JP2003272858A - Organic el display device and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a covering property at succeeding process by controlling the unevenness of the processing of a rib-pattern, namely, uneven shape of the rib-pattern edge and a rib taper, caused by the difference of reflectivity of a semiconductor substrate, generated when forming a rib film at a photo process. <P>SOLUTION: The reflectivity of the surface of the substrate is made uniform by using a reflection preventing film. The reflection preventing film is patterned and formed into a rib layer of the double layer structure together with a photosensitive organic film to be formed at the succeeding process. By the above, the process of forming the photosensitive organic film to be turned into a rib layer is stabilized, and a short circuit between upper and lower electrodes generated when forming the organic EL layer of the upper layer, and defective coverage of the upper layer film are prevented, and the reliability of the organic EL element is improved. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate having a rib layer made of an organic film on the surface and an organic EL device using the substrate.
The present invention relates to a display device and a manufacturing method thereof.

[0002]

2. Description of the Related Art A conventional method will be described below by taking as an example a method of manufacturing an organic EL display device.

A semiconductor substrate which is an organic EL display device is
In general, an electrode wiring layer 2 serving as a gate, a silicon semiconductor layer 3, an electrode wiring layer 4 serving as a source / drain, and a pixel electrode layer 5 are laminated on an insulating transparent substrate 1 such as glass or plastic through an insulating layer 6. It is a TFT substrate (Fig. 3). The gate and the source / drain electrodes are generally made of a low resistance metal material, and the pixel electrode is made of ITO (Indium Tin Oxide).
xide), which is composed of an indium-based conductive oxide film. A hole injecting electrode layer 8 and an electron injecting electrode layer 9 are formed on the TFT substrate via the organic thin film 7, and a desiccant 10 is enclosed and sealed (FIG. 4).

The manufacturing method of the organic thin film 7 differs depending on the light emitting material. For low molecular weight systems, vacuum deposition is mainly studied, and for high molecular weight systems, inkjet methods and printing methods are being studied. In each manufacturing method, a separate film is formed for each color. In the case of the vacuum vapor deposition method, mask vapor deposition is performed for the color separation, but in order to prevent damage to the substrate due to contact between the mask and the substrate at that time, it is exposed on the substrate on which each electrode pattern is arranged before the vapor deposition process. The rib layer 11 made of a volatile organic material is formed into a film through a photo process. In the case of the inkjet method,
Color shift occurs during application.

[0005]

The substrate which is the base material of the TFT substrate is made of a transparent material such as glass or plastic, and the patterned electrode material region and the transparent material region coexist. The surface has a difference in reflectivity between the electrode region and its peripheral region. Therefore, when forming a rib film, unevenness in rib pattern processing caused by a difference in reflectivity from a semiconductor substrate in a photo process, that is, a rib pattern edge (see FIG.
It is necessary to improve the coverage in the next step by controlling (a)) and the unevenness of the rib taper shape (FIG. 5 (b)). As shown in FIG. 6, processing unevenness of the rib pattern causes a short circuit defect 12 between upper and lower electrodes (FIG. 6A) and a coverage defect of the upper layer film (FIGS. 6B and 6C). Then, the depletion layer 13 due to poor coverage in FIG. 6C causes poor reliability due to gas accumulation, local stress, and the like.

[0006]

The semiconductor substrate of the present invention comprises:
In order to stabilize the processing of the photosensitive organic film that becomes the rib layer, an antireflection film is used to make the reflectance of the substrate surface uniform. The antireflection film is patterned together with a photosensitive organic film formed in the next step to form a rib layer having a two-layer structure. Specifically, the first invention is characterized in that the rib layer provided on the substrate has a two-layer structure.
The invention of 1 is characterized in that the rib layer has a two-layer structure of a thermally crosslinkable organic film and a photosensitive organic film. This has the following effects. That is, in the pattern film formation on the substrate, in forming a rib layer for preventing damage to the substrate at the contact between the mask and the substrate, a thermally crosslinkable organic film (antireflection film) that absorbs ultraviolet rays should be formed on the substrate. Is used to control the reflectivity from the substrate surface and improve the workability of the rib layer. It also has the effect of preventing color shift during coating in the case of the inkjet method.

A third invention is an organic EL display device characterized by comprising an organic EL element having at least an organic light emitting layer between a pair of electrodes on the substrate of the first or second invention.

A fourth aspect of the invention is characterized in that a rib film made of a thermally crosslinkable organic film and a photosensitive organic film is provided on a semiconductor substrate having a flattening film for smoothing unevenness caused by metal wiring or the like. Is an organic EL display device. This has the following effects. That is, the electron injection electrode, the organic thin film, and the hole injection electrode can be stacked with good coverage on the rib layer whose workability is improved by controlling the reflectance from the substrate surface.

In the fifth and sixth inventions, the photosensitive organic film is a positive type, and the thermally crosslinkable organic film and the photosensitive organic film are two.
It is characterized in that it is heat-cured at 00 to 250 ° C., and when the photosensitive organic film is exposed and developed, the thermally crosslinkable organic film under the exposed photosensitive organic film is removed, and two layers are formed in the unexposed area. The heat-crosslinkable organic film that becomes a rib layer is cured by the heat treatment,
Stabilize the film quality.

The seventh and eighth inventions are characterized by a method of manufacturing a substrate or an organic EL display device formed by forming the two-layer rib layer of the first to sixth inventions. As a result, the unevenness of the substrate and the difference in the reflectivity caused by the coexistence of substances having different substrate constituent materials are uniformly controlled by the thermally crosslinkable organic film, so that the rib layer can be stably processed.

The ninth and tenth inventions are a method of manufacturing a substrate and an organic EL display device, which is characterized in that the pre-baking temperature of the thermally crosslinkable organic film is set higher than the pre-baking temperature of the photoresist formed in the next step. . This has the effect of suppressing the side etch processability of the antireflection film forming the two-layer rib layer.

An eleventh aspect of the invention is that a pattern edge portion of a photosensitive organic film is provided on a substrate having a surface unevenness caused by laminating a pattern layer such as an electrode material and an interlayer insulating layer, at a position not covered by the uneven portion. With the structure provided, the pattern edge portion of the photosensitive organic film is on the same kind of underlying film. As a result, the photosensitive organic film pattern edge has a stable shape, and has an effect of obtaining good and stable coverage in a thin film covering the photosensitive organic pattern layer.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) A first embodiment of the present invention will be described by taking a schematic manufacturing flow of a semiconductor substrate as an example (see FIGS. 1A to 1D).

SiNx as an undercoat film on the substrate
And SiOx and O _3: a step of forming a film made of TEOS or the like, a step of patterning the crystalline silicon layer serving as the semiconductor layer, a step of the gate electrode patterning, the gate electrode is any height Up to the step of removing the gate electrode and the soft material, leaving the soft material on the side wall of the gate electrode, injecting arbitrary impurities from their surface, and forming an interlayer insulating film,
A semiconductor substrate including at least a step of forming a contact window and a step of patterning the source / drain electrodes and the pixel electrodes respectively has an uneven surface on the substrate (see FIG. 3). A high reflection area (electrode wiring layer) 2 on the electrode pattern and other low reflection areas coexist, and for example, SiOx, SiNx, AlOx, TiO.
Since the interlayer insulating film formed of the x film absorbs light, the reflectivity is low. In the present invention, the coating thickness of the antireflection film (heat-crosslinkable organic film) is adjusted on such a substrate 1 in accordance with the degree of reflection of the substrate surface. Then, an antireflection film 14 (ARC-XLX manufactured by Nissan Kagaku Co., Ltd.) is applied to the surface of the substrate and annealed at about 110 to 130 ° C. if necessary (FIG. 1).
(A)). Next, the photosensitive organic film 15 to be the main rib layer
For example, manufactured by Toray (Polyimide resin DL-100
0), a product of JSR (acrylic resin PC403), a product of Nippon Zeon (novolag resin WIX-2), or the like, which is a positive organic resin which is a photosensitive organic material. Next, after performing pre-baking at about 110 to 130 ° C. to form a pattern of the resin, ultraviolet rays 17 are applied to unnecessary areas through the mask 16 (FIG. 1B). At this time, since the thermally crosslinkable organic film (antireflection film) is applied on the substrate and the ultraviolet light absorbs the light reflected in the high reflection region on the substrate, the influence of uneven reflection of the substrate can be prevented. afterwards,
The resin in the ultraviolet irradiation area is removed with a developing solution. At this time, since the antireflection film 14 is exposed (FIG. 1C), the antireflection film 14 is also removed by etching with the developer. In this way, the rib layer 11 composed of two layers of the antireflection film 14 and the photosensitive organic film 15 is formed. Next, 200-250
It has an effect of stabilizing the film quality of the rib layer 11 composed of the two layers by performing annealing within the temperature range of ℃. After that, the anode, the hole injection electrode layer 8, the organic light emitting layer (organic thin film)
7. An organic EL element having an electron injection electrode layer 9 is formed with good coverage (FIG. 1 (d)). Depending on the case, a hole transport layer and a hole injection layer may be provided between the hole injection electrode layer (anode) and the organic light emitting layer, and the organic light emitting layer and the electron injection electrode layer (cathode) may be combined. An electron transport layer and an electron injection layer may be provided between them.

(Second Embodiment) The second embodiment is based on the first embodiment.
In the rib layer-formed substrate according to the above embodiment, after the antireflection material is applied to the substrate surface, annealing is performed, for example, at 120 to 200 ° C. (FIG. 1A). Next, as a photosensitive organic film which becomes a main rib layer, for example, Toray (polyimide resin DL-1000), JSR (acrylic resin PC403) or Nippon Zeon (novolag resin WIX) is used.
-2) or the like is applied with a positive type resin which is a photosensitive organic material (FIG. 1B). Next, pre-baking is performed at about 110 to 130 ° C. to form a pattern of the resin, and then unnecessary regions are irradiated with ultraviolet rays through a mask (FIG. 1).
(C)). Then, the resin in the ultraviolet irradiation region is removed with a developing solution. At this time, the antireflection film is exposed (see FIG. 1).
Since (d)), this antireflection film is also removed by etching with the developer. Unlike the first embodiment, by treating the annealing temperature of the antireflection film at a temperature higher than the prebaking temperature of the photosensitive resin of the second layer, the etching property of the photosensitive resin and the antireflection film in the developing process is improved. Is provided to prevent a defective processed shape due to side etching. In this way, a rib layer composed of two layers of the antireflection film and the photosensitive organic film is formed (FIG. 1E). Next, 200-25
Annealing is performed within 0 ° C. to stabilize the film quality of the rib layer composed of the two layers.

(Third Embodiment) The third embodiment is the first embodiment.
And an organic EL display device using the substrate on which the rib layer described in the second embodiment is formed.

A semiconductor substrate having irregularities on the surface, or
A rib film composed of two layers of the antireflection film and the photosensitive organic film described in the first and second embodiments is formed on a semiconductor substrate in which unevenness caused by metal wiring or the like is smoothed in advance with a flattening film. Then, after that, an electron injection electrode, an organic thin film, and a hole injection electrode are respectively configured to obtain an organic EL display device.

On the rib layer thus obtained by controlling the substrate surface, electron-injecting electrodes made of a thin film, organic thin films, and hole injecting electrodes are mask-deposited by a vacuum evaporation method. The coverage is good, and it has an effect of preventing defects such as short circuit between electrodes.

(Embodiment 4) In the conventional rib opening, in order to secure a large electrode exposed area, the rib pattern edge is arranged at a position straddling various wirings of the underlying substrate (FIG. 5A). In the case of the fifth embodiment, not only the workability of the rib pattern edge depending on the degree of reflection of the base substrate but also the arrangement condition in which the base substrate and the rib layer are in contact with each other is constant (FIG. 2). As a result, the adhesiveness is stabilized and a depletion layer is not formed, so that there is an effect of preventing defects such as short-circuiting between electrodes between the organic EL element layers.

[0021]

According to the present invention, it is possible to stabilize the processing of the photosensitive organic film which becomes the rib layer on the surface of the substrate having different light reflectivity, and to prevent a short circuit between the upper and lower electrodes or the upper layer film in the formation of the upper organic EL element layer. Prevent poor coverage. Then, an organic EL display device with improved reliability is provided.

[Brief description of drawings]

FIG. 1 is a schematic manufacturing flow and configuration diagram of the present invention.

FIG. 2 is a layout diagram of a pixel portion pattern of the present invention

FIG. 3 is a sectional configuration diagram of a conventional TFT substrate.

FIG. 4 is a schematic configuration diagram of a conventional organic EL display device.

FIG. 5A is a conventional pixel portion pattern layout diagram. (B) Conventional rib layer cross-sectional shape diagram for each pixel unit configuration

FIG. 6 is a diagram showing a conventional rib layer shape and coverage defect of an upper layer film.

[Explanation of symbols]

1 substrate 2-electrode wiring layer (gate electrode) 3 Silicon semiconductor layer 4 electrode wiring layer (source / drain electrode) 5 Pixel electrode layer 6 insulating layers 7 Organic light emitting layer (organic thin film) 8 Hole injection electrode layer 9 Electron injection electrode layer 10 desiccant 11 Rib layer 12 Short circuit failure 13 depletion layer 14 Antireflection film 15 Photosensitive organic film 16 masks 17 UV

Claims (10)

[Claims] 1. A substrate comprising a rib layer having at least a first organic film and a second organic film in this order on the substrate. 2. The first organic film is a thermally crosslinkable organic film,
The substrate according to claim 1, wherein the second organic film is a photosensitive organic film. 3. An organic EL display device comprising the substrate according to claim 1 or 2 and an organic EL display having at least an organic light emitting layer between a pair of electrodes. 4. An organic EL display device, wherein the thermally crosslinkable organic film absorbs ultraviolet rays. 5. The substrate according to claim 2, wherein the photosensitive organic film is a positive type, and the thermally crosslinkable film and the photosensitive organic film are thermally cured at 200 to 250 ° C. 6. The photosensitive organic film is a positive type, and the thermally crosslinkable organic film and the photosensitive organic film are heat-cured at 200 to 250 ° C. The organic EL display device described in 1. 7. A step of forming a thermally crosslinkable organic film on a surface of a substrate, a step of patterning a photosensitive organic film, and a step of removing the thermally crosslinkable organic film opened and exposed in the photosensitive organic film pattern. The method for manufacturing a substrate according to claim 2, further comprising: and a step of heat-treating the thermally crosslinkable organic film and the photosensitive organic film, which are patterned in the step. 8. A step of forming a thermally crosslinkable organic film on a surface of a substrate, a step of patterning a photosensitive organic film, and a step of removing the thermally crosslinkable organic film opened and exposed in the photosensitive organic film pattern. A step of heat-treating the thermally crosslinkable organic film and the photosensitive organic film patterned by the above steps, a step of forming an electron injection electrode, a step of forming an organic thin film layer, and a hole injection electrode. The organic E according to claim 3 or 4, which comprises at least steps.
Manufacturing method of L display device. 9. The substrate is made of a transparent material such as glass or plastic, and on the surface where the patterned electrode material region and the transparent material region coexist, insulation of the electrode material patterned on the substrate and its periphery is provided. The transparent material coexists with a surface area having different reflectance, and the pre-bake temperature of the heat-crosslinkable organic film which is the first organic film used to make the reflectance of the substrate surface uniform, in the next step. The method for manufacturing a substrate according to claim 7, wherein the temperature is higher than the pre-bake temperature of the second organic film to be formed. 10. The substrate is made of a transparent material such as glass or plastic, and in the surface where the patterned electrode material region and the transparent material region coexist, the substrate is patterned electrode material and its surrounding insulation. The transparent material coexists with a surface area having different reflectance, and the pre-bake temperature of the heat-crosslinkable organic film which is the first organic film used to make the reflectance of the substrate surface uniform, in the next step. 9. The method for manufacturing an organic EL display device according to claim 8, wherein the temperature is higher than the pre-bake temperature of the second organic film to be formed.