KR20070005397A - Flat panel display and method for fabricating the same - Google Patents

Abstract

A flat panel display and a fabrication method thereof are provided to simplify a process by forming a gate insulation film comprising an aperture confining a pixel by using an ink jet method. A source/drain electrode(121,125), a pixel electrode and a semiconductor layer(130) contacted with the source/drain electrode are formed on a substrate(110). An insulation film comprising an aperture defining a pixel electrode is formed by using an ink jet method. A gate is formed on the insulation film corresponding to the semiconductor layer. The insulation film acts as a gate insulation film and a pixel separation film confining the pixel electrode.

Description

Flat panel display and manufacturing method thereof {Flat panel display and method for fabricating the same}

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

2A to 2D are cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to an embodiment of the present invention;

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

4A to 4D are cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to another embodiment of the present invention;

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

6A through 6D are cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to another embodiment of the present invention;

7A to 7C are diagrams illustrating an example of an opening pattern of a gate insulating layer in an organic light emitting display device according to an embodiment of the present invention;

Explanation of symbols on the main parts of the drawings

100, 200, 300: organic light emitting display device

110, 210, 310: substrate 130, 230, 330: semiconductor layer

121, 125, 221, 225, 321, 325: source / drain electrodes

140, 240, 340: gate insulating film 145, 245, 345: opening

150, 250, 350: gate 160, 260, 360: lower electrode

170, 270, 370: organic layer 180, 280, 380: upper electrode

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display, and more particularly, to an organic light emitting display device in which a gate insulating film having an opening defining a pixel is formed by an inkjet method, and a manufacturing method thereof.

Organic thin film transistors are being actively researched as driving elements of next generation display devices. Organic thin film transistors (OTFTs) use organic films instead of silicon films as semiconductor layers. Depending on the materials of the organic films, low molecular weight organic materials such as oligothiophene, pentacene, and polythiophene may be used. It is classified into high molecular organic substance such as (polythiophene) series.

In general, a flexible organic light emitting display device uses a flexible substrate as a substrate, and the flexible substrate includes a plastic substrate. Since plastic substrates have very poor thermal stability, it is required to manufacture organic light emitting display devices using low temperature processes.

Accordingly, an organic thin film transistor using an organic film as a semiconductor layer is capable of a low temperature process, and thus has been in the spotlight as a switching element of a flexible organic light emitting display device.

In a conventional organic light emitting display device having an organic thin film transistor, a thin film transistor including a source / drain electrode, a semiconductor layer, and a gate is formed on a substrate, a protective film is formed on the thin film transistor, and a lower electrode is formed on the protective film. , An organic light emitting device including an organic layer and an upper electrode is formed.

A gate insulating film is formed between the source / drain electrodes and the gate of the thin film transistor. The lower electrode is connected to one of the source / drain electrodes of the thin film transistor through a via hole formed in the passivation layer. The pixel isolation layer has an opening that exposes a portion of the lower electrode, and an organic layer is formed on the bud electrode of the opening, and an upper electrode is formed thereon.

The conventional organic light emitting display device as described above has a back light emitting structure, a top light emitting structure, and a double light emitting structure according to a path from which light from an organic layer is emitted. In the bottom emission type organic light emitting display device, light emitted from the organic light emitting layer is emitted toward the substrate. In the top emission type organic light emitting display device, the light emitted from the organic light emitting layer is emitted to the opposite side of the substrate. In the display device, light is simultaneously emitted from the organic light emitting layer in a direction opposite to the substrate.

The organic light emitting display device as described above includes a process of forming a thin film transistor including a source / drain electrode, a semiconductor layer, and a gate, a process of forming a via hole through a mask process after forming a passivation layer, and a via hole on the passivation layer. Forming a lower electrode connected to the thin film transistor through a thin film transistor, depositing a pixel separation film on the lower electrode, and then forming an opening for exposing the pixel electrode through a mask process, and forming an organic layer and an upper electrode Since the process is included, there was a problem that the process is very complicated.

In addition, when the opening is formed in the pixel isolation layer through the photolithography process, a residue of the photoresist remains, which causes a pattern defect.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art as described above, and to provide a flat panel display device and a manufacturing method thereof which simplify the process by forming a gate insulating film having an opening defining a pixel by an inkjet method. There is this.

In order to achieve the above object, the present invention comprises the steps of forming a source / drain electrode and a pixel electrode on the substrate and a semiconductor layer in contact with the source / drain electrode; Forming an insulating film having an opening defining the pixel electrode by an inkjet method; A method of manufacturing a flat panel display device, the method comprising: forming a gate on an insulating layer corresponding to the semiconductor layer.

The manufacturing method of the flat panel display device of the present invention further includes the step of performing a plasma treatment on the substrate surface before forming the insulating film. In the plasma treatment step, the substrate surface corresponding to the opening is plasma-treated using Ar and O 2 plasma or the substrate surface except the opening is plasma-processed using fluorine-based plasma using CF4 or C3F8.

In example embodiments, the pixel electrode extends from one of the source / drain electrodes or is in electrical contact with one of the source / drain electrodes. The semiconductor layer includes an organic semiconductor material, and the source / drain electrodes are made of different materials.

One electrode of the source electrode / drain electrode comprises a transmissive electrode selected from ITO, IZO, ZnO and In 2 O 3 or Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr and compounds thereof And a reflective electrode having a laminated film of a reflective material selected from and a transparent conductive material selected from ITO, IZO, ZnO, and In 2 O 3. The other electrode of the source electrode / drain electrode includes an electrode material for matching the work function with the organic semiconductor layer selected from Au, Pd and Pt.

In example embodiments, the semiconductor layer may include an organic semiconductor material, and the source / drain electrodes and the pixel electrode may include different materials. The source electrode / drain electrode includes an electrode material for matching the work function with the semiconductor layer, selected from Au, Pd, and Pt, and the lower electrode includes a transmissive electrode selected from ITO, IZO, ZnO, and In 2 O 3. Or a reflection having a lamination film of a transparent material selected from ITO, IZO, ZnO and In 2 O 3 and a reflective material selected from Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, and compounds thereof. An electrode.

According to another embodiment, the pixel electrode may include a reflection film extending from one of the source / drain electrodes; A transparent electrode layer is formed to overlap with the reflective film. The semiconductor layer includes an organic semiconductor material, and the reflective film of the pixel electrode is made of the same material as one of the source / drain electrodes.

The reflective film includes a reflective material selected from Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, and compounds thereof, and the transparent electrode layer is transparent selected from ITO, IZO, ZnO, and In 2 O 3. It includes a conductive film.

The other electrode of the source electrode / drain electrode is an electrode material for matching the work function with the semiconductor layer, and includes a conductive material selected from Au, Pd, Pt, MoW oxide, and PEDOT.

The gate insulating layer 140 is PI / Al 2 O 3, polyimide, polyvinyl phenol (PVP, poly vinyl phenol), parylene, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polymethylmethacrylate (PMMA). The film is selected from the group containing). The gate insulating layer 140 is preferably formed on a surface-treated substrate to facilitate inkjet. The surface treatment is performed using a fluorine-based gas such as CF4 or C3F8 or by using an Ar or O2 plasma gas.

The present invention is a substrate; A source electrode and a drain electrode formed on the substrate; A semiconductor layer in contact with the source / drain electrode; A gate formed on the substrate; An insulating film formed between the source / drain electrode and the gate and having an opening; And a pixel electrode partially exposed by the opening of the insulating film, wherein the insulating film provides a flat panel display device formed by an inkjet method.

A flat panel display of the present invention includes a plurality of gate lines and data lines arranged to cross each other on a substrate; A plurality of pixel regions defined by the plurality of gate lines and data lines, each pixel region having a source / drain electrode, a semiconductor layer, and a gate; Pixel electrodes connected to the thin film transistors are arranged, and the openings of the insulating layer have a mesh shape to expose a portion of the pixel electrodes arranged in each pixel region or are arranged along a gate line among a plurality of pixel regions. And a line form exposing a portion of the pixel electrode or a line portion exposing a portion of the pixel electrode arranged along the data line.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a cross-sectional view of an organic light emitting display device according to an embodiment of the present invention. The organic light emitting display device 100 according to an embodiment of the present invention includes a plurality of pixels arranged in a matrix form on a substrate, and each pixel includes two thin film transistors, a switching thin film transistor, a driving thin film transistor, and a capacitor. An organic light emitting element is provided. 1 shows an organic light emitting diode and a driving thin film transistor for driving the organic light emitting diode.

Referring to FIG. 1, source / drain electrodes 121 and 125 are formed on a substrate 110, and a lower electrode 160 includes one electrode of the source / drain electrodes 121 and 125. For example, it extends from the drain electrode 125. The lower electrode 160 serves as a pixel electrode of each pixel. The semiconductor layer 130 is formed to contact the source / drain electrodes 121 and 125.

A gate insulating layer 140 is formed on the substrate, and a gate 150 is formed on the gate insulating layer 140. The gate insulating layer 140 has an opening 145 in a portion corresponding to the lower electrode 160 to serve as a pixel isolation layer to define the lower electrode 160.

The organic layer 170 is formed on the lower electrode 160 of the opening 145, and the upper electrode 180 is formed on the substrate. The organic layer 170 may include at least one organic layer selected from a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer and a hole suppression layer. In the exemplary embodiment of the present invention, the organic layer 170 is formed in the opening 145 of the insulating layer 140, but the present invention is not limited thereto, and the emission layer (not shown) of each pixel may include the opening ( 145 may be formed to be separated from the light emitting layers of neighboring pixels, and the charge transport layer, which is a common layer, may be formed on the entire surface of the substrate.

The substrate 110 may include a glass substrate, a plastic substrate, or a metal substrate. The metal substrate preferably includes SUS (steel use stainless). The plastic substrate is polyethersulphone (PES), polyacrylate (PAR, polyacrylate), polyetherimide (PEI, polyetherimide), polyethylene naphthalate (PEN, polyethyelenen napthalate), polyethylene terephthalate (PET, polyethyeleneterepthalate) , Polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose tri acetate (TAC), cellulose acetate propinonate (CAP) It includes a plastic film selected from the group consisting of.

The semiconductor layer 130 may include an organic semiconductor layer, and may include pentacene, tetracene, anthracene, naphthalene, alpha-6-thiophene, perylene, and the like. Derivatives, rubrene and derivatives thereof, coronene and derivatives thereof, perylene tetracarboxylic diimide and derivatives thereof, perylene tetracarboxylic dianhydride ) And derivatives thereof, polythiophene and derivatives thereof, polyparaperylenevinylene and derivatives thereof, polyfluorene and derivatives thereof, polythiophenevinylene and derivatives thereof, polyparaphenylene and derivatives thereof, polythiophene- Heterocyclic aromatic copolymers and derivatives thereof, oligoacenes and derivatives thereof of naphthalene, oligothiophenes and derivatives thereof of alpha-5-thiophene, phthalocyanines with or without metals and oils thereof Conductor, pyromellitic dianhydride and derivatives thereof, pyromellitic diimide and derivatives thereof, perylenetetracarboxylic dianhydride and derivatives thereof, naphthalene tetracarboxylic acid diimide and derivatives thereof, naphthalene tetracarboxylic acid Organic membranes selected from dianhydrides and derivatives thereof.

Meanwhile, the semiconductor layer 130 may include a silicon film such as an amorphous silicon film or a polycrystalline silicon film, and may include a source / drain region doped with a high concentration of impurities in a portion contacting the source / drain electrodes 121 and 125. It may also include.

The gate insulating layer 140 may be formed of PI / Al 2 O 3, polyimide, polyvinyl phenol (PVP, poly vinyl phenol), parylene, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), and poly methylmethacrylate (PMMA). The film is selected from the group containing). The gate insulating layer 140 is preferably formed on a surface-treated substrate to facilitate inkjet. The surface treatment is performed using a fluorine-based gas such as CF4 or C3F8 or by using an Ar or O2 plasma gas.

In the organic light emitting display device 100 according to an embodiment, the source electrode 121 and the drain electrode 125 are made of different materials. Since the source electrode 121 is important in contact resistance with the semiconductor layer 130, the source electrode 121 includes a material having a work function that matches the semiconductor layer 130. That is, the source electrode 121 includes an electrode material having a larger work function than the organic semiconductor layer 130 and includes a metal electrode material selected from Au, Pt, and Pd.

Meanwhile, since the portion of the drain electrode 125 exposed by the gate insulating layer 140 serves as the lower electrode 160, that is, the anode electrode, the drain electrode 125 preferably includes the lower electrode material.

For example, when the organic light emitting display device 100 has a bottom emission structure, the lower electrode 160 preferably includes a transmissive electrode. The lower electrode 160 preferably includes a transparent conductive film such as ITO, IZO, ZnO, or In 2 O 3. On the other hand, when having a top light emitting structure, the lower electrode 160 includes a reflective electrode, preferably, the lower electrode 160 includes a transparent conductive film, and a reflective film having excellent reflectance under the transparent conductive film. The transparent conductive film for the lower electrode 160 includes ITO, IZO, ZnO, or In 2 O 3, and the like, and the reflective film is Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a compound thereof. And the like.

The upper electrode 180 includes a reflective electrode when the back light emitting structure is formed, and includes Li, Ca, LiF / Ca, LiF / Al, Al, Mg, or a compound thereof. On the other hand, in the case of having a top light emitting structure, the upper electrode 180 includes a transmissive electrode, and has a stacked structure of a metal film and a transparent conductive film. The metal film for the upper electrode 180 may include Li, Ca, LiF / Ca, LiF / Al, Al, Mg, or a compound thereof, and the transparent conductive film may include ITO, IZO, ZnO, In2O3, or the like.

7A to 7C illustrate examples of patterns of the openings 145 of the gate insulating layer 140 in the organic light emitting display according to the exemplary embodiment of the present invention. In the organic light emitting display device 100 according to the present invention, a plurality of gate lines 101 and a plurality of data lines 103 are arranged on a substrate 110, and the plurality of gate lines 101 and a plurality of data lines are provided. A plurality of pixel regions 105 defined by 103 are provided.

In each pixel region 105, an organic light emitting diode including a pixel electrode as the lower electrode 160 as illustrated in FIG. 1, and a thin film transistor for driving the organic light emitting diode are arranged. In addition, a power line (not shown in the drawing) for supplying a power voltage is arranged, which may be arranged to cross the gate line 105 and be parallel to the data line.

7A through 7C schematically illustrate the pixel electrode 160 arranged in the gate line 101, the data line 103, and the pixel region 105. In the exemplary embodiment of the present invention, only one thin film transistor for driving the pixel electrode 160 in each pixel region 105 is illustrated.

Referring to FIG. 7A, the gate insulating layer 140 is formed on a substrate and has a mesh opening 145 exposing a portion of the pixel electrode 160 arranged in each pixel region 105.

Referring to FIG. 7B, the gate insulating layer 140 is formed on a substrate and is arranged in one direction among the pixel electrodes 160 arranged in the plurality of pixel regions 105, that is, the pixel electrodes arranged along the data line. It has a line opening 145 to expose a portion of the.

Referring to FIG. 7C, the gate insulating layer 140 is formed on a substrate and includes a pixel electrode arranged in one direction among the pixel electrodes 160 arranged in the plurality of pixel regions, that is, a part of the pixel electrode arranged along the gate line. It has a line-shaped opening 145 to expose.

2A to 2D are cross-sectional views illustrating a method of manufacturing an organic light emitting display device using an inkjet method according to an embodiment of the present invention.

Referring to FIG. 2A, the source electrode 121 and the drain electrode 125 are formed on the substrate 110, and the semiconductor layer 130 is formed to be in contact with the source electrode 121 and the drain electrode 125. . The substrate 110 uses a plastic substrate, a glass substrate, or a metal substrate. The semiconductor layer 130 includes an organic semiconductor layer. In addition, the semiconductor layer 130 may include a silicon film.

The source electrode 121 includes a material for reducing contact resistance with the semiconductor layer 130, for example, Au, Pd, or Pt. Since the drain electrode 125 is used as a lower electrode of the organic light emitting diode, the drain electrode 125 includes a transmissive electrode material or a reflective electrode material. For example, the drain electrode 125 includes ITO, IZO, ZnO, In2O3, or the like as a transmissive electrode, or Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or the like as a reflective electrode. Lamination films of reflective electrode materials such as these compounds and transparent conductive films such as ITO, IZO, ZnO, or In 2 O 3.

Referring to FIG. 2B, one of the source / drain electrodes 121 and 125, for example, a portion of the drain electrode 125 is surface treated. At this time, the surface treatment process makes the surface hydrophobic using fluorine-based plasma. At this time, the surface treatment process using a fluorine-based plasma uses a fluorine-based gas such as CF4 or C3F8.

Referring to FIG. 2C, a solution including an insulating material for a gate insulating film is discharged from an inkjet head (not shown) to form a gate insulating layer 140 on a substrate. In this case, the gate insulating layer 140 is not formed in the surface-treated portion of the drain electrode 125, and an opening 145 is formed to expose the drain electrode 125.

The gate insulating layer 140 has an opening 145 having a shape as shown in FIGS. 7A to 7C. A portion of the drain electrode 125 exposed to the opening 145 of the gate insulating layer 140 becomes the lower electrode 160 as an anode electrode. Accordingly, the gate insulating layer 140 also functions as a pixel defining layer defining the lower electrode 160 by the opening 145.

As another example, when the adhesion between the substrate surface and the ink is not good, that is, when the substrate surface is hydrophobic, the substrate except for the portion corresponding to the opening 145 exposing a portion of the drain electrode 125 is exposed. It is also possible to surface-treat the surface to form a gate insulating film 140 having an opening 145.

That is, a surface treatment process using Ar and O 2 plasma is performed on the entire surface of the substrate except for the surface of the drain electrode 125 corresponding to the opening 145, thereby improving the adhesion by modifying the surface of the substrate to be hydrophilic. Subsequently, when the ink including the gate insulating material is discharged to the surface of the substrate, the gate insulating layer 140 is coated only on the portion where the surface treatment is performed and the adhesion is improved. Therefore, the gate insulating layer 140 having the opening 145 in which the gate insulating layer 140 is not formed is formed on the surface of the drain electrode 125 which is not subjected to the plasma surface treatment.

The gate insulating layer 140 is PI / Al 2 O 3, polyimide, polyvinyl phenol (PVP, poly vinyl phenol), parylene, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polymethylmethacrylate (PMMA). The film is selected from the group containing).

Referring to FIG. 2D, a gate 150 is formed in a portion of the gate insulating layer 140 corresponding to the semiconductor layer 130. Subsequently, when the organic layer 170 and the upper electrode 180 are formed on the substrate, the organic light emitting display device 100 according to the exemplary embodiment as shown in FIG. 1 is manufactured.

3 is a cross-sectional view of an organic light emitting display device according to another embodiment of the present invention. According to another exemplary embodiment, an organic light emitting display device 200 includes a plurality of pixels arranged in a matrix form on a substrate, and each pixel includes two thin film transistors, a switching thin film transistor, a driving thin film transistor, and a capacitor. An organic light emitting element is provided. FIG. 3 shows only an organic light emitting diode and a driving thin film transistor for driving the organic light emitting diode.

Referring to FIG. 3, the source / drain electrodes 221 and 225 are formed on the substrate 210, and the lower electrode 260 is one of the source / drain electrodes 221 and 225. For example, it is formed on the substrate to be connected to the drain electrode 225. The lower electrode 360 serves as a pixel electrode of each pixel. The semiconductor layer 230 is formed to contact the source / drain electrodes 221 and 225.

A gate insulating layer 240 is formed on the substrate, and a gate 250 is formed on the gate insulating layer 240. The gate insulating layer 240 has an opening 245 in a portion corresponding to the lower electrode 260 to serve as a pixel isolation layer to define the lower electrode 260.

The organic layer 270 is formed on the lower electrode 260 of the opening 245, and the upper electrode 280 is formed on the substrate. The organic layer 270 may include at least one organic layer selected from a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a hole suppression layer.

As in the exemplary embodiment, the substrate 210 includes a glass substrate, a plastic substrate, or a metal substrate, and the semiconductor layer 230 includes an organic semiconductor film or a silicon film.

The gate insulating layer 240 includes an opening 245 for exposing the lower electrode 260. The opening 245 has a mesh or line structure as shown in FIGS. 7A to 7C.

The gate insulating layer 140 is PI / Al 2 O 3, polyimide, polyvinyl phenol (PVP, poly vinyl phenol), parylene, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polymethylmethacrylate (PMMA). The film is selected from the group containing). The gate insulating layer 140 is preferably formed on a surface-treated substrate to facilitate inkjet. The surface treatment is performed using a fluorine-based gas such as CF4 or C3F8 or by using an Ar or O2 plasma gas.

Since the source / drain electrodes 221 and 225 have important contact resistance with the semiconductor layer 230, the source / drain electrodes 221 and 225 include a material having a work function that matches the semiconductor layer 230. The source / drain electrodes 221 and 225 include an electrode material having a larger work function than the organic semiconductor layer 230 and include a metal electrode material selected from Au, Pt, and Pd.

The lower electrode 260 may include a transmissive electrode when the organic light emitting display device 200 has a bottom light emitting structure. The lower electrode 260 preferably includes a transparent conductive film such as ITO, IZO, ZnO, or In 2 O 3. On the other hand, when having a top light emitting structure, the lower electrode 260 includes a reflective electrode, preferably, the lower electrode 260 is provided with a transparent conductive film, and a reflective film having excellent reflectance under the transparent conductive film. The transparent conductive film for the lower electrode 260 includes ITO, IZO, ZnO, or In 2 O 3, and the like, and the reflective film is Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a compound thereof. And the like.

When the upper electrode 280 has a back light emitting structure, it includes a reflective electrode, and includes Li, Ca, LiF / Ca, LiF / Al, Al, Mg, or a compound thereof. On the other hand, in the case of having a top light emitting structure, the upper electrode 280 includes a transmissive electrode, and has a stacked structure of a metal film and a transparent conductive film. The metal film for the upper electrode 280 may include Li, Ca, LiF / Ca, LiF / Al, Al, Mg, or a compound thereof, and the transparent conductive film may include ITO, IZO, ZnO, or In 2 O 3.

4A through 4D are cross-sectional views illustrating a method of manufacturing an organic light emitting display device using an inkjet method according to another embodiment of the present invention.

Referring to FIG. 4A, a source electrode 221 and a drain electrode 225 are formed on the substrate 210, and one of the source / drain electrodes 221 and 225, for example, a drain electrode ( The semiconductor layer 230 is formed to be in contact with the lower electrode 260 connected to the 225 and the source electrode 221 and the drain electrode 225. The substrate 210 may be a plastic substrate, a glass substrate, or a metal substrate. The semiconductor layer 230 includes an organic semiconductor layer. In addition, the semiconductor layer 230 may include a silicon film.

The source / drain electrodes 221 and 225 include a material for reducing contact resistance with the semiconductor layer 230, for example, Au, Pd, or Pt. The lower electrode 260 includes a transmissive electrode material or a reflective electrode material. For example, the lower electrode 260 includes ITO, IZO, ZnO, or In 2 O 3 as a transmissive electrode, or Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr as a reflective electrode. Or a laminated film of a reflective electrode material such as a compound thereof and a transparent conductive film such as ITO, IZO, ZnO, or In 2 O 3.

Referring to FIG. 4B, a portion of the lower electrode 260 is surface treated. At this time, the surface treatment process makes the surface hydrophobic using fluorine-based plasma. At this time, the surface treatment process using a fluorine-based plasma uses a fluorine-based gas such as CF4 or C3F8.

Referring to FIG. 4C, a gate insulating film 240 is formed by discharging a solution including an insulating material for a gate insulating film onto a substrate from an inkjet head (not shown). In this case, the gate insulating layer 240 is not formed in the surface-treated portion of the lower electrode 260, and an opening 245 is formed to expose the lower electrode 260.

The gate insulating layer 240 has an opening 245 having a shape as shown in FIGS. 7A to 7C. Therefore, the gate insulating layer 240 also functions as a pixel defining layer defining the lower electrode 260 by the opening 245.

As another example, in another example, when the adhesion between the substrate surface and the ink is not good, that is, when the substrate surface is hydrophobic, it corresponds to the opening 245 exposing a portion of the lower electrode 260. It is also possible to form a gate insulating film 240 having an opening 245 by surface treatment of the substrate surface excluding the portion.

That is, a surface treatment process using Ar and O 2 plasma is performed on the entire surface of the substrate except for the surface of the lower electrode 260 corresponding to the opening 245, thereby improving the adhesion by modifying the surface of the substrate to be hydrophilic. Subsequently, when the ink including the gate insulating material is discharged onto the surface of the substrate, the gate insulating layer 240 is coated only on a portion where the surface treatment is performed and the adhesion is improved. Accordingly, the gate insulating layer 240 having the opening 245 in which the gate insulating layer 240 is not formed is formed on the surface of the lower electrode 260 which is not subjected to the plasma surface treatment.

The gate insulating layer 140 is PI / Al 2 O 3, polyimide, polyvinyl phenol (PVP, poly vinyl phenol), parylene, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polymethylmethacrylate (PMMA). The film is selected from the group containing).

Referring to FIG. 4D, a gate 250 is formed in a portion of the insulating layer 240 corresponding to the semiconductor layer 230. Subsequently, when the organic layer 270 and the upper electrode 280 are formed on the substrate, an organic light emitting display device 200 according to another exemplary embodiment as shown in FIG. 3 is manufactured. The upper electrode 280 includes a transmissive electrode or a reflective electrode.

5 is a cross-sectional view of an organic light emitting display device according to another embodiment of the present invention. The organic light emitting display device 300 according to another embodiment of the present invention includes a plurality of pixels arranged in a matrix form on a substrate, and each pixel includes two thin film transistors, a switching thin film transistor, a driving thin film transistor, and a capacitor. And an organic light emitting device. FIG. 5 shows only the organic light emitting diode and the driving thin film transistor for driving the organic light emitting diode.

Referring to FIG. 5, source / drain electrodes 321 and 325 are formed on a substrate 310, and a lower electrode 360 includes one electrode of the source / drain electrodes 321 and 325. For example, it is formed on the substrate to be connected to the drain electrode 325. The semiconductor layer 330 is formed to contact the source / drain electrodes 321 and 325.

A gate insulating film 340 is formed on the substrate, and a gate 350 is formed on the gate insulating film 340. The gate insulating layer 340 has an opening 345 having a mesh or line shape as shown in FIGS. 7A to 7C in a portion corresponding to the lower electrode 360. Accordingly, the gate insulating layer 340 serves as a pixel isolation layer that defines a light emitting region of the lower electrode 360.

The organic layer 370 is formed on the lower electrode 360 of the opening 345, and the upper electrode 380 is formed on the substrate. The organic layer 370 includes one or more organic layers selected from a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a hole suppression layer.

As in the exemplary embodiment, the substrate 310 includes a glass substrate, a plastic substrate, or a metal substrate, and the semiconductor layer 230 includes an organic semiconductor film or a silicon film.

The gate insulating layer 140 may include PI / Al 2 O 3, polyimide, polyvinyl phenol (PVP, poly vinyl phenol), parylene, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), and poly methylmethacrylate (PMMA). The film is selected from the group containing). The gate insulating layer 140 is preferably formed on a surface-treated substrate to facilitate inkjet. The surface treatment is performed using a fluorine-based gas such as CF4 or C3F8 or by using an Ar or O2 plasma gas.

The source electrode 321 and the drain electrode 325 are made of different materials, and since the contact resistance of the source electrode 321 with the semiconductor layer 330 is important, a work function is greater than that of the organic semiconductor layer 330. It includes a large electrode material and includes a conductive material selected from Au, Pt, Pd, MoW oxide and PEDOT. Since the drain electrode 325 also acts as a reflective film 361 of the lower electrode 360, a material having excellent reflectivity, for example, Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or These compounds etc. are included.

In the top emission type organic light emitting display device 300 according to another embodiment, the lower electrode 360 serves as a pixel electrode of each pixel, and includes a reflective film 361 and a transparent electrode layer 365. The reflective film 361 of the lower electrode 360 includes Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a compound thereof as the material having excellent reflectivity as described above. The electrode layer 365 includes a transparent conductive film such as ITO, IZO, ZnO, or In 2 O 3.

On the other hand, in the case of having a top light emitting structure, the upper electrode 380 includes a transmissive electrode, and has a stacked structure of a metal film and a transparent conductive film. The metal film for the upper electrode 380 may include Li, Ca, LiF / Ca, LiF / Al, Al, Mg, or a compound thereof, and the transparent conductive film may include ITO, IZO, ZnO, In 2 O 3, or the like.

6A through 6D are cross-sectional views illustrating a method of manufacturing an organic light emitting display device using an inkjet method according to another embodiment of the present invention.

Referring to FIG. 6A, a source electrode 321 and a drain electrode 325 are formed on a substrate 310, and one of the source / drain electrodes 321 and 325, for example, a drain electrode ( The semiconductor layer 330 is formed to contact the transmissive electrode 365, the source electrode 321, and the drain electrode 325 to overlap the 325.

The substrate 310 may be a plastic substrate, a glass substrate, or a metal substrate. The semiconductor layer 330 includes an organic semiconductor layer. In addition, the semiconductor layer 330 may include a silicon film.

The source electrode 321 includes a material for reducing contact resistance with the semiconductor layer 330, for example, a conductive material such as Au, Pd, Pd, MoW oxide, or PEDOT. A portion 361 of the drain electrode 325 overlapping with the transmissive electrode 365 serves as a reflective film to form a lower electrode 360 together with the transmissive electrode 365. Accordingly, the lower electrode 360 may include a transparent electrode layer 365 such as ITO, IZO, ZnO, or In 2 O 3, and a reflective film such as Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a compound thereof. 361.

Referring to FIG. 6B, a portion of the lower electrode 360 is surface treated. At this time, the surface treatment process makes the surface hydrophobic by using a fluorine-based plasma to reduce the adhesion to the ink in the subsequent inkjet process. At this time, the surface treatment process using a fluorine-based plasma uses a fluorine-based gas such as CF4 or C3F8.

Referring to FIG. 6C, a gate insulating film 340 is formed by discharging a solution including an insulating material for a gate insulating film onto a substrate from an inkjet head (not shown). In this case, the gate insulating layer 340 is not formed in the surface-treated portion of the lower electrode 360, and an opening 345 is formed to expose the lower electrode 360.

The gate insulating layer 340 has an opening 345 having a shape as shown in FIGS. 7A to 7C. Therefore, the gate insulating layer 340 also functions as a pixel defining layer defining the lower electrode 360 by the opening 345.

As another example, when the adhesion between the substrate surface and the ink is not good, that is, when the substrate surface is hydrophobic, the substrate surface except for the portion corresponding to the opening 345 exposing the pixel electrode 360 is removed. It is also possible to form the gate insulating film 340 having the opening 345 by surface treatment.

That is, a surface treatment process using Ar and O 2 plasma is performed on the entire surface of the substrate except for the surface of the pixel electrode 360 corresponding to the opening 345, thereby improving the adhesion by modifying the surface of the substrate to be hydrophilic. Subsequently, when the ink including the gate insulating material is discharged to the surface of the substrate, the gate insulating layer 340 is coated only on a portion where the surface treatment is performed and the adhesion is improved. Therefore, the gate insulating layer 340 without the gate insulating layer 340 is formed on the surface of the pixel electrode 360 which is not plasma-treated.

The gate insulating layer 140 is PI / Al 2 O 3, polyimide, polyvinyl phenol (PVP, poly vinyl phenol), parylene, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polymethylmethacrylate (PMMA). The film is selected from the group containing).

Referring to FIG. 6D, the gate 350 is formed in a portion of the insulating layer 340 corresponding to the semiconductor layer 330. Subsequently, when the organic layer 370 and the upper electrode 380 are formed on the substrate, an organic light emitting display device 300 according to another exemplary embodiment as shown in FIG. 3 is manufactured. The upper electrode 380 includes a transmission electrode.

In the exemplary embodiment of the present invention, since the gate insulating layer serves as the pixel isolation layer, a structure in which the upper electrode is directly contacted on the gate electrode is illustrated. However, although not shown in the drawing, a method of forming an insulating layer between the gate electrode and the upper electrode is illustrated. To electrically separate them.

In the exemplary embodiment of the present invention, in the organic light emitting display device having the organic thin film transistor, a structure in which the gate insulating film is used as the pixel isolation layer defining the pixel electrode is illustrated, but the present invention is not necessarily limited thereto. Of course, the present invention can also be applied to a flat panel display such as a liquid crystal display.

In the exemplary embodiment of the present invention, the organic light emitting display device including the top gate thin film transistor has been described. However, the present invention is not limited thereto, and the organic light emitting display device is not limited thereto.

Further, the present invention exemplifies only the driving thin film transistor and the organic light emitting device as one pixel structure arranged in the pixel region. However, the present invention is not limited thereto, and the present invention can be applied to an organic light emitting display device having various pixel structures.

According to the organic light emitting display device and the manufacturing method thereof according to the embodiment of the present invention as described above, since the gate insulating film acts as a pixel separation film defining the pixel electrode, one of the source electrode and the drain electrode of the pixel electrode and the thin film transistor A mask process for forming a via hole connecting the electrode and a process for forming a pixel definition layer defining a light emitting area of the pixel electrode are excluded. This can simplify the structure and process of the device.

Further, in the present invention, since an opening for defining the pixel electrode is formed in the gate insulating film by using a laser transfer method, since a photolithography process for forming the opening of a conventional pixel separation film is excluded, a residue of the photosensitive material remains. As a result, pattern defects can be prevented.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

Claims (18)

Forming a source / drain electrode and a pixel electrode on the substrate and a semiconductor layer in contact with the source / drain electrode; Forming an insulating film having an opening defining the pixel electrode by an inkjet method; And forming a gate on the insulating film corresponding to the semiconductor layer. The method of claim 1, And the insulating film serves as a gate insulating film and at the same time serves as a pixel separation film for defining the pixel electrode. The method of claim 1, The gate insulating layer may include PI / Al 2 O 3, polyimide, polyvinyl phenol (PVP, poly vinyl phenol), parylene, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), and poly methylmethacrylate (PMMA). A flat panel display device comprising a film selected from the group consisting of. The method of claim 1, And plasma-treating the surface of the substrate before forming the insulating film. The method of claim 4, wherein In the plasma processing step, the substrate surface corresponding to the opening is plasma-treated using Ar and O 2 plasma. The method of claim 4, wherein In the plasma processing step, the surface of the substrate excluding the opening is plasma treated using fluorine-based plasma using CF4 or C3F8. The method of claim 1, And the pixel electrode extends from one of the source / drain electrodes or is connected to one electrode. The method of claim 7, wherein The semiconductor layer includes an organic semiconductor material, and the source / drain electrodes are formed of different materials. The method of claim 8, One electrode of the source electrode / drain electrode comprises a transmissive electrode selected from ITO, IZO, ZnO and In 2 O 3 or Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr and compounds thereof It includes a reflective electrode having a reflective film selected from and a transparent conductive material selected from ITO, IZO, ZnO and In2O3, And the other electrode of the source electrode / drain electrode comprises an electrode material selected from Au, Pd, and Pt to match a work function with the organic semiconductor layer. The method of claim 7, wherein The semiconductor layer may include an organic semiconductor material, and the source / drain electrode and the pixel electrode may include different materials. The method of claim 10, The source electrode / drain electrode includes an electrode material for matching a work function with the semiconductor layer, selected from Au, Pd and Pt, The lower electrode includes a transmissive electrode selected from ITO, IZO, ZnO, and In 2 O 3, or a reflective material selected from Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, and a compound thereof, and ITO. And a reflective electrode having a lamination film of a transparent conductive material selected from IZO, ZnO, and In 2 O 3. The method of claim 1, The pixel electrode may include a reflective film extending from one of the source / drain electrodes; And a transparent electrode layer formed to overlap the reflective film. The method of claim 12, The semiconductor layer includes an organic semiconductor material, The reflective film of the pixel electrode is made of the same material as the one of the source / drain electrodes, The reflective film includes a reflective material selected from Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, and compounds thereof. The transparent electrode layer includes a transparent conductive film selected from ITO, IZO, ZnO, and In2O3. The method of claim 13, The other electrode of the source electrode / drain electrode is an electrode material for matching a work function with the semiconductor layer, and includes a conductive material selected from Au, Pd, Pt, MoW oxide, and PEDOT. Method of manufacturing the device. A substrate; A source electrode and a drain electrode formed on the substrate; A semiconductor layer in contact with the source / drain electrode; A gate formed on the substrate; An insulating film formed between the source / drain electrode and the gate and having an opening; A pixel electrode connected to one of the source / drain electrodes and partially exposed by an opening of the insulating layer; And the insulating film is formed by an inkjet method. The method of claim 15, The gate insulating layer may include PI / Al 2 O 3, polyimide, polyvinyl phenol (PVP, poly vinyl phenol), parylene, polyvinyl alcohol (PVA), polyvinyl chloride (PVC), and poly methylmethacrylate (PMMA). A flat panel display comprising a film selected from the group. The method of claim 15, A plurality of gate lines and data lines arranged on the substrate to cross each other; A plurality of pixel areas defined by the plurality of gate lines and data lines, Each pixel region includes a thin film transistor including a source / drain electrode, a semiconductor layer, and a gate; A pixel electrode connected to the thin film transistor is arranged; The opening of the insulating layer may have a mesh shape to expose a portion of the pixel electrode arranged in each pixel region or may be along a line or data line that exposes a portion of the pixel electrode arranged along the gate line among the plurality of pixel regions. And a line shape exposing a portion of the arranged pixel electrodes. The method of claim 15, And a substrate surface below the insulating film except for the openings is surface-treated by fluorine-based plasma using CF4 or C3F8.

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