JP2014044810A - Method for manufacturing organic el device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a high-definition organic EL device with improved display performance and luminous efficiency.SOLUTION: A method for manufacturing an organic EL device includes the steps of: forming an organic compound layer having at least a luminous layer on a substrate; forming an intermediate layer on the organic compound layer; forming a protective layer covering the intermediate layer; forming a resist layer in a prescribed region by photolithography; removing the protective layer, intermediate layer, and organic compound layer provided in a region not covered by the resist layer by dry etching; and removing a layer formed on the organic compound layer remaining on the substrate. The step of forming the intermediate layer further includes the steps of: forming a coating film by applying a solution containing a water-soluble material onto the organic compound layer; and drying the coating film. The steps from the step of drying the coating film to the step of forming the protective layer are performed under an inert gas atmosphere.

Description

  The present invention relates to a method for manufacturing an organic EL device.

  A plurality of organic EL elements included in the organic EL device are electronic elements in which at least a first electrode, a stacked structure (organic compound layer) including an organic light emitting layer, and a second electrode are stacked in this order on a substrate. It is. In the organic EL device, the organic light emitting layer included in the organic EL element is usually patterned in a predetermined shape. Here, as a method of patterning the organic light emitting layer, for example, a method of forming a constituent material of the organic light emitting layer by designating a region by an evaporation method through a shadow mask can be cited. As another method, there are a method of separately applying a constituent material of the organic light emitting layer using an ink jet, and a patterning of the organic light emitting layer by a photolithography method.

  Among these, the patterning of the organic light emitting layer by the photolithography method can be said to be an effective method from the viewpoint of high definition of the pattern. However, when the organic light emitting layer is patterned by photolithography, depending on the solvent used to dissolve the resist material, the organic compound layer that constitutes the organic EL element and has the organic light emitting layer or the like may be dissolved. There is sex. Here, even if the organic compound layer is only partially dissolved by the solvent described above, the light emission efficiency may be reduced or light emission may not be achieved.

  As a method for solving this problem, for example, there is a method proposed in Patent Document 1. In the method proposed in Patent Document 1, an intermediate layer is provided on an organic compound layer, followed by patterning using a photoresist, and then using the patterned photoresist as a mask, the intermediate layer and the organic layer are patterned. In this method, each compound layer is processed by etching.

Japanese Patent No. 4507759

  However, a resist developer used in a general photolithography method is an alkaline aqueous solution. Here, in the method proposed in Patent Document 1, when developing the resist or rinsing with pure water after development, the developer or pure water penetrates into the intermediate layer or develops. A part of the intermediate layer may be dissolved by the liquid or the like. Then, when exposed to an alkaline aqueous solution, the organic compound layer and the electrode (lower electrode) may be altered or dissolved, and as a result, the organic EL element may be damaged.

  Therefore, in order to prevent the developer or pure water from penetrating into the intermediate layer or the developer or the like from dissolving a part of the intermediate layer, the intermediate layer is covered with a highly moisture-proof protective layer, A method for preventing penetration into the intermediate layer is effective.

  However, since the protective layer is formed so as to cover the intermediate layer, when moisture is taken into the intermediate layer due to moisture absorption of the constituent material of the intermediate layer after the intermediate layer is formed, the moisture is confined by the protective layer. The water trapped in the protective layer diffuses to the organic light emitting layer and the anode surface inside the protective layer by a thermal process such as pre-baking and post-baking in the subsequent photo process. As a result, the luminous efficiency of the organic EL device may be lowered.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method for manufacturing a high-definition organic EL device with improved display performance and luminous efficiency.

In the method for producing an organic EL device of the present invention, a plurality of organic EL elements each having at least a light emitting layer are arranged,
An organic EL device manufacturing method in which the light emitting layer is patterned in a predetermined shape,
Forming an organic compound layer having at least a light emitting layer on a substrate;
Forming an intermediate layer on the organic compound layer;
Forming a protective layer covering the intermediate layer;
Forming a resist layer in a predetermined region by photolithography;
Removing a protective layer, an intermediate layer and an organic compound layer provided in a region not covered with the resist layer by dry etching;
Removing a layer formed on the organic compound layer remaining on the substrate,
The step of forming the intermediate layer comprises a step of coating a solution containing a water-soluble material on the organic compound layer to form a coating film, and a step of drying the coating film,
The steps from the step of drying the coating film to the step of forming the protective layer are performed in an inert gas atmosphere.

  The manufacturing method according to the present invention includes a step of providing a protective layer made of a material that does not dissolve in any of water and the organic solvent contained in the photoresist between the intermediate layer and the resist layer. By providing the protective layer, a general photolithography method can be used regardless of the solvent used in the process. Furthermore, a high-definition organic EL device in which display defects are suppressed by performing a process from a process of drying a coating film serving as an intermediate layer to a process of forming a protective layer in an inert gas atmosphere. Is possible.

  As described above, according to the present invention, it is possible to provide a method for manufacturing a high-definition organic EL device with improved display performance and luminous efficiency.

It is a flowchart which shows the process from an intermediate | middle layer film-forming process to a protective layer formation process. It is a cross-sectional schematic diagram which shows the example of the organic EL apparatus manufactured by the manufacturing method of this invention. FIG. 3 is a schematic cross-sectional view illustrating an example of a manufacturing process of the organic EL display device of FIG. 2.

  The present invention is a method of manufacturing an organic EL device in which a plurality of organic EL elements each having at least a light emitting layer are arranged, and the light emitting layer is patterned in a predetermined shape.

The production method of the present invention includes the following steps (A) to (G).
(A) Step of forming an organic compound layer having at least a light emitting layer on a substrate (organic compound layer forming step)
(B) Step of forming an intermediate layer on the organic compound layer (intermediate layer forming step)
(C) Step of forming a protective layer on the intermediate layer (protective layer forming step)
(D) Step of forming a resist layer in a predetermined region by photolithography (resist layer forming step)
(E) The process of removing the protective layer, intermediate | middle layer, and organic compound layer which are provided in the area | region which is not covered with the resist layer by dry etching (process of organic compound layer)
(F) The process of removing the layer formed on the organic compound layer

The step (B) is a step including the following (B1) to (B2).
(B1) A step of forming a coating film by applying a solution containing a water-soluble material on the organic compound layer (intermediate layer coating step)
(B2) Step of drying the coating film (formed in step (B1)) (intermediate layer drying step)

  In the present invention, the steps from the step (B2) (drying step) to the step (C) (protective layer forming step) are performed in an inert gas atmosphere. In the present invention, the inert gas is preferably nitrogen gas or a rare gas such as helium or argon. FIG. 1 is a flowchart showing a process from an intermediate layer forming step to a protective layer forming step. In the present invention, the “step from the drying step to the protective layer forming step” includes an intermediate layer drying step as shown in FIG. 1, but does not include the protective layer forming step itself. More specifically, it refers to a step of drying the coating film serving as the intermediate layer, and a step subsequent to the drying step up to immediately before evacuation performed for the protective layer forming step. Further, in the present invention, the protective layer forming step refers to the protection from the time when evacuation is started just before the protective layer forming step in order to carry the substrate into the protective layer forming apparatus used in the protective layer forming step. The process until the formation of the layer is completed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, a well-known technique or a well-known technique in the technical field can be applied to a part that is not particularly illustrated or described. The embodiment described below is merely one of the embodiments of the present invention, and the present invention is not limited to these.

[Organic EL display device]
FIG. 2 is a schematic cross-sectional view showing an example of an organic EL display device manufactured by the manufacturing method of the present invention. In the organic EL display device 1 of FIG. 2, three types of subpixels, that is, a first subpixel 20 a, a second subpixel 20 b, and a third subpixel 20 c are provided on a substrate 10. Here, the first sub-pixel 20a, the second sub-pixel 20b, and the third sub-pixel 20c constitute a pixel. The three types of subpixels (20a, 20b, 20c) have different organic compound layers. In the present invention, the organic compound layer is a charcoal layer including at least a light emitting layer or a laminate composed of a plurality of layers, and is provided for each subpixel. When the organic compound layer is composed of a plurality of layers, the organic compound layer includes at least one layer such as an electron injection layer, an electron transport layer, a hole injection layer, and a hole transport layer in addition to the light emitting layer. Included. In addition, the light emitting layer included in the organic compound layer may be a single layer or a laminate including a plurality of layers. By the way, “(different from each other) organic compound layer” means that at least one of the characteristics of a light emitting layer or a layer other than the light emitting layer included in each subpixel is different from other subpixels. Here, the characteristics of the layers (the light emitting layer and the layers other than the light emitting layer) include constituent materials, compositions, film thicknesses, film forming methods, layer forming conditions, and the like of a predetermined layer such as the light emitting layer.

  The organic EL display device 1 in FIG. 2 shows a set of pixels including a first sub-pixel 20a, a second sub-pixel 20b, and a third sub-pixel 20c. In the EL display device, a plurality of pixels are arranged in a matrix on the support substrate 10.

  In the organic EL display device 1 of FIG. 2, each subpixel (20 a, 20 b, 20 c) includes a first electrode 21, an organic compound layer 22, an electron injection / transport layer 23, and a second electrode 24. Have.

  The first electrode 21 (21a, 21b, 21c) is an electrode layer (lower electrode, anode) provided on the substrate 10, and is provided individually for each subpixel. The first electrodes 21a, 21b, and 21c are electrically connected to a switching element (not shown) such as a TFT.

  The organic compound layer 22 (22a, 22b, 22c) is provided for each of the first electrodes 21 (21a, 21b, 21c), and is a single layer or a stacked layer composed of a plurality of layers made of a predetermined organic compound. The organic compound layers 22a, 22b, and 22c each have at least a light emitting layer (not shown).

  The electron injection / transport layer 23 is provided to inject / transport electrons injected from the second electrode 24 (upper electrode, cathode) to the organic compound layer 22. In the organic EL display device 1 of FIG. 2, the electron injection / transport layer 23 is provided as a layer common to the sub-pixels (20a, 20b, 20c), but the present invention is not limited to this. is not. That is, the electron injection / transport layer 23 may be provided for each subpixel.

  In the organic EL display device 1 of FIG. 2, the second electrode 24 (upper electrode, cathode) is provided as a layer common to the sub-pixels (20 a, 20 b, 20 c) similarly to the charge injection / transport layer 23. However, the present invention is not limited to this. That is, the second electrode 24 may be provided individually for each subpixel.

[Method for Manufacturing Organic EL Display Device]
Next, the manufacturing method of the organic EL display device of the present invention will be described using the manufacturing method of the organic EL display device of FIG. 2 as a specific example.

As described above, the method for manufacturing an organic EL display device of the present invention includes at least the following steps (A) to (F).
(A) Step of forming an organic compound layer having at least a light emitting layer on the substrate (formation step of organic compound layer)
(B) Step of forming an intermediate layer on the organic compound layer (intermediate layer forming step)
(C) Step of forming a protective layer on the intermediate layer (protective layer forming step)
(D) Step of forming a resist layer in a predetermined region by photolithography (resist layer forming step)
(E) The process of removing the protective layer, intermediate | middle layer, and organic compound layer which are provided in the area | region which is not covered with the resist layer by dry etching (process of organic compound layer)
(F) Step of removing the layer formed on the organic compound layer (intermediate layer removal step)

The step (B) (intermediate layer forming step) is a step including the following (B1) to (B2).
(B1) A step of applying a solution containing a water-soluble material onto the organic compound layer to form a coating film (application step)
(B2) Step of drying the coating film (formed in step (B1)) (drying step)

FIG. 3 is a schematic cross-sectional view illustrating an example of a manufacturing process of the organic EL display device of FIG. FIG. 3 is also a schematic cross-sectional view showing an example of an embodiment in the method for manufacturing an organic EL display device of the present invention. When manufacturing the organic EL display device of FIG. 2, for example, the organic EL display device is manufactured by the following steps.
(1) First electrode formation step (FIG. 3A)
(2) Organic compound layer formation step (FIG. 3B)
(3) Intermediate layer forming step (FIG. 3C)
(4) Step of forming protective layer (FIG. 3 (d))
(5) Resist layer forming step (FIG. 3E)
(6) Exposure process (FIG. 3 (f))
(7) Processing step of organic compound layer (FIG. 3 (g))
(8) Step of removing intermediate layer and protective layer (FIG. 3 (l))
(9) Electron injection / transport layer formation process (FIG. 3 (m))
(10) Second electrode formation step (FIG. 3 (n))

  However, the steps (1) to (10) are merely specific examples, and the present invention is not limited to this mode. Note that the organic EL display device 1 of FIG. 2 needs to produce three types of sub-pixels 20a, 20b, and 20c having different emission colors. Therefore, after the process (1) is performed, Before performing the steps, it is necessary to perform the steps (2) to (7) three times in total. For example, the organic compound layer 22a included in the first subpixel 20a is formed in the steps (2) to (7) (FIG. 3G). Then, after the organic compound layer 22b included in the second subpixel 20b is formed in the steps (2) to (7) (FIG. 3 (h) to FIG. 3 (i)), it is included in the third subpixel 20c. The organic compound layer 22c is formed by the steps (2) to (7) (FIGS. 3 (j) to 3 (k)).

  Next, the steps (1) to (10) will be specifically described.

(Formation process of the first electrode)
First, the first electrodes 21a, 21b, and 21c are formed on the substrate 10. The substrate 10 is not particularly limited as long as it can stably manufacture and drive an organic EL device. For example, an insulating substrate such as glass or Si wafer is preferably used. In the present invention, the substrate 10 includes a base material, a transistor (not shown) as a switching element formed on the surface of the base material using a known method, and a device necessary for causing the organic EL element to emit light. (Not shown). When the substrate 10 is constituted by these constituent members, a combination of the transistor and the device provided on the base material is two-dimensionally arranged as one pixel constituent element. The first electrode (21a, 21b, 21c) and the second electrode 24 are electrically connected to the combination of the transistor and the device, that is, the transistor circuit. When the transistor circuit is provided on the base material as described above, a planarization layer may be provided on the transistor circuit as necessary for the purpose of planarizing unevenness caused by the provision of the transistor circuit. Good.

  The first electrodes 21a, 21b, and 21c are electrode layers made of a known electrode material, and the constituent materials are appropriately selected according to the light extraction direction. When a top emission type organic EL display device is manufactured, the first electrodes 21a, 21b, and 21c are used as reflective electrodes, and the second electrode 25 described later is used as a light transmissive electrode. On the other hand, when a bottom emission type organic EL display device is manufactured, the first electrodes 21a, 21b, and 21c are light-transmissive electrodes, and the second electrode 24 is a reflective electrode.

  When the first electrodes 21a, 21b, and 21c are formed as the reflecting electrodes, the constituent materials of the first electrodes 21a, 21b, and 21c are preferably metal materials such as Cr, Al, Ag, Au, and Pt. Among these metal materials, a material having a high reflectance is more preferable because the light extraction efficiency can be further improved. The reflective electrode is formed for each sub-pixel by forming a thin film of the above metal material in a film thickness range of 50 nm to 300 nm by a known method such as sputtering and processing it into a desired shape using photolithography or the like. Formed separately. Note that a layer made of an oxide conductor having optical transparency such as indium tin oxide or indium zinc oxide is provided on a thin film made of these metal materials for the purpose of protecting the thin film or adjusting the work function. May be further provided. Further, when forming the first electrodes 21a, 21b, and 21c, vapor deposition using a metal mask may be used. Even when vapor deposition using a metal mask is performed, the first electrodes 21a, 21b, and 21c are formed separately for each sub-pixel.

  When the first electrodes 21a, 21b, and 21c are formed as light transmissive electrodes, the constituent materials of the first electrodes 21a, 21b, and 21c are light transmissive oxides such as indium tin oxide and indium zinc oxide. A conductor is mentioned. The light transmissive electrode is formed, for example, by forming a thin film made of the above oxide conductor in a thickness of 10 nm to 100 nm by a known method such as sputtering and processing it into a desired shape using photolithography or the like. Each subpixel is formed separately.

(Formation process of organic compound layer)
The organic compound layer 22 (22a, 22b, 22c) is a constituent member of the organic EL display device, and is a single layer or a laminated body including a plurality of layers including at least a light emitting layer. Examples of the layer other than the light emitting layer included in the organic compound layer 22 include a hole injection layer, a hole transport layer, an electron block layer, a hole block layer, an electron transport layer, and an electron injection layer. However, the present invention is not limited to these. Here, the layer adjacent to the light emitting layer may be a charge transport layer (hole transport layer, electron transport layer) or a charge block layer (electron block layer, hole block layer).

  As a constituent material of the organic compound layer 22 (22a, 22b, 22c), a known light-emitting material or a known charge injection / transport material can be used. Moreover, as a formation method of the organic compound layer 22, well-known methods, such as a vacuum evaporation method, are employable.

(Interlayer deposition process)
The processing method of the organic compound layer 22 (22a, 22b, 22c) will be described below. First, as shown in FIG. 3C, the intermediate layer 30 is formed on the formed first organic compound layer 22a (first-color organic compound layer). By the way, as the constituent material for the organic compound layer 22 (22a, 22b, 22c), for example, a material that hardly dissolves in water such as an arylamine derivative, a stilbene derivative, a polyarylene, or a condensed polycyclic hydrocarbon compound can be used. Thus, when the constituent material of the first organic compound layer 22a is a material that hardly dissolves in water, a material that dissolves in water (water-soluble material) can be suitably used as the constituent material of the intermediate layer 30. Examples of the water-soluble material that can be a constituent material of the intermediate layer 30 include polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyvinyl caprolactam (PVCAP), polyethylene glycol (PEG), polystyrene sulfonic acid, and polyacrylamide 2-methylpropane sulfone. Water-soluble polymers such as acid and vinyl pyrrolidone copolymers are listed.

  As a method for forming the intermediate layer 30, a coating method such as a spin coating method, a dip method, or a slit coating method can be used, but the present invention is not limited to these. Further, the gas atmosphere when forming the intermediate layer 30 may be the air or an inert gas atmosphere described later, and is not particularly limited.

(Intermediate layer drying process)
After coating the coating film to be the intermediate layer 30, the coating film is dried to remove the solvent in the coating film. As a specific method for removing the solvent in the coating film by drying the coating film, preferably, a reduced pressure method (a method of removing the solvent in the coated film in a reduced pressure atmosphere) or a heating method (heating the coating film) And a method of evaporating the solvent in the coating film). When using the heating method, it is preferable to heat at atmospheric pressure rather than heating in a reduced pressure atmosphere. When the coating film to be the intermediate layer 30 is heated under atmospheric pressure, bumping of the solvent contained in the coating film can be relaxed, and generation of bubbles in the intermediate layer 30 can be suppressed. However, if the heating method is employed, the characteristics of the organic EL device due to heat may be deteriorated. Therefore, when the heating method is employed, the glass transition point ( It is preferable to set the treatment temperature so as not to exceed T _g ). When the boiling point of the solvent contained in the coating film to be the intermediate layer 30 is lower than the glass transition point (T _g ) of each constituent material of the organic compound layer 22 and the intermediate layer 30, the treatment temperature is set near the boiling point of the solvent. It is preferable to set to. In particular, since rapid heating may cause bumping of the solvent, the upper limit of the heating temperature is appropriately set in a range not exceeding 20 ° C. higher than the boiling point of the solvent contained in the coating film serving as the intermediate layer 30. It is preferable. For example, when the solvent contained in the coating film to be the intermediate layer 30 is water, when the boiling point of water is lower than T _g of each constituent material of the organic compound layer 22, the heating temperature is set to 120 ° C. or lower. The intermediate layer 30 is dried. When the boiling point of the solvent is higher than the T _g of each constituent material of the organic compound layer 22, is the solvent dried at atmospheric pressure at a treatment temperature of 20 ° C. or lower than the T _g of each constituent material of the organic compound layer 22? The decompression method may be used. Further, the pressure may be reduced while heating at a treatment temperature of 20 ° C. or lower than the T _g of each constituent material of the organic compound layer 22 and can be selected as appropriate. When the pressure reduction method is selected here, it is preferable to reduce the pressure gently because sudden pressure reduction may cause bumping. For example, the pressure is preferably reduced from atmospheric pressure to 1 × 10 ⁻² Pa over 30 minutes.

  In the present invention, the step of drying the intermediate layer 30 is performed in an inert gas atmosphere, that is, in an environment filled with an inert gas. Here, the inert gas means a gas that does not react with the constituent material of the organic compound layer 22, and is preferably a nitrogen gas or a rare gas such as argon or helium. In view of cost, nitrogen gas and argon gas are particularly preferable. Further, the inert gas used in this step (intermediate layer drying step) preferably has a dew point of −70 ° C. or lower, and particularly preferably a dew point of −80 ° C. or lower. For this reason, in the step of drying the intermediate layer 30, the environment (inert gas atmosphere) in which the intermediate layer 30 is placed is also preferably a dew point of −70 ° C. or less, particularly preferably a dew point of −80 ° C. or less. is there. The concentration of oxygen gas contained in the inert gas used in this step and in the environment (inert gas atmosphere) where the intermediate layer 30 is placed is preferably 5 ppm or less.

  As described above, in the present invention, the step of drying the intermediate layer 30 is performed in an inert gas atmosphere. However, the intermediate layer 30 may be preliminarily dried before performing this step (intermediate layer drying step). Here, when the intermediate layer 30 is preliminarily dried, it is not necessarily performed in an inert gas atmosphere, and may be performed in the air. However, when the intermediate layer 30 is preliminarily dried in the air. Is preferably performed in a time equivalent to or shorter than this step (intermediate layer drying step).

  The drying process of the intermediate layer 30 is performed in a chamber, for example. The chamber used in this step (intermediate layer drying step) is not particularly limited, but a chamber capable of setting a pressure (particularly, a reduced pressure setting) or introducing an inert gas, a glove box, or the like is preferably used. Can do. In particular, the glove box is preferable because of its good operability.

In the present invention, when the protective layer 40 forming step described later is performed, it is necessary to perform it in a dry atmosphere, for example, in the inert gas atmosphere described above. However, instead of this dry atmosphere, it may be performed under vacuum (at a degree of vacuum that can be formed using a CVD method or a sputtering method, for example, under a pressure condition lower than 1 × 10 ⁻³ Pa). Therefore, the chamber used is preferably an apparatus in which a chamber used in the drying process of the intermediate layer 30 and a chamber used when forming the protective layer 40 are connected. This apparatus is an apparatus that enables a substrate to be transported in a low-humidity / low-oxygen concentration environment or a vacuum environment at a connection portion between two chambers. Moreover, this apparatus is an apparatus which can perform the process of drying the intermediate | middle layer 30 and the formation process of the protective layer 40 in the environment isolated from external air. For this reason, it is possible to prevent moisture contained in the atmosphere from entering the intermediate layer 30 until the protective layer 40 is formed after the intermediate layer 30 is dried.

(Protective layer formation process)
Next, the protective layer 40 is formed on the intermediate layer 30. The protective layer 40 is formed on the entire substrate surface on which the intermediate layer 30 is formed. Specifically, the protective layer 40 is formed so as to cover the entire intermediate layer 30 formed on the substrate 10. The constituent material of the protective layer 40 is not particularly limited as long as it is a material that does not dissolve in at least the solvent contained in the resist material, the resist layer developer, and water. Examples thereof include inorganic materials such as silicon nitride, silicon oxide, amorphous silicon, alumina, and Al.

  When forming the protective layer 40, it is necessary to select a manufacturing method in which the intermediate layer 30 immediately below does not change or dissolve. For example, it is preferable to form by a dry process such as a sputtering method or a CVD method because the intermediate layer 30 hardly changes or dissolves. As described above, it is particularly preferable to use an apparatus in which the chamber used in the step of drying the intermediate layer 30 and the chamber used when forming the protective layer 40 are connected.

(Resist layer formation process)
Next, a resist layer 50 is formed on the protective layer 40. In the case of forming a resist layer using a coating method, specific methods include spin coating, dipping, and slit coating, but are not particularly limited. At this time, since the intermediate layer 30 and the organic compound layer 22 (22a, 22b, 22c) are all covered with the protective layer 40, they may be affected by the solvent contained in the resist material forming the resist layer 50. Absent. When forming the resist layer 50 using the coating method, it is necessary to remove (pre-bake) the solvent contained in the coating film by heat treatment or reduced pressure treatment after the coating film is formed.

(Exposure process, development process)
The coated / formed resist layer 50 is processed into a predetermined shape through an exposure process and a development process. Here, the exposure step is a step of irradiating the resist layer 50 with light 61 using a photomask 60 having an opening in a predetermined region. By this exposure step, the resist layer 50 can be divided into a region 51 where the light 61 is not irradiated and a region 52 where the light 61 is irradiated. The developing process is a process of selectively removing the resist layer in the region 51 where the light 61 is not irradiated or the region 52 where the light 61 is irradiated using the developer after performing the exposure step. . At this time, since the intermediate layer 30 and the organic compound layer 22 (22a, 22b, 22c) are covered with the protective layer 40, they are not affected by the developer. Since the resist material used as the constituent material of the resist layer in the process shown in FIG. 3 is a positive resist material, the resist layer provided in the region 52 irradiated with the light 61 is selected. Removed. When the development process is completed, a resist layer 50 having a pattern shape corresponding to the region 51 where the light 61 is not irradiated is provided on the protective layer 40. After the development process is completed, the substrate 10 is heated and post-baked.

(Processing of organic compound layer)
Next, the protective layer 40, the intermediate layer 30, and the organic compound layer (first organic compound layer 22a) are sequentially processed using the resist layer 50 having a predetermined patterning shape as a mask. As a method of processing the protective layer 40, the intermediate layer 30, and the organic compound layer (first organic compound layer 22a), for example, partial removal of a target layer using etching is used. Here, the etching used in this step is preferably dry etching. In addition, when performing this process, you may remove suitably the resist layer 50 which has a predetermined pattern shape utilized as a mask.

(Intermediate layer and protective layer removal step)
After repeating the steps from the organic compound layer forming step to the organic compound layer processing step for the number of types of organic EL elements, the intermediate layer 30 and the protective layer 40 are removed. Examples of a method for removing these two layers include, but are not limited to, a method in which the protective layer 40 is removed by dry etching and then the intermediate layer 30 is dissolved and removed. As another method, the intermediate layer 30 and the protective layer 40 can be collectively removed using a lift-off method by washing with water.

(Electron injection / transport layer formation process)
After removing the intermediate layer 30 and the protective layer 40 as described above, the electron injection / transport layer 23 is formed on the organic compound layer 22 (22a, 22b, 22c). The electron injection / transport layer 23 is preferably formed as a layer common to the sub-pixels as shown in FIG. The electron injecting material that is a constituent material of the electron injecting layer preferably has a high work function. For example, alkali metals, alkaline earth metals, alkali metal compounds (oxides, carbonates, halide salts), alkali metal compounds (oxides, carbonates, halide salts), alkali metals or alkali metal compounds as electron transport materials And the like doped with. Here, specific examples of the alkali metal include cesium, potassium, and lithium. Specific examples of the alkaline earth metal include calcium and barium. The electron injection / transport layer 23 is formed by a vacuum deposition method or the like.

(Second electrode formation process, etc.)
When producing a top emission type organic EL display device, the second electrode 24 corresponding to the upper electrode is a transparent electrode made of a transparent conductive material. The transparent conductive material having light transmittance is preferably a material having high light transmittance. Examples thereof include transparent conductive materials such as indium tin oxide, indium zinc oxide, and zinc oxide, and organic conductive materials such as polyacetylene. A semi-transmissive film in which a metal material such as Ag or Al is formed to a thickness of about 10 nm to 30 nm may be used as the second electrode 24. Here, when forming a light transmissive electrode using a transparent conductive material, for the purpose of reducing power consumption, the low resistance characteristic necessary for use as an electrode and the high transmittance necessary for increasing the light extraction efficiency are used. A composition that satisfies both the rate characteristics is preferable. The thin film that becomes the light transmissive electrode can be formed by a known method such as sputtering. In the case of producing a transparent conductive film having both the above-described low resistance characteristics and high transmittance characteristics, it is necessary to appropriately adjust the capacity of the film formation apparatus, the target, the pressure in the apparatus, and the output voltage during film formation. The second electrode 24 can be formed using a known technique such as sputtering. Further, as shown in FIG. 3 (n), the second electrode 24 may be formed as a layer common to each sub-pixel, but is preferably formed selectively in a desired region by masking or the like.

  Incidentally, since the organic EL device is deteriorated by moisture, it is preferable to provide a sealing structure (not shown) for preventing moisture from entering on the second electrode 24. Examples of the sealing structure include a film sealing configuration in which a highly moisture-proof film such as a silicon nitride film or a silicon oxide film is provided as a single layer or a stacked layer. Moreover, it replaces with this film | membrane sealing structure, well-known cap sealing structure etc. which fix the circumference | surroundings of this sealing substrate to the board | substrate 10 using an adhesive agent or glass frit using sealing substrates with high moisture resistance, such as glass. The configuration can also be adopted.

  In accordance with the manufacturing process shown in FIG. 3, the organic EL device shown in FIG. 2 was produced.

(1) First electrode formation step (FIG. 3A)
First, Al was deposited on a glass substrate (substrate 10) having a thin film transistor circuit (not shown) to form an Al layer. At this time, the thickness of the Al layer was set to 100 nm. Next, an indium tin oxide film was formed on the Al layer to form an ITO layer. At this time, the thickness of the ITO layer was 40 nm. Next, the laminated electrode film composed of the Al layer and the ITO layer is patterned by a photolithography method to form first electrodes (21a, 21b, 21c) having a predetermined pattern shape (FIG. 3). (A)). Here, the formed first electrodes (21a, 21b, 21c) had a rectangular shape with a width of 0.6 μm and a length of 1.8 μm, and the interval between the adjacent first electrodes was 0.6 μm. Next, a silicon nitride film was formed on the first electrodes (21a, 21b, 21c) and the substrate 10 to form a SiN film. At this time, the thickness of the SiN film was set to 1.5 μm. Next, patterning is performed by photolithography, so that openings are provided in regions where the first electrodes (21a, 21b, 21c) are provided, and each first electrode is partitioned in units of pixels (20a, 20b, 20c). An inter-pixel separation film (not shown) was formed.

(2) Step of forming the first organic compound layer (FIG. 3B)
Next, a first organic compound formed by depositing a hole injection layer, a hole transport layer, and a blue light emitting layer in this order on the first electrode (21a, 21b, 21c) by vacuum deposition. A layer 22a was formed (FIG. 3B). A known low-molecular organic material that emits blue light was used as the light-emitting material contained in the blue light-emitting layer.

(3) Intermediate layer forming step (FIG. 3C)
Next, a polyvinyl pyrrolidone aqueous solution was applied on the first organic compound layer 22a, and a PVP film was formed by spin coating. Next, the substrate 10 on which the PVP film was formed was transported into a glove box connected to a protective layer forming CVD chamber and filled and circulated with nitrogen as an inert gas. Next, the substrate 10 was heated at 110 ° C. for 20 minutes to dry the PVP film, thereby obtaining an intermediate layer 30 (FIG. 3C). Here, the film thickness of the intermediate layer 30 after drying was 1.5 μm. Next, the substrate 10 was transferred from the glove box to the CVD chamber for forming the protective layer. The substrate 10 was transported in an inert gas atmosphere so that the substrate 10 was not exposed to the atmosphere.

(4) Step of forming protective layer (FIG. 3 (d))
Next, after evacuating the inside of the CVD chamber, a silicon nitride film was formed on the entire surface of the substrate on which the intermediate layer 30 was formed by the CVD method to form the protective layer 40 (FIG. 3D). ). At this time, the thickness of the protective layer 40 was 1 μm.

(5) Resist layer forming step (FIG. 3E)
Next, a positive resist was formed on the protective layer 40 by spin coating, and then the resist film 50 was formed by heating and drying the formed resist film (FIG. 3E).

(6) Exposure process, development process (FIG. 3 (f))
Next, the resist layer 50 was irradiated with light 61 using a Cr photomask 60 having an opening in a region other than the first sub-pixel 20a (FIG. 3F). Next, development with an alkaline developer and rinsing with pure water were sequentially performed to selectively remove the resist layer in the exposed region 52. Next, the substrate 10 was post-baked.

(7) Processing step of organic compound layer (FIG. 3 (g))
Next, using the patterned photoresist layer (resist layer provided in the region 51) as a mask, the protective layer 40, the intermediate layer 30, the first organic compound layer 22a, by dry etching using an RIE apparatus, Were processed (patterned) in this order. Note that when etching the protective layer 40, dry etching using CF ₄ gas was employed, and when etching the intermediate layer 30 and the first organic compound layer 22a, dry etching using O ₂ gas was employed. . Note that when this step was completed, the resist layer provided in the region 51 had disappeared (FIG. 3G).

(8) Formation / processing of second organic compound layer (FIGS. 3 (h) to (i))
Next, the process described in the above (2) to (4) was adopted to form a laminate including the second organic compound layer 22b, the intermediate layer 30, and the protective layer 40. The second organic compound layer 22b included a green light emitting layer having a known low molecular weight organic material that emits green light instead of the blue light emitting layer. Next, using the processes described in the above (5) to (6), a resist layer is selectively provided in the region 51 on the protective layer 40 where the second subpixel 20b is provided (FIG. 3 ( h)). Next, the protective layer 40, the intermediate layer 30, and the second organic compound layer 22b were processed (patterned) in this order by employing the process described in (7) above (FIG. 3 (i)). ).

(9) Formation / processing of third organic compound layer (FIGS. 3 (j) to (k))
Next, using the processes described in (2) to (4) above, a laminate including the third organic compound layer 22c, the intermediate layer 30, and the protective layer 40 was formed. The third organic compound layer 22b included a red light emitting layer having a known low molecular organic material that emits red light instead of the blue light emitting layer. Next, by adopting the processes described in the above (5) to (6), a resist layer is selectively provided in the region 51 on the protective layer 40 where the third subpixel 20c is provided (FIG. 3 ( j)). Next, employing the process described in (7) above, the protective layer 40, the intermediate layer 30, and the third organic compound layer 22c were processed (patterned) in this order (FIG. 3 (k)). ).

(10) Step of removing intermediate layer and release layer (FIG. 3 (l))
Next, by immersing the substrate 10 in running water for 3 minutes, the intermediate layer 30 and the protective layer 40 on the organic compound layers (22a, 22b, 22c) remaining on the substrate 10 were removed at once (FIG. 3 (l)). )).

(11) Electron injection / transport layer formation process (FIG. 3 (m))
Next, after sufficiently dehydrating the substrate 10 from which the intermediate layer 30 and the protective layer 40 have been removed, an electron transport layer and an electron injection layer are formed on the organic compound layers (22a, 22b, 22c) by vacuum deposition. An electron injection / transport layer 23 was formed (FIG. 3M). The electron injection / transport layer 23 was formed as a common layer common to the sub-pixels (20a, 20b, 20c).

(12) Second electrode formation step (FIG. 3 (n))
Next, Ag was deposited on the electron injecting / transporting layer 23 by sputtering to form a second electrode 24 common to the pixels (20a, 20b, 20c) (FIG. 3 (n)).

(13) Sealing process Finally, a silicon nitride film having a thickness of 2 μm was formed on the second electrode 24 to form a sealing film (not shown) for preventing moisture penetration. Thus, an organic EL device was obtained.

(14) Evaluation of the device When the obtained organic EL device was observed with a microscope for the light emission state of the device itself, there was no display failure such as non-light emission, and a set of sub-pixels emitting light in blue, green and red colors was obtained. It was possible to realize an organic EL device in which one pixel was used and the pixels were arranged with a high definition with a pitch of 1.2 μm. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

[Comparative Example 1]
In Example 1 (3), except that the PVP film (intermediate layer) was dried and transported to the apparatus for forming the protective layer of the substrate after the PVP film was formed in the atmosphere. An organic EL device was obtained in the same manner as in Example 1. Hereinafter, a specific method of drying the PVP film (intermediate layer) and transporting the substrate after forming the PVP film to an apparatus for forming a protective layer will be described.

(PVP membrane drying step (intermediate layer forming step)))
After forming the PVP film, the PVP film formed on the substrate 10 was heated in the atmosphere at 110 ° C. for 20 minutes to dry the PVP film. Next, the substrate 10 was transferred in the atmosphere into the protective layer forming CVD chamber, specifically, the load lock chamber of the CVD chamber. Next, after evacuation was performed in the load lock chamber, the substrate 10 was transferred into the CVD chamber.

  Regarding the obtained organic EL device, the light emission state of the device itself was observed with a microscope, and several display defects such as non-light emission were confirmed.

  In Example 3 (3), nitrogen, which is an inert gas, was flowed, and was the same as Example 1 except that the PVP film was dried in a bake chamber maintained in an inert gas atmosphere. Thus, an organic EL device was obtained.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  In Example 1 (3), argon, which is an inert gas, was flowed, and was the same as Example 1 except that the PVP film was dried in a bake chamber maintained in an inert gas atmosphere. Thus, an organic EL device was obtained.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  In Example 1 (3), except that the PVP membrane was dried in a glove box filled and circulated with an inert gas nitrogen and maintained at -70 ° C. and an oxygen concentration of 5 ppm in the system. Thus, an organic EL device was obtained by the same method as in Example 1.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  In Example 1 (3), an inert gas argon is filled and circulated, the dew point in the system is −70 ° C., and the oxygen concentration in the system is maintained at 5 ppm. Was dried. Except for this, an organic EL device was obtained in the same manner as in Example 1.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  In Example 1 (3), except that the PVP membrane was dried in a glove box that was filled and circulated with inert gas nitrogen and the dew point in the system was maintained at -80 ° C. An organic EL device was obtained in the same manner as in Example 1.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  In Example 1 (3), a PVP membrane was filled in a glove box in which nitrogen, which is an inert gas, was charged and circulated, the dew point in the system was −80 ° C., and the oxygen concentration in the system was maintained at 5 ppm. Was dried. Except for this, an organic EL device was obtained in the same manner as in Example 1.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  In Example 1 (3), a PVP membrane was filled in a glove box in which nitrogen as an inert gas was charged and circulated, the dew point in the system was −80 ° C., and the oxygen concentration in the system was maintained at 1 ppm. Was dried. Except for this, an organic EL device was obtained in the same manner as in Example 1.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  In Example 1 (3), the PVP membrane was dried by the method described below. Except for this, an organic EL device was obtained in the same manner as in Example 1.

(PVP membrane drying step (intermediate layer forming step)))
After forming the PVP film, the substrate 10 was transported to a bake chamber connected to a CVD chamber for forming a protective layer and capable of setting a reduced pressure and introducing an inert gas. Next, after the pressure in the baking chamber was gradually reduced from atmospheric pressure to 1 × 10 ⁻² Pa over 30 minutes, this pressure (1 × 10 ⁻² Pa) was maintained for 10 minutes. Next, the pressure in the baking chamber was reduced to 1 × 10 ⁻³ Pa. Next, nitrogen, which is an inert gas, was introduced into the bake chamber to bring the pressure in the bake chamber to atmospheric pressure. Next, the substrate 10 on which the PVP film was formed in the bake chamber was heated at 110 ° C. for 20 minutes. Next, in order to form a protective layer, the pressure in the baking chamber and the CVD chamber was reduced to 1 × 10 ⁻⁴ Pa, and then the substrate 10 was transferred to the CVD chamber.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  In Example 1 (3), the PVP membrane was dried by the method described below. Except for this, an organic EL device was obtained in the same manner as in Example 1.

(PVP membrane drying step (intermediate layer forming step)))
After forming the PVP film, the PVP film formed on the substrate 10 was heated in the atmosphere at 110 ° C. for 10 minutes to perform preliminary drying of the PVP film. Next, the substrate 10 was transferred into a glove box filled and circulated with an inert gas nitrogen, a dew point in the system of −70 ° C., and an oxygen concentration in the system maintained at 5 ppm. Next, the PVP film was heated and dried at 110 ° C. for 10 minutes in the glove box. Note that the glove box used in this example was connected to a CVD chamber for forming a protective layer.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  In Example 1 (3), the PVP membrane was dried by the method described below. Except for this, an organic EL device was obtained in the same manner as in Example 1.

(PVP membrane drying step (intermediate layer forming step)))
After forming the PVP film, the PVP film formed on the substrate 10 was heated in the atmosphere at 110 ° C. for 10 minutes to perform preliminary drying of the PVP film. Next, the substrate 10 was transferred into a glove box filled and circulated with an inert gas nitrogen, a dew point in the system of −75 ° C., and an oxygen concentration in the system maintained at 2 ppm. Next, the PVP film was heated and dried at 110 ° C. for 10 minutes in the glove box. Next, the substrate 10 was sealed in a sealed container in the glove box. Note that the dew point and oxygen concentration in the sealed container are the same as the dew point and oxygen concentration in the glove box. Next, this sealed container is connected to a CVD chamber for forming a protective layer and filled and circulated with nitrogen as an inert gas so that the dew point in the system is −80 ° C. and the oxygen concentration in the system is It was conveyed in a glove box maintained at 1 ppm. Next, after taking out the substrate 10 from the sealed container in the transfer destination glove box, the substrate 10 was transferred into the protective layer forming CVD chamber.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  An organic EL device was obtained in the same manner as in Example 1 except that polyethylene glycol (PEG) was used instead of PVP as the constituent material of the intermediate layer 30 in (3) of Example 1.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  An organic EL device was fabricated in the same manner as in Example 1 except that in Example 1 (4), silicon oxide was deposited on the intermediate layer 30 to form the protective layer 40.

  With respect to the obtained organic EL device, when the light emission state of the device itself was observed with a microscope, display defects such as non-light emission could not be confirmed. Moreover, the element efficiency was equivalent to the element produced only by the vacuum evaporation method using an evaporation mask.

  1: organic EL device, 10: substrate, 20a: first subpixel, 20b: second subpixel, 20c: third subpixel, 21 (21a, 21b, 21c): first electrode, 22 (22a, 22b, 22c): organic compound layer, 23: electron injection / transport layer, 24: second electrode, 30: intermediate layer, 40: protective layer, 50 (51, 52): resist layer, 60: mask, 61: light

Claims (8)

A plurality of organic EL elements having at least a light emitting layer are arranged,
An organic EL device manufacturing method in which the light emitting layer is patterned in a predetermined shape,
Forming an organic compound layer having at least a light emitting layer on a substrate;
Forming an intermediate layer on the organic compound layer;
Forming a protective layer covering the intermediate layer;
Forming a resist layer in a predetermined region by photolithography;
Removing a protective layer, an intermediate layer and an organic compound layer provided in a region not covered with the resist layer by dry etching;
Removing a layer formed on the organic compound layer remaining on the substrate,
The step of forming the intermediate layer comprises a step of applying a solution containing a water-soluble material on the organic compound layer to form a coating film, and a step of drying the coating film,
A method for manufacturing an organic EL device, wherein the steps from drying the coating film to forming the protective layer are performed in an inert gas atmosphere.   2. The method for producing an organic EL according to claim 1, wherein the inert gas atmosphere is a gas atmosphere having a dew point of −70 ° C. or less and a concentration of oxygen gas contained of 5 ppm or less.   The method for manufacturing an organic EL device according to claim 1, wherein the inert gas is nitrogen or a rare gas.   The method of manufacturing an organic EL device according to claim 1, wherein the step of drying the coating film is performed under an atmospheric pressure or a reduced pressure atmosphere.   The said protective layer is comprised with the inorganic material which does not melt | dissolve in any of the solvent contained in the resist material which forms the said resist layer, the developing solution of the said resist layer, and water. The manufacturing method of the organic electroluminescent apparatus as described in any one.   6. The method of manufacturing an organic EL device according to claim 5, wherein the inorganic material is silicon nitride, silicon oxide, amorphous silicon, alumina, or Al.   The method for manufacturing an organic EL device according to claim 1, wherein the step of forming the protective layer includes a vacuuming step for forming the protective layer.   An organic EL device manufactured by the method for manufacturing an organic EL device according to claim 1.

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