JP2005149981A - Organic electroluminescence device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL device having a long life without causing deterioration of functional layers such as a light emitting layer and an electron injecting layer, and also to provide a manufacturing method thereof. <P>SOLUTION: The organic EL device of this invention is of a top-emission type in which a pixel electrode 111, a functional layer 110 having at least a light emitting layer made of an organic material, and a cathode 12 are disposed in this order on a substrate 2, and the cathode 12 has a light transmitting property. The organic EL device is characterized in that the cathode 12 includes at least a titanium nitride layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an organic electroluminescence (hereinafter abbreviated as EL) device and a method for manufacturing the same.

  EL elements using electroluminescence have excellent features such as high visibility due to self-emission and excellent impact resistance, and thus are attracting attention as light emitting elements in various display devices. Panels using top-emission organic EL elements, among other EL elements, have been developed as basic structures for manufacturing large, high-brightness, and high-definition panels because they allow light to be extracted from the top surface of the substrate. It is being advanced.

The top emission type organic EL element has a structure in which a first electrode layer made of a transparent conductive film, an ultra-thin electron injection metal layer, and a second electrode layer made of a transparent conductive film formed on the upper surface thereof are provided. It has been known. As materials constituting these transparent conductive films, indium tin oxide (hereinafter abbreviated as ITO), tin oxide (SnO ₂ ), and the like are known. However, when the transparent electrode layer is formed on the substrate through the organic layer, the substrate temperature is set low from room temperature to nearly 100 ° C. in order to prevent the organic layer from being damaged. As a result, a voltage drop occurred in the wiring line of the transparent conductive layer, resulting in uneven light emission. For this reason, various techniques that do not cause the above-described problems have been proposed (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 10-162959

  In Patent Document 1 described above, a transparent conductive film is formed by a sputtering method, and the sputtering output is suppressed to an extremely low power of about 20 W. That is, by suppressing the sputtering output, the organic layer is prevented from being damaged by the plasma generated during sputtering. However, by suppressing the sputtering output, there is a problem that the lamination efficiency of the transparent conductive film is lowered, the time required for forming the transparent conductive film is increased, and the productivity is lowered. Further, even if the sputtering output is suppressed as described above, there is a problem that the organic layer is damaged by the plasma and a defect such as a non-light emitting point occurs.

In addition, the present inventors have found a method for laminating a transparent conductive film by an ion plating method in order to avoid the above-described sputtering damage to the organic layer. Among the ion plating methods, when a certain type of film forming apparatus is used, the plasma is less likely to come into contact with the surface of the substrate to be formed, and the generation of non-luminescent spots due to film forming damage is small.
However, even in this method, there is a problem that there is some damage to the organic layer, and the period during which the organic layer can emit light is shortened. Furthermore, the transparent conductive film such as ITO has a problem that the lifetime is extremely shortened because the electron injection layer is oxidized at the time of light emission because the oxygen contained therein is easily attached and detached by an external factor, for example, heat. .

  The present invention has been made to solve the above-described problems, and provides an organic EL device having a long lifetime and a method for manufacturing the same without deteriorating functional layers such as a light emitting layer and an electron injection layer. Objective.

  In order to achieve the above object, an organic EL device according to the present invention includes a first electrode, a functional layer having at least a light emitting layer made of an organic material, and a second electrode arranged in this order on a substrate. 2 is an organic EL device in which light is transmitted from the light emitting layer and emitted from above the second electrode, and the second electrode includes at least a titanium nitride layer. Features. The functional layer includes, for example, a layered structure of a light emitting layer and an electron transport / injection layer or a hole transport / injection layer for transporting / injecting electrons and holes into the light emitting layer. . Moreover, you may comprise a functional layer with a light emitting layer single-piece | unit.

  As a result of examining the material of the upper transparent common electrode (the “second electrode” in the present invention) of the top emission type organic EL device, the present inventor has found that titanium nitride has excellent characteristics. That is, although the titanium nitride layer is slightly colored in yellow, it has excellent light transmittance and can sufficiently function as an upper transparent common electrode. In addition, the titanium nitride layer becomes an oxidation barrier layer and does not oxidize the organic light emitting layer or the electron injection layer located on the lower layer side. Therefore, compared with the conventional configuration using a transparent conductive film such as ITO as a single layer. The light emission life can be improved.

The second electrode may be a single titanium nitride layer, but may be composed of two or more layers, and the titanium nitride layer may be disposed on the functional layer side.
When the second electrode is composed of two or more layers, for example, a laminated structure of a titanium nitride layer and a transparent conductive film such as ITO can be employed. In this case, the light transmittance can be improved as compared with the case where the titanium nitride layer is used as a single layer, and a high-luminance organic EL device can be obtained. Furthermore, since the electrical resistance is lower than when the titanium nitride layer is used as a single layer, the function as the upper transparent common electrode can be more fully exhibited. Even when ITO is used, if a titanium nitride layer is placed on the functional layer side, the titanium nitride layer acts as a barrier to prevent the oxygen contained inside the ITO from adversely affecting the light emission life. can do.

In the method for manufacturing an organic EL device according to the present invention, a first electrode, a functional layer having at least a light emitting layer made of an organic material, and a second electrode are arranged in this order on a substrate, and the second electrode transmits light. A method of manufacturing an organic EL device in which light from the light emitting layer is emitted above the second electrode, the step of forming the first electrode, and the formation of the functional layer And forming the second electrode including at least a titanium nitride layer, and forming the titanium nitride layer by using an ion plating method in which a substrate to be processed is disposed outside the plasma generation region. It is characterized by using a film forming apparatus.
According to the above method, since the substrate to be processed is not directly exposed to plasma when the titanium nitride layer is formed, an organic EL device having high luminance and high reliability is obtained without damaging the organic light emitting layer and the electron injection layer. be able to.

Subsequent to the formation of the titanium nitride layer, a transparent conductive layer may be continuously formed in the same film forming apparatus.
For example, a transparent conductive layer such as ITO can also be formed by the above ion plating method. In this case, if the titanium nitride layer and the transparent conductive layer are continuously formed in the same film forming apparatus, the surface of the titanium nitride layer is formed. There are no inconveniences such as contamination and oxidation, the film quality is improved, the production TAT is shortened, and the productivity is improved.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. Note that in FIGS. 1 to 14, the scale of each layer and each member is shown to be different from the actual scale so that each layer and each member can be recognized on the drawings.

FIG. 1 is a schematic plan view showing a wiring structure of an organic EL display device which is an example of the electroluminescence display device of the present embodiment.
As shown in FIG. 1, the electroluminescence display device (organic EL device) 1 according to the present embodiment includes a plurality of scanning lines 101, a plurality of signal lines 102 extending in a direction intersecting the scanning lines 101, and a signal. A plurality of power supply lines 103 extending in parallel with the line 102 are respectively wired. An area partitioned by the scanning line 101 and the signal line 102 is configured as a pixel area.
Connected to the signal line 102 is a data side driving circuit 104 including a shift register, a level shifter, a video line, and an analog switch. Further, a scanning side driving circuit 105 including a shift register and a level shifter is connected to the scanning line 101.

  In each pixel region, a switching thin film transistor 112 to which a scanning signal is supplied to the gate electrode via the scanning line 101 and a pixel signal shared from the signal line 102 via the switching thin film transistor 112 are held. A capacitor cap, a driving thin film transistor 123 to which a pixel signal held by the holding capacitor cap is supplied to a gate electrode, and the power supply line when electrically connected to the power supply line 103 via the driving thin film transistor 123 A pixel electrode 111 into which a driving current flows from 103 and a functional layer 110 sandwiched between the pixel electrode 111 and the cathode 12 are provided. The pixel electrode 111, the cathode 12, and the functional layer 110 constitute a light emitting unit A, and the display device 1 is configured by including a plurality of the light emitting units A in a matrix.

  According to such a configuration, when the scanning line 101 is driven and the switching thin film transistor 112 is turned on, the potential of the signal line 102 at that time is held in the holding capacitor cap, and is driven according to the state of the holding capacitor cap. The on / off state of the thin film transistor 123 is determined. Then, current flows from the power supply line 103 to the pixel electrode 111 through the channel of the driving thin film transistor 123, and further current flows to the cathode 12 through the functional layer 110. The functional layer 110 emits light according to the amount of current flowing through it.

FIG. 2 is a schematic plan view of the display device. FIG. 3 shows an enlarged view of the cross-sectional structure of the display region 2a in the present display device.
As shown in FIG. 3, in the display device 1 of this embodiment, a circuit element unit 14 and a display element unit 10 are sequentially stacked on a substrate 2, and the substrate surface on which the stacked body is formed is a sealing unit (not shown). ). The display element unit 10 includes a light emitting element unit 11 including a light emitting layer 110 b and a cathode (second electrode) 12 formed on the light emitting element unit 11. The cathode 12 and the sealing portion have translucency, and the display device 1 is configured as a so-called top emission type display device in which display light emitted from the light emitting layer is emitted from the sealing portion side. ing.

As the substrate 2, any of a transparent substrate, a semitransparent substrate, and an opaque substrate can be used. Examples of the transparent or translucent substrate include glass, quartz, resin (plastic, plastic film) and the like, and an inexpensive soda glass substrate is particularly preferably used. Examples of the opaque substrate include a thermosetting resin, a thermoplastic resin, and the like in addition to a ceramic sheet such as alumina or a metal sheet such as stainless steel subjected to an insulation treatment such as surface oxidation.
As shown in FIG. 2, the substrate 2 is partitioned into a display region 2 a located at the center and a non-display region 2 b surrounding the display region 2 a located at the periphery of the substrate 2.
The display area 2a is an area formed by the light emitting portions A arranged in a matrix, and a non-display area 2b is formed outside the display area 2a. In the non-display area 2b, a dummy display area adjacent to the display area 2a is formed.

As shown in FIGS. 2 and 3, the circuit element section 14 is provided with the above-described scanning line, signal line, storage capacitor, switching thin film transistor, driving thin film transistor 123, and the like, and is arranged in the display region 2a. Each light emitting section A thus driven is driven.
One end of the cathode 12 is connected to the cathode wiring 120 formed on the substrate 2 from the light emitting element portion 11, and one end of the wiring is connected to the wiring 5 a on the flexible substrate 5. Further, the wiring 5 a is connected to a driving IC 6 (driving circuit) provided on the flexible substrate 5.

Further, the above-described power supply lines 103 (103R, 103G, 103B) are wired in the non-display area 2b of the circuit element unit 14.
Further, the above-described scanning side drive circuits 105 and 105 are arranged on both sides of the display area 2a in FIG. The scanning side drive circuits 105 and 105 are provided in the circuit element section 14 below the dummy area. Further, in the circuit element section 14, a drive circuit control signal wiring 105a and a drive circuit power supply wiring 105b connected to the scanning side drive circuits 105 and 105 are provided. Further, an inspection circuit 106 is disposed above the display area 2a in FIG.

More specifically, the display device 1 includes a functional layer 110 including a circuit element unit 14 in which a circuit such as a TFT is formed on a substrate 2, a pixel electrode (first electrode) 111, and a light emitting layer 110b. The light emitting element part 11 in which is formed and the cathode 12 are sequentially laminated.
In the circuit element portion 14, a base protective film 2c made of a silicon oxide film is formed on the substrate 2, and an island-shaped semiconductor film 141 made of polycrystalline silicon is formed on the base protective film 2c. Note that a source region 141a and a drain region 141b are formed in the semiconductor film 141 by high concentration P ion implantation. Further, a portion where P is not introduced is a channel region 141c.
In the circuit element portion 14, a gate insulating film 142 that covers the base protective film 2c and the semiconductor film 141 is formed. A gate electrode 143 (scanning line 101) made of Al, Mo, Ta, Ti, W, or the like is formed on the gate insulating film 142 at a position corresponding to the channel region 141c of the semiconductor film 141. The semiconductor film 141, the gate insulating film 142, and the gate electrode 143 constitute a thin film transistor 123.

Further, a transparent first interlayer insulating film 144a and a second interlayer insulating film 144b are formed on the gate electrode 143 and the gate insulating film 142, and the first and second interlayer insulating films 144a and 144b are insulated. Contact holes 145 and 146 are formed through the films 144a and 144b and connected to the source and drain regions 141a and 141b of the semiconductor film 141, respectively. The contact hole 145 is connected to the pixel electrode, and the pixel electrode 111 and the semiconductor source region 141 a are electrically connected through the contact hole 145. Further, the contact hole 146 is connected to the power supply line 103, and a pixel signal is supplied from the power supply line 103 through the contact hole 146.
The driving circuit is configured as described above. The circuit element unit 14 is also formed with the storage capacitor cap and the switching thin film transistor 142 described above, but these are not shown in FIG.

The pixel electrodes 111 are formed by patterning in a substantially rectangular shape in plan view on the second interlayer insulating film 144b, and a plurality of pixel electrodes 111 are arranged in a matrix in the display region 2a.
The pixel electrode 111 is made of a highly reflective metal film such as an aluminum (Al) film or a silver (Ag) film, and efficiently emits light emitted to the substrate 2 side to the upper sealing portion side. It is made to emit to.
The pixel electrode 111 is formed, for example, so that the layer thickness of the Al film ranges from 100 nm to 500 nm, and ITO (indium tin oxide film) is formed on the Al film so that the layer thickness ranges from 50 nm to 200 nm. You may laminate and form.

The light emitting element unit 11 mainly includes a functional layer 110 stacked on each of the plurality of pixel electrodes 111 and a bank layer 112 provided between each pixel electrode 111 and the functional layer 110 to partition each functional layer 110. It is configured. A cathode 12 made of a titanium nitride layer is disposed on the functional layer 110, and the pixel electrode 111, the functional layer 110, and the cathode 12 constitute a light emitting portion A.
Note that an insulating protective film may be disposed between the bank layer 112 and the second interlayer insulating film 144b in order to insulate the adjacent pixel electrodes 111 and protect them. As the insulating protective film, a silicon oxide film can be formed to a thickness of 1 μm by, for example, a CVD method or a sputtering method.

The bank layer 112 is made of a resist having excellent heat resistance and solvent resistance such as acrylic resin and polyimide resin, and an opening 112d is formed corresponding to the position where the pixel electrode 111 is formed.
In each region partitioned by the bank layer 112, the electrode surface 111a of the pixel electrode 111 is lyophilic with plasma processing using oxygen as a processing gas and exhibits lyophilicity. On the other hand, the wall surface of the opening 112d and the upper surface 112f of the bank layer 112 are fluorinated (liquid repellent) by plasma treatment using tetrafluoromethane as a processing gas, and exhibit liquid repellency.
Note that when the hole injection / transport layer 110a and the light emitting layer 110b are formed by vapor deposition, the formation of the bank layer 112 may be omitted. The bank layer 112 is necessary when the hole injection / transport layer 110a and the light emitting layer 110b are formed by an ink jet method, and is not necessary when these layers are formed by an evaporation method.

The functional layer 110 is adjacent to the hole injection / transport layer 110a stacked on the pixel electrode 111, the light emitting layer 110b formed adjacent to the hole injection / transport layer 110a, and the light emitting layer 110b. And an electron injection layer 110c formed.
The hole injection / transport layer 110a is formed to a thickness of, for example, 5 nm to 50 nm and has a function of injecting holes into the light emitting layer 110b and a function of transporting holes inside the hole injection / transport layer 110a. . As the hole injection / transport layer forming material, for example, a mixture of a polythiophene derivative such as polyethylenedioxythiophene (PEDOT) and polystyrene sulfonic acid can be used.
The electron injection layer 110c is formed to have a thickness of, for example, 5 nm to 20 nm, and has a function of injecting electrons into the light emitting layer 110b and a function of transporting electrons inside the electron injection layer 110c. When the layer thickness is smaller than 5 nm, the effect of improving the electron injection efficiency is lost, and when the layer thickness is larger than 20 nm, the internal resistance is increased and the light emission voltage is increased. As the electron injection layer 110c, for example, a co-deposited film of bathocuproine (BCP) and cesium, a co-evaporated film of Mg and Ag, LiF / Ca / Al, or the like can be preferably used.

  By providing the hole injection / transport layer 110a and the electron injection layer 110c between the pixel electrode 111 and the light emitting layer 110b and between the cathode 12 and the light emitting layer 110b, respectively, the light emission efficiency of the light emitting layer 110b is achieved. And device characteristics such as lifetime are improved. The hole injecting / transporting material may be different for each color of the light emitting layer 110b, or the hole injecting / transporting layer 110a may not be provided for the light emitting layer 110b of a specific color. Is possible.

  The light emitting layer 110b has three types, a red light emitting layer 110b1 that emits red (R), a green light emitting layer 110b2 that emits green (G), and a blue light emitting layer 110b3 that emits blue (B). The light emitting layers 110b1 to 110b3 are arranged in stripes. As the material of the light emitting layer 110b, cyanopyriphenylene vinylene can be used as the red light emitting layer 110b1, and the blue light emitting layer 110b3 polyphenylene vinylene can be used as the green light emitting layer 110b2. Note that an organic compound other than the organic compounds described above can be used as a material for the light-emitting layer 110b.

A light-transmitting conductive layer made of titanium nitride is used as the material of the cathode 12, and the cathode 12 is formed on the entire surface of the light emitting element portion 11. Then, it plays a role of flowing a current through the functional layer 110 in a pair with the pixel electrode 111.
According to the configuration of the present embodiment, although titanium nitride constituting the cathode 12 is slightly colored in yellow, it has excellent light transmittance and can sufficiently function as an upper transparent common cathode. Further, the titanium nitride layer serves as an oxidation barrier, and in order to suppress oxidation of the light emitting layer 110b and the electron injection layer 110c located on the lower layer side, a conventional upper transparent common cathode using a transparent conductive film such as ITO is used as a single layer. The light emission life can be improved as compared with the configuration.

Next, a method for manufacturing the display device of this embodiment will be described with reference to the drawings.
The manufacturing method of the display device 1 of the present embodiment includes, for example, (1) a circuit element portion forming step, (2) a bank portion forming step, (3) a plasma processing step, and (4) a hole injection / transport layer forming step, (5) A light emitting layer forming step, (6) an electron injection layer forming step, and (7) a cathode forming step are provided. In addition, a manufacturing method is not restricted to this, When other processes are removed as needed, it may be added.

(1) Circuit element portion forming step As shown in FIG. 4, for example, a thin film transistor 123 is formed on a substrate 2 such as glass through a base protective film 2c by a known method. Next, in order to flatten the upper surface side of the substrate 2 on which the thin film transistor 123 is formed, a material having excellent flatness, such as polyimide or acrylic, is dropped by a spin coat method, and the second interlayer serving as a flattening insulating film is formed. An insulating film 144b is formed. Next, a through hole for connecting the thin film transistor 123 and the pixel electrode 111 of each pixel is formed in the second interlayer insulating film 144b and the first interlayer insulating film 144a. The through hole is formed by patterning an insulating film by a photolithography method and then removing an exposed portion by a development process. Thereafter, this is baked to form the second interlayer insulating film 144b and the like as a planarizing film. Then, for example, Al is deposited by sputtering, vapor deposition or the like so as to have a film thickness of 100 to 500 nm. Furthermore, when ITO is laminated | stacked and it is set as a pixel electrode, it forms into a film by sputtering method, a vapor deposition method, etc. so that ITO may become a film thickness of 50-200 nm. Thereafter, the ITO and Al films are patterned by a photolithography method to form the pixel electrode 111. For example, ITO can be etched by wet etching using aqua regia, and Al can be etched by dry etching using plasma of a gas containing a chlorine-based gas, for example.

(2) Bank Layer Forming Step The bank layer forming step is a step of forming the bank layer 112 having the opening 112d at a predetermined position of the substrate 2. After the pixel electrode 111 is formed on the interlayer insulating films 144a and 144b, a photosensitive material having heat resistance and solvent resistance such as acrylic resin and polyimide resin is applied as shown in FIG. A bank layer 112 having an opening 112d is formed in the region where the pixel electrode 111 is disposed. The bank layer is necessary when the following hole injection / transport layer, light emitting layer, etc. are formed by a droplet discharge method such as inkjet, and is not necessary when formed by a vapor deposition method or the like. is there.

(3) Plasma processing step The plasma processing step is performed for the purpose of activating the surface of the pixel electrode 111 and further surface-treating the surface of the bank layer 112. In particular, in the activation process, cleaning on the pixel electrode 111 and adjustment of the work function are mainly performed. Further, a lyophilic process on the surface of the pixel electrode 111 and a lyophobic process on the surface of the bank layer 112 are performed.

(4) Hole Injection / Transport Layer Formation Step In the light emitting element formation step, a hole injection / transport layer is formed on the pixel electrode 111.
In the hole injection / transport layer forming step, as a droplet discharge method, for example, an inkjet apparatus is used to discharge the first composition containing the hole injection / transport layer forming material onto the electrode surface 111a (first droplet). Discharge process). Thereafter, drying treatment and heat treatment are performed to form the hole injection / transport layer 110 a on the pixel electrode 111.
Subsequent steps including the hole injection / transport layer forming step are preferably an atmosphere free of water and oxygen. For example, it is preferably performed in an inert gas atmosphere such as a nitrogen atmosphere or an argon atmosphere.

The manufacturing method by inkjet is as follows.
As shown in FIG. 6, a composition 110d containing a hole injection / transport layer forming material is discharged from a plurality of nozzles formed in the inkjet head H1. Here, each opening 112d is filled with the composition 110d by scanning the ink jet head, but it is also possible to scan the substrate 2. Further, the composition 110d can be filled by moving the inkjet head H1 and the substrate 2 relatively. In addition, in the process performed using the inkjet head H1 after this, the above point is the same.

  Next, a drying process as shown in FIG. 7 is performed to evaporate the polar solvent contained in the composition and deposit the hole injection / transport layer forming material to a layer thickness of, for example, 5 to 50 nm. Most of the hole injecting / transporting layer 110a formed in this manner is dissolved in the light emitting layer 110b to be applied in a later step, but a part of the hole injecting / transporting layer 110a is thin between the hole injecting / transporting layer 110a and the light emitting layer 110b. Remain. Accordingly, the energy barrier between the hole injection / transport layer 110a and the light emitting layer 110b can be lowered to facilitate the movement of holes and improve the light emission efficiency.

(5) Light emitting layer forming step The light emitting layer forming step includes a surface modification step, a light emitting layer forming material discharging step, and a drying step.
The surface modification step is performed to improve the adhesion between the hole injection / transport layer 110a and the light emitting layer 110b and the uniformity of film formation. Next, as a light emitting layer forming step, a composition containing a light emitting layer forming material is discharged onto the hole injection / transport layer 110a by an ink jet method (droplet discharge method), and then dried to perform hole injection / A light emitting layer 110b having a thickness of, for example, about 5 to 50 nm is formed on the transport layer 110a.
As shown in FIG. 8, the inkjet head H5 and the substrate 2 are moved relatively, and each color (for example, blue (B) in this case) containing a light emitting layer forming material is discharged from the discharge nozzle H6 formed on the inkjet head H5. 2 The composition 110e is discharged.

Next, after discharging the composition to a predetermined position, the discharged composition droplet 110e is dried to evaporate the nonpolar solvent contained in the composition. Thereby, the light emitting layer forming material is deposited, and a blue (B) light emitting layer 110b3 as shown in FIG. 9 is formed.
Subsequently, as shown in FIG. 10, the red (R) light emitting layer 110b1 is formed using the same process as that of the blue (B) light emitting layer 110b3 described above, and finally the green (G) light emitting layer 110b2 is formed. To do. Note that the order of forming the light emitting layers 110b is not limited to the order described above, and may be formed in any order. For example, the order of formation can be determined according to the light emitting layer forming material.
In this manner, the hole injection / transport layer 110a and the light emitting layer 110b are formed on the pixel electrode 111.

(6) Electron Injection Layer Formation Step In the electron injection layer formation step, as shown in FIG. 11, an electron injection layer 110c made of a co-deposited film of bathocuproine (BCP) and cesium is formed on the entire surface of the light emitting layer 110b and the bank layer 112. Form.
For the electron injection layer 110c, for example, co-evaporation of Mg and Ag, LiF / Ca / Al, or the like can be used. Preferably, the electron injection layer 110c is formed by a vapor deposition method, a sputtering method, a CVD method, or the like. It is preferable that the light emitting layer 110b is prevented from being damaged by heat.

(7) Cathode formation step In the cathode formation step, as shown in FIG. 13, a cathode material layer made of titanium nitride is formed on the entire surface of the electron injection layer 110c by an ion plating method using a film formation apparatus 200. The cathode 12 is formed by patterning by photolithography.
FIG. 12 is a schematic view of an ion plating film forming apparatus according to the present embodiment. As shown in FIG. 12, the film formation apparatus 200 includes a plasma generation unit 210 that generates argon plasma, a film formation unit 220 that performs film formation, and a substrate transfer unit that transfers the substrate 2 stacked up to the electron injection layer 110c. 230 and an exhaust part (not shown) for exhausting the gas in the film forming part 220.

In the film forming part 220, a base part 221 on which the vapor deposition material 223 (titanium nitride) that is the material of the functional layer protective film 12a or the cathode 12 is placed is disposed, and the electron injection layer 110c is located at a position facing the base part 221. The board | substrate 2 laminated | stacked to is conveyed and arrange | positioned. Argon plasma generated by the plasma generation unit 210 is introduced into titanium nitride of the base unit 221, and the titanium nitride is evaporated and deposited on the entire surface of the electron injection layer 110c.
In this apparatus, the substrate 2 is disposed outside the plasma generation region, and the substrate 2 is not directly exposed to the plasma when the titanium nitride layer is formed, so that the light emitting layer 110b and the electron injection layer 110c are damaged. Therefore, an organic EL device with high luminance and high reliability can be obtained.

  Hereinafter, although detailed description is omitted, a sealing member made of a sealing resin film, a sealing substrate, or the like is disposed on the cathode 12 or above the cathode 12 with a space therebetween. Further, the cathode 12 is connected to the wiring 5 a of the substrate 2 illustrated in FIGS. 2 and 3, and the wiring of the circuit element unit 14 is connected to the driving IC 6, whereby the display device 1 of this embodiment is obtained.

[Second Embodiment]
The second embodiment of the present invention will be described below with reference to FIG.
The basic configuration of the organic EL device of the present embodiment is the same as that of the first embodiment, and only the configuration of the cathode is different.
FIG. 14 is a diagram showing a cross-sectional structure of the organic EL device of the present embodiment, and corresponds to FIG. 3 of the first embodiment. In FIG. 14, the same reference numerals are given to the same components as those in FIG. 3, and detailed description thereof will be omitted.

In the case of the first embodiment, the cathode 12 is composed of a single layer of titanium nitride, whereas in the case of this embodiment, the cathode 12 is composed of a titanium nitride layer 12a and an ITO layer as shown in FIG. 12b has a two-layer structure. The titanium nitride layer 12a is disposed on the lower layer side, the ITO layer 12b is disposed on the upper layer side, that is, the titanium nitride layer 12a is in contact with the functional layer 110 side.
In the step of forming the cathode 12 of this embodiment, after the titanium nitride layer 12a is formed in the ion plating film forming apparatus 200 shown in FIG. 12 as in the first embodiment, the deposition on the base 221 is performed. The material 223 is changed from TiN to ITO, and subsequently, an ITO layer 12b is laminated on the titanium nitride layer 12a in a nitrogen gas atmosphere containing argon gas to form a cathode material layer, and the cathode 12 is patterned by photolithography. Form.

  In this embodiment, since the cathode 12 has a two-layer structure of the titanium nitride layer 12a and the ITO layer 12b, the light transmittance can be improved as compared with the case where the titanium nitride layer is used as a single layer. A luminance organic EL device can be obtained. In addition, since the electrical resistance is lower than when the titanium nitride layer is used as a single layer, the function as the upper common electrode can be more fully exhibited. Even if the ITO layer 12b is used, the titanium nitride layer 12a is disposed on the functional layer 110 side, so that the oxygen contained in the ITO layer 12b is adversely affected by the titanium nitride layer 12a serving as a barrier. Therefore, the light emission life can be improved. Further, since the ion plating film forming apparatus described above is used for film formation of the cathode material, the substrate is not directly exposed to plasma, and the functional layer 110 is not damaged and has high brightness and high reliability. An organic EL device can be obtained. Further, if the ITO layer 12b is continuously formed, the surface of the titanium nitride layer 12a is free from problems such as contamination and oxidation, the film quality is improved, the manufacturing TAT is shortened, and the productivity is improved.

The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the second embodiment, the cathode is composed of a titanium nitride layer and an ITO layer, but a transparent conductive film other than ITO may be laminated. In addition, the specific configuration such as the film configuration and the film thickness in the above embodiment can be changed as appropriate. Furthermore, although the case where the R, G, and B light emitting layers 110b are arranged in stripes has been described, the present invention is not limited to this, and various arrangement structures can be employed. For example, in addition to the stripe arrangement, a mosaic arrangement or a delta arrangement may be used.

It is a figure which shows the wiring structure of the display apparatus of the 1st Embodiment of this invention. It is a top view of a display apparatus same as the above. It is sectional drawing which shows the principal part of a display apparatus equally. It is process drawing explaining the manufacturing method of a display apparatus equally. It is process drawing explaining the manufacturing method of a display apparatus equally. It is process drawing explaining the manufacturing method of a display apparatus equally. It is process drawing explaining the manufacturing method of a display apparatus equally. It is process drawing explaining the manufacturing method of a display apparatus equally. It is process drawing explaining the manufacturing method of a display apparatus equally. It is process drawing explaining the manufacturing method of a display apparatus equally. It is process drawing explaining the manufacturing method of a display apparatus equally. It is the schematic of the film-forming apparatus which concerns on this Embodiment. It is process drawing explaining the manufacturing method of a display apparatus equally. It is sectional drawing which shows the principal part of the display apparatus of the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electroluminescent display device (organic EL device), 2 ... Substrate, 12 ... Cathode (second electrode), 12a ... Titanium nitride layer, 12b ... ITO layer, 110 ... Functional layer, 110b ... Light emitting layer, 111 ... Pixel Electrode (first electrode)

Claims (4)

A functional layer having a first electrode, at least a light emitting layer made of an organic material, and a second electrode are arranged in this order on a substrate, the second electrode has light transparency, and light from the light emitting layer Is an organic electroluminescent device that is emitted above the second electrode,
The organic electroluminescent device, wherein the second electrode includes at least a titanium nitride layer.   The organic electroluminescence device according to claim 1, wherein the second electrode is composed of two or more layers, and the titanium nitride layer is disposed on the functional layer side. A functional layer having a first electrode, at least a light emitting layer made of an organic material, and a second electrode are arranged in this order on a substrate, the second electrode has light transparency, and light from the light emitting layer Is a method of manufacturing an organic electroluminescent device that is emitted above the second electrode,
Forming the first electrode, forming the functional layer, and forming the second electrode including at least a titanium nitride layer,
The method of manufacturing an organic electroluminescence device, wherein the titanium nitride layer is formed by using an ion plating film forming apparatus in which a substrate to be processed is disposed outside a plasma generation region.   4. The method of manufacturing an organic electroluminescence device according to claim 3, wherein the transparent conductive layer is continuously formed in the same film forming apparatus following the formation of the titanium nitride layer.

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