etching of the first conductive film and the second conductive film (first etching process and second etching process). Using the ICP etching method, the film is formed into a desired taper shape by appropriately adjusting the etching conditions (the amount of power applied to the coil-type electrode, the amount of power applied to the substrate-side electrode, the electrode temperature on the substrate side, etc.) Can be etched. Here, after a mask made of resist is formed, 700 W RF (13.56 MHz) power is applied to the coil-type electrode at a pressure of 1 Pa as a first etching condition, and CF is used as an etching gas. _Four And Cl ₂ And O ₂ Each gas flow rate ratio is 25/25/10 (sccm), 150 W RF (13.56 MHz) power is applied to the substrate side (sample stage), and a substantially negative self-bias voltage is applied. To do. The electrode area size on the substrate side is 12.5 cm × 12.5 cm, and the coil-type electrode area size (here, a quartz disk provided with a coil) is a disk having a diameter of 25 cm. The W film is etched under this first etching condition so that the end portion is tapered. Then, the resist mask is not removed and the second etching condition is changed, and the etching gas is changed to CF. _Four And Cl ₂ The gas flow ratio is 30/30 (sccm), and 500 W of RF (13.56 MHz) power is applied to the coil-type electrode at a pressure of 1 Pa to generate plasma and etching for about 30 seconds. Went. 20 W of RF (13.56 MHz) power is also applied to the substrate side (sample stage), and a substantially negative self-bias voltage is applied. CF _Four And Cl ₂ Under the second etching condition in which is mixed, the W film and the TaN film are etched to the same extent. Here, the first etching condition and the second etching condition are referred to as a first etching process.
[0178]
Next, a second etching process is performed without removing the resist mask. Here, as the third etching condition, CF as an etching gas is used. _Four And Cl ₂ Each gas flow rate ratio was 30/30 (sccm), 500 W RF (13.56 MHz) power was applied to the coil-type electrode at a pressure of 1 Pa, plasma was generated, and etching was performed for 60 seconds. . 20 W of RF (13.56 MHz) power is also applied to the substrate side (sample stage), and a substantially negative self-bias voltage is applied. Then, the resist mask is not removed and the etching condition is changed to the fourth etching condition. _Four And Cl ₂ And O ₂ The gas flow ratio is 20/20/20 (sccm), and 500 W of RF (13.56 MHz) power is applied to the coil-type electrode at a pressure of 1 Pa to generate plasma for about 20 seconds. Etching was performed. 20 W of RF (13.56 MHz) power is also applied to the substrate side (sample stage), and a substantially negative self-bias voltage is applied. Here, the third etching condition and the fourth etching condition are referred to as a second etching process. At this stage, the gate electrode and each electrode having the first conductive layer as a lower layer and the second conductive layer as an upper layer are formed.
[0179]
Next, after removing the resist mask, a first doping process is performed to dope the entire surface using the gate electrode as a mask. The first doping process may be performed by an ion doping method or an ion implantation method. The condition of the ion doping method is that the dose is 1.5 × 10 ¹⁴ atoms / cm ² The acceleration voltage is set to 60 to 100 keV. Typically, phosphorus (P) or arsenic (As) is used as the impurity element imparting n-type conductivity. The first impurity region (n ^- Region) is formed.
[0180]
Next, a new mask made of resist is formed. At this time, in order to reduce the off-current value of the switching TFT, the mask covers the channel formation region and a part of the semiconductor layer forming the switching TFT of the pixel portion. Form. The mask is also provided to protect the channel formation region of the semiconductor layer forming the p-channel TFT of the driver circuit and the surrounding region. In addition, the mask is formed so as to cover the channel formation region of the semiconductor layer forming the current control TFT of the pixel portion and the surrounding region.
[0181]
Next, a second doping process is selectively performed using the mask made of the resist, so that an impurity region (n ^- Region). The second doping process may be performed by an ion doping method or an ion implantation method. Here, phosphine (PH _Three Gas) diluted to 5% with hydrogen at a flow rate of 30 sccm and a dose of 1.5 × 10 ¹⁴ atoms / cm ² And the acceleration voltage is 90 keV. In this case, the resist mask and the second conductive layer serve as a mask for the impurity element imparting n-type conductivity, and a second impurity region is formed. In the second impurity region, 1 × 10 ¹⁶ ~ 1x10 ¹⁷ /cm ^Three An impurity element imparting n-type is added in a concentration range of. Here, a region having the same concentration range as the second impurity region is n ^- Also called a region.
[0182]
Next, a third doping process is performed without removing the resist mask. The third doping process may be performed by an ion doping method or an ion implantation method. Typically, phosphorus (P) or arsenic (As) is used as the impurity element imparting n-type conductivity. Here, phosphine (PH _Three Gas) diluted to 5% with hydrogen at a flow rate of 40 sccm and a dose of 2 × 10 ¹⁵ atoms / cm ² And the acceleration voltage is 80 keV. In this case, the resist mask, the first conductive layer, and the second conductive layer serve as a mask for the impurity element imparting n-type conductivity, and a third impurity region is formed. The third impurity region has 1 × 10 ²⁰ ~ 1x10 ^{twenty one} /cm ^Three An impurity element imparting n-type is added in a concentration range of. Here, a region having the same concentration range as the third impurity region is n ⁺ Also called a region.
[0183]
Next, after removing the resist mask, a new resist mask is formed and a fourth doping process is performed. By the fourth doping treatment, a fourth impurity region and a fifth impurity region in which an impurity element imparting p-type conductivity is added to the semiconductor layer forming the semiconductor layer for forming the p-channel TFT are formed. .
[0184]
The fourth impurity region has 1 × 10 ²⁰ ~ 1x10 ^{twenty one} /cm ^Three An impurity element imparting p-type is added in a concentration range of. The fourth impurity region is a region to which phosphorus (P) is added in the previous step (n ^- The concentration of the impurity element imparting p-type is 1.5 to 3 times that of the impurity element, and the conductivity type is p-type. Here, a region having the same concentration range as the fourth impurity region is represented by p. ⁺ Also called a region.
[0185]
The fifth impurity region is formed in a region overlapping the tapered portion of the second conductive layer, and is 1 × 10. ¹⁸ ~ 1x10 ²⁰ /cm ^Three An impurity element imparting p-type is added in a concentration range of. Here, a region having the same concentration range as the fifth impurity region is represented by p. ^- Also called a region.
[0186]
Through the above steps, impurity regions having n-type or p-type conductivity are formed in each semiconductor layer. The conductive layer becomes the gate electrode of the TFT.
[0187]
Next, an insulating film (not shown) that covers substantially the entire surface is formed. In this example, a 50 nm-thickness silicon oxide film was formed by plasma CVD. Of course, this insulating film is not limited to the silicon oxide film, and another insulating film containing silicon may be used as a single layer or a laminated structure.
[0188]
Next, a step of activating the impurity element added to each semiconductor layer is performed. This activation step may be a rapid thermal annealing method (RTA method) using a lamp light source, a method of irradiating a YAG laser or an excimer laser from the back surface, a heat treatment using a furnace, or a combination thereof. By different methods.
[0189]
Further, in this embodiment, an example in which an insulating film is formed before the activation is shown, but an insulating film may be formed after the activation.
[0190]
Next, a first interlayer insulating film made of a silicon nitride film is formed and subjected to a heat treatment (heat treatment at 300 to 550 ° C. for 1 to 12 hours) to hydrogenate the semiconductor layer. This step is a step of terminating dangling bonds in the semiconductor layer with hydrogen contained in the first interlayer insulating film. The semiconductor layer can be hydrogenated regardless of the presence of an insulating film made of a silicon oxide film. As another means of hydrogenation, plasma hydrogenation (using hydrogen excited by plasma) may be performed.
[0191]
Next, a second interlayer insulating film made of an organic insulating material is formed on the first interlayer insulating film. In this embodiment, an acrylic resin film having a film thickness of 1.6 μm is formed by a coating method, and a 200 nm silicon nitride film is further laminated by a sputtering method. Although an example in which a silicon nitride film is laminated on 1.6 μm acrylic resin is shown here, the material or film thickness of the interlayer insulating film is not particularly limited, and the gate electrode and the power supply line formed thereon When a capacitor is formed between the organic insulating film and the inorganic insulating film, the film thickness may be appropriately set to 0.5 μm to 2.0 μm.
[0192]
Next, a pixel electrode is formed so as to be in contact with and overlapping with a connection electrode to be formed later in contact with the drain region of the current control TFT made of a p-channel TFT. In this embodiment, the pixel electrode functions as an anode of the organic light emitting element, and a transparent conductive film is used in order to allow the light emission of the organic light emitting element to pass through the pixel electrode.
[0193]
Next, a contact hole reaching the conductive layer to be a gate electrode or a gate wiring and a contact hole reaching each impurity region are formed. In this embodiment, a plurality of etching processes are sequentially performed. In this embodiment, after the third interlayer insulating film is etched using the second interlayer insulating film as an etching stopper, the second interlayer insulating film is etched using the first interlayer insulating film as an etching stopper, and then the first interlayer insulating film is etched. The insulating film was etched.
[0194]
After that, electrodes such as a source wiring, a power supply line, a lead electrode, and a connection electrode are formed using Al, Ti, Mo, W, or the like. Here, patterning was performed using a laminated film of a Ti film (film thickness: 100 nm), an Al film containing silicon (film thickness: 350 nm), and a Ti film (film thickness: 50 nm) as materials for these electrodes and wirings. Thus, a source electrode and a source wiring, a connection electrode, a lead electrode, a power supply line, and the like are appropriately formed. The lead electrode for making contact with the gate wiring covered with the interlayer insulating film is provided at the end of the gate wiring, and the end of each other wiring is also connected to an external circuit or an external power source. An input / output terminal portion provided with a plurality of electrodes is formed. Further, the connection electrode provided so as to be in contact with and overlapping the previously formed pixel electrode is in contact with the drain region of the current control TFT.
[0195]
As described above, a driver circuit having an n-channel TFT, a p-channel TFT, and a CMOS circuit in which these are complementarily combined, and a plurality of n-channel TFTs or p-channel TFTs are provided in one pixel. A pixel portion can be formed.
[0196]
The pixel electrode functions as an anode of the organic light emitting element. In addition, an insulating film called a bank is formed on both ends of the pixel electrode, and a layer containing an organic compound and a cathode of the light emitting element are formed on the pixel electrode.
[0197]
The cathode also functions as a wiring common to all pixels, and is electrically connected to a terminal portion connected to the FPC via a connection wiring. Further, all elements included in the pixel portion and the driving circuit are covered with a cathode and a protective film. Furthermore, you may bond together with a cover material (board | substrate for sealing) and an adhesive agent. The cover material may be provided with a recess and a desiccant may be installed.
[0198]
[Example 3]
In this example, an example of the second container shown in Embodiment Mode 3 is shown in FIG.
[0199]
FIG. 10 is a cross-sectional view of the second container containing the first container.
[0200]
In FIG. 10, reference numeral 301 denotes a first container, typically a crucible, in which an EL material 302 is accommodated. The crucible 301 can be lightly closed with a crucible lid 303. The second container is composed of two parts, and the upper part 304a and the lower part 304b are sealed with an O-ring 305 or the like. The upper part 304a is provided with a spring 306 so that the upper lid 307 is movable. The lower part 304b is also provided with a spring 308 so that the lower lid 309 is movable. The crucible 301 is arranged so as to be sandwiched between the upper lid 307 and the lower lid 309. The lower lid 309 is provided with a convex portion (not shown) for fixing the crucible 301, and the crucible lid 303 is pressed by the upper lid 307. Note that the crucible lid and the upper lid may be integrated.
[0201]
The interiors of the second containers 304a and 304b are filled with an inert gas (typically nitrogen).
[0202]
When this second container is placed in a processing chamber capable of being evacuated and brought into a vacuum state, the upper part 304a of the second container is detached by the restoring force of the spring due to the difference between the internal pressure and the external pressure. At the same time, the crucible 301 is pushed out by the restoring force of the spring. Thus, the 2nd container shown in FIG. 10 is a container which can be opened comparatively easily by making a vacuum state from atmospheric pressure. Therefore, work after opening, for example, work for removing the upper part 304a and the crucible lid 303 and work for taking out the first container can be performed by a robot or the like. Further, the second container shown in FIG. 10 can be a container that is resistant to impact and suitable for conveyance.
[0203]
This embodiment can be freely combined with any one of Embodiment Modes 1 to 4, Embodiment 1, and Embodiment 2.
[0204]
[Example 4]
By implementing the present invention, all electronic devices incorporating a module having an organic light emitting element (active matrix EL module) are completed.
[0205]
Such electronic devices include video cameras, digital cameras, head mounted displays (goggles type displays), car navigation systems, projectors, car stereos, personal computers, personal digital assistants (mobile computers, mobile phones, electronic books, etc.), etc. Can be mentioned. Examples of these are shown in FIGS.
[0206]
FIG. 11A illustrates a personal computer, which includes a main body 2001, an image input portion 2002, a display portion 2003, a keyboard 2004, and the like.
[0207]
FIG. 11B shows a video camera, which includes a main body 2101, a display portion 2102, an audio input portion 2103, operation switches 2104, a battery 2105, an image receiving portion 2106, and the like.
[0208]
FIG. 11C illustrates a mobile computer, which includes a main body 2201, a camera unit 2202, an image receiving unit 2203, operation switches 2204, a display unit 2205, and the like.
[0209]
FIG. 11D illustrates a goggle type display including a main body 2301, a display portion 2302, an arm portion 2303, and the like.
[0210]
FIG. 11E shows a player using a recording medium (hereinafter referred to as a recording medium) on which a program is recorded, and includes a main body 2401, a display portion 2402, a speaker portion 2403, a recording medium 2404, an operation switch 2405, and the like. This player uses a DVD (Digital Versatile Disc), CD, or the like as a recording medium, and can perform music appreciation, movie appreciation, games, and the Internet.
[0211]
FIG. 11F illustrates a digital camera, which includes a main body 2501, a display portion 2502, an eyepiece portion 2503, an operation switch 2504, an image receiving portion (not shown), and the like.
[0212]
FIG. 12A shows a cellular phone, which includes a main body 2901, an audio output portion 2902, an audio input portion 2903, a display portion 2904, operation switches 2905, an antenna 2906, an image input portion (CCD, image sensor, etc.) 2907, and the like.
[0213]
FIG. 12B illustrates a portable book (electronic book), which includes a main body 3001, display portions 3002 and 3003, a storage medium 3004, operation switches 3005, an antenna 3006, and the like.
[0214]
FIG. 12C illustrates a display, which includes a main body 3101, a support base 3102, a display portion 3103, and the like.
[0215]
Incidentally, the display shown in FIG. 12C is a medium or small size display, for example, a screen size of 5 to 20 inches. Further, in order to form a display portion having such a size, it is preferable to use a substrate having a side of 1 m and perform mass production by performing multiple chamfering.
[0216]
As described above, the applicable range of the present invention is so wide that the present invention can be applied to methods for manufacturing electronic devices in various fields. Further, the electronic device of this example can be realized by using any combination of Embodiment Modes 1 to 4 and Examples 1 to 3.
[0217]
【The invention's effect】
According to the present invention, a light-emitting device having excellent TFT characteristics (on current, off-current, Vth, S value, etc.) can be manufactured in an active matrix light-emitting device including an organic light-emitting element.
[Brief description of the drawings]
FIG. 1 is a diagram showing TFT characteristics in which a cathode is formed by a resistance heating method.
FIG. 2 is a diagram showing TFT characteristics.
FIG. 3 is a cross-sectional view showing the present invention. (Embodiment 1)
FIG. 4 is a cross-sectional view showing the present invention. (Embodiment 1)
FIG. 5 is a diagram showing a manufacturing apparatus. (Embodiment 2)
6 is a diagram showing a third embodiment. FIG.
7 is a diagram showing a fourth embodiment. FIG.
FIG. 8 is a diagram showing a manufacturing apparatus. Example 1
FIG. 9 is a top view of a light emitting device. (Example 2)
10 is a diagram showing Example 3. FIG.
FIG 11 illustrates an example of an electronic device.
FIG 12 illustrates an example of an electronic device.
FIG. 13 is a diagram showing TFT characteristics in which a cathode is formed by an electron gun evaporation method. (Comparative example)
FIG. 14 is a diagram showing TFT characteristics. (Comparative example)

Claims (14)

Forming a thin film transistor,
Forming an anode above the thin film transistor;
A layer containing an organic compound is formed on the anode by a vapor deposition method in which a vapor deposition material is heated by resistance heating,
A cathode is formed by a vapor deposition method in which a vapor deposition material made of a metal material is heated by resistance heating on the layer containing the organic compound,
In the vapor deposition method for forming the layer containing the organic compound by the resistance heating, a first container containing an organic material is sealed with a second container, and a substrate and the second container are placed in a manufacturing apparatus having a vacuum exhaust unit. After the inside of the manufacturing apparatus is evacuated, the first container is taken out from the second container and placed, and then the first container is heated by resistance heating on the substrate. It has a step of performing the deposition,
In the first container, an organic material is purified by sublimation on an inner wall thereof. Forming a thin film transistor,
Forming an anode above the thin film transistor;
A layer containing an organic compound is formed on the anode by a vapor deposition method in which a vapor deposition material is heated by resistance heating,
A lower layer of the cathode is formed by a vapor deposition method in which a vapor deposition material made of a metal material is heated by resistance heating on the layer containing the organic compound,
An upper layer of the cathode is formed by a vapor deposition method in which a vapor deposition material made of a metal material is heated with an electron gun on the lower layer of the cathode,
In the vapor deposition method for forming the layer containing the organic compound by the resistance heating, a first container containing an organic material is sealed with a second container, and a substrate and the second container are placed in a manufacturing apparatus having a vacuum exhaust unit. After the inside of the manufacturing apparatus is evacuated, the first container is taken out from the second container and placed, and then the first container is heated by resistance heating on the substrate. It has a step of performing the deposition,
In the first container, an organic material is purified by sublimation on an inner wall thereof. Forming a thin film transistor,
Forming an anode above the thin film transistor;
A layer containing an organic compound is formed on the anode by a vapor deposition method in which a vapor deposition material is heated by resistance heating,
A lower layer of the cathode is formed by a vapor deposition method in which a vapor deposition material made of a metal material is heated by resistance heating on the layer containing the organic compound,
Forming a cathode upper layer made of a transparent conductive film by sputtering on the cathode lower layer;
In the vapor deposition method for forming the layer containing the organic compound by the resistance heating, a first container containing an organic material is sealed with a second container, and a substrate and the second container are placed in a manufacturing apparatus having a vacuum exhaust unit. After the inside of the manufacturing apparatus is evacuated, the first container is taken out from the second container and placed, and then the first container is heated by resistance heating on the substrate. It has a step of performing the deposition,
In the first container, an organic material is purified by sublimation on an inner wall thereof.   4. The method for manufacturing a light-emitting device according to claim 3, wherein the transparent conductive film is an indium tin oxide alloy, an indium zinc oxide alloy, or zinc oxide.   5. The method for manufacturing a light-emitting device according to claim 1, wherein the vapor deposition material made of the metal material is an alloy material containing a metal element belonging to Group 1 or Group 2 of the periodic table. .   2. The method for manufacturing a light-emitting device according to claim 1, wherein the cathode is a film formed by co-evaporation of an element belonging to Group 1 or Group 2 of the periodic table and aluminum.   5. The light emitting device according to claim 2, wherein the lower layer of the cathode is a film formed by co-evaporation of an element belonging to Group 1 or 2 of the periodic table and aluminum. Manufacturing method. Forming a thin film transistor,
Forming a cathode above the thin film transistor;
A layer containing an organic compound is formed on the cathode by a vapor deposition method in which a vapor deposition material is heated by resistance heating,
An anode is formed by a vapor deposition method in which a vapor deposition material made of a metal material is heated by resistance heating on the layer containing the organic compound,
In the vapor deposition method for forming the layer containing the organic compound by the resistance heating, a first container containing an organic material is sealed with a second container, and a substrate and the second container are placed in a manufacturing apparatus having a vacuum exhaust unit. After the inside of the manufacturing apparatus is evacuated, the first container is taken out from the second container and placed, and then the first container is heated by resistance heating on the substrate. It has a step of performing the deposition,
In the first container, an organic material is purified by sublimation on an inner wall thereof. Forming a thin film transistor,
Forming a cathode above the thin film transistor;
A layer containing an organic compound is formed on the cathode by a vapor deposition method in which a vapor deposition material is heated by resistance heating,
On the layer containing the organic compound, a lower layer of the anode is formed by a vapor deposition method in which a vapor deposition material made of a metal material is heated by resistance heating,
The upper layer of the anode is formed by a vapor deposition method in which a vapor deposition material made of a metal material is heated with an electron gun on the lower layer of the anode,
In the vapor deposition method for forming the layer containing the organic compound by the resistance heating, a first container containing an organic material is sealed with a second container, and a substrate and the second container are placed in a manufacturing apparatus having a vacuum exhaust unit. After the inside of the manufacturing apparatus is evacuated, the first container is taken out from the second container and placed, and then the first container is heated by resistance heating on the substrate. It has a step of performing the deposition,
In the first container, an organic material is purified by sublimation on an inner wall thereof.   The vapor deposition material made of the metal material according to claim 8 or 9 is a conductive material containing one or more elements selected from Pt, Cr, W, Ni, Zn, Sn, and In. A method for manufacturing a light-emitting device. In any one of claims 1 to 10, wherein the substrate and not more than 20cm apart distance between the first container, the light emitting device characterized by performing deposition using a vapor deposition mask on the substrate Manufacturing method. The method for manufacturing a light-emitting device according to claim 11 , wherein the vapor deposition mask includes a mechanism for circulating a cooling medium. In any one of claims 1 to 12, when performing the deposition, it rotates the substrate, and a method for manufacturing a light emitting device characterized by moving the first container. In any one of claims 1 to 13, wherein the light emitting device, a video camera, a digital camera, a goggle type display, a car navigation, a method for manufacturing a light emitting device which is a personal computer or a portable information terminal.

Images