KR20060057970A - Organic electro luminescence display and methode for manufacturing the same - Google Patents

Abstract

The present invention relates to an organic light emitting display device and a method of manufacturing the same, wherein any one of the source / drain electrodes is formed through a thin film transistor including a gate electrode and a source / drain electrode on a substrate, and via holes formed in an insulating layer on the substrate. A pixel electrode having a triple structure connected to one and having a stacked structure of a lower pixel electrode, a reflective electrode and an upper pixel electrode, an organic layer provided on the upper pixel electrode and having at least a light emitting layer, and on the organic layer In an organic light emitting display device including an opposing electrode provided, a reflective electrode is formed between Ag and Sg, Tb, Au, and Cu by using Ag alloy material containing Ag between the lower pixel electrode and the upper pixel electrode. Resistance and high efficiency characteristics can be imparted.

Reflective electrode material, Ag alloy,

Description

Organic electroluminescent display and method for manufacturing the same {Organic electro luminescence display and methode for manufacturing the same}

1A is a cross-sectional view of an organic electroluminescent display formed by the prior art.

1B is a cross-sectional view of an organic light emitting display device formed by another conventional technique.

2 is a cross-sectional view of an organic light emitting display device according to the present invention;

3 is a graph showing reflection characteristics according to the types of reflective electrodes;

<Description of Symbols for Main Parts of Drawing>

100, 200: substrate 110, 210: buffer film

120, 220 source / drain regions 122, 222 polysilicon pattern

130, 230: gate insulating film 132, 232: gate electrode

140, 240: interlayer insulating film 150, 250: source electrode

152, 252: drain electrodes 160, 260: protective film

170 and 270: first insulating films 180a, 180b and 282: reflective electrodes

182: pixel electrode 280a: lower pixel electrode

280b: upper pixel electrode 190, 290: second insulating film pattern

192, 292: organic film layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display device, and more specifically, Ag, which contains Sm, Tb, Au, and Cu in Ag, is used as a reflecting film of the first electrode. The present invention relates to an organic light emitting display device having efficiency characteristics and a method of manufacturing the same.

In general, organic electroluminescent displays (OLEDs) in flat panel displays have a wider operating temperature range than other flat panel displays, are more resistant to shock and vibration, have a wider viewing angle, and a higher response speed. As it has the advantage of providing fast moving images, it is attracting attention as the next generation flat panel display device.

Such an organic light emitting display device may be classified into a passive matrix type requiring a separate driving source according to a driving method and an active matrix type having integrally a thin film transistor functioning as a switching element. .

Since the active matrix type organic light emitting display device is indirectly driven by a thin film transistor, which is a switching element, the voltages supplied to the pixels can be completely independent of each other and be continuous, and thus have many advantages such as high resolution, high image quality, and large area. Have

In addition, the organic light emitting display device may further include a bottom emission structure that emits light emitted from the light emitting layer in a downward direction of the substrate and a top emission structure that emits upward of the substrate. It can be divided into branches.

1A is a cross-sectional view illustrating an organic light emitting display device formed by the prior art.

First, a buffer film 110 having a predetermined thickness is formed on the substrate 100, and a thin film transistor including a polysilicon pattern 122, a gate electrode 132, and source / drain electrodes 150 and 152 is formed. . In this case, source / drain regions 120 in which impurities are ion-implanted on both sides of the polysilicon pattern 122 are provided, and a gate insulating layer 130 is provided on the entire surface including the polysilicon pattern 122.

Next, a passivation layer 160 having a predetermined thickness is formed on the entire surface, and the passivation layer 160 is etched by a photolithography process, and any one of the source / drain electrodes 150 and 152, for example, a drain electrode ( A first via hole (not shown) exposing 152 is formed. The protective film 160 may be formed of silicon nitride, silicon oxide, or a stacked structure thereof as an inorganic insulating film.

Next, a first insulating layer 170 is formed on the entire surface. The first insulating layer 170 may be formed of one material selected from the group consisting of polyimide, benzocyclobutene series resin, spin on glass, and acrylate. It may be formed for the planarization of the pixel area.

Subsequently, the first insulating layer 170 is etched by a photolithography process to form a second via hole (not shown) that exposes the first via hole.

Next, a stacked structure of a reflective electrode (not shown) and a pixel electrode thin film (not shown) are formed over the entire surface. In this case, the reflective electrode is formed using one of metals having high reflectance such as aluminum (Al) or an alloy of these metals. When the reflective electrode is formed as described above, a top emission type organic EL device is formed, and when the reflective film is formed in a subsequent process, a bottom emission type organic EL device is formed.

The pixel electrode thin film is formed using a transparent metal material such as indium tin oxide (ITO).

Subsequently, the stacked structure is etched to form the pixel electrode 182 and the reflective electrode 180a.

Thereafter, a second insulating film pattern 190 defining a light emitting area is formed on the entire surface. The second insulating layer pattern 190 is a material selected from the group consisting of polyimide, benzocyclobutene series resin, phenol resin, and acrylate. Can be formed.

Subsequently, at least an organic layer 192 including an emission layer and an opposite electrode (not shown) are formed to complete the organic light emitting display device.

In the above-described top emission type organic light emitting display device, when the reflective electrode and the pixel electrode are formed in a stacked structure, a galvanic phenomenon in which the electromotive material of the stacked structure is corroded is simultaneously exposed to the electrolyte solution used in the photolithography process. This causes damage to the pixel electrode, which causes a problem of deteriorating optical characteristics such as lowering of luminance.

FIG. 1B is a cross-sectional view of an organic light emitting display device formed by another conventional technology, and illustrates a reflection electrode 180b having an island structure to solve the above problem. This prevents the reflective electrode 180b and the pixel electrode 182 from being simultaneously exposed to the electrolyte solution used for photolithography.

As described above, in the case of forming the reflective electrode using aluminum, the pixel electrode and the reflective electrode have to be patterned separately. In addition, since the top emission type organic light emitting display device uses a resonance effect of light, it is important to form the pixel electrode as thin as possible to facilitate color coordinate adjustment. However, when the thickness of the pixel electrode is made thin, a short circuit may occur in the stepped via hole.

The present invention has been made to solve the above problems, and an object of the present invention is to contain a small amount of Sm, Tb, Au, and Cu material of a pixel electrode having a stacked structure of a lower pixel electrode, a reflective electrode, and an upper pixel electrode. The present invention provides an organic light emitting display device having improved efficiency by forming an electrode having high adhesion, high reflectivity, and low resistance by using Ag alloy.

In order to achieve the above object, a thin film transistor including a gate electrode and a source / drain electrode on the substrate;

A pixel electrode having a triple structure connected to any one of the source / drain electrodes through a via hole formed in the insulating film on the substrate, and having a lower pixel electrode, a reflective electrode and an upper pixel electrode;

An organic layer provided on the upper pixel electrode and having at least a light emitting layer;

It includes a counter electrode provided on the organic film layer,

The insulating film is a laminated structure of a protective film and a planarization film;

The insulating film is a laminated structure of an inorganic insulating film and an organic insulating film,

The thickness of the lower pixel electrode is 10 to 300Å,

The reflective electrode using Ag alloy material,

The thickness of the reflective electrode is 600 to 1200Å,

The thickness of the upper pixel electrode is 10 to 300Å,

The counter electrode may be a transparent electrode.

At this time, the organic electroluminescence of the Ag alloy material is composed of Sm of 0.1 to 0.3 atomic%, Tb of 0.1 to 0.5 atomic%, Au of 0.1 to 0.4 atomic% and Cu of 0.4 to 1.0 atomic% Provide a display device.

In addition, the manufacturing method for achieving the above object,

Forming a thin film transistor including a gate electrode and a source / drain electrode on the substrate;

Forming an insulating film over the entire surface;

Etching the insulating film to form a via hole exposing any one of the source / drain electrodes;

Forming a stacked structure of a lower pixel electrode thin film, a reflective film, and an upper pixel electrode thin film on an entire surface thereof;

Etching the stacked structure to form a triplet pixel electrode having a lower pixel electrode, a reflective electrode and an upper pixel electrode connected to any one of the source / drain electrodes through the via hole;

Forming an organic layer including at least an emission layer on the upper pixel electrode;

Forming a counter electrode on the organic layer;

The insulating film is formed of a laminated structure of a protective film and a planarization film,

The insulating film is formed of a laminated structure of an inorganic insulating film and an organic insulating film,

The via hole is formed by two photolithography processes,

The lower pixel electrode is formed to a thickness of 10 to 300Å,

The reflective electrode is formed of an Ag alloy material,

The reflective electrode is formed to a thickness of 600 to 1200Å,

The upper pixel electrode has a thickness of 10 to 300 10,

The counter electrode may be formed of a transparent electrode.

At this time, the organic electroluminescence of the Ag alloy material is composed of Sm of 0.1 to 0.3 atomic%, Tb of 0.1 to 0.5 atomic%, Au of 0.1 to 0.4 atomic% and Cu of 0.4 to 1.0 atomic% A method of manufacturing a display device is provided.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a cross-sectional view of an organic light emitting display device according to an exemplary embodiment of the present invention, wherein a lower pixel electrode 280a, a reflective electrode 282 formed of an Ag alloy material, and an upper pixel electrode 280b are formed on an upper surface of a substrate 200. The pixel electrode of the structure is provided.

The organic light emitting display device according to the present invention is formed by the following method.

First, a buffer film 210 having a predetermined thickness is formed by plasma-enhanced chemical vapor deposition (PECVD) of silicon oxide on the entire surface of the substrate 200 made of glass, quartz, plastic, and metal. . In this case, the buffer layer 210 may or may not be formed to prevent diffusion of impurities in the substrate 200 during the crystallization process of the amorphous silicon layer formed in a subsequent process.

Next, an amorphous silicon layer (not shown) having a predetermined thickness is deposited on the buffer layer 210, and the amorphous silicon layer is deposited using Excimer Laser Annealing (ELA), Sequential Lateral Solidification (SLS), Metal Induced Crystallization (MIC), or the like. The polycrystalline silicon pattern 222 is formed in the thin film transistor region in the unit pixel by crystallization and patterning by using a MILC (Metal Induced Lateral Crystallization) method. The region of the polycrystalline silicon pattern 222 may include source / drain regions 220 formed in a subsequent process.

Next, a gate insulating film 230 of a predetermined thickness is formed on the entire surface. The gate insulating layer 230 may be formed of silicon oxide, silicon nitride, or a stacked structure thereof.

A metal film (not shown) used as a gate electrode material is formed on the gate insulating film 230. Subsequently, the metal film is etched to form a gate electrode 232. Thereafter, impurities are ion-implanted into the polysilicon patterns 222 on both sides of the gate electrode 232 to form the source / drain regions 220.

Next, an interlayer insulating film 240 of a predetermined thickness is formed on the entire surface. In general, a silicon nitride film is used as the interlayer insulating film 240.

Next, the interlayer insulating film 240 and the gate insulating film 230 are etched to form contact holes (not shown) that expose the source / drain regions 220. An electrode material is formed on the entire surface including the contact hole, and the source / drain electrodes 250 and 252 connected to the source / drain regions 220 are formed by etching the electrode material through a photolithography process. In this case, as the electrode material, molybdenum tungsten (MoW), aluminum-neodymium (Al-Nd) or Ti and Ag alloys may be used, and a multilayer structure composed of several layers may be used.

Thereafter, a silicon nitride film, a silicon oxide film, or a stacked structure thereof is deposited on the entire surface to form a protective film 260.

Subsequently, the passivation layer 260 is etched to form a first via hole (not shown) that exposes one of the source / drain electrodes 250 and 252, for example, the drain electrode 252.

The first insulating layer 270 is formed on the entire surface. The first insulating layer 270 is formed to a thickness such that the thin film transistor region can be completely flattened, and is made of polyimide, benzocyclobutene series resin, spin on glass, and acrylate. It may be formed of one material selected from the group consisting of (acrylate).

Next, the first insulating layer 270 is etched to form a second via hole (not shown) that exposes one of the source / drain electrodes 250 and 252 through the first via hole.

Then, a thin film for lower pixel electrode (not shown) is formed on the entire surface. The lower pixel electrode thin film is formed to a thickness of 10 to 300 kW using a metal electrode having a transmissive property, such as indium tin oxide (ITO), IZO, In ₂ O ₃ or Sn ₂ O ₃ , preferably 30 to 300 It is formed to a thickness of 130Å. The lower pixel electrode thin film is formed to improve an interface property, that is, adhesion between the reflective electrode and the first insulating layer 270 formed in a subsequent process.

Next, a reflective electrode thin film (not shown) is formed on the lower pixel electrode thin film. At this time, the reflective electrode is formed to increase the brightness and light efficiency by acting as a light reflection. According to the present invention, the thin film for the reflective electrode is made of Ag alloy composed of Sm of 0.1 to 0.3 atomic% in Ag, Tb of 0.1 to 0.5, Au of 0.1 to 0.4 atomic% and Cu of 0.4 to 1.0 atomic%. To form. At this time, the reflective electrode thin film is formed to a thickness of 600 to 1200 Å, preferably to a thickness of 800 to 1000 Å.

Next, an upper pixel electrode thin film (not shown) is formed on the reflective electrode thin film. The thin film for the upper pixel electrode is formed to a thickness of 10 to 300Å, preferably to a thickness of 30 to 130Å to facilitate color coordinate adjustment.

Next, the stacked structure of the upper pixel electrode thin film, the reflective electrode thin film, and the lower pixel electrode thin film is etched to form a triple structure including an upper pixel electrode 280b, a reflective electrode 282, and a lower pixel electrode 280a. A pixel electrode is formed. In this case, a portion of the lower pixel electrode 280a is connected to one of the source / drain electrodes 250 and 252, for example, the drain electrode 252, through the second via hole. The galvanic phenomenon does not occur even when the pixel electrode thin film and the reflective electrode are simultaneously exposed to the electrolyte solution used in the etching process.

Next, a second insulating film (not shown) is formed over the entire surface.

Thereafter, the second insulating film is etched to form a second insulating film pattern 290 defining a light emitting area.

Subsequently, the emission layer 292 is formed in the emission region exposed by the second insulating layer pattern 290. The organic layer 292 is formed by a low molecular weight deposition method or a laser thermal transfer method. The organic layer 292 may be formed of a thin film including at least one light emitting layer and at least one of an electron injection layer, an electron transport layer, a hole injection layer, a hole transport layer, a hole suppression layer and the like.

Although not shown in the drawings, a counter electrode is formed on the organic layer to complete the organic light emitting device. In this case, the counter electrode is formed of a transparent electrode.

3 is a graph showing reflectivity according to the type of reflective electrode, in which only 1000 NAlNd is used as the reflective electrode material (X), and a laminated structure in which ITO is formed on the AlNd upper surface is used as the reflective electrode material (Y And Ag alloy composed of Sm having a composition of 0.3 atomic%, Tb having a composition of 0.1 atomic% and Au, 0.4 having a composition of 0.4 atomic% and Cu having a composition of 0.4 to 1.0 atomic% (Z) Reflectance according to the wavelength of light. Here, when the Ag electrode composed of Sm of 0.1 to 0.3 atomic%, Tb of 0.1 to 0.5 atomic%, Au of 0.1 to 0.4 atomic% and Cu of 0.4 to 1.0 atomic% is used as the reflective electrode material ( As shown in the graph in Z), the reflectance is increased by about 10% compared to the case of using AlNd as a reflective material (X) and the case of forming ITO on AlNd and a reflective material (Y).

As described above, an Ag alloy composed of Sm of 0.1 to 0.3 atomic%, Tb of 0.1 to 0.5 atomic%, Au of 0.1 to 0.4 atomic% and Cu of 0.4 to 1.0 atomic% is used for the reflection electrode. When used as a material, the efficiency can be increased by about 20% compared to the Al or Al alloy material used as a reflective electrode of an organic light emitting display device, and the adhesion, chemical stability, low resistance and thermal stability can be increased. It is possible to implement an organic light emitting display device having a.                     

It is to be understood that the techniques of the present invention described above may be variously modified and changed by those skilled in the art without departing from the spirit and scope of the invention as set forth in the claims below. There will be.

Claims (23)

A thin film transistor including a gate electrode and a source / drain electrode on the substrate; A triplet pixel electrode connected to any one of the source / drain electrodes through a via hole formed in the insulating film on the substrate, and having a reflective electrode formed of a lower pixel electrode and an Ag alloy film and an upper pixel electrode; An organic layer provided on the upper pixel electrode and having at least a light emitting layer; And an opposing electrode disposed on the organic layer. The method of claim 1, The Ag alloy film has an organic electroluminescent display device comprising Sm of 0.1 to 0.3 atomic%, Tb of 0.1 to 0.5 atomic%, Au of 0.1 to 0.4 atomic% and Cu of 0.4 to 1.0 atomic%. The method of claim 1, And a lower pixel electrode having a thickness of about 10 to about 300 microns. The method of claim 1, The organic light emitting display device of which the reflective electrode has a thickness of 600 to 1200 Å. The method of claim 1, And an upper pixel electrode having a thickness of about 10 to about 300 microns. The method of claim 1, And the insulating layer has a stacked structure of a protective layer and a planarization layer. The method of claim 1, And the insulating layer has a stacked structure of an inorganic insulating layer and an organic insulating layer. The method of claim 1, And the counter electrode is a transparent electrode. The method of claim 3, wherein An organic light emitting display device having a thickness of the lower pixel electrode of about 30 to about 130 microns. The method of claim 4, wherein The organic light emitting display device of which the thickness of the reflective electrode is 800 to 1000Å. The method of claim 5, The organic light emitting display device of which the thickness of the upper pixel electrode is 30 to 130Å. Forming a thin film transistor including a gate electrode and a source / drain electrode on the substrate; Forming an insulating film over the entire surface; Etching the insulating film to form a via hole exposing any one of the source / drain electrodes; Forming a stacked structure of a lower pixel electrode thin film, a reflective electrode thin film made of Ag alloy, and an upper pixel electrode thin film on the entire surface; Etching the stacked structure to form a triplet pixel electrode having a lower pixel electrode, a reflective electrode and an upper pixel electrode connected to any one of the source / drain electrodes through the via hole; Forming an organic layer including at least an emission layer on the upper pixel electrode; And forming a counter electrode on the organic layer. The method of claim 12, Fabrication of an organic electroluminescent display device comprising Sm of 0.1 to 0.3 atomic%, Tb of 0.1 to 0.5 atomic%, Au of 0.1 to 0.4 atomic% and Cu of 0.4 to 1.0 atomic% Way. The method of claim 12, The lower pixel electrode is formed to have a thickness of 10 to 300Å. The method of claim 12, And the reflective electrode is formed to a thickness of 600 to 1200 GHz. The method of claim 12, And the upper pixel electrode is formed to have a thickness of about 10 to about 300 micrometers. The method of claim 12, And the insulating layer is formed by stacking a protective layer and a planarization layer. The method of claim 12, And the insulating layer is formed by stacking an inorganic insulating layer and an organic insulating layer. The method of claim 12, The via hole is formed by two photolithography processes. The method of claim 12, The counter electrode is a method of manufacturing an organic light emitting display device, characterized in that formed as a transparent electrode. The method of claim 14, And a thickness of the lower pixel electrode is about 30 to about 130 micrometers. The method of claim 15, And a thickness of the reflective electrode is 800 to 1000 mW. The method of claim 16, The thickness of the upper pixel electrode is a manufacturing method of an organic light emitting display device, characterized in that formed in 30 to 130Å.

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