JP4748386B2 - Organic EL device - Google Patents

Description

  The present invention relates to an organic EL element, and more particularly to an organic EL element having a passivation film that exhibits excellent passivation properties and excellent adhesion to a planarization layer.

Multilayer organic electroluminescence that has a thin film laminated structure of organic molecules that is excellent in viewing angle dependency and high-speed response with respect to liquid crystal display elements, etc., and emits light with high luminance of 1000 cd / m ² or more at an applied voltage of 10 V. Since a luminescence (hereinafter referred to as organic EL) element has been reported by Tang et al., Organic EL elements have been actively studied for practical use (see, for example, Non-Patent Document 1).

  Since pioneer in November 1997 commercialized green monochrome organic EL displays for vehicles, it has long-term stability and high-speed response to meet the diverse needs of society. There is an urgent need for practical use of organic EL displays capable of high-definition full-color display.

  One example of a method for making the organic EL display multi-colored or full-colored is a method in which light emitters of three primary colors of red, green, and blue (hereinafter abbreviated as RGB) are separately arranged in a matrix and light is emitted. . In order to emit three colors of RGB, a color filter or a color conversion layer (hereinafter also referred to as a color conversion filter layer) is formed by a photo process.

  The color conversion filter layer is obtained by dispersing a color conversion pigment in a resin. Here, since the color conversion filter layer cannot be dried at a temperature exceeding 200 ° C. due to the problem of thermal stability of the dye to be mixed, moisture or pattern formation contained in the coating liquid in the color conversion filter layer There is a high possibility that moisture mixed in during the process is contained.

  Further, when forming the color conversion layer, the RGB color conversion filter layers need to have a thickness of about 12 μm in order to efficiently convert the light from the organic EL layer into the respective colors. Further, in order to prevent color bleeding, it is necessary to prevent the color conversion filter layers from overlapping each other. For example, in the case of 70 dpi, the RGB sub-pixels (RGB single-color pixels) are arranged at intervals of 120 μm, and the RGB color conversion filter layers need to be formed approximately 10 μm apart to prevent color bleeding. is there. As a result, a groove having a width of 10 μm and a depth of 10 μm is formed between the sub-pixels.

  In order to form a transparent electrode or an organic EL layer thereon, a flattening layer is provided to fill and flatten the groove. A transparent organic resin such as an acrylic resin is used for the planarizing layer.

  Even after the flattening layer is formed, the flattening layer cannot be dried at a sufficiently high temperature due to the problem of thermal stability of the dye of the color conversion filter layer, and the flattening layer is likely to contain moisture.

  The organic EL element has a problem that current-luminance characteristics are reduced by driving for a certain period.

  A typical cause of the deterioration of the light emission characteristics is the growth of dark spots (light emission defect points). 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 during storage as well as energization, and is considered to be accelerated particularly by oxygen or moisture present around the element.

That is, if a small amount of moisture remaining in the color conversion filter layer or the flattening layer is diffused into the organic EL layer, dark spots are generated. In order to prevent this, a passivation film having a thickness of 200 to 300 nm is provided.
As the passivation film, a film made of a transparent inorganic oxide such as silicon oxide, aluminum oxide or titanium oxide (for example, see Patent Document 1), or a film made of an inorganic oxynitride such as silicon nitride oxide (for example, see Patent Document 2). Etc.) formed by sputtering or CVD.

  Since the passivation film is an inorganic material and the planarizing layer is an organic material, it usually has poor affinity and poor adhesion. Therefore, in order to secure the adhesion between the passivation film and the planarizing layer, before forming the passivation film on the planarizing layer, the surface of the planarizing layer is irradiated with ultraviolet rays so that oxygen and hydroxyl groups are applied to the surface of the planarizing layer. It is modified by introducing it.

JP-A-8-279394 JP 2003-297551 A C. W. Tang, S. A. VanSlike, Appl. Phys. Lett. 51, 913 (1987)

  When oxygen or a hydroxyl group is introduced to the surface of the planarizing layer by irradiating with ultraviolet rays, good adhesion can be obtained with a passivation film made of an inorganic oxide. Oxides easily pass oxygen and moisture, and a passivation film made of an inorganic oxide is inferior in passivation properties.

  Inorganic nitrides have excellent passivation properties, but there is a problem that adhesion with an organic layer having oxygen or a hydroxyl group on the surface is insufficient, and peeling is likely to occur in a subsequent photo process.

  A passivation film made of an inorganic oxynitride has good adhesion to an organic layer having oxygen or hydroxyl groups on its surface if its oxygen concentration is high, but it is still slightly inferior to the passivation property even if it is not as inorganic oxide. There was a problem.

  This invention is made | formed in view of such a condition, and it aims at providing the organic EL element which has a passivation film which has the passivation property of inorganic nitride, and the favorable adhesiveness to a planarization layer.

  That is, the organic EL element of the present invention includes a transparent substrate, one or more kinds of color conversion filter layers provided on the transparent substrate, a planarization layer formed so as to cover the color conversion layer, An organic EL device comprising a passivation film formed on a planarization layer, wherein the surface of the passivation film in contact with the planarization layer is an acid having a nitrogen ratio (nitrogen / nitrogen + oxygen) of 0.1 to 0.5. It is made of nitride, and the surface opposite to the surface in contact with the planarization layer is made of nitride.

  As one embodiment of such an organic EL element, the passivation film comprises a first passivation layer in contact with the planarization layer and a second passivation layer in contact with the planarization layer via the first passivation layer, One passivation layer is made of oxynitride having a nitrogen ratio (nitrogen / nitrogen + oxygen) of 0.1 to 0.5, and the second passivation layer is made of nitride.

  As an example of another embodiment, the surface of the passivation film that contacts the planarization layer is made of an oxynitride having a nitrogen ratio (nitrogen / nitrogen + oxygen) of 0.1 to 0.5, and is a surface that contacts the planarization layer. The surface on the opposite side is made of nitride, and at least part of the thickness direction of the passivation layer has a composition distribution in which the nitrogen / oxygen ratio increases as the distance from the planarization layer increases.

  According to the present invention, it is possible to ensure excellent passivation performance while maintaining the adhesion between the passivation film and the planarization layer, so that the organic EL element can be reduced from the color conversion filter layer, which causes a decrease in the light emission characteristics of the organic EL element. It is possible to provide a color organic EL display that can suppress the movement of moisture and oxygen to the EL element and can maintain stable light emission characteristics over a long period of time.

In the organic EL element of the present invention, an organic EL layer sandwiched between a transparent electrode and a reflective electrode is formed on a color conversion filter.
In the color conversion filter, three types (R, G, and B) of color conversion filter layers (R, G, and B) having a predetermined pattern are formed on a transparent substrate. A set is arranged in a matrix. A flattening layer for covering the color conversion filter layer and flattening the upper surface thereof is formed, and a passivation film is formed on the flattening layer. Hereinafter, each layer will be described in detail.

(Transparent substrate)
The transparent substrate is transparent to visible light (wavelength 400 to 700 nm), withstands the conditions (solvent, temperature, etc.) used for forming the layer to be laminated, and has excellent dimensional stability. preferable. A preferable transparent substrate includes a glass substrate and a rigid resin substrate formed of a resin such as a polyolefin resin, an acrylic resin, a polyester resin (including polyethylene terephthalate), a polycarbonate resin, or a polyimide resin. Alternatively, a flexible film formed of a polyolefin resin, an acrylic resin (including polymethyl methacrylate), a polyester resin (including polyethylene terephthalate), a polycarbonate resin, or a polyimide resin may be used as the transparent substrate.

(Color conversion filter layer)
The color conversion filter layer is composed of a color filter layer, a color conversion layer, or a laminate of a color filter layer and a color conversion layer. The color filter layer is a layer that does not have a color conversion function and transmits light of a wavelength in a selected range to improve the color purity of output light. When using the laminated body of a color filter layer and a color conversion layer, a color filter layer is normally arrange | positioned between a transparent substrate and a color conversion layer. The color filter layer can be formed using any material known in the art such as a material used in a liquid crystal display or the like.

  The color conversion layer 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).

  The color conversion dye in the present invention absorbs light in the near ultraviolet region or visible region, particularly light in the blue or blue-green region, emitted from a light emitter, and emits visible light having a different wavelength as fluorescence. Preferably, at least one fluorescent dye that emits fluorescence in the red region may be used, and may be combined with one or more fluorescent pigments that emit fluorescence in the green region.

  That is, when an organic EL element that emits light in the blue or blue-green region is used as the light source, if light from the element is passed through a simple red filter to obtain light in the red region, light having a wavelength in the red region is originally used. Because there is little, it becomes very dark output light. On the other hand, light in the red region having sufficient intensity can be output by converting the light in the blue or blue-green region from the element into light in the red region by the color conversion dye in the red conversion layer. It becomes. Therefore, in the present invention, the red color conversion filter layer is preferably composed of a color conversion layer, and more preferably is composed of a laminate of a color filter layer and a color conversion layer.

  On the other hand, the light in the green region may be output after the light from the element is converted into the light in the green region by another color conversion dye, similarly to the light in the red region. Alternatively, if the light emission of the element sufficiently includes light in the green region, the light from the element may simply be output through the green filter. Furthermore, regarding the light in the blue region, the light from the organic EL element can be output through a simple blue filter.

  Examples of fluorescent dyes that absorb light in the blue to blue-green region emitted from the luminescent material and emit fluorescence in the red region include rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, sulforhodamine, basic violet 11 Pyridine dyes such as rhodamine dyes such as basic red 2, cyanine dyes, 1-ethyl-2- [4- (p-dimethylaminophenyl) -1,3-butadienyl] -pyridinium perchlorate (pyridine 1) Or oxazine dyes. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent.

  Examples of fluorescent dyes that absorb blue to blue-green light emitted from a light emitter and emit green light include 3- (2′-benzothiazolyl) -7-diethylamino-coumarin (coumarin 6), 3- (2′-Benzimidazolyl) -7-diethylamino-coumarin (coumarin 7), 3- (2′-N-methylbenzimidazolyl) -7-diethylamino-coumarin (coumarin 30), 2,3,5,6-1H, 4H -Coumarin-based dyes such as tetrahydro-8-trifluoromethylquinolidine (9,9a, 1-gh) coumarin (coumarin 153), or basic yellow 51 which is a coumarin dye-based dye, and further, solvent yellow 11 and solvent yellow 116 And naphthalimide dyes. Furthermore, various dyes (direct dyes, acid dyes, basic dyes, disperse dyes, etc.) can be used if they are fluorescent.

  The color conversion dye used in the present invention includes polymethacrylate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer resin, alkyd resin, aromatic sulfonamide resin, urea resin, melamine resin, benzoguanamine resin, and these resins. An organic color conversion pigment may be obtained by kneading into a mixture or the like in advance to obtain a pigment. In addition, these color conversion dyes and organic color conversion pigments (in the present specification, the above two are collectively referred to as color conversion dyes) may be used singly, and two kinds may be used to adjust the hue of fluorescence. A combination of the above may be used.

  The color conversion pigment used in the present invention is contained in the color conversion layer in an amount of 0.01 to 5% by mass, more preferably 0.1 to 2% by mass, based on the weight of the color conversion layer. If the content of the color conversion dye is less than 0.01% by mass, sufficient wavelength conversion cannot be performed, or if the content exceeds 5%, the color conversion efficiency decreases due to effects such as density quenching. Bring.

  The matrix resin used in the color conversion layer of the present invention is insoluble by photocuring or photothermal combination type curable resin (resist) by light and / or heat treatment to generate radical species or ionic species to polymerize or crosslink. Any infusible material can be used as long as it is usually used for a color conversion layer of an organic EL element.

(Flattening layer)
The planarizing layer can be formed without impairing the function of the color conversion filter layer, and can be formed from a material having appropriate elasticity. A preferable material has high transparency in the visible region (transmittance of 50% or more in the range of 400 to 800 nm), a surface hardness of 2H or more, a Tg of 100 ° C. or more, and a color conversion filter layer. It is a polymer material that can form a smooth coating film and does not deteriorate the function of the color conversion layer.

Examples of such polymer materials include acrylic resin, imide-modified silicone resin, a material in which an inorganic metal compound (TiO ₂ , Al ₂ O ₃ , SiO _2, etc.) is dispersed in acrylic, polyimide, silicone resin, or the like, acrylate Examples of the resin include a monomer / oligomer / polymer reactive vinyl group, a resist resin, and a thermosetting resin such as a fluorine-based resin.

  The surface of the planarizing layer on the side in contact with the passivation film is preferably subjected to ultraviolet treatment before the passivation film is formed. By this ultraviolet ray treatment, the surface of the organic resin that forms the planarization layer by irradiating ultraviolet rays in an oxygen-containing atmosphere is broken by bonding the carbon atoms and hydrogen to the surface and reacting with oxygen in the atmosphere for planarization. The oxygen atoms or hydroxyl groups are bonded to the carbon atoms on the surface of the layer.

  Examples of the ultraviolet treatment include a method of irradiating ultraviolet rays using a low pressure mercury lamp or an excimer lamp in an oxygen-containing atmosphere.

(Passivation layer)
In the present invention, a passivation film is formed on the planarizing layer. In this passivation film, the surface in contact with the planarization layer is made of oxynitride having a nitrogen ratio (nitrogen / nitrogen + oxygen) of 0.1 to 0.5, and the surface opposite to the surface in contact with the planarization layer is nitride. It is made up of. The thickness of the passivation film can be increased as long as it has transparency in the visible range, but is usually in the range of 200 to 300 nm.

  Since the surface of the passivation film in contact with the planarization layer is made of oxynitride having a nitrogen ratio of 0.1 to 0.5, the adhesion of the passivation film to the planarization layer is improved. When the nitrogen ratio exceeds 0.5, the adhesion of the passivation film to the planarization layer is lowered. On the other hand, when the nitrogen ratio is less than 0.1, the passivation effect of the passivation film decreases.

  If the surface of the passivation film opposite to the surface in contact with the planarization layer is an oxide or oxynitride, the passivation effect is reduced.

  The passivation film in the present invention includes a first passivation layer in contact with the planarization layer and a second passivation layer in contact with the planarization layer through the first passivation layer, and the first passivation layer has a nitrogen ratio ( (Nitrogen / nitrogen + oxygen) may be made of 0.1-0.5 oxynitride, and the second passivation layer may be made of nitride.

  In this case, the thickness of the first passivation layer is preferably 20 to 50 nm from the viewpoints of adhesion to the planarization layer and a passivation effect. The thickness of the second passivation layer is preferably 250 nm or more from the viewpoint of the passivation effect.

  In addition, as the passivation film in the present invention, the surface of the passivation film in contact with the planarization layer is made of an oxynitride having a nitrogen ratio (nitrogen / nitrogen + oxygen) of 0.1 to 0.5, and the surface in contact with the planarization layer is The opposite surface may be made of nitride, and may have a composition distribution in which the nitrogen / oxygen ratio increases as the distance from the planarization layer increases, at least in part in the thickness direction of the passivation layer.

  In this case, the thickness of the layer made of oxynitride having a nitrogen ratio of 0.1 to 0.5 is preferably 20 to 100 nm from the viewpoint of adhesion to the planarization layer and a passivation effect. In addition, the thickness of the nitride layer is preferably 200 nm or more from the viewpoint of the passivation effect.

As the oxynitride and nitride constituting the passivation layer, the gas permeability coefficient of 10 ⁻¹³ cc · cm / cm ² · s · cmHg or less with respect to water vapor and oxygen (according to the gas permeability test method of JIS K7126: 1987) Any of those having at least one selected from silicon, titanium, aluminum, gallium and indium are preferred. This passivation film is formed by sputtering using, for example, an RF magnetron sputtering apparatus, using oxynitride or a metal constituting nitride as a sputtering target, and sputtering using argon and nitrogen or argon, oxygen and nitrogen as sputtering gases. Alternatively, an oxynitride is obtained.

  If sputtering is performed in an argon, oxygen, and nitrogen atmosphere in the first stage and sputtering is performed in a nitrogen and argon atmosphere in the second stage, a first passivation layer made of oxynitride and a second layer made of nitride are formed. A passivation film consisting of a passivation layer is obtained. First, sputtering is performed in an atmosphere of argon, oxygen, and nitrogen. Sputtering is continued while gradually reducing the oxygen concentration and increasing the nitrogen concentration. Finally, sputtering is performed in nitrogen and argon. In this way, a passivation film is obtained in which the surface in contact with the planarization layer is made of oxynitride and the surface opposite to the surface in contact with the planarization layer is made of nitride.

(Transparent electrode)
The transparent 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 transparent electrode is made of ITO (In—Sn oxide), NESA film, Sn oxide, In oxide, IZO (In—Zn oxide), Zn oxide, Zn—Al oxide, Zn—Ga oxide, or These oxides can be formed using a conductive transparent metal oxide in which a dopant such as F or Sb is added. The transparent electrode 21 is formed using a vapor deposition method, a sputtering method (including a reactive sputtering method) or a chemical vapor deposition (CVD) method, and preferably formed using a sputtering method (including a reactive sputtering method). The The transparent electrode usually has a thickness of 50 nm or more, preferably 50 nm to 1 μm, more preferably 100 to 300 nm. When a transparent electrode consisting of a plurality of partial electrodes is required, a transparent electrode consisting of a plurality of partial electrodes may be formed using a mask that gives a desired shape, or a reverse tapered cross-sectional shape may be used. You may form the transparent electrode which consists of a some partial electrode using the separation partition which has.

  The transparent electrode can be used as either an anode or a cathode. When using a transparent electrode as a cathode, it is desirable to improve the electron injection efficiency by providing a buffer layer at the interface with the organic EL layer. As the material of the buffer layer, alkali metals such as Li, Na, K, or Cs, alkaline earth metals such as Ba and Sr, alloys containing them, rare earth metals, or fluorides of these metals can be used. However, it is not limited to them. The film thickness of the buffer layer can be appropriately selected in consideration of the driving voltage, transparency, and the like, but in a normal case, it is preferably 10 nm or less.

(Organic EL layer)
The organic EL layer 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. For example, 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 (diphenyl) (Vinyl) biphenyl (DPVBi), etc.), porphyrin compounds, benzothiazole compounds, benzimidazole compounds, benzoxazole compounds and the like, and materials such as 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 host compounds 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.

  Each layer constituting the organic EL layer can be formed using any means known in the art such as vapor deposition (resistance heating or electron beam heating).

(Reflective electrode)
The reflective electrode 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 reflective electrode may be used as a cathode or an anode. When the reflective electrode is used as a cathode, the aforementioned buffer layer may be provided at the interface between the reflective electrode and the organic EL layer to improve the efficiency of electron injection into the organic EL layer. Alternatively, when a reflective electrode is used as a cathode, an alkali metal such as lithium, sodium, or potassium, which is a material having a low work function, calcium, magnesium, Electron injection efficiency can be improved by adding an alkaline earth metal such as strontium to form an alloy. When the reflective electrode is used as an anode, the above-mentioned conductive transparent metal oxide layer may be provided at the interface between the reflective electrode and the organic EL layer to improve the efficiency of hole injection into the organic EL layer.

  The reflective electrode 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. When a reflective electrode composed of a plurality of partial electrodes is required, a reflective electrode composed of a plurality of partial electrodes may be formed using a mask that gives a desired shape, or an inversely tapered cross-sectional shape may be formed. You may form the reflective electrode which consists of a some partial electrode using the separation partition which has.

Example 1
Blue conversion filter layer and green conversion filter comprising a plurality of stripes each having a width of 0.1 mm, a pitch of 0.33 mm, and a film thickness of 12 μm on a coning glass (50 × 50 × 1.0 mm) as a transparent substrate And a red color conversion filter layer were formed.

A UV curable resin (epoxy-modified acrylate) is applied by spin coating on a substrate on which color conversion filter layers for RGB colors are formed, and the thickness of the flattening layer on the color conversion filter layer becomes 5 μm. A planarization layer was formed as described above. At this time, the pattern of the color conversion filter layer of each color was not deformed, and the upper surface of the flattening layer was flat. The surface of the planarizing layer was subjected to surface modification by irradiating with 150 mJ / cm ² of ultraviolet light at a wavelength of 185 nm with a low-pressure mercury lamp. ESCA analysis confirmed that carbon on the surface of the planarization layer was bonded to hydrogen before ultraviolet irradiation treatment, whereas carbon on the surface was bonded to oxygen or hydroxyl group after ultraviolet irradiation. .

Immediately after the ultraviolet irradiation, the substrate is placed on a sputtering apparatus, and the partial pressure ratio of a mixed gas of oxygen and nitrogen and argon gas as a sputtering gas is 1: 3, and the nitrogen ratio in the mixed gas of oxygen and nitrogen (nitrogen + oxygen = 10) At several points in the range from 0 to 10, a first passivation layer made of silicon oxynitride with a sputtering pressure of 0.6 Pa and a sputtering power density of 4 W / cm ² was formed to a thickness of 20 nm. Next, the supply of oxygen gas is stopped, the sputtering gas is changed to a nitrogen gas / argon gas partial pressure ratio of 1: 3, a second passivation layer made of silicon nitride at a sputtering pressure of 0.6 Pa and a sputtering power density of 4 W / cm ^2. Was formed to a thickness of 280 nm.

  The adhesion of the obtained passivation film to the planarization layer was evaluated by a cross-cut test (JIS K5400). In this evaluation, for each nitrogen ratio, an average was obtained by measuring a total of nine locations on each of three substrates on three substrates including reproducibility.

Evaluation criteria for adhesion at that time are shown below.
10: Each cut is fine, smooth on both sides, and the intersection of the cuts and the square do not come apart at a glance.
8: There is a slight peeling at the intersection of the cuts, there is no peeling at a glance of the square, and the area of the defect is within 5% of the total square area.
6: There are peeling on both sides of the cut and the intersection, and the area of the missing part is 5 to 15% of the total square area.
4: The width of the peeling due to the cut is wide, and the area of the missing part is 15 to 35% of the total square area.
2: The width | variety by a cut is wider than four points, and the area of a defect | deletion part is 35 to 65% of a total square area.
0: The area of peeling is 65% or more of the total square area.

  The result is shown in FIG. As shown in FIG. 1, the adhesion was 8 points or more up to a nitrogen ratio of 0 to 7 in the mixed gas of oxygen and nitrogen at the time of forming the first passivation layer, and it was practically durable.

  Further, when the adhesion evaluation results were plotted by the nitrogen ratio (nitrogen / nitrogen + oxygen) of silicon oxynitride of the first passivation layer of the obtained passivation film, as shown in FIG. When the ratio was 0.5 or less, the adhesion was 8 points or more, and when the ratio exceeded 0.5, the adhesion was insufficient.

Further, on the Si wafer, a passivation film made of a first passivation layer made of silicon oxynitride having a composition of 20 nm and a second passivation layer made of silicon nitride having a thickness of 280 nm was formed under the same sputtering conditions as described above.
These Si wafers with a passivation film were immersed in a 10% aqueous potassium hydroxide solution heated to 75 ° C. for 30 minutes, and the number of etch pits generated on the Si wafer was measured. As a result, it was found that the number of etch pits decreased when the partial pressure ratio of oxygen and nitrogen during the formation of the first passivation layer was between 6: 4 and 0:10, and the passivation effect was good. Moreover, when the evaluation result of the passivation effect was plotted by the nitrogen ratio (nitrogen / nitrogen + oxygen) of silicon oxynitride of the first passivation layer of the obtained passivation film, as shown in FIG. As described above, it was found that the number of etch pits is small and a good passivation effect is exhibited.

(Example 2)
A substrate having an ultraviolet-treated planarized layer obtained in the same manner as in Example 1 was placed in a sputtering apparatus, and the partial pressure ratio of a mixed gas of oxygen and nitrogen and argon gas as a sputtering gas was 1: 3, and the sputtering pressure was set at 0. A passivation film was formed at 6 Pa and a sputtering power density of 4 W / cm ² . At the beginning of sputtering, the ratio of nitrogen and oxygen was set to 7: 3, and after forming the film to a thickness of 20 nm, the oxygen partial pressure was gradually decreased so that the oxygen partial pressure became 0 when the thickness reached 100 nm. A 280 nm passivation film was formed. The nitrogen ratio in the oxynitride on the surface in contact with the planarization layer was 0.5. The score of adhesion of the thus produced passivation film was 8 points. Further, a passivation film was formed on the Si wafer in the same manner except that a Si wafer was used instead of the substrate having the planarizing layer.
When these Si wafers with a passivation film were immersed in a 10% aqueous potassium hydroxide solution heated to 75 ° C. for 30 minutes and the number of etch pits generated on the Si wafer was measured, the number of etch pits was 2, which was effective for the passivation effect. It was excellent.

(Example 3)
Except that titanium, aluminum, gallium, and indium were used instead of silicon as the target, the nitrogen ratio of oxynitride was 0.3 on the substrate having the planarization layer in the same manner as in Example 1 and Example 2, respectively. The surface in contact with the passivation film and the planarization layer composed of the first passivation layer made of oxynitride and the second passivation layer made of nitride is made of oxynitride, and the surface opposite to the planarization layer is A passivation film surface in contact with the flattening layer, which is made of a nitride having a thickness of 180 nm and has a composition distribution in which the nitrogen / oxygen ratio increases as the distance from the flattening layer increases to provide adhesion and passivation. The relationship with the nitrogen ratio was investigated. Although there was some difference in the passivation level, all showed good adhesion when the nitrogen ratio of the oxynitride was 0.5 or less, and good passivation when it was 0.1 or more.

  According to the present invention, it is possible to provide an organic EL device having excellent passivation properties and excellent adhesion to a flattening layer, so that it is possible to provide a color display with less dark spots and excellent long-term stability.

It is a figure which shows the relationship of the adhesiveness with respect to the planarization layer when the nitrogen ratio (nitrogen + oxygen = 10) in the oxygen nitrogen mixed gas at the time of sputtering is changed. It is a figure which shows the relationship between the nitrogen ratio (nitrogen / nitrogen + oxygen) in the silicon oxynitride in a 1st passivation layer, and the adhesiveness with respect to a planarization layer. It is a figure which shows the relationship between the nitrogen ratio of the oxynitride layer of the passivation film on Si wafer, and the number of etch pits.

Claims (4)

A transparent substrate, one or more color conversion filter layers provided on the transparent substrate, a planarization layer formed to cover the color conversion layer, and a passivation film formed on the planarization layer The surface of the passivation film in contact with the planarization layer is made of an oxynitride having a nitrogen ratio (nitrogen / nitrogen + oxygen) of 0.1 to 0.5, and is in contact with the planarization layer. surface of the surface opposite to the Ri Do a nitride, oxynitride forming the passivation film, nitride, titanium, aluminum, one or more oxynitride selected from gallium and indium, Ru nitride der An organic EL device characterized by that.   The passivation film includes a first passivation layer in contact with the planarization layer and a second passivation layer in contact with the planarization layer through the first passivation layer, and the first passivation layer has a nitrogen ratio (nitrogen / nitrogen + 2. The organic EL device according to claim 1, wherein the second passivation layer is made of a nitride.   The surface of the passivation film in contact with the planarization layer is made of oxynitride having a nitrogen ratio (nitrogen / nitrogen + oxygen) of 0.1 to 0.5, and the surface opposite to the surface in contact with the planarization layer is made of nitride. The organic EL element according to claim 1, wherein the organic EL element has a composition distribution in which the nitrogen / oxygen ratio increases as the distance from the planarization layer increases in at least a part of the thickness direction of the passivation layer. The organic EL element according to claim 1, wherein the planarizing layer is made of an organic resin, and a surface in contact with the passivation film is subjected to ultraviolet treatment.

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