JP5857333B2 - Organic EL device and manufacturing method thereof - Google Patents

Description

  The present invention relates to an organic EL element using an organic electroluminescent element (hereinafter referred to as “organic EL element”), which is an electroluminescent element, and a method for producing the same.

In recent years, an organic EL display panel in which a plurality of organic EL elements are arranged on a substrate along a matrix direction has been put to practical use as a light-emitting display.
Each organic EL element is a current-driven light emitting element and has a basic structure in which a light emitting layer containing an organic light emitting material is disposed between a pair of electrodes of an anode and a cathode. A charge injection layer, a charge transport layer, and the like are interposed between the anode and the organic light emitting layer and between the cathode and the organic light emitting layer, if necessary. At the time of driving, a voltage is applied between the pair of electrodes, and light is emitted in association with recombination of holes injected from the anode into the organic light emitting layer and electrons injected from the cathode into the light emitting layer. A hole injection layer for efficiently injecting holes into the organic light emitting layer is formed between the anode and the organic light emitting layer.

  In a general manufacturing process, a planarizing film (interlayer insulating film) made of a resin material is formed on a substrate on which a TFT layer is formed, and a metal material layer containing, for example, aluminum or an aluminum alloy is formed thereon as an anode material. To do. The metal material layer is baked, and a transparent conductive film made of, for example, IZO or ITO is formed thereon. On top of this, a hole injection layer is formed of a metal oxide film made of, for example, tungsten oxide or molybdenum oxide (see, for example, Patent Document 1).

  The metal material layer, the transparent conductive film, and the transition metal oxide film are etched and patterned based on the photolithography method, respectively, and are formed as an anode, a transparent electrode, and a hole injection layer in the same order.

JP 2002-134268 A

In a conventional manufacturing process of an organic EL element, there is a case where a metal material layer that has been formed is baked, and a film density is increased (baked) to reduce resistance.
The present invention provides a method for manufacturing a device that can satisfactorily prevent peeling from a base when a metal material layer (metal film) formed on a substrate is baked.

  In order to solve the above problems, a device manufacturing method according to an embodiment of the present invention includes a first step of forming a resin film containing a resin material on a substrate, and a metal film containing a metal material on the resin film. A second step of forming a conductive layer on the metal film, a third step of forming a conductive film different from the metal film, and a metal oxide comprising a transition metal oxide on the conductive film A fourth step of forming a physical film and a fifth step of baking the metal film after the third step or after the fourth step are performed.

In the device manufacturing method according to one embodiment of the present invention, a metal film is formed over a resin film, a conductive film is formed over at least the metal film, and then the firing process of the metal film is performed.
In this way, by firing in a state where at least a conductive film is formed on the metal film, the metal film can be reinforced against the deformation stress, so that deformation of the metal film accompanying firing is suppressed. Thereby, a device in which the laminated structure around the metal film is appropriately maintained can be realized.

It is typical sectional drawing and front view which show the structure of the organic electroluminescence display panel 100 which concerns on embodiment. 5 is a diagram showing a part of the manufacturing process of the organic EL display panel 100. FIG. 5 is a diagram showing a part of the manufacturing process of the organic EL display panel 100. FIG. It is a figure which shows the problem in the manufacturing process of a general organic electroluminescent display panel. It is a flowchart which shows a part of manufacturing process of the organic electroluminescence display panel of embodiment. It is a flowchart which shows a part of manufacturing process of a common organic electroluminescent display panel.

<Aspect of the Invention>
The device manufacturing method according to one aspect of the present invention includes a first step of forming a resin film containing a resin material on a substrate, a second step of forming a metal film containing a metal material on the resin film, A third step of forming a conductive film containing a conductive material on the metal film and different from the metal film; and a fourth step of forming a metal oxide film made of a transition metal oxide on the conductive film. And after the said 3rd process or the 4th process, the 5th process of baking the said metal film shall be implemented.

Here, as another aspect of the present invention, the step prior to the fifth step may be performed at a temperature equal to or lower than the temperature required for the baking.
As another aspect of the present invention, the method includes a sixth step of forming an organic film containing an organic material on the metal film, and the fifth step is performed after the fourth step and before the sixth step. You can also.

As another aspect of the present invention, a material containing aluminum can be used as the metal material of the metal film.
As another embodiment of the present invention, a conductive material containing indium can be used as the conductive film.
As another embodiment of the present invention, a material containing molybdenum oxide or tungsten oxide can be used as the transition metal oxide.

  Further, as another aspect of the present invention, a sixth step of forming a resist film containing a photosensitive resist material on the metal oxide film after the fourth step and after the fifth step, and on the resist film Through a seventh step of exposing a part of the metal oxide film from below the resist film, an eighth step of dry etching the exposed metal oxide film, and through the dry etched region, A ninth step of performing wet etching on the conductive film and the metal film.

Further, as another aspect of the present invention, it may have a tenth step of forming an organic film containing an organic material on the metal film after the fourth step and after the fifth step.
Moreover, as another aspect of the present invention, the temperature required for the baking can be in the range of 200 ° C. or higher and 230 ° C. or lower.
Furthermore, the manufacturing method of the organic EL element which is one embodiment of the present invention includes a substrate preparation step, a TFT layer formation step of forming a TFT layer on the substrate, and a step of forming a metal material layer above the TFT layer. And forming a transparent conductive film on the metal material layer; forming a metal oxide film made of a transition metal oxide on the transparent conductive film; and firing the metal material layer. Etching the metal oxide film to form a hole injection layer; etching the transparent conductive film to form a transparent conductive film; and etching the metal material layer to form a first electrode. A step of applying an ink containing an organic light emitting material above the hole injection layer and drying to form an organic light emitting layer; and a second electrode forming step of forming a second electrode above the organic light emitting layer And having the firing Extent and it shall be carried out in or the metal oxide film forming step after the transparent conductive film forming step.

Here, as another aspect of the present invention, each step prior to the firing step can be performed at a temperature equal to or lower than the temperature required for the firing.
As another aspect of the present invention, the metal oxide film can be etched by dry etching.
As another aspect of the present invention, the transparent conductive film and the metal material layer can be etched together by wet etching.

Moreover, as another aspect of the present invention, the temperature required for the baking can be in the range of 200 ° C. or higher and 230 ° C. or lower.
As another aspect of the present invention, the organic EL element according to any one of the aspects of the present invention is arranged in a plurality of planes along a first direction and a second direction intersecting each other, and each of the organic EL elements An organic EL display panel having partitions provided so as to divide the organic light emitting layer individually or in groups.
<Background to the present embodiment>
The present inventors conducted experiments on general organic EL elements.
Hereafter, the problem in the baking process at the time of manufacture of the organic EL element which the present inventors confirmed is demonstrated using FIG.

  As shown in FIG. 4A, a planarizing film 2 and a metal material layer 3′X are sequentially formed on the TFT substrate 1, and then a firing process is performed. At this time, moisture present in the planarizing film 2 due to the heating of firing may be generated as bubbles at the interface between the planarizing film 2 and the metal material layer 3'X (FIG. 4B). Due to the expansion of the bubbles, the metal material layer 3′X is partially separated from the interface (FIG. 4C), and the adhesion of the metal material layer 3′X to the planarizing film 2 is lowered. Further, peeling may occur due to thermal expansion of the metal material layer itself. Further, since the peeled portion is fragile, it may be lost in a subsequent process such as a cleaning process, and the base (in this case, the planarizing film 2) may be exposed to the outside.

Such a problem is not only a manufacturing process of an organic EL element, but also a device such as a substrate having a thin film to be an electrode, such as a thin film transistor or a solar cell, which has a process of forming a metal film on a resin film and baking the film. This can occur in the same manufacturing process.
Therefore, as a result of intensive studies by the present inventors, in the present embodiment, when the metal film formed on the substrate is baked by devising the timing for performing the baking process, the moisture in the resin film is different from the metal film. The present inventors have found a method of manufacturing a device that prevents the problem of pushing up the metal film by forming bubbles at the interface, prevents peeling between the substrate and the substrate, avoids etching defects, and allows good patterning.

By using this manufacturing method for the organic EL device and the manufacturing method thereof, the anode and other constituent layers can be formed satisfactorily.
<Embodiment>
FIG. 1 is a cross-sectional view schematically showing a configuration of a display panel 100 according to an embodiment as an example of a device of the present invention. The display panel 100 can constitute a display device with a drive control unit (not shown) connected thereto.
(Configuration of display panel 100)
The configuration of the display panel 100 will be described with reference to FIG.

In the display panel 100, pixels (pixels) are arranged in a matrix along the upper surface of the TFT substrate 1. Each pixel is composed of a set of adjacent organic EL elements of RGB sub-pixels of RGB.
The organic EL elements 20a, 20b, and 20c shown in FIG. 1 are a top emission type arranged on the TFT substrate 1. The organic EL element 20a is a blue subpixel, the organic EL element 20b is a green subpixel, The EL elements 20c correspond to red subpixels, respectively.

The TFT substrate 1 is formed with a TFT layer (not shown) for driving the organic EL elements 20a to 20c of the entire panel in an active matrix system on the upper surface of a substrate body (not shown), and the flat surface thereon. It is configured to be covered with the chemical film 2.
The substrate body is the substrate that is the base part of the panel, and is alkali-free glass, soda glass, non-fluorescent glass, phosphate glass, borate glass, quartz, acrylic resin, styrene resin, polycarbonate resin, epoxy resin It is formed of an insulating material such as resin, polyethylene, polyester, silicone resin, or alumina.

The flattening film 2 is a resin film provided to flatten the surface of the TFT substrate 1 and insulate the TFT from the outside, and is made of an organic material having excellent insulating properties, for example, polyimide, polyamide, or an acrylic resin material.
Next, the structure of the organic EL elements 20a to 20c will be described.
On the planarizing film 2, an anode (first electrode) 3, a transparent electrode 4, and a hole injection layer 5 are sequentially stacked.

  Here, the anode 3 is made of a material having low electrical resistance including aluminum or an aluminum alloy, and is formed as a reflective anode having a film thickness of about 400 nm. Aluminum or aluminum alloy is preferable because it is highly reflective and relatively inexpensive. As an example of an aluminum alloy, an aluminum-cobalt-germanium-lanthanum (Al-Co-Ge-La) alloy and an aluminum-carbon-magnesium (Al-C-Mg) alloy are preferable. In addition, aluminum-neodymium (Al-- Nd) alloy, aluminum-zirconium (Al-Zr) alloy, aluminum-copper (Al-Cu) alloy, aluminum-silicon (Al-Si) alloy, aluminum-silicon-copper (Al-Si-Cu) alloy, etc. It is done.

The transparent electrode 4 is made of a conductive material containing indium, for example, a transparent electrode material such as IZO (indium zinc oxide). The film has a thickness of about 16 nm and covers the upper surface of the anode 3. The anode (reflective anode) 3 and the transparent electrode 4 may be used together as an anode.
The anode 3 and the transparent electrode 4 are patterned into a shape separated for each sub-pixel (for each of the organic EL elements 20a, 20b, and 20c).

  The hole injection layer 5 is a layer for efficiently injecting holes into the organic light emitting layer 8 from the anode 3 side, and is formed of a transition metal oxide film of molybdenum oxide (MoOx) or tungsten oxide (WOx). (X is a positive number). Here, a tungsten oxide film is used. The tungsten oxide film has a film structure in which oxygen atoms are partially bonded to tungsten atoms. The thickness of the hole injection layer 5 is preferably in the range of about 0.1 to 20 nm. The hole injection layer 5 may be uniformly formed on the substrate side, but it is desirable to pattern the hole injection layer 5 from the viewpoint of satisfactorily adhering the bank 6 to the anode 3.

  On the hole injection layer 5, a bank 6 made of an insulating material is provided so as to partition adjacent sub-pixels with at least different emission colors. The bank 6 is formed of an organic material such as an insulating resin. Examples of the organic material include acrylic resins, polyimide resins, novolac type phenol resins, and the like, but preferably have organic solvent resistance in consideration of the production process. In addition, since the bank 6 is subjected to an etching process, a baking process, and the like in the formation process, it is preferable that the organic material has high resistance to the processes. The surface of the bank 6 may be subjected to a fluorine treatment in order to give water repellency advantageous when ink is applied in the manufacturing process.

  In the region partitioned by the bank 6, a hole transport layer 7 and an organic light emitting layer 8 are laminated. Further, on the organic light emitting layer 8, an electron injection layer 9, a cathode (second electrode) 10 and a sealing layer 11 are continuous over the organic EL elements 20a, 20b and 20c of the entire panel beyond the upper part of the bank 6. Is formed. Note that the edge portions of the anode 3, the transparent electrode 4, and the hole injection layer 5 are covered by the lower portion of the bank 6 so as to be hidden. The bank 6 may have a so-called pixel bank structure in which the organic light emitting layers 8 of the individual organic EL elements 20a, 20b, and 20c are individually partitioned, or the organic light emitting layer 8 of the organic EL elements 20a, 20b, and 20c of the same light emission color. Alternatively, a line bank structure may be used in which a group is partitioned into stripes.

  The hole transport layer 7 serves to transport holes from the anode 3 side and inject them into the organic light emitting layer 8. Specific examples of the material include 4,4′-bis [N- (naphthyl) -N-phenyl-amino] biphenyl (α-NPB or α-NPD), N, N′-bis (3-methylphenyl). And triarylamine compounds such as-(1,1'-biphenyl) -4,4'-diamine (TPD). It can be manufactured by a wet process using a solution containing these materials.

  The organic light emitting layer 8 has a function of emitting light by injecting holes and electrons and recombining them to generate an excited state. The organic light emitting layer 8 can also be formed by a wet method. The material is, for example, an oxinoid compound, a perylene compound, a coumarin compound, an azacoumarin compound, an oxazole compound, an oxadiazole compound, a perinone compound, a pyrrolopyrrole compound, a naphthalene compound described in Patent Publication (JP-A-5-163488), Anthracene compound, fluorene compound, fluoranthene compound, tetracene compound, pyrene compound, coronene compound, quinolone compound and azaquinolone compound, pyrazoline derivative and pyrazolone derivative, rhodamine compound, chrysene compound, phenanthrene compound, cyclopentadiene compound, stilbene compound, diphenylquinone compound, Styryl compound, butadiene compound, dicyanomethylenepyran compound, dicyanomethylenethiopyran compound, fluorescein compound , Pyrylium compounds, thiapyrylium compounds, serenapyrylium compounds, telluropyrylium compounds, aromatic ardadiene compounds, oligophenylene compounds, thioxanthene compounds, anthracene compounds, cyanine compounds, acridine compounds, metal complexes of 8-hydroxyquinoline compounds, 2-bipyridine compounds It is preferably formed of a fluorescent substance such as a metal complex of the above, a Schiff salt and a group III metal complex, an oxine metal complex, or a rare earth complex.

The electron injection layer 9 has a function of transporting electrons injected from the cathode 10 side to the organic light emitting layer 8. For example, it is composed of barium, phthalocyanine, lithium fluoride, or a combination thereof.
The cathode 10 is made of a light transmissive material such as ITO or IZO (indium zinc oxide). In addition, for example, a layer including an alkali metal, an alkaline earth metal, or a halide thereof and a layer including silver may be stacked in this order.

The sealing layer 11 has a function of suppressing exposure of the organic light emitting layer 8 and the like to moisture and air, and is made of a light-transmitting material such as SiN (silicon nitride) or SiON (silicon oxynitride). It is preferable to form.
In the organic EL display panel 100 having the above configuration, in the manufacturing process, the metal material layer (3′X) constituting the anode 3 is baked to form at least the transparent electrode 4 (transparent conductive film 4X) film. It carries out from. By firing in the state where at least the transparent electrode 4 is formed on the anode 3 in this way, the cap effect by the transparent electrode 4 is exhibited, and the anode 3 can be fired while being reinforced. As a result, it is possible to prevent the water vapor derived from the planarizing film 2 from forming bubbles at the interface with the anode 3 during the firing process and causing the anode 3 to peel off. Further, thermal expansion of the metal material layer 3′X due to heating can be prevented together. Therefore, the anode 3 can be disposed on the surface of the planarizing film 2 with good adhesion even after the baking process is completed, and the laminated structure of the organic EL elements 20a, 20b, and 20c can be reliably realized.

Accordingly, excellent light emission characteristics can be expected in the organic EL display panel 100.
(Method for manufacturing organic EL display panel 100)
Here, the overall manufacturing method of the organic EL display panel 100 will be described in part based on the flowchart of FIG.

A substrate body made of the above material is prepared. Based on the reactive sputtering method, a TFT layer is formed on the surface of the substrate body to obtain a TFT substrate 1 (S1).
Next, a planarizing film (interlayer insulating film) 2 having a thickness of about 4 μm is formed so as to cover the TFT layer (S2). The planarizing film 2 can be formed by spin-coating a known photosensitive organic material (for example, a siloxane copolymer type photosensitive polyimide).

On the planarizing film 2 (on the TFT substrate 1), a metal material such as aluminum or an aluminum alloy is used to form a metal material layer into a thin film (S3). A transparent conductive film made of a transparent electrode material such as IZO is formed on the surface of the metal material layer (S4).
Next, a metal material such as molybdenum or tungsten is formed by reactive sputtering to form a metal oxide film (S5). Thereafter, a firing step of the metal material layer is performed (S6).

Next, a photosensitive resist is formed on the metal oxide film based on a photolithography method (S7). The metal oxide film is dry etched to form the hole injection layer 5 (S8). Subsequently, the transparent electrode 4 and the anode 3 are formed in the same order by wet etching the transparent conductive film and the metal material layer (S9). The resist that is no longer needed is peeled off (S10).
The anode 3, the transparent electrode 4, and the hole injection layer 5 may be formed using any of dry etching and wet etching. These may be etched individually or in combination with any one of them.

Next, a photosensitive resist material or a resist material containing a fluorine-based or acrylic-based material is prepared as a bank material. This material is applied onto the hole injection layer 5 by a spin coating method and patterned based on a photoresist method. Thereafter, the bank 6 is formed by heat curing (S11).
Next, ink containing a hole transport layer material is dropped into the region between the banks 6 based on, for example, an ink jet method. The hole transport layer 7 is formed by drying this ink.

  Further, an ink containing an organic EL material is dropped on the upper surface of the hole transport layer 7, and the ink is dried to form the organic light emitting layer 8. The ink application method may be any of a dispenser method, a nozzle coating method, a spin coating method, intaglio printing, letterpress printing, and the like. The ink is preferably dried by, for example, vacuum drying. After ink drying, baking is performed in a nitrogen atmosphere. The average film thickness of the organic light emitting layer 8 is, for example, 70 nm.

Next, a thin film made of barium is formed based on the vacuum deposition method so as to cover the organic light emitting layer 8 and the bank 6. Next, based on the co-evaporation method, a film of the compound Alq mixed with barium is formed with a predetermined film thickness (for example, 20 nm) to form the electron injection layer 9.
Next, on the electron injection layer 9, an IZO thin film is formed to a thickness of, for example, 100 nm based on, for example, a plasma coating method to form the cathode 10.

Next, the sealing layer 11 is formed on the cathode 10 using a material such as SiN or SiON based on a vacuum deposition method or the like.
Thus, the organic EL display panel 100 is completed.
(About manufacturing processes of anode 3, transparent electrode 4, hole injection layer 5, etc.)
In the organic EL display panel 100 according to the embodiment, the anode 3, the transparent electrode 4, the hole injection layer 5, and the bank 6 can be sequentially manufactured based on, for example, the order of the manufacturing steps shown in FIG. 2. As one of the features of the manufacturing process, the baking process of the anode (metal material film) is performed when the metal material layer film formation, the transparent conductive film film formation, and the metal oxide film film formation are all performed.

2 and 3 are schematic cross-sectional views showing respective steps from “metal material layer deposition” to “resist stripping” in the flow of FIG. 2A to 2F and FIG. 3A to FIG. 3D are cross-sectional views in each step of the organic EL display panel 100 of FIG. Such a cross-sectional structure can be actually confirmed using a TEM or the like.
First, as described above, a TFT layer is formed on the surface of a substrate body (not shown) to obtain a TFT substrate 1 (FIG. 5 (S1)). A planarizing film 2 having a film thickness of about 4 μm is formed by spin-coating a known photosensitive organic material (for example, siloxane copolymer type photosensitive polyimide) so as to cover the surface of the TFT substrate 1 (FIG. 2A ), FIG. 5 (S2)).

  Next, a metal material layer 3′X made of ACL (aluminum alloy), a transparent conductive film 4X made of IZO, and a metal oxide film 5X made of a transition metal compound (here, tungsten oxide) are formed on the surface of the planarizing film 2. Then, based on the vacuum film formation method, the films are stacked in the same order (FIGS. 2B to 2D and FIGS. 5S3 to 5S5). The metal oxide film 5X can also be formed by a reactive sputtering method.

  Here, when the film formation of the metal material layer 3′X, the transparent conductive film 4X, and the metal oxide film 5X is completed, a firing process of the metal material layer 3X is performed (FIG. 5 (S6)). The firing temperature at this time is higher than each step before the firing step (as an example, a range of 200 ° C. or higher and 230 ° C. or lower), and is fired for a time of 15 minutes or longer. By performing this firing step, the metal material layer 3X with improved film density and reduced electrical resistance can be obtained. In addition, the film density of the transparent conductive film 4X can be improved and the electric resistance can be reduced by this baking process. Thus, the manufacturing process can be facilitated by firing the metal material layer 3X and the transparent conductive film 4X together.

  Thus, by forming the transparent conductive film 4X and the metal oxide film 5X on the metal material layer 3′X, the flatness of the metal material layer 3′X is improved and the metal material layer 3′X is reinforced. it can. If the firing process of the metal material layer 3′X is performed in this state, it is possible to effectively prevent moisture in the planarization film 2 from becoming bubbles at the interface between the planarization film 2 and the metal material layer 3′X. Good adhesion between the planarizing film 2 and the metal material layer 3′X can be maintained.

  Thereafter, patterning of the metal oxide film 5X is performed based on the photolithography method (FIG. 5 (S7)). First, a photosensitive resist film R is provided on the upper surface of the metal oxide film 5X, and exposure is performed from above the pattern mask (FIG. 2 (f)). When a positive photosensitive resist is used for the photosensitive resist film R, the pattern mask shields light from the portion where the anode 3 is to be formed, and forms an opening so as to expose other portions. As a commercial product of a positive photosensitive resist, for example, OFPR-5000 manufactured by Tokyo Ohka Kogyo Co., Ltd. can be used.

Next, as shown in FIG. 3A, resist development is performed using a developer (resist developer) made of an alkaline aqueous solution. As an example of the developer in this embodiment, a 2.38 wt% aqueous solution of TMAH (tetramethylammonium hydride) can be used. As a developing condition, it is a standard that the room temperature (about 25 ° C. to 30 ° C.) and the developing time are about 1 minute.
Thereafter, the metal oxide film 5X is patterned based on dry etching (FIG. 3B, FIG. 5 (S8)). An example of conditions for dry etching a metal oxide film 5X having a thickness of about 12 nm is shown. Of course, other etching conditions may be used.

Equipment: ICP dry etching equipment Gas and flow rate: CF ₄ : 180 sccm / O ₂ : 20 sccm
Power: Source: 500W Bias: 400W
Pressure: 10mmTorr
Temperature: 35 ° C
Processing time: 7 sec
In the present embodiment, since the metal material layer 3X and the planarization film 2 are in good contact with each other while preventing the generation of bubbles, peeling of the metal material layer 3X is suppressed even if such an etching process is performed. The hole injection layer 5 can be formed satisfactorily. For this reason, even when the organic EL display panel 100 is a high-definition type composed of fine subpixels, good production can be expected.

  Next, wet etching is performed (FIG. 5 (S9)). As shown in FIG. 3C, the metal material layer 3X and the transparent conductive film 4X are collectively etched using the same etchant (etchant). As this etching solution, for example, a hydrofluoric acid based mixed acid can be used. Here, as shown in the drawing, it is desirable to set the etching conditions so that the end surfaces of the metal material layer 3X and the transparent conductive film 4X are aligned. As the wet etching method, a dip type that erodes in a container filled with an etching solution is desirable for performing a uniform etching process, but a spray type that sprays the etching solution, a substrate mounted on a turntable, and the etching solution is dropped. There are spin types and any of them may be adopted.

Here, an example of conditions in the case of etching an anode (ACL) having a thickness of about 400 nm and a transparent conductive film (IZO) having a thickness of about 16 nm is shown. Etching conditions may be other than this.
Chemical solution: Mixed acid (phosphoric acid: 60-70%, nitric acid: 5-10%, acetic acid: <10%, water: 10-25%)
Liquid temperature: 30 ° C
Processing time: 270 sec
Method: Spray etching After completion of the etching, the substrate is washed with water and dried.

  As described above, when the metal material layer 3X, the transparent conductive film 4X, and the metal oxide film 5X are sequentially laminated, the hole injection layer 5 is patterned by dry etching, and the transparent electrode 4 and the anode 3 are patterned by wet etching. The optimum etching conditions can be set for each etching target. Thereby, it is possible to prevent side etching from being excessively performed on each layer, and to pattern each layer in a good shape.

Next, as shown in FIG. 3D, the photosensitive resist film R is peeled off (FIG. 5 (S10)). This completes the patterning of the anode, transparent electrode, and hole injection layer.
In the manufacturing process of the present embodiment, the metal material layer 3X is peeled from the surface of the planarizing film 2 by performing the baking process of the metal material layer 3′X at least after the film formation of the transparent conductive film 4X as described above. It is hard to do and is laminated with good adhesion. For this reason, each process after a baking process can be implemented efficiently. In this respect, it is possible to expect an effect of suppressing an increase in production cost and improving yield.

When the above steps are completed, the bank 6 is formed by the above-described method (FIG. 5 (S11)).
(Comparison with general manufacturing process)
FIG. 6 is a diagram showing a flow from a general TFT formation step (S101) to a bank formation step (S117). S101 to S103 correspond to the same order as S1 to S3 described above.
Here, FIG. 4A is a cross-sectional view showing the state of the substrate immediately after S103. In this general example, immediately after the metal material layer is formed, the baking step S104 of the layer is performed. Therefore, the metal material layer is not reinforced by the transparent conductive film at the time of baking. Accordingly, the moisture in the planarizing film 2 appears as bubbles at the heating temperature in the firing step, and pushes up the metal material layer 3X (FIG. 4B). The metal material layer 3X itself is also easily deformed by thermal expansion due to heating. As a result, a peeled portion projecting in a circular shape having a diameter of about 50 to 60 μm is generated on the surface of the fired metal material layer 3X by bubbles being pushed up. This peeled part falls off during the subsequent cleaning process and the like, causing a problem that the underlying planarization film 2 is exposed (FIG. 4C). On the other hand, in the present embodiment, as described above, the firing step is performed after forming the transparent conductive film 4X on at least the metal material layer 3′X, and the metal material layer 3′X is not easily deformed. Therefore, such problems are effectively suppressed.

In the process of FIG. 4, each of the metal material layer, the transparent conductive film, and the metal oxide film is patterned after etching, and the number of processes is relatively large (FIG. 4 (S103) to (S116)). On the other hand, in this embodiment, after forming each of the metal material layer, the transparent conductive film, and the metal oxide film, the baking process is performed only once, and the transparent electrode and the anode are formed using the same photosensitive resist film R. Patterning is performed (S6 to S10 in FIG. 5). For this reason, a very efficient manufacturing process can be implemented.
<Performance confirmation test>
In order to confirm the effect of the present invention, the following performance confirmation test was performed.

  In order to manufacture a sample device, a planarizing film was formed on the substrate surface, and a metal material layer made of aluminum having a predetermined thickness was formed thereon. Thereafter, a laminated body in which a transparent conductive film made of IZO, a metal oxide film made of molybdenum oxide (WOx), and the like were laminated according to each sample was formed. Thereafter, each laminate was fired at 200 to 230 ° C. for 15 minutes. After the firing treatment, the surface state of the sample device was observed with an SEM or the like to confirm the state of occurrence of peeling (bubble generation). Table 1 shows the structure of each sample device and the confirmation result of the occurrence of peeling.

As shown in the experimental results of Table 1, No. 1 in which the firing step was performed without forming anything on the metal material layer (Al). Looking at the sample devices 1 and 2, it was found that, regardless of whether the thickness of the metal material layer was 200 nm or 400 nm, a relatively large circular bubble (exfoliation) having a diameter of about 50 to 60 μm was generated on the surface.
In contrast, No. 1 was obtained by laminating a transparent conductive film (IZO) with a thickness of 100 μm on the metal material layer (Al). No peeling occurred in the sample device of 3. This is because the metal material layer is reinforced by the capping effect of the transparent conductive film disposed as the upper layer of the metal material layer and can resist deformation stress. As a result, the moisture in the flattened film becomes bubbles in the baking process. This is considered to be because the flatness was maintained.

In order to obtain the effect of the present invention, it is sufficient that at least a transparent conductive film is laminated on the metal material layer to obtain a certain cap effect, and the metal material layer is reinforced as the thickness of the transparent conductive film increases. It is possible to prevent the occurrence of peeling more strongly. However, it should be noted that the transparency decreases as the thickness of the transparent conductive film increases.
On the other hand, even if the film thickness of the transparent conductive film (IZO) is relatively thin as about 16 nm, if a metal oxide film (WOx) with a film thickness of about 12 nm is laminated on the transparent conductive film, the metal material layer It is No. that it can prevent peeling. It was confirmed from the results of 4 sample devices. Therefore, in order to obtain the effect of the present invention satisfactorily and to ensure the transparency of the element, the transparent conductive film and the metal oxide film are used rather than the firing process after the thick transparent conductive film is formed. It is considered that a higher capping effect on the metal material layer can be expected by performing the baking process after forming the film.
<Other matters>
Although the top emission type organic EL display panel has been described in the above embodiment, the present invention is not limited to this and may be a bottom emission type. In this case, it should be noted that the first electrode (anode) is made of a transparent material.

In the above embodiment, the firing step of the metal material layer 3′X is performed after the metal oxide film 5X is formed. However, this is not essential, and the firing step is performed at least after the formation of the transparent conductive film 4X. That's fine. Even in this method, since the transparent conductive film 4X exists on the metal material layer 3′X, generation of bubbles between the planarizing film 2 and the metal material layer 3′X can be prevented.
In the above-described embodiment, the configuration in which the hole transport layer, the electron injection layer, and the like are provided is illustrated, but these layers may be omitted as appropriate.

  INDUSTRIAL APPLICABILITY The present invention can be used as, for example, a display device for a mobile phone display or a television, an organic EL device used for various light sources, an organic EL device using the same, and a manufacturing method thereof. In any application, it is possible to expect an organic EL element or an organic EL display panel that can exhibit good light emission characteristics or image display performance.

R Photosensitive resist film 1 TFT substrate 2 Planarizing film 3′X Metal material layer (before firing)
3X metal material layer (fired)
3 Anode (reflective anode)
4X transparent conductive film 4 transparent electrode 5X transition metal oxide film 5 hole injection layer 6 bank (partition)
7 hole transport layer 8 organic light emitting layer 9 electron injection layer 10 cathode 11 sealing layer 20a, 20b, 20c organic EL element 100 organic EL display panel

Claims (11)

A first step of forming a resin film containing a resin material on a substrate;
A second step of forming a metal film containing a metal material on the resin film;
A third step of forming a transparent conductive film containing a conductive material and different from the metal film on the metal film;
A fourth step of forming a metal oxide film made of a transition metal oxide on the transparent conductive film;
A fifth step of firing the metal film after the fourth step;
A sixth step of forming a resist film containing a photosensitive resist material on the metal oxide film after the fifth step ;
A seventh step of exposing the resist film and exposing a part of the metal oxide film from below the resist film;
An eighth step of dry etching the exposed metal oxide film;
And a ninth step of performing wet etching on the transparent conductive film and the metal film through the dry-etched region . The device manufacturing method according to claim 1, wherein the step before the fifth step is performed at a temperature equal to or lower than the temperature required for the baking. The device manufacturing method according to claim 1, wherein a material containing aluminum is used as a metal material of the metal film. The device manufacturing method according to claim 1, wherein a conductive material containing indium is used as the transparent conductive film. The device manufacturing method according to claim 1, wherein a material containing molybdenum oxide or tungsten oxide is used as the transition metal oxide. Method of manufacturing a device according to any one of claims 1 to 5, the range of temperatures below 230 ° C. 200 ° C. or more according to the firing. Substrate preparation process;
A TFT layer forming step of forming a TFT layer on the substrate;
Forming a metal material layer above the TFT layer;
Forming a transparent conductive film on the metal material layer;
Forming a metal oxide film made of a transition metal oxide on the transparent conductive film;
Firing the metal material layer;
Etching the metal oxide film to form a hole injection layer;
Etching the transparent conductive film to form a transparent electrode;
Etching the metal material layer to form a first electrode;
Applying an ink containing an organic light emitting material above the hole injection layer and drying to form an organic light emitting layer;
A second electrode forming step of forming a second electrode above the organic light emitting layer,
The manufacturing method of the organic EL element which implements the said baking process after the transparent conductive film formation process or the said metal oxide film formation process. The method for producing an organic EL element according to claim 7 , wherein each step after the step of forming the metal material layer and before the baking step is performed at a temperature equal to or lower than the temperature required for the baking. The method for manufacturing an organic EL device according to claim 7 or 8 performs etching the metal oxide film by dry etching. Method of manufacturing an organic EL device according to any one of claims 7 to 9 for etching the transparent conductive film and the metal material layer collectively by wet etching. The manufacturing method of the organic EL element according to any one of claims 7 to 10 , wherein a temperature required for the firing is in a range of 200 ° C or higher and 230 ° C or lower.

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