JP2008108590A - Organic el element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of an organic EL element superior in adhesion of a moisture/oxygen shielding layer and a cathode separation barrier rib. <P>SOLUTION: The manufacturing method of an organic EL element comprises at least the following processes (A)-(D). (A) a process to form a region having a resin as a main component on a substrate and form a first barrier layer on this region, (B) a process to form a first electrode on the first barrier layer, (C) a process to form a second barrier layer 8 (moisture/oxygen shielding layer) on the first barrier layer and roughen the surface of this second barrier layer, and (D) a process to form a second electrode (cathode) separation barrier rib 11 on the second barrier layer. Herein, the roughening of the surface is carried out by a blast by dry ice particles, a sputtering using an inert gas, or a dry etching using an etching gas. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an organic EL (electroluminescence) element used as a display device.

  In 1987, Eastman Kodak's C.I. W. Since Tang's announcement of a highly efficient organic EL device in a two-layer stacked device (CW Tang, SA VanSlyke, Appl. Phys. Lett. 51, 913 (1987)) In the meantime, various organic EL elements have been developed and are partially put into practical use in portable terminals and the like.

Display devices using organic EL elements include a passive matrix display device and an active matrix display device. In the former, a light emitting layer is formed at a pixel position where a plurality of anode lines and a plurality of cathode lines intersect, and each pixel is lit for a selected time during one frame period. The structure is simple, the manufacturing cost is low, and it is excellent for small screen panels.
Coloring methods include a three-color coating method, a color conversion method (hereinafter CCM method), a color filter method, and the like. Among these methods, the CCM method and the color filter method do not require the use of a metal mask at the time of film formation, and the color conversion layer and the color filter only need to be formed on the substrate by a photo process. It is advantageous.

An important practical issue as a color display is that it has a fine color display function and has long-term stability including color reproducibility. However, the color organic EL display has a defect that the light emission characteristic (current-luminance characteristic) is remarkably lowered by driving for a certain period.
A typical cause of the deterioration of the light emission characteristics is the growth of dark spots. This dark spot is a light emitting defect point. When oxidation proceeds during driving and during storage, the growth of dark spots proceeds and spreads over the entire light emitting surface. This dark spot is considered to be caused by oxidation or aggregation of the laminated material constituting the element due to oxygen or moisture in the element. The growth proceeds not only during energization but also during storage. In particular, the growth is accelerated by (1) oxygen or moisture present around the element, and (2) oxygen or moisture present as an adsorbate in the organic laminated film. And (3) it is considered that it is also affected by moisture adsorbed on components at the time of device fabrication or moisture intrusion at the time of production.

  As a moisture supply source, it is considered that moisture inherent in the color filter and / or the color conversion layer is released. As a technique for preventing moisture from entering the organic EL element, an inorganic oxide layer having a film thickness of 0.01 to 200 μm is disposed on the substrate (Patent Document 1), and silicon oxide, aluminum oxide, and oxidation are formed on the planarization layer. Titanium (Patent Document 2) is proposed to function as a moisture / oxygen barrier layer. In addition, nitrides are used.

  However, the inventors' experiments have shown that even in a panel using a moisture / oxygen barrier film, dark spots grow starting from the electrodes formed on the moisture / oxygen barrier film when driven for a long time. Yes. This is because pinholes generated when the moisture / oxygen barrier layer is formed and film formation defects due to adhesion of dust occur, so that moisture / oxygen enters the organic EL element from the portions not covered by the electrodes. Met.

  In order to compensate for this defect, there is a method in which a moisture / oxygen barrier layer is formed between the electrodes in addition to the above structure (Patent Document 3). The moisture / oxygen barrier layer (hereinafter also referred to as “second barrier layer”) is required to have a barrier property and be capable of patterning such as dry etching. As described above, an oxide such as silicon oxide or a nitride such as silicon nitride is used. Of these, silicon nitride is the most desirable material because of its excellent barrier properties.

In the case of a passive matrix display device, a voltage is applied to a location where an upper second electrode (cathode) line formed in a direction orthogonal to a lower first electrode (anode) patterned in a stripe shape intersects to emit light. Therefore, the cathode is separated by mask film formation or separated by a cathode separation partition as described in Patent Document 4. The former requires a mask film forming mechanism in the vapor deposition apparatus and is not suitable for a high-definition panel. The latter method is superior from the viewpoint of cost and high definition, and a cathode separation partition is required.
JP-A-8-27939 Japanese Patent No. 3304287 JP 2004-39311 A JP-A-8-315981

A photosensitive resin such as a novolac resin or an acrylic resin is used as the material of the partition wall so as to have a reverse mesa structure. The barrier rib is formed on the patterned blocking film (second barrier layer).
However, nitrides such as silicon nitride used as a moisture / oxygen barrier layer (second barrier layer) have a problem that adhesion to the above-described cathode separation barrier is poor. Even if a surface treatment such as ultraviolet irradiation is applied, the adhesion is insufficient. For this reason, there is a problem that a separation partition is peeled off from the barrier film, resulting in a defect in which separation is insufficient.

According to the present invention, the above problem is
(A) forming a region mainly composed of a resin on the substrate, and forming a first barrier layer on the region;
(B) forming a first electrode on the first barrier layer;
(C) forming a second barrier layer on the first barrier layer and roughening the surface of the second barrier layer;
(D) forming a second electrode separation partition on the second barrier layer;
A method for producing an organic EL device having
It is solved by.

By roughening the surface of the second barrier layer, the surface area can be increased, the anchor effect of the second electrode (cathode) separation partition can be increased, and the adhesion can be improved.
The roughening of the second barrier layer is preferably performed by any of dry etching, blasting with dry ice particles, or sputtering with inert gas ions.

  In the manufacture of an organic EL element, it is necessary not to impair the barrier property of the barrier layer in the roughening step, and the process should not cause cracks or defects. Moreover, even if the surface is roughened, if a residue or contamination is present, it is contrary to the purpose of improving the adhesion, and therefore, a process in which the residue or contamination does not occur is desirable. In addition, if there is a residue, a cleaning process must be introduced, which is not preferable from the viewpoint of reduction in the reliability of the panel due to the mixing of moisture and cost. Therefore, in the case of roughening with normally used abrasive grains or the like, it is difficult to remove the abrasive grains and there is damage to the lower part, which is difficult. Further, a method including a wet process is not preferable for the above reason.

The dry etching method, the dry ice particle blasting method, or the sputtering method using an inert gas ion (reverse bias sputtering method) does not have such inconvenience, and has an anchor effect and is sufficiently fine to satisfy adhesion. A rough surface can be formed, which is suitable as a means used for manufacturing an organic EL device.
In the present invention, the surface of the second barrier layer is preferably roughened so that its arithmetic average roughness is 1 nm or more. By setting the surface roughness within this range, the adhesion between the second barrier layer and the second electrode separation partition is improved as compared with the prior art, and a good organic EL element can be provided without any short circuit between the electrodes. . Regarding the surface roughness of the second barrier layer, in addition to the arithmetic average roughness measured by AFM being 1 nm or more, the maximum protrusion height is preferably 10 nm or more, and the maximum protrusion height is further increased. It is desirable that the upper limit of the thickness be 1/5 or less of the thickness of the second barrier layer.

  According to the above configuration, a barrier layer having excellent moisture / oxygen barrier properties and an electrode separation partition wall having excellent adhesion can be formed on the barrier layer. It is possible to provide a passive matrix-driven organic EL element that maintains excellent light emission characteristics over a long period of time without being short-circuited properly.

Embodiments of the present invention will be described below with reference to the drawings.
1, 2 and 3 show embodiments of organic EL elements. 1 is a perspective plan view of an organic EL element according to the present invention, FIG. 2 is a cross-sectional view taken along the line AA ′ in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line BB ′ in FIG.
In the organic EL device 100 of the present invention, a plurality of stripe-shaped first electrodes (anodes) 7, a second barrier layer 8, an organic EL layer 9, and a second electrode (cathode) 10 are sequentially laminated on a transparent substrate 1. It has a structure. The organic EL layer 9 and the second electrode 10 are separated by a plurality of second electrode separation partitions 11 extending in a direction orthogonal to the long side direction of the first electrode 7. The end of the second electrode 10 is connected to the extraction electrode 12.

  As shown in FIG. 2, between the transparent substrate 1 and the first electrode 7, there are a black matrix 2, a color filter 3, a color conversion layer 4 (4R, 4G, 4B), a planarization layer 5 and a first barrier layer. 6. As shown in FIG. 3, the second electrode separation partition 11 is formed on the second barrier layer 8. As shown in FIG. 1, the second barrier layer is formed in a lattice shape so that the light emitting region is opened, and the second electrode separation partition extends in a direction orthogonal to the first electrode. With such a configuration, each first electrode 7, the organic EL layer 9, and the second electrode 10 are arranged so as to be orthogonal to each other, and one pixel is formed in a portion where the first electrode and the second electrode overlap (see FIG. 1-3).

  The transparent substrate 1 is preferably transparent to visible light (wavelength 400 to 700 nm), withstands the conditions (solvent, temperature, etc.) used for forming the layer to be laminated, and is excellent in dimensional stability. Preferred transparent substrates include glass substrates and rigid resin substrates formed of resins such as polyolefins, acrylic resins (including polymethyl methacrylate), polyester resins (including polyethylene terephthalate), polycarbonate resins, or polyimide resins. . Alternatively, a flexible film formed from polyolefin, acrylic resin (including polymethyl methacrylate), polyester resin (including polyethylene terephthalate), polycarbonate resin, polyimide resin, or the like may be used as the substrate.

  On the transparent substrate 1, a color modulation unit composed of the color filter 3, the color conversion layer 4, or a laminate of the color filter and the color conversion layer can be provided. These constitute a region mainly composed of resin. The color filter is a layer that transmits only light in a desired wavelength range. Further, when adopting a laminated structure with the color conversion layer, the color filter is effective in improving the color purity of the light subjected to wavelength distribution conversion in the color conversion layer. The color filter can be formed using, for example, a commercially available color filter material for liquid crystal (such as a color mosaic manufactured by Fuji Film Electromaterials).

  The color conversion layer 4 is a layer made of a color conversion dye and a matrix resin. The color conversion dye is a dye that converts the wavelength distribution of incident light and emits light in different wavelength ranges, and preferably converts the wavelength distribution of near-ultraviolet light or blue to blue-green light from the organic light emitting layer. Thus, it is a pigment that emits light in a desired wavelength band (for example, blue, green, or red). Color conversion dyes are known in the art, such as rhodamine dyes and cyanine dyes that emit red light; coumarin dyes and naphthalimide dyes that emit green light; and coumarin dyes that emit blue light. Any thing that can be used.

  In one transparent substrate 1, a plurality of types of color modulation units, for example, a red modulation unit (3R, 4R) that absorbs light from an organic light emitting layer and emits red light, and a green modulation unit (3G, which emits green light). 4G), a blue modulation unit (3B, 4B) that emits blue light may be provided. In the present invention, a configuration that enables full color display by arranging a plurality of types of color modulation units in a matrix may be employed.

The color modulation part can be formed by applying the material of each layer using a spin coat method, a roll coat method, a cast method, a dip coat method, etc., and then patterning using a photolithographic method or the like.
A black matrix 2 and a flattening layer 5 can be formed between the color modulation portions and on the color modulation portions as necessary. The flattening layer is made of a resin to alleviate the level difference in the color modulation portion and ensure the adhesion of the first barrier layer 6. For the planarizing layer, a material having a high visible light transmittance such as an acrylic material is used. The planarizing layer usually has a thickness of 1 μm or more, preferably 2 μm to 10 μm.

  A first barrier layer 6 is formed on the upper part of a region mainly composed of resin, such as a color modulation part. The first barrier layer functions as a barrier layer for preventing moisture emitted from the color modulation portion to be coated and the planarization layer 5 from propagating to the organic EL layer side. The material can be formed using an insulating inorganic oxide such as SiOx, SiNx, SiNxOy, AlOx, TiOx, TaOx, ZnOx, inorganic nitride, inorganic oxynitride, or the like. Desirably, SiOx and SiNxOy having a small refractive index difference from the color modulation material are selected. Usually, the barrier layer is formed with a film thickness of 100 nm to 1 μm. The first barrier layer is formed using a plasma CVD method or a sputtering method.

The first electrode (anode) 7 formed on the first barrier layer is composed of a plurality of transparent electrodes, and is made of a conductive material such as SnO ₂ , In ₂ O ₃ , ITO, IZO, ZnO: Al using a sputtering method. It is formed by depositing a conductive metal oxide. The first electrode preferably has a transmittance of 50% or more, more preferably 85% or more with respect to light having a wavelength of 400 to 800 nm. The first electrode usually has a thickness of 50 nm or more, preferably 50 nm to 1 μm, more preferably 100 to 300 nm.

The first electrode is also formed as an extraction terminal for connecting to the external drive circuit from the display unit. A lead portion for connecting the second electrode and the external drive circuit is formed at the end portion of the second electrode.
In order to suppress the resistance of the first electrode, metals such as Al, Mo, Ni, Cr, and W can be used as the auxiliary electrode. Even if the auxiliary electrode is formed on any of the display portion, the lead-out portion of the first electrode with the external drive circuit, and the lead-out electrode 12 of the second electrode, there is an effect of suppressing the resistance.

In particular, in the portion where the second electrode and the lead wire of the second electrode are joined, the auxiliary electrode and the second electrode are directly joined to prevent the second electrode and the first electrode from contacting and oxidizing. You can also take
The first electrode 7 is configured such that passive matrix driving can be performed by forming the second electrode 10 as a plurality of striped electrodes extending in a direction intersecting (preferably orthogonal) the first direction. It is preferable.

  A second barrier layer 8 is formed on the first barrier layer 6. At this time, the second barrier layer is formed so as to contact the first barrier layer and fill the space between the first electrodes (FIGS. 1 and 2). The second barrier layer includes a pixel region (a portion where the organic EL layer is sandwiched between the first electrode and the second electrode and functions as a light emitting region), a second electrode, a connection portion of the extraction electrode of the second electrode, the extraction electrode, and the outside. It is formed excluding the connection part with the drive circuit.

The second barrier layer 8 can be formed on the entire surface of the substrate by using an insulating inorganic nitride such as SiNx or SiNxOy as a material from the viewpoint of barrier properties. In a normal case, the second barrier layer is formed with a film thickness of 100 nm to 1 μm. The second barrier layer is formed using a plasma CVD method or a sputtering method.
Next, a roughening process is performed. This is done by spraying dry ice particles onto the surface of the second barrier layer together with a high-pressure and high-speed gas, or by roughening the surface by sputtering with an inert gas such as Ar. The surface properties after roughening are desirably an arithmetic average roughness of 1 nm or more and a maximum protrusion height of 10 nm or more. The upper limit of the maximum protrusion height is preferably 1/5 or less of the thickness of the second barrier layer from the viewpoint of barrier properties. The measurement is performed with AFM (SPI3800 (trade name), Seiko Instruments Inc.), and the measurement region is preferably about 10 μm × 10 μm. DF20 (trade name, manufactured by Seiko) is used for the probe, and the measurement mode is DFM.

The dry ice blasting method is a type of blasting method in which dry ice particles having a size of several microns are sprayed onto the substrate surface together with a high-pressure and high-speed inert gas. However, the impinged dry ice is vaporized and does not leave a residue.
In the reverse bias sputtering method, plasma of an inert gas such as Ar is generated by applying a negative voltage to a substrate and applying a positive voltage to a flat plate electrode at a position facing the substrate. The generated gas ions are attracted to the surface of the substrate and the substrate is sputtered, whereby the surface is roughened. Therefore, heavier elements such as Kr and Xe are more effective for the gas used.

  In dry etching, an etching gas is introduced into a vacuum vessel, and the gas is excited by a high frequency, microwave, or the like to generate plasma and generate radicals and ions. The reaction is performed by reacting radicals and ions generated by the plasma with the second barrier layer to convert the reaction product into a volatile gas and exhausting the reaction product to the outside through a vacuum exhaust system. At this time, the effect is used because the surface is slightly roughened. Since this etching proceeds from the outermost surface, only the surface can be roughened while maintaining the barrier property by controlling the treatment time.

  Since the barrier layer on the pixel portion (light emitting region) is removed by etching at the time of patterning described below, roughening can be performed over the entire surface of the substrate, and masking or the like is unnecessary. Further, since the portion where the adhesion is a problem is other than the pixel portion, no adverse effect is caused even if the surface is roughened. In addition, the roughening improves the adhesion of the resist when the second barrier layer is patterned, leading to an improvement in etching quality.

Next, the second barrier layer 8 is patterned into a predetermined shape. As an etching method for patterning the second barrier layer, it is desirable to use a dry etching method using RIE plasma or ICP plasma. Therefore, a resist agent (“OFRP-800” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.)) is applied to form a predetermined pattern. In order to make the angle of the second barrier layer in contact with the first electrode an acute angle and to increase the selectivity between the first electrode and the metal electrode used as the auxiliary electrode, dry etching uses a mixed gas of fluorine-based gas and oxygen. For example, when SiNx is used for the second barrier layer, dry etching can use a mixed gas of SF ₆ gas and oxygen, a mixed gas of SF ₆ , HCl, and oxygen. When SiOx is used, a mixed gas of CF ₄ and oxygen, a mixed gas of SF ₆ , CHF ₃ and oxygen, or the like can be used.

As shown in FIG. 4, the second barrier layer 8 covers the end portion of the first electrode 7 in the pixel region and is formed between the adjacent first electrodes, and the end portion of the second electrode (not shown). It is formed in the lower part. As a result, the light emitting region 13 of one pixel is defined. Further, by forming between the first electrodes, it has a function of preventing the permeation of moisture penetrating the first barrier layer 6.
Next, a second electrode separation partition 11 is formed on the second barrier layer 8. Using a resin such as a novolac resin, a separation partition wall is formed in the extending direction of the second electrode (cathode) having a reverse tapered cross-sectional shape by photolithography. Thereby, the second electrode 10 formed on the upper part is electrically separated. The second barrier layer 8 and the separation partition 11 are roughened and thus have good adhesion, but the adhesion is further improved by performing ultraviolet / ozone treatment together.

The organic EL layer 9 includes at least an organic light emitting layer, and includes a hole transport layer, a hole injection layer, an electron transport layer, and / or an electron injection layer as necessary. Each of these layers is formed to have a film thickness sufficient to realize desired characteristics in each layer. For example, what consists of the following layer structures is employ | adopted.
(1) Organic light emitting layer (2) Hole injection layer / organic light emitting layer (3) Organic light emitting layer / electron injection layer (4) Hole injection layer / organic light emitting layer / electron injection layer (5) Hole transport layer / Organic light emitting layer / electron injection layer (6) Hole injection layer / hole transport layer / organic light emitting layer / electron injection layer (7) Hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection Layer (In the above configuration, the electrode functioning as the anode is connected to the left side, and the electrode functioning as the cathode is connected to the right side)
Any known material can be used as the material of the organic light emitting layer. In order to obtain light emission from blue to blue-green, for example, a condensed aromatic ring compound, a ring assembly compound, a metal complex (such as an aluminum complex such as Alq ₃ ), a styrylbenzene compound (4,4′-bis (diphenylvinyl) ) Biphenyl (DPVBi), etc.), porphyrin compounds, benzothiazole compounds, benzimidazole compounds, benzoxazole compounds such as fluorescent brighteners, and aromatic dimethylidin compounds are preferably used. Or you may form the organic light emitting layer which emits the light of a various wavelength range by adding a dopant to a host compound. Examples of the host compound include distyrylarylene compounds (for example, IDE-120 manufactured by Idemitsu Kosan Co., Ltd.), N, N′-ditolyl-N, N′-diphenylbiphenylamine (TPD), aluminum tris (8-quinolinolate) (Alq). ₃ ) etc. can be used. As dopants, perylene (blue purple), coumarin 6 (blue), quinacridone compounds (blue green to green), rubrene (yellow), 4-dicyanomethylene-2- (p-dimethylaminostyryl) -6-methyl- 4H-pyran (DCM, red), platinum octaethylporphyrin complex (PtOEP, red), or the like can be used.

  As a material for the hole injection layer, Pc (including CuPc) or indanthrene compounds can be used. The hole transport layer can be formed using a material having a triarylamine partial structure, a carbazole partial structure, or an oxadiazole partial structure. Materials that can be used preferably include TPD, [alpha] -NPD, MTDAPB (o-, m-, p-), m-MTDATA, and the like.

Materials for the electron transport layer include aluminum complexes such as Alq ₃ ; oxadiazole derivatives such as PBD and TPOB; triazole derivatives such as TAZ; triazine derivatives such as those having the structure shown below; phenylquinoxalines; A thiophene derivative such as BMB-2T can be used. As the material for the electron injection layer, an aluminum complex such as Alq ₃ or an aluminum quinolinol complex doped with an alkali metal or an alkaline earth metal can be used.

Optionally, a thin film (film) of an electron injecting material such as an alkali metal, an alkaline earth metal, an alloy containing them, or an alkali metal fluoride is formed at the interface between the organic EL layer 9 and the second electrode used as the cathode. A buffer layer formed with a thickness of 10 nm or less may be provided to increase the electron injection efficiency.
Each layer constituting the organic EL layer 9 and, optionally, any means known in the art such as vapor deposition (resistance heating or electron beam heating) can be used.

  The second electrode 10 includes a plurality of electrode groups, and is preferably formed using a highly reflective metal, amorphous alloy, or microcrystalline alloy. High reflectivity metals include Al, Ag, Mo, W, Ni, Cr, and the like. High reflectivity amorphous alloys include NiP, NiB, CrP, CrB, and the like. The highly reflective microcrystalline alloy includes NiAl and the like. The second electrode may be used as a cathode or an anode. When the second electrode is used as a cathode, the above-described buffer layer may be provided at the interface between the second electrode and the organic EL layer to improve the efficiency of electron injection into the organic EL layer.

  The second electrode 10 can be formed using any means known in the art such as vapor deposition (resistance heating or electron beam heating), sputtering, ion plating, laser ablation, etc., depending on the material used. it can.

(Example 1)
In this example, an organic EL device according to an embodiment of the present invention is produced. An organic EL element having a pixel number of 160 × 120 (RGB) and a pixel pitch of 0.33 mm was produced. On a fusion glass (Corning 1737 glass, 100 × 100 × 1.1 mm) as the transparent substrate 1, a black matrix material (Fuji Film Electronics Materials Co., Ltd .: Color Mosaic CK-7800) is applied using a spin coating method. Application and patterning were performed by a photolithography method to obtain a black matrix 2 having openings with a width of 0.03 mm, a pitch of 0.11 mm, and a film thickness of 1 μm.

  Next, a blue filter material (Fuji Film Electronics Materials Co., Ltd .: Color Mosaic CB-7001) is applied using a spin coating method, and patterning is performed by a photolithographic method, with a width of 0.08 mm, a pitch of 0.33 mm, and a thickness. A blue conversion filter layer (comprising only the color filter 3B) composed of a plurality of stripes having a thickness of 10 μm was obtained.

  Coumarin 6 (0.7 parts by weight) as a fluorescent dye was dissolved in 120 parts by weight of a solvent, propylene glycol monoethyl acetate (PGMEA). To this solution, 100 parts by weight of V259PA / P5 manufactured by Nippon Steel Chemical Co., Ltd. was added and dissolved to obtain a coating solution. The coating solution is applied and patterned by a photolithography method to form a green color conversion filter layer (consisting of only the color conversion layer 4G) having a plurality of stripes having a width of 0.08 mm, a pitch of 0.33 mm, and a thickness of 10 μm. ).

  Coumarin 6 (0.6 parts by weight), rhodamine 6G (0.3 parts by weight) and basic violet (0.3 parts by weight) were dissolved in 120 parts by weight of PGMEA as fluorescent dyes. 100 parts by weight of B259PA / P5 manufactured by Nippon Steel Chemical Co., Ltd. was added to the solution and dissolved to obtain a coating solution. After applying this coating solution and patterning for photolithography, a red color conversion filter layer (consisting of only the color conversion layer 4R) composed of a plurality of stripes having a width of 0.08 mm, a pitch of 0.33 mm, and a thickness of 10 μm. Got).

Subsequently, the planarization layer 5 was formed for the purpose of relaxing the steps of the blue, green, and red color modulation portions. A flattened acrylic material (manufactured by JSR Corporation: NN810) was applied and exposed with a photomask having an opening wider than the black matrix 2 formation region to form a pattern having a thickness of 5 μm.
Next, the first barrier layer 6 (SiNx film) was formed to a thickness of about 300 nm using a parallel plate type plasma CVD apparatus. The atmosphere was SiH ₄ gas 50 sccm and N ₂ gas 200 sccm, the RF applied power was 150 W, and the substrate stage temperature was 100 ° C.

Using a DC sputtering method (target In—Zn oxide, sputtering gas: O ₂ and Ar), 200 nm of IZO was deposited on the entire surface of the first barrier layer 6 at room temperature. Next, patterning is performed by a photolithography method using an aqueous oxalic acid solution as an etching solution, and a plurality of 0.1 mm wide and 0.11 mm pitches located above the color conversion filter layer and extending in the same direction as the stripes of the color conversion filter. A first electrode 7 having a stripe was formed.

Next, a second barrier layer 8 (SiNx film) was formed to a thickness of about 300 nm using a parallel plate type plasma CVD apparatus. The atmosphere was SiH ₄ gas 50 sccm and N ₂ gas 200 sccm, the RF applied power was 150 W, and the substrate stage temperature was 100 ° C.
Then, a roughening process is performed. This is done by spraying dry ice particles supplied from the dry ice particle manufacturing apparatus onto the substrate surface together with a pressurized inert gas such as Ar, N ₂ , He, or Kr. In this example, Ar gas was used, the average particle diameter was about 5 μm, and the gas pressure was 10 kg / cm ² . The substrate temperature was 50 ° C. The arithmetic average roughness before the treatment was 0.5 nm, whereas it was 3.5 nm after the treatment. The measurement was performed with AFM, and the measurement area was 10 μm × 10 μm.

Next, a positive resist (Tokyo Ohka Kogyo Co., Ltd .: TFR-1250) is applied, and the pixel portion has an opening of 80 × 300 μm in accordance with the opening of the black matrix 2, and the second electrode 10 and the extraction electrode are joined. The resist pattern was formed by performing exposure using a mask having an opening at the junction with the external drive circuit and the external drive circuit.
Next, the exposed second barrier layer was etched using the above apparatus with an atmosphere of SF ₆ gas of 100 sccm, oxygen gas of 50 sccm, and applied power of 1500 W. Thereafter, the resist was peeled off to obtain a pattern of the second barrier layer 8.

Subsequently, UV / ozone treatment is performed using a low-pressure mercury lamp. Irradiation is performed at an illuminance of 1.35 mW / cm ² for 5 minutes, and immediately thereafter, a negative photoresist (ZPN 1168 manufactured by Nippon Zeon Co., Ltd.) is applied by spin coating. Then, pre-baking is performed, a predetermined pattern is baked using a photomask, post-exposure baking is performed on a 110 ° C. hot plate for 60 seconds, development is performed, and finally heating is performed on a 160 ° C. hot plate for 15 minutes. Thus, the cathode separation partition wall 11 formed of a plurality of stripes extending in a direction orthogonal to the stripes of the first electrode 7 and having a reverse tapered cross section was formed.

Next, the substrate on which the structure below the cathode separation barrier 11 is formed is mounted in a resistance heating vapor deposition apparatus, and a hole injection layer, a hole transport layer, an organic light emitting layer, and an electron injection layer are sequentially formed without breaking the vacuum. did. During film formation, the internal pressure of the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. Copper phthalocyanine (CuPc) with a film thickness of 100 nm is used as the hole injection layer, and 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α with a film thickness of 20 nm is used as the hole transport layer. -NPD) was used as an organic light-emitting layer, and 30 nm-thick 4,4'-bis (2,2'-diphenylvinyl) biphenyl (DPVBi) was used, and 20 nm-thick Alq ₃ was used as an electron injection layer. .

Next, without breaking the vacuum, the second electrode 10 is formed by depositing Mg / Ag (mass ratio 10/1) having a thickness of 200 nm, and the organic EL element 100 having the structure shown in FIG. Obtained.
The organic EL device thus obtained was sealed with a sealing glass and a UV curable adhesive in a dry nitrogen atmosphere in the glove box (both oxygen and moisture concentrations were 10 ppm or less).
(Example 2)
An organic EL element was produced in the same manner as in Example 1 except that sputtering with Ar ions was performed as the roughening step of the second barrier layer 8 in Example 1.

After forming the second barrier layer, it was put into the sputtering apparatus (reverse sputtering apparatus), and Ar gas pressure was 1 Pa, power was 1.5 kW, and processing was performed for 3 minutes. The arithmetic average roughness before the treatment was 0.5 nm, whereas it was 3.1 nm after the treatment. The measurement was performed with AFM, and the measurement area was 10 μm × 10 μm.
(Example 3)
An organic EL device was produced in the same manner as in Example 1 except that a dry etching method was performed as the roughening step of the second barrier layer 8 in Example 1.

After forming the second barrier layer, it is put into the dry etching apparatus, and SF ₆ gas, HCl gas, and oxygen are introduced at a flow rate ratio of 15: 100: 50 to make the total pressure 26.7 Pa. The treatment was performed for 15 seconds at a high frequency of 100 MHz and a power of 0.45 kW. The arithmetic average roughness before the treatment was 0.5 nm, but after the treatment, it was 2.1 nm. The measurement was performed with AFM, and the measurement area was 10 μm × 10 μm.
(Comparative example)
An organic EL device was produced in the same manner as in Example 1 except that the surface roughening treatment on the second barrier layer 8 was not performed and only the UV / ozone treatment was performed.
(Evaluation)
In order to evaluate the degree of separation of the cathode 10, a plurality of organic EL elements were prepared in each example, and the ratio of short-circuiting among 1000 cathode lines was determined. Further, the adhesion between the second barrier layer 8 and the cathode separation partition 11 was evaluated by an adhesion test based on JIS K 5400. The results are summarized in Table 1. In Examples 1 to 3, the short-circuit ratio was 0%, whereas in the comparative example in which the second barrier layer was not roughened, the ratio was 23%. Also, the adhesion was 10 points in all examples, but 0 in the comparative example.

  Moreover, as a result of observing the surface of the element of an Example and a comparative example, the comparative example showed the deformation | transformation part and peeling part, such as a fall, in the shape of the cathode separation partition. However, since the adhesion was improved in the examples, the above-described abnormality was not observed, and an EL element without a short circuit became possible.

1 is a perspective plan view of an organic EL element according to the present invention. It is A-A 'arrow sectional drawing of FIG. It is a B-B 'arrow sectional view of Drawing 1. It is the top view to which the edge part of FIG. 1 was expanded.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Black matrix 3 Color filter 4 Color conversion layer 5 Flattening layer 6 1st barrier layer 7 1st electrode 8 2nd barrier layer 9 Organic EL layer 10 2nd electrode 11 2nd electrode separation partition 12 Extraction electrode 13 Light emission Region 100 Organic EL device

Claims (9)

(A) forming a region mainly composed of a resin on the substrate and forming a first barrier layer on the region;
(B) forming a first electrode on the first barrier layer;
(C) forming a second barrier layer on the first barrier layer and roughening the surface of the second barrier layer;
(D) forming a second electrode separation partition on the second barrier layer;
The manufacturing method of the organic EL element which has this. 2. The method of manufacturing an organic EL element according to claim 1, wherein in (A), the resin-based region has a color filter, a color conversion layer, or both a color filter and a color conversion layer. In (B), there are a plurality of first electrodes, each having a stripe shape,
3. The method of manufacturing an organic EL element according to claim 1, wherein, in (C), the second barrier layer is formed so as to be in contact with the first barrier layer and to fill the space between the first electrodes. The method for producing an organic EL element according to any one of claims 1 to 3, wherein in (C), dry ice particles are sprayed together with a high-pressure gas to roughen the surface of the second barrier layer. The method for producing an organic EL element according to claim 1, wherein in (C), the surface of the second barrier layer is roughened by sputtering using an inert gas. The method for producing an organic EL element according to claim 1, wherein in (C), the surface of the second barrier layer is roughened by dry etching using an etching gas. The method for producing an organic EL element according to claim 1, wherein, in (C), the arithmetic average roughness of the surface of the roughened second barrier layer is 1 nm or more. The method for producing an organic EL element according to claim 1, wherein the second electrode separation partition has a resin as a main component. The organic EL element manufactured by the manufacturing method of the organic EL element as described in any one of Claims 1-8.