KR20070120343A - Organic electro-luminescence display and fabricating method thereof - Google Patents

Abstract

An organic light emitting display device and a manufacturing method thereof are provided to reduce light loss due to a gate insulation film and a protective film by directly emitting light toward a substrate through an anode. An organic light emitting display device includes a TFT(Thin Film Transistor), an anode(40), a gate insulation film(12), a partition(30), an organic light emitting layer(50), and a cathode(60). The anode is connected to the TFT and formed on a substrate. The gate insulation film is formed to cover a gate electrode of the TFT and expose the anode. The partition has a hole for exposing the anode. The organic light emitting layer is formed in the hole and generates light. The cathode is formed on the organic light emitting layer.

Description

Organic electroluminescent display device and manufacturing method therefor {ORGANIC ELECTRO-LUMINESCENCE DISPLAY AND FABRICATING METHOD THEREOF}

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

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

3A to 3D are cross-sectional views illustrating a method of manufacturing an anode and a gate electrode according to the present invention.

<Brief description of symbols for the main parts of the drawings>

10 gate electrode 12 gate insulating film

14 ohmic contact layer 16 source electrode

18 active layer 19 drain electrode

20: substrate 30: partition wall

40: anode 50: organic light emitting layer

60: cathode 70, 70a, 70b: photoresist pattern

72, 72a, 72b: transparent conductive films 74a, 74b, 74c: gate metal films

80 mask

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device for reducing light loss and a method of manufacturing the same.

Video display device that implements a variety of information on the screen is a key technology in the information and communication era, and is developing in a direction of thinner, lighter, portable and high performance. Accordingly, flat panel display devices such as organic light emitting display devices that can reduce weight and volume, which are disadvantages of cathode ray tubes (CRTs), have been in the spotlight. The organic light emitting display device is a self-luminous device using a thin light emitting layer between electrodes and has an advantage of thinning like a paper.

In general, an organic light emitting display device includes an organic light emitting layer for generating light, an anode for transmitting light generated in the organic light emitting layer, and a cathode for reflecting light generated in the organic light emitting layer.

At this time, since the light generated by the organic light emitting layer is emitted in all directions and exits to outside, the refractive indexes of the various layers of the organic light emitting layer, the gate insulating film formed on the anode and the substrate, and the protective film are different so that the light does not come out. There is a problem in that the light loss occurs by falling to the side.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide an organic light emitting display device and a method of manufacturing the same, which can reduce light loss.

In order to achieve the above technical problem, a method of manufacturing an organic light emitting display device according to the present invention comprises the steps of forming an anode and a gate electrode on the substrate; Forming a gate insulating film on the substrate to expose the anode; Forming an active layer and an ohmic contact layer on the gate insulating film; Forming source / drain electrodes facing each other with the active layer therebetween; Forming a partition having a hole exposing the anode; Forming an organic light emitting layer on the anode exposed through the partition and forming a cathode on the organic light emitting layer.

The forming of the anode and the gate electrode may include forming a transparent conductive film on the substrate; Forming a cathode by patterning the transparent conductive film through a photolithography process and an etching process; Forming a gate metal film on the substrate on which the anode is formed; The gate metal layer is patterned through a photolithography process and an etching process to form a gate electrode.

The forming of the anode and the gate electrode may include sequentially forming a transparent conductive film and a gate metal film on the substrate; Forming a photoresist pattern on the gate metal layer through a photolithography process using a slit mask; Forming an anode and a gate electrode by patterning the gate metal film and the transparent conductive film using the photoresist pattern; Ashing the photoresist pattern; Removing the gate metal film remaining on the anode using the ashed photoresist pattern; And stripping the photoresist pattern.

In order to achieve the above technical problem, the organic light emitting display device according to the present invention includes a thin film transistor; An anode connected to the thin film transistor and formed on a substrate; A gate insulating film formed to cover the gate electrode of the thin film transistor and to expose the anode; A partition having a hole exposing the anode; An organic light emitting layer formed in the hole provided by the barrier and generating light; It characterized in that it comprises a cathode formed on the organic light emitting layer.

The anode is formed of a transparent conductive film, and the gate electrode is formed of a gate metal film.

The anode may be formed of a transparent conductive film, and the gate electrode may be formed by sequentially stacking a transparent conductive film and a gate metal film.

Other technical problems and advantages of the present invention in addition to the above technical problem will be apparent from the description of the preferred embodiment of the present invention with reference to the accompanying drawings.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS.

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

As shown in FIG. 1, an organic light emitting display device includes a thin film transistor formed on a substrate 20, a thin film transistor connected to a thin film transistor on a substrate 20, an anode 40 for transmitting light, and an anode ( The partition 30 which exposes 40, the organic light emitting layer 50 which produces light, and the cathode 60 which reflects light are provided.

The thin film transistor supplies a driving signal for injecting holes into the anode 40. The thin film transistor includes a gate electrode 10 connected to a gate line, an active layer 18 formed on the gate insulating film 12, an ohmic contact layer 14 formed on the active layer 18, and an ohmic contact layer ( A source electrode 16 formed on one side of the 14 and the drain electrode 19 formed on the other side of the ohmic contact layer 14 and connected to the anode 40 are formed.

The anode 40 is connected to the drain electrode 19 to supply a driving signal for injecting holes through the thin film transistor. The anode 40 transmits visible light generated from the organic light emitting layer 50 to the outside. The anode 40 is formed on the substrate 20 using indium tin oxide (ITO), indium zinc oxide (IZO), or the like, which are transparent conductive materials to transmit light.

The partition wall 30 is formed to have a hole 34 exposing the anode 40 of each pixel region. The barrier 30 is made of an organic insulating material.

The organic light emitting layer 50 is formed to include a hole transport layer, a hole injection layer, a light emitting layer, an electron injection layer, and an electron transport layer on the substrate 20 on which the cathode 60 is formed. The light emitting layer included in the organic light emitting layer 50 emits light according to the amount of current supplied to the anode 40 and is reflected by the cathode 60 to emit light toward the substrate 20 via the anode 40 or emit light. It exits to the board | substrate 20 via this anode 40. FIG.

The cathode 60 is formed on the substrate 20 on which the organic light emitting layer 50 is formed, and a driving signal for injecting electrons is supplied to the cathode 60. The cathode 60 reflects the light generated from the organic emission layer 50 toward the substrate 20 and emits the light to the outside. For this purpose, the cathode 60 uses a metal or two or more alloys such as Al having high reflectance.

As such, when the driving signal is applied to each of the anode 40 and the cathode 60, electrons and holes are emitted, and electrons and holes emitted from the anode 40 and the cathode 60 are organic. Recombination in the emission layer 50 generates visible light. In this case, the visible light generated in the organic light emitting layer 50 emits light directly to the substrate 20 through the anode 40 by removing the insulating film and the protective film, and the transmittance may be adjusted by compensating for the light loss due to the difference in refractive index.

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

Referring to FIG. 2A, an anode 40 is formed on the substrate 20.

Specifically, the anode 40 is formed by patterning the transparent conductive film on the substrate 20 by patterning the transparent conductive film through a photolithography process and an etching process using a mask. In this case, the anode 40 uses ITO, IZO, or the like, which are transparent conductive materials.

Referring to FIG. 2B, the gate electrode 10 is formed on the substrate 20 on which the anode 40 is formed.

Specifically, the gate electrode 10 is formed by applying a gate metal film on the substrate 20 on which the anode 40 is formed, and then patterning the gate metal film through a photolithography process and an etching process.

Meanwhile, as illustrated in FIGS. 2A and 2B, the anode 40 and the gate electrode 10, which are formed using separate masks, may be simultaneously formed using a slit mask. This will be described in detail with reference to FIGS. 3A to 3C.

As shown in FIG. 3A, a transparent conductive film 72, a gate metal film 74, and a photoresist are sequentially formed on the substrate 20. In this case, ITO or IZO is used as the transparent conductive film 72, and Al, Mo, Cr, Cu, etc. are used as the gate metal film 74. The photoresist pattern 70 is formed by patterning the photoresist on the substrate 20 by an exposure process and a development process using the slit mask 80. As shown in FIG. 3B, the photoresist pattern 70 is formed to a first thickness on the region where the gate electrode 10 is to be formed, and has a second thickness that is thinner than the first thickness on the region where the anode 40 is to be formed. Is formed.

The gate electrode 10 and the anode 40 are formed by patterning the transparent conductive film 72 and the gate metal film 74 through an etching process using the photoresist pattern 70 as a mask. Thereafter, as shown in FIG. 3C, the photoresist pattern 70a formed to a second thickness located on the anode 40 is removed by ashing the photoresist patterns 70a and 70b and positioned on the gate electrode 10. The photoresist pattern 70b formed to the first thickness is reduced in thickness.

Thereafter, the gate metal film 74 is etched using the ashed photoresist pattern to remove the gate metal film 74 on the anode 40.

Then, as shown in FIG. 3C, the photoresist pattern 70a remaining on the gate electrode 10 is stripped through a stripping process.

Referring to FIG. 2C, a gate insulating layer 12 is formed on the substrate 20 on which the anode 40 and the gate electrode 10 are formed.

Specifically, the gate insulating layer 12 is formed by applying an inorganic insulating material to the entire surface to cover the anode 40 and the gate electrode 10 and then patterning the insulating material through a photolithography process and an etching process. In this case, the gate insulating layer 12 is formed to expose the anode 40. Herein, an inorganic insulating material such as SiOx, SiNx, or the like is used as the inorganic insulating material.

Referring to FIG. 2D, an active layer 18 and an ohmic contact layer 14 are formed on the gate insulating layer 12.

Specifically, the active layer 18 and the ohmic contact layer 14 are formed by sequentially depositing a-si and n + a-si layers on the gate insulating layer 12 and patterning them through a photolithography process and an etching process.

Referring to FIG. 2E, source / drain electrodes 16 and 19 are formed on the active layer 18 and the ohmic contact layer 14.

Specifically, the source / drain electrodes 16 and 19 are formed by depositing a source / drain metal on the active layer 18 and the ohmic contact layer 14 by a sputtering method and then patterning them through a photolithography process and an etching process. Source / drain patterns are formed. Here, the active layer 18 is exposed by etching the ohmic contact layer 14 in which the source / drain metal is exposed using a mask.

Referring to FIG. 2F, the partition wall 30 is formed on the substrate 20 on which the thin film transistor and the anode 40 are formed.

Specifically, after the organic insulating material is deposited on the substrate 20 on which the thin film transistor and the anode 40 are formed, the hole for exposing the anode 40 by patterning the organic insulating material through a photolithography process and an etching process using a mask. Partition wall 30 is formed. The barrier 30 is made of an organic insulating material. When the photosensitive organic insulating material is used, holes may be formed only by a photolithography process.

Referring to FIG. 2G, the organic emission layer 50 is formed on the anode 40 on which the partition wall 30 is formed.

Specifically, the organic light emitting layer 50 is formed by sequentially laminating a hole injection layer, a hole transport layer, a light emitting layer, an electron injection layer, and an electron transport layer on the substrate 20 on which the partition wall 30 is formed. The organic emission layer 50 is formed by sequentially depositing pixel areas of a corresponding color.

Referring to FIG. 2H, the cathode 60 is formed to cover the partition 30 and the organic emission layer 50.

Specifically, the cathode 60 is formed by coating a material having a high reflectance on the partition 30 and the organic light emitting layer 50. As the cathode 60, a metal having high reflectance such as aluminum is used.

On the other hand, the electroluminescent device according to the present invention is applicable to not only organic electroluminescent devices but also inorganic electroluminescent devices.

As described above, the organic light emitting display device and the manufacturing method thereof according to the present invention remove the gate insulating film so that the anode is exposed, and remove the protective film so that light is emitted directly to the substrate through the anode. Light loss can be reduced.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the description of the specification but should be defined by the claims.

Claims (6)

Forming an anode and a gate electrode on the substrate; Forming a gate insulating film on the substrate to expose the anode; Forming an active layer and an ohmic contact layer on the gate insulating film; Forming source / drain electrodes facing each other with the active layer therebetween; Forming a partition having a hole exposing the anode; Forming an organic light emitting layer on the anode exposed through the partition wall; and And forming a cathode on the organic light emitting layer. The method of claim 1, Forming the anode and the gate electrode Forming a transparent conductive film on the substrate; Forming a cathode by patterning the transparent conductive film through a photolithography process and an etching process; Forming a gate metal film on the substrate on which the anode is formed; And forming a gate electrode by patterning the gate metal layer through a photolithography process and an etching process. The method of claim 1, Forming the anode and the gate electrode Sequentially forming a transparent conductive film and a gate metal film on the substrate; Forming a photoresist pattern on the gate metal layer through a photolithography process using a slit mask; Forming an anode and a gate electrode by patterning the gate metal film and the transparent conductive film using the photoresist pattern; Ashing the photoresist pattern; Removing the gate metal film remaining on the anode using the ashed photoresist pattern; And stripping the photoresist pattern. A thin film transistor; An anode connected to the thin film transistor and formed on a substrate; A gate insulating film formed to cover the gate electrode of the thin film transistor and to expose the anode; A partition having a hole exposing the anode; An organic light emitting layer formed in the hole provided by the barrier and generating light; And an anode formed on the organic light emitting layer. The method of claim 4, wherein The anode is formed of a transparent conductive film, and the gate electrode is formed of a gate metal film. The method of claim 4, wherein And the anode is formed of a transparent conductive film, and the gate electrode is formed by sequentially stacking a transparent conductive film and a gate metal film.

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