JP2010073327A - Method of manufacturing electroluminescent display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing an electroluminescent display enabled to prevent processing failure of an electrode shape or emission failure of a display, through reduction of processes needed for processing of the electrode shape. <P>SOLUTION: The method of manufacturing the electroluminescent display 1 constituted of a substrate 11, and a plurality of electroluminescent elements 10 arranged on the substrate 11 with a lower electrode 12, an organic compound layer 13 at least containing a light-emitting layer, and an upper electrode 14 laminated in that order with either the lower electrode 12 or the upper electrode 14 as an electrode composed of inorganic oxide, includes a process (a) and a process (b). The process (a) of forming an electrode made of inorganic oxide as a continuous layer among the plurality of electroluminescent elements, and a process (b) of irradiating light on the electrode made of the inorganic oxide and making an electric resistance of all or a part of areas where light irradiation is carried out higher than before the irradiation and carrying out patterning. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electroluminescent display device.

  2. Description of the Related Art Conventionally, in the manufacture of an electroluminescent display device (organic electroluminescence display device), a method using laser light is particularly known as a method for processing an electrode layer into a specific shape. For example, Patent Document 1 discloses a method of processing an electrode shape by irradiating an electrode sandwiching an organic compound layer including a light emitting layer with a laser beam and removing a region irradiated with the laser beam.

  The processing method shown in Patent Document 1 will be described below with reference to the drawings. FIG. 17 is a schematic cross-sectional view showing a specific example of an electroluminescent display device processed by the method of Patent Document 1.

  In the electroluminescent display device 170 of FIG. 17, a lower electrode 172, an organic compound layer 173, and an upper electrode 174 are stacked in this order on a substrate 171. 17 is provided with a laser protective layer 175 for protecting the substrate 171 and the lower electrode 172 from laser light. Further, in the electroluminescent display device 170 of FIG. 17, a laser absorption layer 176 is provided on the upper electrode 174. The function of this laser absorption layer 176 will be described later.

  Here, in the electroluminescent display device 170 of FIG. 17, a lower electrode 172, an organic compound layer 173, and an upper electrode 174 are stacked in this order, and a laser protective layer 175 is interposed between the lower electrode 172 and the organic compound layer 173. The area where there is no light emission area 176. At this time, if the lower electrode 172 is a transparent electrode and the upper electrode 174 is a reflective electrode, the light 177 emitted from the light emitting layer included in the organic compound layer 173 travels toward the substrate. On the other hand, the part where the laser protective layer 175 is exposed by processing with laser light is an inter-pixel region 178. By providing this inter-pixel region 178, each light emitting region 176 can be driven independently.

  Next, a specific method of processing with laser light will be described with reference to the drawings. FIG. 18 is a schematic cross-sectional view showing a state of processing by laser light, which is one of the steps for manufacturing the electroluminescent display device 170 of FIG. When irradiating the laser beam, the laser beam 180 is selectively irradiated to the processing region 181 as shown in FIG. At this time, the laser beam 180 reaches the laser absorption layer 176 located in the processing region 181. Then, the laser absorption layer 176 irradiated with the laser light is heated, decomposed, and scattered. Thereafter, the upper electrode 174 and the organic compound layer 173 located in the processing region 181 are also heated and decomposed and scattered by the laser light in the same manner as the laser absorption layer 176. As a result, the upper electrode 174 is insulated into a desired shape, and each light emitting region 176 is partitioned and processed into a desired shape.

Japanese Patent Laid-Open No. 9-50888

  By the way, with respect to the electroluminescent display device, an electroluminescent display device having a configuration in which light is extracted from the opposite direction of the substrate with the aim of improving the external extraction of light, that is, a so-called top emission configuration has been developed. Here, when the electroluminescent display device of FIG. 17 is considered as a specific example, when the electroluminescent display device is configured to have a top emission configuration, a conductive thin film is used as a lower electrode 172 to form a conductive thin film. A laminate coated with an object is used. On the other hand, a thin film made of a conductive and translucent inorganic oxide is used as the upper electrode 174.

  In manufacturing a top emission type electroluminescent display device, a method disclosed in Patent Document 1 is also conceivable as a specific method for partitioning each light emitting region. However, the method disclosed in Patent Document 1 has the following problems particularly when the upper electrode 174 is processed.

  That is, when the light absorption characteristic of the laser absorption layer 176 reaches a visible wavelength, light generated from the light emitting layer included in the organic compound layer 173 is absorbed by the laser absorption layer 176 and lost. For this reason, when considering the luminance characteristics with respect to the power consumption of the display device, the configuration is disadvantageous.

  On the other hand, as a constituent material of the laser absorption layer 176, it is possible to use a material having a light absorption characteristic on the longer wavelength side or shorter wavelength side than the visible light so as not to prevent the visible light from being taken out of the display device. It is. However, in general, light on the longer wavelength side than visible light is the absorption wavelength region of the inorganic oxide constituting the upper electrode 174, and light on the shorter wavelength side than visible light is absorbed by the organic compound constituting the organic compound layer 173. It is a wavelength region. Therefore, the configuration in which the laser absorption layer 7 having similar absorption characteristics is provided on the organic layer 5 and the electrode 6 having higher light absorption on the longer wavelength side or shorter wavelength side than the visible light is useless in manufacturing the display device. There are many.

  In the processing method disclosed in Patent Document 1, heat is generated from the laser absorption layer during laser irradiation. When this heat is diffused into the organic compound layer, wrinkles and wrinkles are likely to occur on the processed end face, for example, the processed end face of the upper electrode. In addition, processing defects such as delamination progress between the organic compound layer and the upper electrode tend to occur. Furthermore, the organic compound layer is easily denatured. This modification affects the emission spectrum abnormality and the light emission lifetime of the electroluminescent display device.

  The present invention has been made in view of the above problems. An object of the present invention is to provide a method of manufacturing an electroluminescent display device that can reduce the process required for processing the electrode shape and prevent the electrode shape processing failure and the light emission failure of the display device.

A method of manufacturing an electroluminescent display device of the present invention includes a substrate,
A plurality of lower electrodes, an organic compound layer including at least a light emitting layer, and an upper electrode are stacked in this order, and either the lower electrode or the upper electrode is an electrode made of an inorganic oxide. A method of manufacturing an electroluminescent display device comprising an electroluminescent element,
It includes the following steps (a) and (b).

(A) Step of forming an electrode made of the inorganic oxide as a continuous layer between a plurality of electroluminescent elements (b) Light irradiation is performed on the electrode made of the inorganic oxide in an oxidizing gas atmosphere, and light is emitted. A patterning process in which the entire or part of the irradiated region has a higher electrical resistance than before light irradiation.

  According to the present invention, it is possible to provide a method of manufacturing an electroluminescent display device that can reduce the process required for processing the electrode shape and prevent the electrode shape processing failure and the light emission failure of the display device.

  The present invention provides an electroluminescent device comprising a substrate, a plurality of electroluminescent elements arranged on the substrate, and a lower electrode, an organic compound layer including at least a light emitting layer, and an upper electrode stacked in this order. It is a manufacturing method of a display device. In this electroluminescent display device, either the lower electrode or the upper electrode described above is an electrode made of an inorganic oxide.

The method for manufacturing an electroluminescent display device of the present invention includes the following steps (a) and (b).
(A) The process which forms the electrode which consists of inorganic oxides as a continuous layer between several electroluminescent elements (b) Light irradiation is performed with respect to the electrode which consists of inorganic oxides in oxidizing gas atmosphere, and light irradiation is carried out Patterning by making the entire region or a part of the electrical resistance of the performed region higher than that before light irradiation

  In the step (a), when forming a continuous electrode (hereinafter referred to as a common electrode) between a plurality of electroluminescent elements, a thin film to be a common electrode is formed on the entire device. When forming this thin film, it is desirable that the entire surface of the underlying member is covered with this thin film, but the film thickness need not be uniform.

  Known inorganic oxides such as indium tin oxide (ITO) and indium zinc oxide (IZO) can be used as the inorganic oxide constituting the common electrode.

  As described above, if the constituent material of the common electrode is a light-transmitting inorganic oxide, the common electrode can be partially processed in the low resistance region and the high resistance region without impairing the transmittance to visible light. It becomes possible.

  In the step (b), the oxidizing gas refers to a gas capable of introducing oxygen ions into an oxygen depletion portion existing in the crystal lattice of the inorganic oxide that is a constituent material of the common electrode. Examples of the oxidizing gas include oxygen gas and ozone.

  In the step (b), the light irradiation is light irradiation with laser light.

  Here, the pulsed light source of the laser light source is preferable to the continuous wave method. In the pulse oscillation method, it is easy to synchronize the displacement of the laser irradiation portion and the laser oscillation by moving the substrate to be irradiated or using a polygon mirror. In the pulse oscillation method, activation energy necessary for the reaction can be supplied to the laser irradiation site, and energy storage and dissipation after the irradiation can be easily controlled.

  The light source of the laser beam used in the step (b) preferably has a wavelength that is highly absorbable with respect to the inorganic oxide that is a constituent material of the common electrode. In general, inorganic oxides have characteristics such as conductivity and translucency, but also have a characteristic of high light absorption at near infrared wavelengths. For this reason, in the step (b), the wavelength of the laser light source is preferably a near infrared wavelength. Near-infrared laser light has low energy and does not cause mechanical breakdown of the electrode. For this reason, the process controllability of the electrode shape is better than the method of processing while scattering a part of the electrode. In addition, the laser intensity per unit area required for partial processing of the electrode is smaller when it is modified with higher resistance than the method of processing while scattering a part of the electrode. The organic layer can be prevented from being denatured by being dissipated into the organic layer.

  Furthermore, it is preferable that the light source of the laser beam used in the step (b) has a wavelength with low absorbance to the constituent material of the organic compound layer. It is preferable to adjust the wavelength of the light source of the laser light so that at least the light absorbency with respect to the constituent material of the organic compound layer is lower than the absorbency with respect to the inorganic oxide that is the constituent material of the common electrode.

  When the pulse width of the laser light source used is on the order of picoseconds to sub-picoseconds, the inorganic oxide that is a constituent material of the common electrode has a wavelength of visible light and ultraviolet light due to the multiphoton absorption process. Energy transfer occurs even in the wavelength region. On the other hand, when the pulse width is on the order of picoseconds to sub-picoseconds, the energy supplied to the object to be irradiated by the laser light irradiation does not dissipate outside the irradiation area of the object to be irradiated.

  Therefore, the pulse width of the laser light used in the step (b) is preferably 1 picosecond or less. When the pulse width of the laser light is 1 picosecond or less, a visible light laser and an ultraviolet ray are used in addition to the near infrared laser. Lasers can also be used.

  Here, the electroluminescent display device manufactured by the manufacturing method of the present invention may be configured by a substrate and a plurality of pixels arranged on the substrate. Here, as an aspect of the pixel, for example, a lower electrode, an organic compound layer composed of a laminate of at least two layers including a light emitting layer, and an upper electrode are laminated in this order, and an intermediate electrode is interposed between the organic compound layers. The aspect in which a layer is provided is raised. In this embodiment, the organic compound layer is preferably a laminate of 2 or more and 3 or less layers in view of the voltage applied to the device itself.

  Hereinafter, specific embodiments of the electroluminescent display device manufactured by the embodiment of the present invention and the manufacturing method of the present invention will be described in detail.

<Example 1>
FIG. 1 is a schematic cross-sectional view showing a first embodiment of an electroluminescent display device manufactured by the manufacturing method of the present invention.

  In the electroluminescent display device 1 of FIG. 1, an electroluminescent element 10 in which a lower electrode 12, an organic compound layer 13, and an upper electrode 14 are stacked in this order is formed on a substrate 11.

  Further, the electroluminescent display device 1 of FIG. 1 includes a light emitting region 1A and an inter-pixel region 1B when viewed in a plan view.

  In the electroluminescent display device 1 of FIG. 1, the substrate 11 includes a base material 111 made of glass or the like, an insulating layer 112 provided on the base material 111, an insulating protective layer 113 provided on the insulating layer 112, and a base material. And a thin layer transistor (TFT) 114 provided on 111. Note that the TFT 114 is embedded in a laminated body including the insulating layer 112 and the insulating protective layer 113, but the upper portion is exposed from the insulating protective layer 113.

  On the substrate 11, a flattening layer 15 is provided for flattening irregularities generated when the insulating protective layer 113 and the TFT 114 are formed.

  A lower electrode 12 is provided on the planarization layer 15. The lower electrode 12 is electrically connected to the TFT 114 through the contact hole 16. Here, when the lower electrode 12 is a transparent electrode made of an inorganic oxide, a light reflecting layer 17 may be provided between the lower electrode 12 and the planarizing layer 15 as shown in FIG. When the lower electrode 12 is a transparent electrode made of an inorganic oxide, the high resistance region 121 (light irradiation region) may be formed by performing partial laser light irradiation by a method described later.

  An organic compound layer 13 is provided on the lower electrode 12. The organic compound layer 13 is not limited as long as it has at least a light emitting layer.

  An upper electrode 14 is provided on the organic compound layer 13. Here, when the upper electrode 14 is a transparent electrode made of an inorganic oxide, the high resistance region 141 (light irradiation region) may be formed by performing partial laser light irradiation by a method described later.

  In the electroluminescent display device 1 of FIG. 1, after providing the upper electrode 14, in order to protect the device from oxygen, moisture, etc. in the atmosphere, the electroluminescent device 1 is covered with a cap glass 18 to apply an electric field by a known method. The light emitting display device 1 itself is sealed.

  Incidentally, the electroluminescent display device 1 of FIG. 1 is a top emission type electroluminescent display device in which light is reflected from the opposite side of the substrate 11 because the light reflecting layer 17 is provided immediately below the lower electrode 12. Therefore, the traveling direction 19 of the light emitted from the light emitting layer included in the organic compound layer 13 is on the opposite side of the substrate 11 as shown in FIG.

  Next, a specific method for manufacturing the electroluminescent display device of FIG. 1 will be described.

[Step 1: Formation of TFT and insulating protective layer]
First, after the TFT 114 is formed on the base material 111 made of glass or the like, the insulating layer 112 and the insulating protective layer 113 are sequentially formed so as to fill a portion other than the upper portion of the TFT 114. Here, as a method of forming the insulating layer 112, the insulating protective layer 113, and the TFT 114, a known method can be employed.

[Step 2: Formation of planarization layer]
Next, a thin film that becomes the planarization layer 15 is formed so as to cover the TFT 114 and the insulating protective layer 113. As a constituent material of the planarization layer 15, oligomer materials such as Photo Needs (manufactured by Toray Industries, Inc.), Optmer (manufactured by JSR Corporation), V-259PA (manufactured by Nippon Steel Chemical Co., Ltd.) and the like are preferably used. Further, the planarizing layer 15 is formed by applying the above-described oligomer material onto the substrate 11 by a spin coat method and then baking and curing the oligomer material. When forming the thin film to be the planarizing layer 15, it is preferable to wash the surface of the substrate 11 after the firing and curing steps and store it in a reduced pressure environment of 1 Pa or less.

[Step 3: Formation of contact hole]
A contact hole 16 is formed in the planarization layer 15 in order to energize the TFT 114 and the lower electrode 12. Specifically, the contact hole 16 is formed by the following method. First, a photoresist layer is formed on the planarizing layer 15 with a film thickness of 1 μm by spin coating. The photoresist layer is subjected to exposure and development processing using the portion where the contact hole 16 is disposed as an opening. Using the photoresist layer thus treated as a mask, dry etching treatment is performed on the planarization layer 15 by reactive ion etching (RIE). Then, the photoresist layer is removed by a wet process.

  FIG. 2 is a schematic cross-sectional view showing the substrate 11 on which the planarizing layer 15 having the contact holes 16 is formed.

[Step 4: Formation of Light Reflecting Layer]
After the contact hole 16 is formed, the light reflecting layer 17 is formed in a desired pattern at a desired position.

As a constituent material of the light reflecting layer, a simple metal such as silver, aluminum, magnesium, silicon, chromium, or an alloy containing these simple metals as a main component can be used. Furthermore, a dielectric multilayer film made of oxide and fluoride (for example, TiO ₃ , SiO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , CaF ₂ , MgF ₂ ) or the like may be used.

  When forming the light reflection layer 17, first, a thin film to be the light reflection layer 17 is formed, and then patterned by a wet process (such as etching) using a photoresist. When forming the thin film used as the light reflection layer 17, the film thickness is not particularly limited, but is preferably about 100 nm.

  FIG. 3 is a schematic cross-sectional view showing the substrate 11 on which the light reflecting layer 17 is formed.

[Step 5: Deposition of lower electrode]
After the light reflection layer 17 is formed, the lower electrode 12 is formed.

  Examples of the constituent material of the lower electrode 12 include light transmissive electrode materials, such as indium oxide (ITO, IZO, etc.).

  When forming the lower electrode 12, a thin film to be the lower electrode 12 is formed so as to cover the TFT 114, the planarization layer 15, and the light reflection layer 17. Here, as a method of forming a thin film to be the lower electrode 12, a known method such as a sputtering method or a vacuum deposition method can be employed.

  Although the film thickness of the thin film used as the lower electrode 12 is not specifically limited, Preferably, it is about 140 nm.

  FIG. 4 is a schematic cross-sectional view showing the substrate 11 on which a thin film to be the lower electrode 12 is formed. In FIG. 4, the TFT 114 is electrically connected to the thin film that becomes the lower electrode 12 through the contact hole 16.

  In order to investigate the conductivity and light transmittance of the lower electrode 12, a sample was prepared by forming a thin film on the glass substrate under the same film forming conditions as the lower electrode 12 and with the same film thickness (140 nm). Then, the sheet resistance value according to the four probe method and the light transmittance at λ = 550 nm were measured. As a result, it has been found that the sheet resistance value is 80Ω / sq and the light transmittance is 85%.

[Step 6: Lower electrode high resistance treatment]
Next, in order to determine the light emitting region of the electroluminescent display device and prevent a short circuit between the lower electrode 12 and the upper electrode 14, in the region corresponding to the inter-pixel region of the thin film that will be the lower electrode 12 formed earlier. The following high resistance treatment is performed.

  That is, after forming a thin film to be the lower electrode 12, this thin film is irradiated with a near infrared laser.

Here, the case where the near infrared laser (titanium sapphire laser) light which has the following characteristics is irradiated as a specific example is demonstrated. However, the present invention is not limited to this.
Wavelength: 800nm
Pulse width: 100 fs
Luminous intensity per irradiation: 2.5 nJ / μm ²
Process atmosphere gas: Nitrogen and oxygen mixed gas controlled to have a dew point of -70 ° C. or lower (volume ratio of nitrogen to oxygen 8: 2)
Processing atmosphere gas pressure: 1 atm

  Note that the focused surface is the surface of the lower electrode 12 when this laser light irradiation is performed.

  Next, a specific method of laser light irradiation will be described with reference to the drawings.

  FIG. 5 is a schematic cross-sectional view showing how the lower electrode 12 is irradiated with laser light. When laser light irradiation is performed on the region of the lower electrode 12 where the resistance is increased, laser light is irradiated from a laser light irradiation device (not shown) having an objective lens 21 at the tip, as shown in FIG. . Since the objective lens 21 is provided at the tip at this time, the laser beam is emitted in a state where the luminous flux 22 is narrowed as shown in FIG. In the high resistance process, the objective lens 21 is scanned onto the inter-pixel region while irradiating the inter-pixel region with laser light. The electric resistance of the region (high resistance region 121) irradiated with the laser light is increased.

  Here, the following experiment was conducted in order to verify the effect of increasing the electrical resistance of the lower electrode by laser light irradiation. That is, laser light irradiation (high resistance treatment) was performed on a film sample formed on the flat glass substrate with the same film formation conditions and the same film thickness as the lower electrode 12. When the sheet resistance value of the film sample after laser light irradiation (after high resistance treatment) was evaluated by the four-terminal method, it was found to be 10 MΩ / sq. On the other hand, the light transmittance at a wavelength of 550 nm was 82%. For this reason, it has been shown that the electrical resistance can be increased while maintaining the transmittance of the irradiated region by the laser light irradiation.

[Step 7: Formation of organic compound layer]
After forming the lower electrode 12, the organic compound layer 13 is formed. Specific examples of the method for forming the organic compound layer 13 include the following methods, but the present invention is not limited thereto.

  First, a compound represented by the following formula (1) is formed on the lower electrode 12 to form a hole transport layer.

  Next, a compound represented by the following formula (2) as a host and a compound represented by the following formula (3) as a dopant are co-evaporated to form a light emitting layer.

  Next, 2,9-bis [2- (9,9'-dimethylfluorenyl)]-1,10-phenanthroline is formed to form an electron transport layer.

  Next, Al and Li are co-evaporated to form an electron injection layer.

  As described above, the organic compound layer 13 in which the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer are laminated in this order is formed.

  FIG. 6 is a schematic cross-sectional view showing the substrate 11 on which the organic compound layer 13 is formed. In FIG. 6, the organic compound layer 13 is formed on the lower electrode 12 and is a laminated body that is formed in common regardless of the light emitting region or the inter-pixel region, but the light emitting color is different for each light emitting region. The organic compound layer may be formed separately. At this time, if the emission color of the light emitted from the light emitting layer in each light emitting region is the three primary colors (a group of red, green and blue or a group of cyan, magenta and yellow), a full color electroluminescent display device is manufactured. Is possible.

[Step 8: Film formation of upper electrode and high resistance treatment]
Next, the upper electrode 14 is formed on the organic compound layer 13. In this embodiment, the constituent material of the upper electrode 14 is an electrode material having translucency such as indium zinc oxide (IZO).

  Here, the thin film to be the upper electrode 14 may be formed by the same method as that for the lower electrode 12 described above. FIG. 7 is a schematic cross-sectional view showing the substrate 11 on which the upper electrode 14 is formed.

  After forming a thin film to be the upper electrode 14, the resistance of the upper electrode 14 is increased by partial laser light irradiation. The irradiation conditions of the laser and laser light used when performing this high resistance treatment may be the same as those of the lower electrode 12 described above.

  Next, a specific method of laser light irradiation will be described with reference to the drawings.

  FIG. 8 is a schematic cross-sectional view illustrating a state in which laser light irradiation is performed on the inter-pixel region of the upper electrode 14. When laser light irradiation is performed on the inter-pixel region of the upper electrode 14, the laser light is irradiated while scanning an objective lens 21 provided at the tip of a laser light irradiation device (not shown) as shown in FIG. However, the laser beam irradiation method is not limited to this. The electric resistance of the region (high resistance region 141) irradiated with the laser light is increased.

  Incidentally, as in the case of the lower electrode 12, the upper electrode 14 also applies laser light irradiation (high resistance treatment) to the film sample formed under the same film formation conditions and the same film thickness as the upper electrode 14. Carried out. As a result, the sheet resistance value after laser light irradiation was 10 MΩ / sq, and the light transmittance at a wavelength of 550 nm was 76%.

  In addition, when the resistance increase process is performed on the upper electrode 14, the constituent material of the organic compound layer 13 provided below the upper electrode 14 is almost absorbed by the irradiated laser light from the viewpoint of the wavelength. Absent. For this reason, even if it irradiates with a laser beam, the upper electrode 14 and the organic compound layer 13 do not peel, or the organic compound layer 13 itself is not discolored.

[Step 9: Sealing]
After the above-described resistance increasing process for the upper electrode 14, the electroluminescent display device is sealed. When sealing, the substrate 11 formed up to the upper electrode 14 is usually moved into a glove box filled with a dry nitrogen atmosphere (for example, dry nitrogen having a dew point of −70 ° C. or less). Do.

  As a specific method for sealing the electroluminescent display device, there is a method in which a cap glass is first covered with the electroluminescent display device, and then a cured resin that blocks moisture is applied to the legs of the cap glass.

  Here, the cap glass is a member obtained by cutting a glass substrate into a concave shape. The cap glass removes foreign matter on the glass surface by a two-fluid cleaning process using a fluid in which dry air and pure water are mixed. Next, dry air is blown to remove water adhering to the cap glass. After the moisture is removed in this manner, a moisture absorbent is preferably applied on the concave side of the cap glass and in the vicinity of the legs for the purpose of preventing moisture in the atmosphere from entering the apparatus.

  On the other hand, when the cap glass is disposed on the apparatus, it is preferable that the concave surface side is opposed to the light emitting surface side of the substrate. Further, when the cap glass is disposed on the device, it is preferable that the leg portion of the cap glass is disposed outside the display area of the device.

  Examples of the curable resin to be applied to the leg portion of the cap glass include an ultraviolet curable resin that is cured by ultraviolet irradiation.

  When a voltage is applied to the electroluminescent display device manufactured by the above process, the region excluding the region subjected to the high resistance process is turned on.

<Example 2>
The second embodiment described below is a modification of the first embodiment. Specifically, an electroluminescent display device was produced in the same manner as in Example 1 except that steps 6 and 8 were changed as follows.

[Step 6]
The lower electrode 12 was irradiated with a laser beam having the following characteristics. This laser light is wavelength converted light by a titanium sapphire laser.
Wavelength: 360nm
Pulse width: 100 fs
Luminous intensity per irradiation: 1.5 nJ / μm ²
Process atmosphere gas: Nitrogen and oxygen mixed gas containing dew point -70 ° C or less and containing 0.05 ppm of ozone (volume ratio of nitrogen to oxygen 8: 2)
Processing atmosphere gas pressure: 1 atm

  As in Example 1, an experiment was conducted to verify the effect of increasing the electrical resistance of the lower electrode 12 by laser light irradiation. As a result, the sheet resistance value was 1 MΩ / sq, and the light transmittance at a wavelength of 550 nm was 83%.

[Step 8]
The laser beam used in the above step 6 was used to irradiate the upper electrode 14.

  As in Example 1, an experiment was conducted to verify the effect of increasing the electrical resistance of the upper electrode 14 by laser light irradiation. As a result, the sheet resistance value was 1 MΩ / sq, and the light transmittance at a wavelength of 550 nm was 78%.

  When a voltage is applied to the electroluminescent display device manufactured by the above process, the region excluding the region subjected to the high resistance process is turned on.

<Example 3>
FIG. 9 is a schematic cross-sectional view showing a second embodiment of the electroluminescent display device manufactured by the manufacturing method of the present invention. In the electroluminescent display device 9 of FIG. 9, the description of the same members as those of the electroluminescent display device 1 of FIG. 1 may be omitted.

  In the electroluminescent display device 9 of FIG. 9, a lower electrode 92, a first organic compound layer 93, a first intermediate electrode layer 94, a second organic compound layer 95, and an upper electrode 96 are laminated on a substrate 91 in this order.

  In the electroluminescent display device 9 of FIG. 9, each of the first organic compound layer 93 and the second organic compound layer 95 is a laminate including a light emitting layer (not shown). However, it is only necessary to have at least a light emitting layer, and details of the layer structure are not limited.

  In addition, the electroluminescent display device 9 of FIG. 9 is composed of two types of light emitting regions 9A and 9B and an inter-pixel region 9C when viewed in plan.

  The electroluminescent device 9 in FIG. 9 selectively selects a light emitting layer included in the first organic compound layer 93 and a light emitting layer included in the second organic compound layer 95 by appropriately selecting a method of electrical connection. Can emit light. Further, depending on the method of electrical connection, light emission of the light emitting layer included in the first organic compound layer 93 and light emission of the light emitting layer included in the second organic compound layer 95 can be controlled independently.

  For example, in the pixel region 9A, the lower electrode 92 is electrically connected to the TFT 914b, the first intermediate electrode layer 94 is electrically connected to the ground terminal 915, and the upper electrode 96 is electrically connected to the TFT 914a. Thus, in the pixel region 9A, each electrode layer is electrically connected to a different member. For this reason, light emission of the light emitting layer included in the first organic compound layer 93 and light emission of the light emitting layer included in the second organic compound layer 95 can be controlled independently.

  On the other hand, in the pixel region 9 </ b> B, the first intermediate electrode layer 94 and the upper electrode 96 are short-circuited in the short-circuit region 962. For this reason, it is possible to extract only light emitted from the light emitting layer included in the first organic compound layer 94 without extracting light emitted from the light emitting layer included in the second organic compound layer 95.

  On the other hand, although not shown in FIG. 9, only the light emission of the light emitting layer included in the second organic compound layer 96 can be taken out by short-circuiting the lower electrode 92 and the first intermediate electrode layer 94.

  Next, a specific method for manufacturing the electroluminescent display device of FIG. 9 will be described.

[Step 1: Formation of TFT and insulating protective layer]
First, after forming TFTs 914a to 914c on a base material 911 made of glass or the like, an insulating layer 912 and an insulating protective layer 913 are sequentially formed so as to fill portions other than the upper portions of the TFTs 914a to 914c. Next, the ground terminal 915 is separately received at a predetermined position on the insulating protective layer 913. Here, as a method of forming the insulating layer 912, the insulating protective layer 913, the TFTs 914a to 914c, and the ground terminal 915, a known method can be employed.

[Step 2. Formation of planarization layer]
Next, a thin film to be the planarization layer 97 is formed so as to cover the TFTs 914a to 914c, the ground terminal 915, and the insulating protective layer 913. The constituent material of the planarizing layer 97 and the method of forming the layer may be the same as those in the first embodiment.

[Step 3: Formation of first contact hole]
Next, in order to electrically connect the lower electrode 92 and the TFT, first, the first contact hole 101 is formed at a desired position. Here, the method for forming the first contact hole 101 may be the same as in the first embodiment.

  FIG. 10 is a schematic cross-sectional view showing a substrate on which a planarizing layer 97 having the first contact hole 101 is formed.

[Step 4: Formation of Light Reflecting Layer]
Next, the light reflecting layer 98 is formed on the planarizing film 97.

  The reflective electrode 98 can use the material used in Example 1 as a constituent material. The reflective electrode 98 can be formed by the same method as in the first embodiment.

[Step 5: Lower electrode film formation and higher resistance treatment]
Next, the lower electrode 92 is formed. When the lower electrode 92 is formed, a thin film to be the lower electrode 92 is formed so as to cover the TFTs (914a to 914c), the planarizing layer 97, and the light reflecting layer 98. Here, as the constituent material of the lower electrode and the method of forming the thin film to be the lower electrode, the same material and the same forming method as in Example 1 can be adopted. By forming this thin film, the TFT 914b and the TFT 914c are electrically connected to the thin film that becomes the lower electrode 92 through the first contact hole 101, respectively.

  After forming a thin film to be the lower electrode 92, the thin film is irradiated with laser light. The laser beam to be irradiated and the conditions for laser beam irradiation may be the same as those in the first embodiment. The electric resistance of the region (high resistance region 921) irradiated with the laser light is increased.

[Step 6: Formation of first organic compound layer]
Next, the first organic compound layer 93 is formed on the lower electrode 92. The layer configuration of the first organic compound layer 93 is not particularly limited as long as the light emitting layer is included. A known material can be used as the constituent material of the first organic compound layer 93. The first organic compound layer 93 is a laminated body that is formed on the lower electrode 92 and is formed in common regardless of the light emitting region or the inter-pixel region, but the organic compound has a different emission color in each light emitting region. The layers may be formed separately. At this time, if the emission color of the light emitted from the light emitting layer in each light emitting region is the three primary colors (a group of red, green and blue or a group of cyan, magenta and yellow), a full color electroluminescent display device is manufactured. Is possible.

[Step 7: Film formation of first intermediate electrode layer and high resistance treatment]
Next, the first intermediate electrode layer 94 is formed on the first organic compound layer 93. An example of the constituent material of the first intermediate electrode layer 94 is an oxide compound such as indium zinc oxide (IZO).

  In addition, the following measurement was performed in order to investigate the electroconductivity and light transmittance of the first organic compound layer 93. That is, a sample in which a thin film was formed on a glass substrate under the same film formation conditions as the first organic compound layer 93 and with the same film thickness (60 nm), and the sheet resistance value by the four-terminal method and λ = The light transmittance at 550 nm was measured. As a result, it has been found that the sheet resistance value is 250 Ω / sq and the light transmittance is 85%.

  Next, after the light emitting region is specified, the first intermediate electrode layer 94 has a high height for the purpose of distinguishing the light emitting region from the inter-pixel region and preventing a short circuit between the lower electrode 92 and the first intermediate electrode layer 94. Perform resistance treatment. The high resistance process will be specifically described with reference to the drawings. FIG. 11 is a schematic cross-sectional view showing how the first intermediate electrode layer 94 is irradiated with laser light. After forming a thin film to be the first intermediate electrode layer 94, the thin film is irradiated with laser light. The laser beam to be irradiated and the conditions for laser beam irradiation may be the same as those in the first embodiment. The electric resistance of the region (high resistance region 941) irradiated with the laser beam is increased.

  Note that when the first intermediate electrode layer 94 is subjected to a high resistance treatment, the laser beam to be radiated is from the first organic compound layer 93 provided below the first intermediate electrode layer 94 from the viewpoint of the wavelength. The component material hardly absorbs. For this reason, even if it irradiates with a laser beam, the 1st intermediate electrode layer 94 and the 1st organic compound layer 93 do not peel, or the 1st organic compound layer 93 itself does not discolor.

[Step 8: Formation of second organic compound layer]
Next, the second organic compound layer 95 is formed on the first intermediate electrode layer 94. The layer configuration, the constituent material, and the formation method of the second organic compound layer 95 are the same as in the case of forming the first organic compound layer 93 described in the previous step 6. However, the materials may be selected so that the emission color of the light emitting layer included in the first organic compound layer 93 and the emission color of the light emitting layer included in the second organic compound layer 95 are different.

  FIG. 12 is a schematic cross-sectional view showing a substrate on which a second organic compound layer is formed.

[Step 9: Formation of second contact hole]
Next, a second contact hole is formed. In this embodiment, a second contact hole is formed to electrically connect the terminal of the TFT 914a and the ground terminal 915 and at least the upper electrode 96.

The second contact hole is formed by, for example, laser light irradiation. More specifically, the second organic compound layer 95 was irradiated with a titanium sapphire laser having the following characteristics as a laser beam.
Wavelength: 800nm
Pulse width: 100 fs
Luminous intensity per irradiation: 7.5 nJ / μm ²
Process atmosphere gas: Nitrogen and oxygen mixed gas containing dew point -70 ° C or less and containing 0.05 ppm of ozone (volume ratio of nitrogen to oxygen 8: 2)
Processing atmosphere gas pressure: 1 atm

  When performing this laser light irradiation, the in-focus surface is the surface of the TFT 914a or the ground terminal 915.

  FIG. 13 is a schematic cross-sectional view showing a state after the second contact hole 102 is formed.

[Step 10: Upper electrode film formation and high resistance treatment]
Next, the upper electrode 97 is formed so as to cover the second organic compound layer 95 and the second contact hole 102.

  First, a thin film to be the upper electrode 96 is formed. As a method of forming the upper electrode 96, a method similar to that of the first intermediate electrode layer 94 described above can be employed. FIG. 14 is a schematic cross-sectional view showing the substrate 11 on which the upper electrode 96 is formed.

  Next, a high resistance treatment is performed by irradiating a desired region of the upper electrode 96 with laser light. As a specific method for increasing the resistance, the same method as that for the first intermediate electrode layer 94 described above can be employed. The electric resistance of the region (high resistance region 961) irradiated with the laser light is increased. FIG. 15 is a schematic cross-sectional view showing how the upper electrode 96 is irradiated with laser light.

[Step 10: Sealing]
After the resistance increasing process of the upper electrode 96 is performed, the electroluminescent display device formed up to the upper electrode 96 is sealed. A specific method of sealing is the same as that in the first embodiment.

  The electroluminescent display device manufactured by the above process emits light from the first organic compound layer 93 in the light emitting region 9A, emits light from the second organic compound layer 95, and from the first organic compound layer 93 in the light emitting region 9B. Can be controlled independently.

  FIG. 16 is a diagram showing an equivalent circuit of the electroluminescent display device of FIG. In FIG. 16, there are four types of elements 160A to 160D.

  In the equivalent circuit of FIG. 16, the element 160A is incorporated in a circuit including a switching transistor 161A, a driving transistor 162A, and a capacitor 163A. In the equivalent circuit of FIG. 16, the element 160B is incorporated in a circuit including a switching transistor 161B, a driving transistor 162B, and a capacitor 163B. In the equivalent circuit of FIG. 16, the element 160C is incorporated in a circuit including a switching transistor 161C, a driving transistor 162C, and a capacitor 163C.

  In the equivalent circuit of FIG. 16, the element 160A corresponds to the light emitting element related to the first organic compound layer 93 in the light emitting region 9A. In the equivalent circuit of FIG. 16, the element 160B corresponds to the light emitting element according to the second organic compound layer 95 in the light emitting region 9A. In the equivalent circuit of FIG. 16, the element 160C corresponds to the light emitting element according to the first organic compound layer 93 in the light emitting region 9B. In the equivalent circuit of FIG. 16, the element 160D corresponds to the light emitting element according to the second organic compound layer 95 in the light emitting region 9B. The display element 160D is short-circuited as shown in FIG. 9 so as not to emit light.

  In the equivalent circuit of FIG. 16, the potential of the gate signal line 164 is set to a high level. Then, the switching transistors 161A to 161C are turned on. The voltages of the capacitors 162A to 162C connected to the gates of the drive transistors 163A to 163C are set to gate-source voltages sufficient to allow the current for driving the display elements A to C to flow through the drive transistors. Is done. Next, when the potential of the gate signal line 167 is set to a low level, the switching transistors 161A to 161C are turned off, and the voltages of the capacitors 162A to 162C are held.

Thereafter, the potential of the first power supply line 168 is set to V _cc and the potential of the second power supply line 169 is set to −V _cc , and a current corresponding to the voltage level of the capacitor flows between the source and drain of the driving transistor. By doing so, it is possible to independently control the light emission of each of the light emitting elements 160A to 160C with a desired luminance.

  The electrode shape processing method by controlling the resistance value of the conductive and translucent inorganic oxide electrode of the present invention is excellent in electrode shape processing controllability, and is an inorganic oxide electrode in a low resistance and high resistance range. Visible light transmittance is maintained. Therefore, it is suitable for forming a so-called top emission structure or forming an electrode shape of an organic electroluminescence display device in which a plurality of light emitting layers are deposited.

It is a cross-sectional schematic diagram which shows the 1st aspect of the electroluminescent display apparatus manufactured with the manufacturing method of this invention. It is a cross-sectional schematic diagram which shows the board | substrate in which the planarization layer which has a contact hole was formed. It is a cross-sectional schematic diagram which shows the board | substrate in which the light reflection layer was formed. It is a cross-sectional schematic diagram which shows the board | substrate in which the thin film used as a lower electrode was formed. It is a cross-sectional schematic diagram which shows a mode that laser beam irradiation is performed about a lower electrode. It is a cross-sectional schematic diagram which shows the board | substrate in which the organic compound layer was formed. It is a cross-sectional schematic diagram which shows the board | substrate in which the upper electrode was formed. It is a cross-sectional schematic diagram which shows a mode that laser beam irradiation is performed about the area | region between pixels of an upper electrode. It is a cross-sectional schematic diagram which shows the 2nd aspect of the electroluminescent display apparatus manufactured with the manufacturing method of this invention. It is a cross-sectional schematic diagram which shows the board | substrate in which the planarization layer which has a 1st contact hole was formed. It is a cross-sectional schematic diagram which shows a mode that laser beam irradiation is performed about a 1st intermediate electrode layer. It is a cross-sectional schematic diagram which shows the board | substrate in which the 2nd organic compound layer was formed. It is a cross-sectional schematic diagram which shows the state after forming a 2nd contact hole. It is a cross-sectional schematic diagram which shows the board | substrate in which the upper electrode was formed. It is a cross-sectional schematic diagram which shows a mode that laser beam irradiation is performed about an upper electrode. FIG. 10 is a diagram illustrating an equivalent circuit of the electroluminescent display device of FIG. 9. It is a cross-sectional schematic diagram which shows the specific example of the electroluminescent display apparatus processed by the method of patent document 1. FIG. FIG. 18 is a schematic cross-sectional view showing a state of processing by laser light, which is one of the steps for manufacturing the electroluminescent display device 170 of FIG. 17.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,9 Electroluminescent display apparatus 10 Electroluminescent element 11,91 Substrate 111,911 Base material 112,912 Insulating layer 113,913 Insulating protective layer 114,914,914a, 914b, 914c Thin film transistor (TFT)
12, 92 Lower electrode 121, 921 High resistance region of lower electrode 13 Organic compound layer 14, 96 Upper electrode 141, 961 High resistance region of upper electrode 15, 97 Planarization film 16 Contact hole 101 First contact hole 102 Second contact Hole 17, 98 Light reflecting layer 18, 99 Cap glass 19 Direction of light 21 Objective lens 22 Laser beam 915 Ground terminal 93 First organic compound layer 94 First intermediate electrode layer 941 High resistance region of first intermediate electrode layer 95 Biorganic compound layer 962 Short-circuit region of upper electrode 160A, 160B, 160C Display element 161A, 161B, 161C Switching transistor 162A, 162B, 162C Capacitance 163A, 163B, 163C Drive transistor 167 Gate signal line 164-166 Data 168 first power supply line 169 second power supply line

Claims (2)

A substrate,
A plurality of lower electrodes, an organic compound layer including at least a light emitting layer, and an upper electrode are stacked in this order, and either the lower electrode or the upper electrode is an electrode made of an inorganic oxide. A method of manufacturing an electroluminescent display device comprising an electroluminescent element,
A method for manufacturing an electroluminescent display device comprising the following steps (a) and (b):
(A) Step of forming an electrode made of the inorganic oxide as a continuous layer between a plurality of electroluminescent elements (b) Light irradiation is performed on the electrode made of the inorganic oxide in an oxidizing gas atmosphere, and light is emitted. A patterning process in which the entire or part of the irradiated region has a higher electrical resistance than before light irradiation. A substrate,
A plurality of lower electrodes, an organic compound layer made of a laminate of at least two layers including a light emitting layer, and an upper electrode are stacked in this order, and an intermediate electrode layer is disposed between the organic compound layers. A method of manufacturing an electroluminescent display device comprising: a lower electrode, an intermediate electrode layer, and a pixel in which any one of the upper electrode is an electrode made of an inorganic oxide,
A method for manufacturing an electroluminescent display device comprising the following steps (a) and (b): (A) Step of forming an electrode made of the inorganic oxide as a continuous layer between a plurality of pixels (b) Light irradiation is performed on the electrode made of the inorganic oxide in an oxidizing gas atmosphere. Patterning by making the entire region or a part of the electrical resistance of the performed region higher than that before light irradiation

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