KR20150066428A - Organic electro luminescent device - Google Patents

Abstract

Provided is an organic electroluminescent device to improve capacity of a storage capacitor and an opening ratio without increase of the area of the storage capacitor. The organic electroluminescent device comprises: a first substrate in which a pixel area, and an element area and a light emitting area in the pixel area are defined; the storage capacitor having a stacked structure of a first storage electrode, a first buffer layer, and a second storage electrode in the element area on the first substrate; a second buffer layer formed above the storage capacitor; a plurality of thin film transistors formed in the element area above the second buffer layer; and a protective layer formed above the thin film transistors. The storage capacitor is formed to be overlapped with at least on thin film transistor among the transistors.

Description

[0001] The present invention relates to an organic electroluminescent device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device, and more particularly, to an organic electroluminescent device capable of improving the aperture ratio and improving resolution while improving the capacity of a storage capacitor in one pixel region.

In recent years, as the society has become a full-fledged information age, a display field for processing and displaying a large amount of information has rapidly developed, and various flat panel display devices have been developed in response to this.

Specific examples of such flat panel display devices include a liquid crystal display device (LCD), a plasma display panel (PDP), a field emission display (FED) And electroluminescence display device (ELD). These flat panel display devices are excellent in performance of thinning, light weight, and low power consumption, and are rapidly replacing existing cathode ray tubes (CRTs).

Among such flat panel display devices, organic electroluminescent devices have high luminance and low operating voltage characteristics.

In addition, since the organic electroluminescent device is a self-luminous type that emits light by itself, it has a large contrast ratio, can realize an ultra-thin display, can realize a moving image with a response time of several microseconds (μs) There is no limitation of the viewing angle, it is stable even at low temperature, and it is driven with a low voltage of 5 to 15 V direct current, so that it is easy to manufacture and design a driving circuit.

Accordingly, the organic electroluminescent device having the above-described advantages has recently been used in various IT devices such as a TV, a monitor, and a mobile phone.

Organic electroluminescent devices having such characteristics are roughly divided into a passive matrix type and an active matrix type. In a passive matrix type, a scan line and a signal line cross each other to form an element in a matrix form. In order to drive the scanning lines in order to drive the scanning lines sequentially, it is necessary to give an instantaneous luminance equal to the average luminance multiplied by the number of lines in order to obtain the required average luminance.

However, in the active matrix method, a thin film transistor (a thin film transistor), which is a switching element for turning on / off a pixel, is positioned for each pixel region, and a first electrode connected to the thin film transistor is turned on (on) / off (off), and the second electrode facing the first electrode becomes a common electrode.

In the active matrix system, the voltage applied to the pixel region is charged in the storage capacitor, and the power is applied until the next frame signal is applied. Thus, regardless of the number of scanning lines, do.

Accordingly, since the same luminance is exhibited even when a low current is applied, an active matrix type organic electroluminescent device is mainly used since it has advantages of low power consumption, high definition and large size.

1 is a cross-sectional view of one pixel region including a driving thin film transistor of a conventional organic electroluminescent device.

A semiconductor layer 13 composed of a first region 13a of pure polysilicon and a second region 13b doped with an impurity, a gate insulating film 16, and a gate electrode (not shown) are formed on the first substrate 10, An interlayer insulating film 23 having a semiconductor layer contact hole 25 exposing the second region 13b and source and drain electrodes 33 and 36 are sequentially stacked to form a driving thin film transistor DTr, And the source and drain electrodes 33 and 36 are connected to a power supply line (not shown) and the organic light emitting diode E, respectively.

The organic electroluminescent diode E includes a first electrode 47 and a second electrode 63 which are opposed to each other with the organic light emitting layer 60 interposed therebetween. The first electrode 47 is formed in contact with one electrode of the driving thin film transistor DTr for each pixel region P and the second electrode 63 is formed over the organic light emitting layer 60 .

On the other hand, a storage capacitor StgC for holding an input image signal is formed in the pixel region P until the next image signal is input.

In the structure of the storage capacitor StgC, a first storage electrode 15 made of doped polysilicon is formed on the same layer on which the semiconductor layer 13 is formed, and on the gate insulation film 15 serving as a dielectric layer, And a second storage electrode 18 is formed on the gate insulating layer 16 to form a first storage capacitor StgC1. The second storage electrode 18 is formed of the same material as the gate electrode 21.

The interlayer insulating layer 23 is formed on the second storage electrode 18 and a power supply line is formed on the interlayer insulating layer 23 so that a part of the interlayer insulating layer 23 is electrically connected to the third storage electrode 38, . At this time, the second storage electrode 18, the interlayer insulating film 23, and the third storage electrode 38 constitute a second storage capacitor StgC2.

Therefore, in the conventional organic electroluminescent device 1 having the above-described configuration, the first storage capacitor StgC1 and the second storage capacitor StgC2 are connected in parallel to acquire the storage capacity of the two storage capacitors StgC1 and StgC2 .

On the other hand, in recent years, high-resolution display devices are rapidly progressing.

In the display device, resolution is defined as the number of pixels per unit area (PPI), and a high-resolution display device generally refers to a display device having a pixel per inch (300PI) or more. In recent years, A display device having an ultra-high resolution as described above is also required.

On the other hand, in order to realize high resolution of the display device, the number of pixel areas per unit area of the display area for displaying an image must be increased, which means that the size of one pixel area is smaller.

When the size of one pixel region is reduced, the size of the constituent elements naturally decreases to reduce the area of the storage capacitor, which means a decrease in storage capacity.

Further, as each pixel region becomes smaller, the size of the organic electroluminescence layer for displaying an image becomes smaller, so that the storage capacity for holding the organic electroluminescence layer until the next frame becomes a little small, but is not completely proportional.

That is, the storage capacity due to the reduction of the area of the storage capacitor is reduced rather than the actual pixel area is reduced, so that the area for forming the storage capacitor in one pixel area has to be further increased.

The ratio of an area where an image can be formed to a total area of one pixel area is called an aperture ratio. In the conventional organic electroluminescent device, when the area of the storage capacitor is increased in each pixel area, the area of the storage capacitor The area occupied by the barrier rib is relatively increased, so that the aperture ratio is reduced.

On the other hand, a flexible organic electroluminescent device display is a flexible plastic substrate which can be folded and unfolded by replacing a glass substrate with a plastic film. The flexible organic electroluminescent display can be manufactured in various shapes because it is light and shock- The research is actively being carried out.

Unlike a glass substrate, a flexible substrate made of a plastic film is susceptible to contact with moisture and oxygen, so that flexibility and damage to the internal circuit may be caused by moisture and oxygen that slowly flow into the substrate .

In addition, a flexible substrate is liable to be charged by static electricity, and a problem arises that an image quality is deteriorated due to a malfunction of a thin film transistor due to the electric field.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an organic electroluminescent device and a method of manufacturing the same, which can improve the aperture ratio while improving the storage capacitor capacity without increasing the area of the storage capacitor.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a first substrate having a pixel region, an element region and a light emitting region defined in the pixel region; A storage capacitor having a stacked structure of a first storage electrode, a first buffer layer and a second storage electrode in the device region on the first substrate; A second buffer layer formed on the storage capacitor; A switching and driving thin film transistor formed in the device region above the second buffer layer; And a protective layer formed over the switching and driving thin film transistor,

Wherein the storage capacitor overlaps with either the switching and driving thin film transistors or both the switching and driving thin film transistors.

And a moisture-proof layer between the first substrate and the first storage electrode constituting the storage capacitor.

And the first substrate is a flexible substrate.

The first and second storage electrodes are made of a metal material, and the first buffer layer is made of an inorganic insulating material.

The switching and driving thin film transistor includes a semiconductor layer, a gate insulating layer, a gate electrode, an interlayer insulating layer having a semiconductor layer contact hole exposing the semiconductor layer, and an interlayer insulating layer which contacts the semiconductor layer through the semiconductor layer contact hole, Source and drain electrodes of the organic electroluminescent device.

The semiconductor layer may be formed of polysilicon or an oxide semiconductor material.

A first auxiliary pattern is further formed on the interlayer insulating film,

The first auxiliary pattern is connected to the drain electrode of the switching thin film transistor, the gate electrode of the driving thin film transistor, and the storage capacitor.

The first auxiliary pattern is connected to the second storage electrode of the storage capacitor through the storage contact hole exposing the second storage electrode provided in the interlayer insulating layer, the gate insulating layer, and the second buffer layer.

The first auxiliary pattern is connected to the first storage electrode of the storage capacitor through the interlayer insulating film, the gate insulating film, the second buffer layer, and the storage contact hole exposing the first storage electrode provided in the first buffer layer. .

And the first auxiliary pattern is connected to the gate electrode of the driving thin film transistor through a gate contact hole exposing the gate electrode provided in the interlayer insulating film.

An organic light emitting diode is further formed in the light emitting region on the protective layer,

The organic light emitting diode is connected to the drain electrode of the driving thin film transistor through the drain contact hole exposing the drain electrode of the driving thin film transistor provided in the protective layer.

The organic electroluminescent device according to the present invention is characterized in that a storage capacitor is formed by overlapping a switching thin film transistor and / or a driving thin film transistor, thereby forming a separate storage capacitor formed in each device region apart from the switching and driving thin film transistor The area of the device region is reduced in each pixel region and the use of the reduced device region as the light emitting region has the effect of improving the aperture ratio.

Furthermore, since the electrodes of the data wiring and the storage capacitor are formed twice as much as the conventional one, the parasitic capacitance between the data wiring and the electrode of the storage capacitor is reduced by half, thereby improving the picture quality.

Further, since the storage capacitor provided with the device region can be formed by utilizing substantially the entire surface of the device region, the storage capacitor capacity can be sufficiently secured. Therefore, even if the organic electroluminescent device realizes high resolution, It has an effect of restricting the problem such as quality deterioration.

Furthermore, since the storage capacitor overlaps with the switching or driving thin film transistor to serve as a light shielding element for blocking external light from entering the first and second semiconductor layers of each thin film transistor, There is an effect that the erroneous operation of the switching and driving thin film transistor by the formation of the light leakage current due to the light incident on the two semiconductor layers is fundamentally prevented.

In addition, when a flexible substrate is applied, moisture and oxygen introduced into the substrate are shielded to protect the internal circuit, and a storage capacitor (StgC) formed under the thin film transistor has an electric field generated from static electricity generated from a flexible substrate It is possible to simplify the manufacturing process since it is not necessary to perform additional barrier layer addition process.

1 is a cross-sectional view of one pixel region including a driving thin film transistor of a conventional organic electroluminescent device.
2 is a circuit diagram of one pixel of a general active matrix organic electroluminescent device.
FIG. 3 is a cross-sectional view of one pixel region including a switching and driving thin film transistor, a storage capacitor, and an organic light emitting diode according to a first embodiment of the present invention.
4A and 4B are cross-sectional views of a pixel region including a switching and driving thin-film transistor, a storage capacitor, and an organic light emitting diode according to a modification of the first embodiment of the present invention. .
FIG. 5 is a cross-sectional view of one pixel region including a switching and driving thin film transistor, a storage capacitor, and an organic light emitting diode according to a second embodiment of the present invention.
6A and 6B are cross-sectional views of a pixel region including a switching and driving thin-film transistor, a storage capacitor, and an organic light emitting diode according to a modification of the second embodiment of the present invention. .

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

First, the basic structure and operating characteristics of the organic electroluminescent device will be described in detail with reference to the drawings.

2 is a circuit diagram of one pixel region of a general organic light emitting device.

As shown in the figure, the organic light emitting device has a structure in which each pixel region P includes a gate wiring, a data wiring, a power supply wiring, a switching thin film transistor STr, a driving thin film transistor DTr, (StgC) and an organic electroluminescent diode (E).

A plurality of gate lines GL are formed spaced apart from each other in a first direction and a plurality of data lines DL are formed in a second direction crossing the first direction. And a power supply line PL for applying a power source voltage is formed at a distance from each data line DL.

At this time, a region captured by the gate line GL and the data line DL is defined as a pixel region P. [

In each pixel region P, a switching thin film transistor STr is formed at the intersection of the data line DL and the gate line GL, and a switching transistor STr is electrically connected to the switching thin film transistor STr. And a thin film transistor DTr is formed.

At this time, the first electrode, which is one terminal of the organic electroluminescent diode E, is connected to the drain electrode of the driving thin film transistor DTr, the second electrode which is the other terminal is connected to the power supply line PL, The power supply line PL transfers a power supply voltage to the organic light emitting diode E.

A storage capacitor StgC is formed between the gate electrode and the source electrode of the driving thin film transistor DTr.

Therefore, when a signal is applied through the gate line GL, the switching thin film transistor STr is turned on and the signal of the data line DL is transmitted to the gate electrode of the driving thin film transistor DTr, The driving thin film transistor DTr is turned on so that light is output through the organic electroluminescent diode E.

At this time, when the driving thin film transistor DTr is turned on, the level of a current flowing from the power supply line PL to the organic light emitting diode E is determined, It becomes possible to implement a gray scale.

The storage capacitor StgC maintains a constant gate voltage of the driving thin film transistor DTr when the switching thin film transistor STr is turned off so that the switching thin film transistor STr is turned off the level of the current flowing through the organic electroluminescent diode E can be maintained constant until the next frame even if the off state is established.

Hereinafter, the structure of the organic electroluminescent device according to the embodiment of the present invention for displaying an image by such driving will be described.

≪ Embodiment 1 >

3 is a cross-sectional view of one pixel region including a switching and driving thin film transistor, a storage capacitor, and an organic light emitting diode according to a first embodiment of the present invention.

In this case, for convenience of description, a region where the switching and driving thin film transistors STr and DTr and the storage capacitor StgC are formed in each pixel region P is referred to as an element region DA and an organic light emitting diode E The region where the switching and driving TFTs STr and DTr are formed in the device region DA is defined as the switching and driving regions STrA and DTrA, .

The organic electroluminescent device 101 according to the present invention includes a first substrate 101 on which switching and driving thin film transistors STr and DTr, a storage capacitor StgC and an organic electroluminescent diode E are formed, , And a second substrate (not shown) for encapsulation.

First, the structure of the first substrate 101 will be described.

A first storage electrode 103 made of a metal material is formed on the first substrate 101 to correspond to each device region DA.

A first buffer layer 104 made of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the first storage electrode 103. At this time, the first buffer layer 104 preferably has a thickness of 1000 to 4000 ANGSTROM.

The first buffer layer 104 serves as a dielectric layer as a constituent element of the storage capacitor StgC in the organic electroluminescent device 100 according to the first embodiment of the present invention. In the capacitor, Thickness is a factor that determines the storage capacitor (StgC) capacity.

That is, as the thickness of the first buffer layer 104 becomes thicker, the storage capacitor StgC becomes smaller in inverse proportion thereto, and as the thickness becomes thinner, the capacity of the storage capacitor StgC increases in proportion thereto .

Therefore, in order to realize a large capacity of the storage capacitor StgC, the first buffer layer 104 should have a thickness of 500 to 3000 ANGSTROM.

In the conventional organic electroluminescent device (1 in FIG. 1), the gate insulating film (16 in FIG. 1) or the interlayer insulating film (23 in FIG. 1) The interlayer insulating film (23 in FIG. 1) has a limitation in forming a thin film layer for performing a role as a dielectric layer of the storage capacitor (StgC1, StgC2 in FIG. 1) It was impossible.

However, in the case of the organic electroluminescent device 100 according to the first embodiment of the present invention, the first buffer layer 104 is a component independently acting as a dielectric layer of the storage capacitor StgC, SiO ₂₎ than it is possible to a dielectric constant is formed as a high silicon nitride (SiNx) to reduce the area of the storage capacitor, and can be adjusted appropriately in thickness as necessary, in which case the storage by as much as possible made thinner in the range of the process error is not generated The capacity of the capacitor StgC can be maximized.

On the other hand, a second storage electrode 106 is formed on the first buffer layer 104 and overlapped with the first storage electrode 103. At this time, the first storage electrode 103, the first buffer layer 104, and the second storage electrode 106 formed in the respective device regions form a storage capacitor StgC.

In the figure, the storage capacitor StgC is formed in the switching region STrA and the driving region DTrA in each device region DA as an example. However, as a variation thereof, FIGS. 4A and 4B The storage capacitor StgC has a structure in which the storage capacitance of the storage capacitor StgC is set to a predetermined value, as shown in a cross-sectional view of one pixel region including a driving thin film transistor, a storage capacitor, and an organic light emitting diode of the organic electroluminescence device according to various modifications of the embodiment. It may be formed so as to overlap only the switching thin film transistor STr (see FIG. 4A) or the driving thin film transistor FTr only (see FIG. 4B) in each device region DA for implementation.

A second buffer layer 108 made of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the first substrate 101 on the second storage electrode 106 .

At this time, the second buffer layer 108 prevents polycrystallization of the amorphous silicon layer to form polycrystalline silicon first and second semiconductor layers 113 and 115, The first and second semiconductor layers 113 and 115 are formed to prevent deterioration of characteristics of the first and second semiconductor layers 113 and 115 due to the release of alkali ions from the inside of the first substrate 101.

Next, the second buffer layer 108 is formed of pure polysilicon corresponding to each switching and driving region STrA and DTrA in each device region. The central portion of the first region 113a and the second region 115a form a channel, First and second semiconductor layers 113 and 115 are formed on both sides of the first regions 113a and 115a, respectively. The first and second semiconductor layers 113 and 115 are formed of a second region 113b and 115b doped with a high concentration of impurities in the polysilicon.

Although not shown in the drawing, the first and second semiconductor layers 113 and 115 may have a predetermined width between the first and second regions 113a and 115a and the second region 113b and 115b, A third region (not shown) doped with impurities at a low concentration relative to the concentration of the doped impurities of the first and second impurity regions 113b and 115b may be further provided.

Such a third region (not shown) is usually referred to as a lightly doped drain (LDD) region.

In the drawing, the first and second semiconductor layers 113 and 115 are formed of first and second regions 113a, 115a, 113b, and 115b, respectively.

In the first embodiment of the present invention, the first and second semiconductor layers 113 and 115 are made of polysilicon. However, the first and second semiconductor layers 113 and 115 And may be made of any one of oxide semiconductor materials such as IGZO (Indium Gallium Zinc Oxide), ZTO (Zinc Tin Oxide), ZIO (Zinc Indium Oxide), and ZnO (Zinc Oxide). In the case where the first and second semiconductor layers 113 and 115 are made of an oxide semiconductor material, the second and third regions 113b and 115b (not shown) doped with impurities are omitted.

Next, an inorganic insulating material such as silicon oxide (SiO2) is deposited on the entire surface of the first substrate 101, covering the first and second semiconductor layers 113 and 115 provided in the switching and driving regions StrA and DTrA, SiO ₂₎ or (and the gate insulating film 116 made of a silicon nitride (SiNx)) are formed.

The switching and driving regions StrA and DTrA are formed on the gate insulating layer 116 in correspondence to the first and second semiconductor layers 113 and 115 so as to be more precisely formed on the first and second semiconductor layers 113 and 113, The first and second gate electrodes 220a and 220b are formed corresponding to the first regions 113a and 115a, respectively.

The first and second gate electrodes 120a and 120b may be formed of a metal material having low resistance characteristics such as aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, molybdenum Molybdenum alloy (MoTi), or a multi-layer structure composed of two or more materials.

In the drawing, the first and second gate electrodes 120a and 120b have a single layer structure.

Although not shown in the drawing, the first gate electrode 120a (120a, 120b), which is made of the same material as the first and second gate electrodes 120a and 120b and has the switching region STrA, And extends in one direction corresponding to the boundary of each pixel region P and has a gate wiring (not shown).

An interlayer insulating film 123 made of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the first and second gate electrodes 120a and 120b and a gate wiring (not shown) And is formed on the entire surface of the substrate 101.

A semiconductor layer contact hole 125 exposing the second regions 113b and 115b of the first and second semiconductor layers 113 and 115 is formed in the interlayer insulating layer 123 and the gate insulating layer 116, And a storage contact hole sch for exposing the second storage electrode 106 is formed in the interlayer insulating layer 123 and the gate insulating layer 116 and the second buffer layer 108. The driving thin film transistor A gate contact hole gch exposing the second gate electrode 120b of the gate electrode DTr is formed.

4A and 4B illustrate an organic light emitting device according to various modified embodiments of the first embodiment of the present invention. The storage contact hole sch includes the interlayer insulating layer 123 and the gate insulating layer 116 And the second buffer layer 108 as well as the first buffer layer 104 to expose the surface of the first storage electrode 103.

Referring to FIG. 3, when the first and second semiconductor layers 113 and 115 are made of an oxide semiconductor material, the semiconductor layer contact holes gch are formed in the first and second semiconductor layers 113 and 115, Thereby exposing the both side end surfaces of the base plate.

A first source electrode 133a and a drain electrode 136a which are in contact with the second region 113b of the first semiconductor layer 113 through the semiconductor layer contact hole 125 are formed on the interlayer insulating layer 123, And a second source electrode (not shown) and a drain electrode 136b are formed in contact with the second region 115b of the second semiconductor layer 115, respectively.

When the first and second semiconductor layers are made of an oxide semiconductor material, the first source electrode 133a and the drain electrode 136a are in contact with the first semiconductor layer 113, respectively, (Not shown) and the drain electrode 136b are in contact with the second semiconductor layer 115, respectively.

A first auxiliary pattern 137 which is in contact with the second gate electrode 120b and is connected to the first drain electrode 136a is formed on the interlayer insulating layer 123 through the gate contact hole gch .

Although not shown in the drawing, the interlayer insulating film 123 is formed on the boundary of each pixel region P and extends in the direction crossing the gate interconnection (not shown) (Not shown), and a power supply line (not shown) connected to the second source electrode (not shown) is provided in parallel with the data line (not shown). At this time, a region captured by the gate wiring (not shown) and the data wiring (not shown) becomes the pixel region P. [

The first and second source and drain electrodes 133a and 136a and the second source and drain electrodes 136a and 136b and the data line (not shown), the power source line (not shown) Layered structure made of any one of aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, molybdenum (Mo) and molybdenum alloy (MoTi) Or more of the above materials to form a multi-layer structure.

In the drawing, first and second source and drain electrodes 133a and 136a, a second source and drain electrode (not shown), a data line (not shown), a power source line (not shown), and a first auxiliary pattern 137 A single layer structure is shown as an example.

The first semiconductor layer 113, the gate insulating film 116, the first gate electrode 120a, and the interlayer insulating film 123, which are sequentially stacked in the switching region STrA, The first and second gate electrodes 133a and 136a constitute a switching thin film transistor STr and the second semiconductor layer 115, the gate insulating film 116, the second gate electrode 120b, And the second source and drain electrodes 133b and 136b, which are spaced apart from each other, constitute a driving thin film transistor DTr.

Next, the first and second source and drain electrodes 133a and 136a, the second source and drain electrodes (not shown), the data line (not shown), the power source line (not shown), and the first auxiliary pattern 137 A protective layer 160 made of an organic insulating material, for example, photo-acrylic, or an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiN x) is provided.

At this time, the passivation layer 160 is provided with a drain contact hole 163 for exposing the second drain electrode 136b.

In the drawing, the protective layer 160 is made of an organic insulating material, and the surface of the protective layer 160 is flat.

A first electrode 165 electrically connected to the second drain electrode 136b through the drain contact hole 163 is formed in the light emitting region EA in each pixel region P above the protective layer 160 .

The first electrode 165 may be made of indium-tin-oxide (ITO), which is a transparent conductive material having a relatively high work function value to serve as an anode electrode. Alternatively, the first electrode 165 may have a work function (Al), an aluminum alloy (AlNd), a silver (Ag), a magnesium (Mg), a gold (Au) and an aluminum magnesium alloy (AlMg) .

Next, a bank 167 is formed on each pixel region P above the first electrode 165, more precisely, at the boundary of each light emitting region EA. At this time, the bank 167 is formed to surround the luminescent region EA and expose the center of the first electrode 165, overlapping the rim of the first electrode 165.

The bank 167 is made of a transparent organic insulating material such as polyimide or a black material such as a black resin.

An organic light emitting layer 170 is formed on the first electrode 165 of the light emitting region EA surrounded by the banks 167 of each pixel region P, A second electrode 173 is formed on the entire surface of the bank 167 to have a single plate shape.

At this time, the first and second electrodes 165 and 173 and the organic light emitting layer 170 formed therebetween form an organic light emitting diode (E).

Although not shown in the drawing, the first electrode 165 and the organic light emitting layer 170 are formed between the organic light emitting layer 170 and the second electrode 173, respectively. In order to improve the light emitting efficiency of the organic light emitting layer 170, A first luminescence compensation layer (not shown) and a second luminescence compensation layer (not shown) having a multilayer structure may be further formed.

When the first electrode 165 serves as an anode electrode, the first emission compensation layer (not shown) of a multilayer is sequentially stacked on the first electrode 165, and a hole injection layer and a hole transporting layer and the second emission compensation layer (not shown) may be sequentially stacked from the organic emission layer 170 and may include an electron transporting layer and an electron injection layer.

Although the first luminescence compensation layer (not shown) and the second luminescence compensation layer (not shown) have a bilayer structure as an example, the bilayer structure is not necessarily required. That is, the first emission compensation layer (not shown) may be a hole injection layer or a hole transport layer to form a single layer structure, and the second emission compensation layer (not shown) may also be an electron injection layer or an electron transport layer, .

In addition, the first emission compensation layer (not shown) may further include an electron blocking layer, and the second emission compensation layer (not shown) may further include a hole blocking layer.

Meanwhile, when the first electrode 165 serves as a cathode electrode, the positions of the first and second emission compensation layers (not shown) are changed from each other.

The second electrode 173 may be formed of a metal material having a relatively low work function value such as aluminum (Al), an aluminum alloy (AlNd), or the like, so as to serve as a cathode electrode when the first electrode 165 serves as an anode electrode. ), Silver (Ag), magnesium (Mg), gold (Au), and aluminum magnesium alloy (AlMg). When the first electrode 165 serves as a cathode electrode And is made of indium-tin-oxide (ITO) having a relatively high work function value to serve as an anode electrode.

Meanwhile, a second substrate (not shown) for encapsulation may be provided corresponding to the first substrate 101 having the above-described configuration.

The first substrate 101 and the second substrate (not shown) are provided with an adhesive (not shown) made of a sealant or a frit along an edge thereof. The adhesive (not shown) And the second substrate (not shown) are adhered to each other to maintain the panel state. At this time, a vacuum state may be established between the first substrate 101 and the second substrate (not shown) which are spaced apart from each other, or an inert gas atmosphere may be formed by being filled with an inert gas.

Meanwhile, the second substrate (not shown) for the encapsulation may be made of a plastic material having a flexible property, or may be made of a glass material.

Although the organic electroluminescent device 101 according to the embodiment of the present invention has a second substrate (not shown) for encapsulation spaced apart from the first substrate 101, The second substrate (not shown) may be configured to contact the second electrode 173 provided on the uppermost layer of the first substrate 101 in the form of a film including an adhesive layer.

As another modification according to the first embodiment of the present invention, an organic insulating film (not shown) or an inorganic insulating film (not shown) may further be provided on the second electrode 173 to form a capping film, An organic insulating film (not shown) or an inorganic insulating film (not shown) may be used as an encapsulation film (not shown). In this case, the second substrate (not shown) may be omitted.

The organic electroluminescent device 101 according to the first embodiment of the present invention having such a structure is characterized in that the storage capacitor StgC includes a switching thin film transistor STr and a driving thin film transistor STn, (DTr) or both of the two thin film transistors. Therefore, the organic electroluminescent device 101 according to the first embodiment of the present invention does not require a region for forming a separate storage capacitor StgC in each device region DA.

Therefore, the organic electroluminescent device 101 according to the first embodiment of the present invention reduces the area of the device area DA within each pixel area P and utilizes the reduced device area DA as the light emitting area There is an effect of improving the aperture ratio.

In addition, the organic electroluminescent device 101 according to the first embodiment of the present invention can form the storage capacitor StgC having the device region DA by utilizing almost the entire surface of the device region DA, The capacity of the capacitor StgC can be sufficiently secured.

Therefore, even if the organic EL device 101 according to the first embodiment of the present invention realizes a high resolution of 300 PPI or more, it has an effect of originally suppressing problems such as deterioration of display quality due to a small capacity of the storage capacitor StgC .

Furthermore, since the storage capacitor StgC overlaps with the switching or driving thin film transistor, the storage capacitor StgC functions as a light shielding element for blocking external light from entering the first and second semiconductor layers of the thin film transistors, There is an effect of originally preventing malfunction of the thin film transistor due to formation of light leakage current caused by light incident on the first and second semiconductor layers.

5 is a cross-sectional view of one pixel region including a switching and driving thin film transistor, a storage capacitor, and an organic light emitting diode according to a second embodiment of the present invention.

In the case of the reference numerals, 100 is added to the same components as in the first embodiment.

In this case, for convenience of description, a region where the switching and driving thin film transistors STr and DTr and the storage capacitor StgC are formed in each pixel region P is referred to as an element region DA and an organic light emitting diode E The region where the switching and driving TFTs STr and DTr are formed in the device region DA is defined as the switching and driving regions STrA and DTrA, .

The organic electroluminescent device 201 according to the present invention includes a first substrate 201 on which switching and driving thin film transistors STr and DTr, a storage capacitor StgC and an organic electroluminescent diode E are formed, , And a second substrate (not shown) for encapsulation.

First, the structure of the first substrate 201 will be described.

The first substrate 201 may be a glass substrate or a flexible substrate. When the first substrate 201 is a flexible substrate, the first substrate 201 may be made of polyethylene terephthalate (PET), polycarbonate (PC), polyolefin, polyethersulfone (PES) Or the like.

On the other hand, if the substrate of the organic electroluminescent device is replaced with a flexible substrate, it is flexible and can be folded and unfolded, so that it is not only light and impact-resistant, but also bent or bent.

A moisture permeation preventive layer 202 made of silicon oxide (SiO 2) or silicon nitride (SiNx) is formed as an inorganic insulating material on the first substrate 201.

Particularly, when the first substrate 201 is formed as a flexible substrate, unlike the glass substrate, it is indispensable to block water and oxygen gradually flowing into the substrate. Therefore, the moisture barrier 202 for blocking the moisture is essential to be.

The moisture permeation preventive layer 202 may be formed of a single layer of silicon oxide (SiO2) and silicon nitride (SiNx) as an inorganic insulating material, or may be laminated on each other. The inorganic insulating material and the organic insulating material may be laminated It can also be used as a charge.

Next, a first storage electrode 203 made of a metal material is formed on the moisture permeation preventive layer 202 to correspond to each device region DA.

A first buffer layer 204 made of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the first storage electrode 203. At this time, the first buffer layer 204 preferably has a thickness of 2000 to 4000 ANGSTROM.

The first buffer layer 204 serves as a dielectric layer as a component of the storage capacitor StgC in the organic electroluminescent device 200 according to the second embodiment of the present invention. Thickness is a factor that determines the storage capacitor (StgC) capacity.

That is, as the thickness of the first buffer layer 204 becomes thicker, the storage capacitor StgC becomes smaller in inverse proportion to the increase in thickness, and the thinner the storage capacitor StgC becomes, the smaller the capacity of the storage capacitor StgC becomes. .

Therefore, in order to realize a large capacity of the storage capacitor StgC, the first buffer layer 204 should have a thickness of 500 to 3000 ANGSTROM.

In the conventional organic electroluminescent device (1 in FIG. 1), the gate insulating film (16 in FIG. 1) or the interlayer insulating film (23 in FIG. 1) The interlayer insulating film (23 in FIG. 1) has a limitation in forming a thin film layer for performing a role as a dielectric layer of the storage capacitor (StgC1, StgC2 in FIG. 1) It was impossible.

However, in the case of the organic electroluminescent device 200 according to the second embodiment of the present invention, the first buffer layer 204 is a component that independently performs a role as a dielectric layer of the storage capacitor StgC, SiO ₂₎ than it is possible to a dielectric constant is formed as a high silicon nitride (SiNx) to reduce the area of the storage capacitor, and can be adjusted appropriately in thickness as necessary, in which case the storage by as much as possible made thinner in the range of the process error is not generated The capacity of the capacitor StgC can be maximized.

A second storage electrode 206 is formed on the first buffer layer 204 and overlapped with the first storage electrode 203. At this time, the first storage electrode 203, the first buffer layer 204, and the second storage electrode 206 formed in each device region form a storage capacitor StgC.

The storage capacitor StgC is formed in the switching region STrA and the driving region DTrA in each device region DA as an example. The storage capacitor StgC has a structure in which the storage capacitance of the storage capacitor StgC is set to a predetermined value, as shown in a cross-sectional view of one pixel region including the driving thin film transistor, the storage capacitor, and the organic light emitting diode of the organic electroluminescence device according to various modifications of the embodiment. Or may be formed so as to overlap only the switching thin film transistor STr (see FIG. 6A) or the driving thin film transistor FTr only (see FIG. 6B) in each device region DA for implementation.

A second buffer layer 208 made of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the first substrate 201 on the second storage electrode 206 .

At this time, the second buffer layer 208 is formed to prevent the polysilicon and the second storage electrode 206 from being short-circuited, and to crystallize the amorphous silicon layer to form the first and second semiconductor layers 213 and 215 of polysilicon The first and second semiconductor layers 213 and 215 are formed to prevent deterioration of characteristics of the first and second semiconductor layers 213 and 215 due to the release of alkali ions from the inside of the first substrate 201.

Next, the second buffer layer 208 is formed of pure polysilicon corresponding to the respective switching and driving regions STrA and DTrA in each device region, and the central portion thereof includes first regions 213a and 215a in which channels are formed, The first and second semiconductor layers 213 and 215 including the second regions 213b and 215b doped with a high concentration of impurities are formed in both sides of the first regions 213a and 215a.

Although not shown in the drawing, the first and second semiconductor layers 213 and 215 may have a predetermined width between the first and second regions 213a and 215b and the second region 213b and 215b, A third region (not shown) doped with impurities at a low concentration relative to the concentration of the doped impurities of the second impurity regions 213b and 215b may be further provided.

Such a third region (not shown) is usually referred to as a lightly doped drain (LDD) region.

In the drawing, the first and second semiconductor layers 213 and 215 are formed of first and second regions 213a, 215a, 213b and 215b, respectively.

In the second embodiment of the present invention, the first and second semiconductor layers 213 and 215 are made of polysilicon. However, the first and second semiconductor layers 213 and 215 must be formed of polysilicon. And may be made of any one of oxide semiconductor materials such as IGZO (Indium Gallium Zinc Oxide), ZTO (Zinc Tin Oxide), ZIO (Zinc Indium Oxide), and ZnO (Zinc Oxide). In the case where the first and second semiconductor layers 213 and 215 are made of an oxide semiconductor material, the second and third regions 213b and 215b (not shown) doped with impurities are omitted.

Next, an inorganic insulating material such as silicon oxide (SiO2) is deposited on the entire surface of the first substrate 201, covering the first and second semiconductor layers 213 and 215 provided in the switching and driving regions StrA and DTrA, SiO ₂₎ or (and) the gate insulation film 216 consisting of silicon nitride (SiNx) is formed.

The switching and driving regions StrA and DTrA are formed on the gate insulating layer 216 in correspondence to the first and second semiconductor layers 213 and 215 so that the first and second semiconductor layers 213 and 213, The first and second gate electrodes 220a and 220b are formed corresponding to the first regions 213a and 215a, respectively.

The first and second gate electrodes 220a and 220b may be formed of a metal material having low resistance characteristics such as aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, molybdenum Molybdenum alloy (MoTi), or a multi-layer structure composed of two or more materials.

In the drawing, the first and second gate electrodes 220a and 220b have a single layer structure.

Although not shown in the drawing, the first gate electrode 220a (220a, 220b), which is made of the same material as the first and second gate electrodes 220a and 220b and has the switching region STrA, And extends in one direction corresponding to the boundary of each pixel region P and has a gate wiring (not shown).

An interlayer insulating film 213 made of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is formed on the first and second gate electrodes 220a and 220b and the gate wiring (not shown) And is formed on the entire surface of the substrate 201.

A semiconductor layer contact hole 225 is formed in the interlayer insulating layer 213 and the gate insulating layer 216 to expose the second regions 213b and 215b of the first and second semiconductor layers 213 and 215, And a storage contact hole sch for exposing the second storage electrode 206 is formed in the interlayer insulating layer 213, the gate insulating layer 216 and the second buffer layer 208, A gate contact hole gch exposing the second gate electrode 220b of the gate electrode DTr is formed.

6A and 6B illustrate an organic light emitting device according to various modified examples of the second embodiment of the present invention. The storage contact hole sch is formed of the interlayer insulating film 213 and the gate insulating film 216 And the second buffer layer 208 as well as the first buffer layer 204 to expose the surface of the first storage electrode 203.

5, when the first and second semiconductor layers 213 and 215 are made of an oxide semiconductor material, the semiconductor layer contact holes gch are formed in the first and second semiconductor layers 213 and 215, Thereby exposing the both side end surfaces of the base plate.

A first source electrode 233a and a drain electrode 236a which are in contact with the second region 213b of the first semiconductor layer 213 through the semiconductor layer contact hole 225 are formed on the interlayer insulating film 213, And a second source electrode (not shown) and a drain electrode 236b are formed to be in contact with the second region 215b of the second semiconductor layer 215, respectively.

In the case where the first and second semiconductor layers are made of an oxide semiconductor material, the first source electrode 233a and the drain electrode 236a are in contact with the first semiconductor layer 213, (Not shown) and the drain electrode 236b are in contact with the second semiconductor layer 215, respectively.

A first auxiliary pattern 237 which is in contact with the second gate electrode 220b and is connected to the first drain electrode 236a is formed on the interlayer insulating layer 213 through the gate contact hole gch .

Although not shown in the figure, a data line (not shown) extending in a direction intersecting the gate line (not shown) at the boundary of each pixel region P and connected to the first source electrode 233a is formed on the interlayer insulating film 213, (Not shown), and a power supply line (not shown) connected to the second source electrode (not shown) is provided in parallel with the data line (not shown). At this time, a region captured by the gate wiring (not shown) and the data wiring (not shown) becomes the pixel region P. [

The first and second source and drain electrodes 233a and 236a and the second source and drain electrodes 236a and 236b and the data line (not shown), the power source line (not shown), and the first auxiliary pattern 237 have low resistances Layered structure made of any one of aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, molybdenum (Mo) and molybdenum alloy (MoTi) Or more of the above materials to form a multi-layer structure.

(Not shown), a power supply wiring (not shown), and a first auxiliary pattern 237 are formed on the first source and drain electrodes 233a and 236a and the second source and drain electrodes 236a and 236b A single layer structure is shown as an example.

The first semiconductor layer 213, the gate insulating film 216, the first gate electrode 220a, and the interlayer insulating film 213, which are sequentially stacked in the switching region STrA, The gate electrodes 233a and 236a constitute a switching thin film transistor STr and are electrically connected to the second semiconductor layer 215, the gate insulating layer 216, the second gate electrode 220b, And the second source and drain electrodes 233b and 236b, which are spaced apart from each other, constitute a driving thin film transistor DTr.

Next, the first source and drain electrodes 233a and 236a, the second source and drain electrodes (not shown), the data line (not shown), the power supply line (not shown), and the first auxiliary pattern 237 A protective layer 260 made of an organic insulating material such as photoacrylic or an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiN x) is provided.

At this time, the passivation layer 260 is provided with a drain contact hole 263 for exposing the second drain electrode 236b.

In the figure, the protective layer 260 is made of an organic insulating material, and the surface of the protective layer 260 is flat.

A first electrode 265 electrically connected to the second drain electrode 236b through the drain contact hole 263 is formed in the emission region EA in each pixel region P above the protective layer 260 .

The first electrode 265 may be made of indium-tin-oxide (ITO), which is a transparent conductive material having a relatively high work function to serve as an anode electrode, or may be formed of ITO (Al), an aluminum alloy (AlNd), a silver (Ag), a magnesium (Mg), a gold (Au) and an aluminum magnesium alloy (AlMg) .

Next, banks 267 are formed on the first electrode 265 at each pixel region P, more precisely at the boundary of each light emitting region EA. At this time, the bank 267 is formed so as to surround the luminescent region EA and expose the center of the first electrode 265, overlapping the rim of the first electrode 265.

The bank 267 may be made of a transparent organic insulating material such as polyimide or a black material such as a black resin.

An organic light emitting layer 270 is formed on the first electrode 265 of the light emitting region EA surrounded by the banks 267 of each pixel region P, A second electrode 273 is formed on the entire upper surface of the bank 267 and has a single plate shape.

At this time, the first and second electrodes 265 and 273 and the organic light emitting layer 270 formed therebetween form an organic light emitting diode E.

Although not shown in the drawing, the first electrode 265 and the organic light emitting layer 270 are formed between the organic light emitting layer 270 and the second electrode 273, A first luminescence compensation layer (not shown) and a second luminescence compensation layer (not shown) having a multilayer structure may be further formed.

When the first electrode 265 serves as an anode electrode, the first emission compensation layer (not shown) of a multilayer is sequentially stacked on the first electrode 265, and a hole injection layer and a hole transporting layer and the second emission compensation layer (not shown) may be sequentially stacked from the organic emission layer 270 and may include an electron transporting layer and an electron injection layer.

Although the first luminescence compensation layer (not shown) and the second luminescence compensation layer (not shown) have a bilayer structure as an example, the bilayer structure is not necessarily required. That is, the first emission compensation layer (not shown) may be a hole injection layer or a hole transport layer to form a single layer structure, and the second emission compensation layer (not shown) may also be an electron injection layer or an electron transport layer, .

In addition, the first emission compensation layer (not shown) may further include an electron blocking layer, and the second emission compensation layer (not shown) may further include a hole blocking layer.

Meanwhile, when the first electrode 265 serves as a cathode electrode, the positions of the first and second emission compensation layers (not shown) are changed each other.

The second electrode 273 may be formed of a metal material having a relatively low work function value such as aluminum (Al), an aluminum alloy (AlNd), or the like, so as to serve as a cathode electrode when the first electrode 265 serves as an anode electrode. ), Silver (Ag), magnesium (Mg), gold (Au), and aluminum magnesium alloy (AlMg). When the first electrode 265 serves as a cathode electrode And is made of indium-tin-oxide (ITO) having a relatively high work function value to serve as an anode electrode.

Meanwhile, a second substrate (not shown) for encapsulation may be provided corresponding to the first substrate 201 having the above-described structure.

The first substrate 201 and the second substrate (not shown) are provided with an adhesive (not shown) made of a sealant or a frit along an edge thereof. The adhesive (not shown) And the second substrate (not shown) are adhered to each other to maintain the panel state. At this time, a vacuum state may be established between the first substrate 201 and the second substrate (not shown) which are spaced apart from each other, or an inert gas atmosphere may be formed by being filled with an inert gas.

Meanwhile, the second substrate (not shown) for the encapsulation may be made of a plastic material having a flexible property, or may be made of a glass material.

Although the organic electroluminescent device 201 according to the embodiment of the present invention has a second substrate (not shown) for encapsulation spaced apart from the first substrate 201, The second substrate (not shown) may be configured to contact the second electrode 273 provided on the uppermost layer of the first substrate 201 in the form of a film including an adhesive layer.

As another modification of the second embodiment of the present invention, an organic insulating layer (not shown) or an inorganic insulating layer (not shown) may be further formed on the second electrode 273 to form a capping layer. An organic insulating film (not shown) or an inorganic insulating film (not shown) may be used as an encapsulation film (not shown). In this case, the second substrate (not shown) may be omitted.

The organic electroluminescent device 201 according to the second embodiment of the present invention having such a structure is characterized in that the storage capacitor StgC is formed by a switching thin film transistor STr and a driving thin film transistor STn, (DTr) or both of the two thin film transistors. Therefore, the organic electroluminescent device 201 according to the second embodiment of the present invention does not require a region for forming a separate storage capacitor StgC in each device region DA.

Therefore, the organic electroluminescent device 201 according to the second embodiment of the present invention reduces the area of the device area DA in each pixel area P and utilizes the reduced device area DA as the light emitting area There is an effect of improving the aperture ratio.

In addition, the organic electroluminescent device 201 according to the second embodiment of the present invention can be formed by utilizing almost the entire surface of the device region DA as the storage capacitor StgC having the device region DA, The capacity of the capacitor StgC can be sufficiently secured.

Therefore, even if the organic EL device 201 according to the second embodiment of the present invention realizes a high resolution of 300 PPI or more, it has an effect of originally suppressing problems such as deterioration of display quality due to a small capacity of the storage capacitor StgC .

Furthermore, since the storage capacitor StgC overlaps with the switching or driving thin film transistor, the storage capacitor StgC functions as a light shielding element for blocking external light from entering the first and second semiconductor layers of the thin film transistors, There is an effect of originally preventing malfunction of the thin film transistor due to formation of light leakage current caused by light incident on the first and second semiconductor layers.

In addition, when the organic electroluminescent device 201 according to the second embodiment of the present invention is formed of a flexible substrate, a moisture permeation preventive layer 202 is additionally formed on the substrate so that moisture and oxygen introduced into the substrate can be blocked And the storage capacitor StgC formed under the thin film transistor also acts as a blocking layer for shielding the electric field generated from the static electricity generated in the flexible substrate, The manufacturing process can be simplified.

The present invention is not limited to the above-described embodiments and modifications, and various changes and modifications can be made without departing from the spirit of the present invention.

100: Organic electroluminescent device
101: first substrate
103: first storage electrode
104: first buffer layer
106: second storage electrode
108: second buffer layer
113: first semiconductor layer
113a, 113b, and 113c: first, second, and third regions (of the first semiconductor layer)
115: second semiconductor layer
115a, 115b and 115c: first, second and third regions (of the second semiconductor layer)
116: gate insulating film
120a, 120b: first and second gate electrodes
123: Interlayer insulating film
125: semiconductor layer contact hole
126: gate contact hole
133a: a first source electrode
136a, 136b: first and second drain electrodes
137: first auxiliary pattern
160: protective layer
DA: device region
DTr: driving thin film transistor
DTrA: driving area
EA: light emitting region
gch: gate contact hole
P: pixel area
sch: Story Contact Hole
StgC: storage electrode
STr: switching thin film transistor
STrA: Switching area

Claims (12)

A first substrate having a pixel region and an element region and a light emitting region defined in the pixel region;
A storage capacitor formed in the device region on the first substrate and having a stacked structure of a first storage electrode, a first buffer layer, and a second storage electrode;
A second buffer layer formed on the storage capacitor;
A plurality of thin film transistors formed in the device region above the second buffer layer; And
And a protective layer formed on the plurality of thin film transistors,
Wherein the storage capacitor is formed to overlap with at least one thin film transistor among the plurality of thin film transistors.
The method according to claim 1,
And an anti-moisture barrier layer formed between the first substrate and the first storage electrode.
3. The method of claim 2,
Wherein the first substrate is a flexible substrate.
3. The method according to claim 1 or 2,
Wherein the first and second storage electrodes are made of a metal material, and the first buffer layer is made of an inorganic insulating material.
3. The method according to claim 1 or 2,
Wherein the plurality of thin film transistors each include a semiconductor layer, a gate insulating film, a gate electrode, an interlayer insulating film having a semiconductor layer contact hole exposing the semiconductor layer, and an interlayer insulating film which contacts the semiconductor layer through the semiconductor layer contact hole, And a drain electrode.
6. The method of claim 5,
The plurality of thin film transistors are switching and driving thin film transistors,
Wherein the storage capacitor overlaps with either the thin film transistor of the switching and driving thin film transistor or the switching and driving thin film transistor.
6. The method of claim 5,
Wherein the semiconductor layer is made of polysilicon or an oxide semiconductor material.
6. The method of claim 5,
Further comprising a first auxiliary pattern formed on the interlayer insulating film,
Wherein the first auxiliary pattern is connected to a drain electrode of the switching thin film transistor, a gate electrode of the driving thin film transistor, and the storage capacitor.
9. The method of claim 8,
Wherein the first auxiliary pattern is connected to the second storage electrode through a storage contact hole exposing the second storage electrode included in the interlayer insulating layer, the gate insulating layer, and the second buffer layer.
9. The method of claim 8,
Wherein the first auxiliary pattern is connected to the first storage electrode through the storage contact hole exposing the first storage electrode included in the interlayer insulating layer, the gate insulating layer, the second buffer layer, and the first buffer layer. Light emitting element.
9. The method of claim 8,
Wherein the first auxiliary pattern is connected to the gate electrode of the driving thin film transistor through a gate contact hole exposing the gate electrode provided in the interlayer insulating film.
6. The method of claim 5,
And an organic light emitting diode formed on the protective layer and in the light emitting region,
Wherein the organic light emitting diode is connected to the drain electrode of the driving thin film transistor through the drain contact hole exposing the drain electrode of the driving thin film transistor provided in the passivation layer.

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