KR20140084603A - Dual sided emission type Organic electro luminescent device - Google Patents

Abstract

The present invention relates to a double-side display type organic electro-luminescence device and a manufacturing method thereof. The double-side display type organic electro-luminescence device includes: a substrate defining multiple first pixel areas and second pixel areas; driving and switching thin-film transistors included in respective element area in the first and second pixel areas; a protection layer formed above the driving or switching thin-film transistors; and an organic electro-luminescence diodes which are connected to drain electrodes of the driving thin-film transistors and are included in respective light emission areas in the first and second pixel areas. The electro-luminescence diodes are formed on the protection layers in the first pixel areas to emit light upward, and the electro-luminescence diodes are formed on gate insulation layers in the second pixel areas to emit light downward through first openings in the protection layers.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bi-directional display type 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 a double-side emission organic electroluminescent device having the same level of display quality.

An organic electroluminescent device, which is one of flat panel displays (FPDs), has high luminance and low operating voltage characteristics. In addition, since it 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), has no viewing angle limit, 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.

In addition, since the fabrication process of the organic electroluminescent device is all the deposition and encapsulation equipment, the manufacturing process is very simple.

An organic electroluminescent device having such characteristics is largely 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 a matrix type device, The scan lines are sequentially driven with time in order to drive the scan lines. Therefore, in order to represent the required average luminance, the instantaneous luminance must be equal to the average luminance multiplied by the number of lines.

However, in the active matrix method, a thin film transistor (TFT), which is a switching element for turning on / off a pixel region, is disposed for each pixel region, and a driving thin film transistor A power supply line, and an organic light emitting diode, and is formed for each pixel region.

At this time, the first electrode connected to the driving thin film transistor is turned on / off in the pixel region unit, and the second electrode facing the first electrode serves as a common electrode, Thereby forming the organic electroluminescent diode.

In the active matrix system having such a constitutional characteristic, the voltage applied to the pixel region is charged in the storage capacitor StgC, and power is applied until the next frame signal is applied, Continue to run for one screen without. 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 schematic cross-sectional view of a portion of a display region of a conventional organic light emitting device.

As shown in the figure, in the conventional organic electroluminescent device 1, the first and second substrates 10 and 70 are arranged so as to face each other.

In the first substrate 10, a display area AA and a non-display area (not shown) are defined outside the display area AA. In the display area AA, a gate wiring (not shown) A plurality of pixel regions P defined as regions captured by data lines (not shown) are provided, and power lines (not shown) are provided in parallel with the data lines (not shown). A switching and driving thin film transistor (not shown) DTr is formed in each of the plurality of pixel regions P and a first electrode 47 is formed to be connected to the driving thin film transistor DTr.

An organic light emitting layer 55 including organic light emitting patterns 55a, 55b and 55c for emitting red, green and blue colors is formed on the first electrode 47 And a second electrode 58 is formed on the entire surface of the display region on the organic light emitting layer 55.

The second substrate 70 is opposed to the first substrate 10 having the above-described components for encapsulation, and the first substrate 10 and the second substrate 70 A face seal 80 is provided or a seal pattern (not shown) is provided along the rim of the first substrate 10 and the second substrate 70 so that the first substrate 10 and the second substrate 70 are adhered to each other to maintain the state of the panel .

On the other hand, the organic electroluminescent device having the above-described configuration is an upper light emitting device or a lower light emitting device, and the organic electroluminescent device having such a configuration can be finally obtained only through the surface of the first substrate or the second substrate surface .

On the other hand, in recent years, effort and research have been actively conducted to develop a bidirectional display device capable of displaying the same image or different images in both directions by moving away from a display device that displays an image in only one direction.

Therefore, in order to respond to the trend of such a display device, it is required that the organic electroluminescent device has a structure capable of bidirectional viewing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an organic electroluminescent device capable of displaying the same image or different images in both directions and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a double-sided display type organic electroluminescent device including: a substrate having a first pixel region and a second pixel region defined therein; A driving and switching thin film transistor provided in each element region in each of the first and second pixel regions; A protective layer formed over the driving and switching thin film transistors; And an organic light emitting diode (OLED) connected to a drain electrode of the driving thin film transistor and provided in each of the light emitting regions in the first and second pixel regions, wherein the organic light emitting diode And the organic light emitting diode is formed on the gate insulating layer through the first opening provided in the passivation layer in the second pixel region, and the organic light emitting diode emits light at the bottom.

In this case, the organic light emitting diode includes a first electrode, an organic light emitting layer, and a second electrode. The first electrode of the first pixel region includes a lower layer made of a metal material and an upper layer made of a transparent conductive material And the first electrode included in the second pixel region has a single layer structure of a transparent conductive material.

The protective layer may include a drain contact hole exposing a drain electrode of the driving thin film transistor in the first pixel region, and the drain electrode and the first electrode may be in contact with each other through the drain contact hole. And one end of the drain electrode of the driving thin film transistor in the second pixel region extends to the light emitting region and contacts the first electrode formed on the gate insulating film.

The driving and switching film transistors included in the respective device regions of the first and second pixel regions may be formed by stacking a polysilicon semiconductor layer, a gate insulating film, a gate electrode, and an interlayer insulating film, .

In this case, the semiconductor layer of the polysilicon includes an active region corresponding to the gate electrode and an ohmic region doped with impurities on both sides of the active region, the interlayer insulating layer including a semiconductor layer contact hole exposing the respective ohmic regions, And a second opening exposing the first electrode in correspondence with the light emitting region of the two pixel regions, and each of the source and drain electrodes is connected to the ohmic region of the semiconductor layer through the semiconductor layer contact hole, .

Each of the gate electrodes has a double layer structure of a lower layer of a transparent conductive material and an upper layer of a low resistance metal material. In this case, a storage region is further defined in each of the first and second pixel regions, A first storage electrode made of polysilicon doped with impurities forming the ohmic region is provided on the same layer on which the semiconductor layer is formed, and a second storage electrode corresponding to the first storage electrode is formed on the interlayer insulating film, The first storage electrode and the second storage electrode overlapping each other with the second storage electrode having a single layer structure and the gate insulating film interposed between the two storage electrodes constitute a storage capacitor.

A gate wiring connected to the gate electrode of the switching thin film transistor and extending in one direction on the gate insulating film; A data line connected to the source electrode of the switching thin film transistor and a power line connected to the driving thin film transistor and spaced apart from the data line, the gate line intersecting the interlayer insulating film.

A bank is formed by overlapping the edges of the first electrodes at the boundaries of the first and second pixel regions.

A method of manufacturing a double-sided display type organic electroluminescent device according to an embodiment of the present invention includes the steps of forming a plurality of first pixel regions and a plurality of second pixel regions in a device region defined in first and second pixel regions on a substrate Forming a semiconductor layer of polysilicon; Forming a gate insulating film over the semiconductor layer of the polysilicon; A gate electrode having a bilayer structure of a lower layer made of a transparent conductive material and an upper layer made of a metal material over each of the device regions above the gate insulating film and an anode pattern having the same double layer structure as the gate electrode corresponding to the second pixel region ; Forming an ohmic region in the semiconductor layer by doping the impurity using the gate electrode as a doping-preventing mask; Forming an interlayer insulating film having a contact hole on the gate electrode and exposing the ohmic region of each semiconductor layer and a first opening corresponding to the anode pattern of the second pixel region; A source electrode and a drain electrode that are in contact with the ohmic region and are spaced apart from each other through the semiconductor layer contact holes are formed on the interlayer insulating film to form a switching and driving thin film transistor in each device region, The drain electrode of the driving thin film transistor having one end thereof is extended to be in contact with one end of the anode pattern, and the upper layer of the anode pattern is removed to form a first anode electrode; And a drain contact hole having a first thickness over the switching and driving thin film transistor and exposing a drain electrode of a driving thin film transistor provided in the first pixel region, wherein a second thickness corresponding to the anode pattern is smaller than the first thickness Forming a protective layer on the substrate; Forming a second anode electrode having a double layer structure of a lower layer of a metal material and an upper layer of a transparent conductive material in the first pixel region on the protective layer; Removing the protective layer having the second thickness to expose the first anode electrode; Forming an organic light emitting layer corresponding to the first and second anode electrodes; And forming a cathode electrode over the organic light emitting layer.

At this time, the step of forming the semiconductor layer may include forming a first storage electrode made of the same material as the semiconductor layer in a storage region in each of the first and second pixel regions, Wherein forming the gate electrode comprises forming a gate electrode on the first storage electrode and a gate electrode on the gate electrode, And forming a single layer of the second storage electrode.

The forming of the gate electrode and the anode pattern of the double layer structure and the second storage electrode of the single layer structure may include sequentially forming a transparent conductive material layer and a metal layer on the gate insulating layer; Forming a first photoresist pattern of a first thickness over the low resistance metal layer and a second photoresist pattern of a second thickness thinner than the first thickness; Forming a storage pattern having an anode pattern and a bilayer structure with the gate electrode of the bilayer structure by removing the transparent conductive material layer located under the metal layer exposed to the outside of the first and second photoresist patterns; Exposing the storage pattern by ashing and removing the second photoresist pattern; Forming a first layer of a transparent conductive material on the first storage electrode by etching and removing an upper layer of the storage pattern; And advancing the strip to remove the first photoresist pattern.

The step of forming the gate electrode may include forming a gate wiring connected to the gate electrode of the switching thin film transistor and extending in one direction, and the step of forming the source and drain electrodes may include crossing the gate wiring A data line connected to the source electrode of the switching thin film transistor, and a power line spaced apart from the data line.

Forming a buffer layer on the substrate before forming the semiconductor layer; And forming banks at the boundaries of the first and second pixel regions overlapping the edges of the first and second anode electrodes.

In the organic electroluminescent device according to the present invention, light emitted from the second substrate surface is emitted from the first pixel region, and light emitted from the first substrate surface is emitted from the second pixel region.

Therefore, the user can selectively view the image through the first substrate surface or view the image through the second substrate surface through the double-sided display type organic electroluminescent device according to the embodiment of the present invention, The effect of improving the selection width of the image viewing is obtained.

Further, there is provided an organic electroluminescent device that responds to both-side display of a display device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view of a portion of a display area of a conventional organic electroluminescent device. FIG.
3 is a cross-sectional view of a portion of a display region of a double-sided display type organic electroluminescent device according to an embodiment of the present invention, illustrating a first pixel region that emits light at the top.
FIG. 4 is a cross-sectional view of a portion of a display region of a double-sided display type organic electroluminescent device according to an embodiment of the present invention, illustrating a second pixel region that emits light below. FIG.
FIGS. 5A to 5Q are cross-sectional views illustrating steps of manufacturing a double-sided display type organic electroluminescent device according to an embodiment of the present invention.
FIGS. 6A to 6Q are cross-sectional views illustrating steps of manufacturing a double-sided display type organic electroluminescent device according to an embodiment of the present invention.

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

First, the structure and operation of the organic electroluminescent device will be briefly described with reference to FIG. 2, which is a circuit diagram for one pixel of the organic electroluminescent device.

As shown, one pixel of the organic electroluminescent device includes a switching thin film transistor STr, a driving thin film transistor DTr, a storage capacitor StgC, and an organic light emitting diode E.

That is, a gate line GL is formed in a first direction and a data line DL is formed in a second direction intersecting the first direction to define a pixel region P, A power supply line PL for applying a power supply voltage is formed.

A switching thin film transistor STr is formed at the intersection of the data line DL and the gate line GL and a driving thin film transistor DTr electrically connected to the switching thin film transistor STr is formed have.

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 of the other electrode is grounded, The electrode is connected to the power supply line PL so that the power supply line PL transfers the 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 thin film transistor DTr is turned on so that light is output through the organic light emitting diode E.

At this time, when the driving thin film transistor DTr is turned on, a level of a current flowing from the power supply line PL to the organic light emitting diode E is determined. Accordingly, the organic light emitting diode E The storage capacitor StgC is capable of maintaining a constant gate voltage of the driving thin film transistor DTr when the switching thin film transistor STr is turned off The level of the current flowing through the organic light emitting diode E can be kept constant until the next frame even if the switching thin film transistor STr is turned off.

FIGS. 3 and 4 are cross-sectional views of a portion of a display region of a double-sided display type organic electroluminescent device according to an exemplary embodiment of the present invention, respectively, illustrating a top-emitting pixel region and a bottom-emitting pixel region. A region where the switching and driving thin film transistor DTr is formed in each pixel region P is defined as an element region DA and a region where the organic electroluminescent layer 163 is formed is defined as a light emitting region EA .

The double-sided display type organic electroluminescent device 101 according to the embodiment of the present invention is characterized in that a plurality of pixel regions P constituting a display region are divided into a pixel region in which light is emitted in the upper portion and a pixel region in which light is emitted in the lower portion . Hereinafter, for convenience of description, the upper light emitting pixel region is defined as a first pixel region P1, the lower light emitting pixel region is defined as a second pixel region P2, and an element region And an element region and a light emitting region provided in the first element region DA1 and the first light emitting region EA1 and the second pixel region P2 are referred to as a second element region DA2 and a second light emitting region EA2).

In the double-sided display type organic electroluminescent device according to the embodiment of the present invention, the first pixel region P1 and the second pixel region P2 are arranged so as to alternate regularly so that the same image in both directions or different images .

Since the neighboring three pixel regions that emit red, green, and blue light are typically the minimum units for realizing one full color, the double-sided display type organic electroluminescent device 101 according to the embodiment of the present invention has a red Three first pixel regions P1 for emitting red, green and blue light are divided into a first region (not shown) and three second pixel regions P2 for emitting red, green and blue light in a second region (not shown) (Not shown) and the second area (not shown) alternately and repeatedly so that the user can look at the first substrate or look at the second substrate opposite to the first substrate, And the like.

It will be appreciated that the arrangement of the first pixel region P1 and the second pixel region P2 may be variously modified in addition to the arrangement as described above.

For example, the first pixel region P1 and the second pixel region P2 may be alternately arranged in units of pixel lines.

Hereinafter, the configuration of the double-sided display type organic electroluminescent device 101 according to the embodiment of the present invention will be described in more detail.

The double-sided display type organic electroluminescent device 101 according to the embodiment of the present invention includes a driving and switching thin film transistor (DTr1, DTr2) (not shown) and a first organic electroluminescent A substrate 110, and a second substrate 170 for encapsulation. At this time, the second substrate 170 may be omitted by being replaced with an inorganic insulating film, an organic insulating film, or the like.

First, the structure of the first substrate 110 provided with the driving and switching thin film transistors (DTr1 and DTr2) (not shown) and the organic light emitting diode E will be described.

Each of the device regions DA1 and DA2 in the first and second pixel regions P1 and P2 of the first substrate 110 is made of pure polysilicon and each of the active regions 113a, And an ohmic region 113b doped with impurities at a high concentration on both sides of the active region 113a.

A first storage electrode made of polysilicon doped with a high concentration of impurities as in the ohmic region 113b is formed in the storage region StgA in each pixel region (DTr1, DTr2, not shown). Although it is shown that the storage area StgA is provided only in the first pixel area P1, the storage area StgA is also provided in the second pixel area P2.

A buffer layer 111 made of an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) may be further formed on the entire surface between the semiconductor layer 113 and the first substrate 110.

The buffer layer 111 is formed to prevent deterioration of the characteristics of the semiconductor layer 113 due to the release of alkali ions from the inside of the first substrate 110 when the semiconductor layer 113 is crystallized.

A gate insulating layer 116 is formed on the entire surface of the semiconductor layer 113 and a work function value corresponding to the active region 113a of the semiconductor layer 113 is formed on the gate insulating layer 116 A gate electrode 118 having a double structure of a lower transparent electrode 118a made of indium-tin-oxide (ITO) and an upper layer 118b made of a low resistance metal material is formed.

A gate wiring (not shown) having a double layer structure which is connected to a gate electrode (not shown) of a switching thin film transistor (not shown) and extends in one direction and has the same structure as the gate electrode 118 is formed on the gate insulating layer 116, Respectively.

A single layer structure of the transparent conductive material forming the lower layer 118a of the gate electrode 118 corresponding to the first storage electrode 115 on the gate insulating film 116 in the storage region StgA is referred to as a second layer structure A storage electrode 119 is formed.

At this time, as one of the most characteristic structures in the double-sided display type organic electroluminescent device 101 according to the embodiment of the present invention, the second light emitting region EA2 of the second pixel region P2 has the gate insulating film 116 (Hereinafter referred to as the second pixel region P2), which is a single layer structure of only a transparent conductive material having a high work function value, constituting the lower layer 118a of the gate electrode 118, 122 ") are formed.

Next, an interlayer insulating film 123 is formed on the entire surface of the gate electrode 118, the gate wiring (not shown), and the second storage electrode 119. At this time, the interlayer insulating layer 123 is removed from the light emitting region of the second pixel region P2, thereby exposing the second anode 122.

At this time, a semiconductor layer contact hole 125 is formed in the interlayer insulating layer 123 and the gate insulating layer 116 below the interlayer insulating layer 123 to expose the ohmic regions 113b located on both sides of the active regions 113a.

A data line (not shown) is formed on the interlayer insulating layer 123 including the semiconductor layer contact hole 125 to define pixel regions P intersecting the gate lines (not shown) Thereby forming power supply wiring (not shown).

The source and drain electrodes 133a and 133b are in contact with the ohmic regions 113b exposed through the semiconductor layer contact holes 125 and spaced apart from each other in the device regions DA1 and DA2 above the interlayer insulating film 123, 133b, 136a, 136b) are formed.

At this time, the source and drain electrodes 133a and 133b, 136a and 136b, and the ohmic region 113b contacting the electrodes 133a and 133b and 136a and 136b, The gate insulating layer 116 and the gate electrode 118 formed on the semiconductor layer 113 constitute driving thin film transistors DTr1 and DTr2 and switching thin film transistors (not shown), respectively.

As one of the most characteristic structures of the double-sided display type organic electroluminescent device 101 according to the embodiment of the present invention, a driving thin film transistor (TFT) provided in the second device region DA2 in the second pixel region P2 The drain electrode 136b of the second light emitting portion DTr2 extends to the second light emitting region EA2 and is in contact with one end of the second anode electrode 122. [

Each of the switching thin film transistors (not shown) is electrically connected to the driving thin film transistors DTr1 and DTr2 and a gate wiring (not shown) and a data wiring (not shown). The data wiring Is connected to a source electrode (not shown) of the switching thin film transistor (not shown).

In addition, a protective layer 140 having a flat surface over the entire surface of the driving and switching thin film transistors (DTr1 and DTr2) (not shown) is formed.

A drain contact hole 143 is formed in the passivation layer 140 to expose a drain electrode 136 of a driving TFT DTr included in the first device region DA1. In the region EA2, a first opening op1 for exposing the second anode electrode 122 is formed.

The protective layer 140 having the drain contact hole 143 and the first opening op1 for exposing the second anode electrode 122 is formed on the first electrode The first anode electrode 146 is formed in the first light emitting region EA1 in contact with the drain electrode 136a of the thin film transistor DTr1 through the drain contact hole 143. [

At this time, the first anode electrode 146 has a bilayer structure, and the lower layer 146a serves as a reflector and the upper layer 146b serves as a substantial anode electrode.

That is, the upper layer 146b of the first anode electrode 146 is made of a transparent conductive material such as indium-tin-oxide (ITO) having a large work function value to serve as an anode electrode, The lower layer 147a of the organic light emitting layer 146 is formed of a metal material having excellent reflection efficiency such as aluminum or silver so that light emitted from the organic light emitting layer 163 formed on the first anode electrode 146 And reflects the light upward to improve the luminous efficiency.

The first anode electrode 146 having such a bilayer structure is formed only for the first light emitting region EA1. This is because a second anode electrode 122 having a single layer structure of a transparent conductive material is formed on the gate insulating layer 116 in the second emission region EA2.

Next, the first and second anode electrodes 146 and 122 are formed on the boundary of each pixel region P above the first anode electrode 146 having the bilayer structure in such a manner as to surround the respective light- And the bank 155 is formed.

In this case, the bank 155 is formed of a transparent organic insulating material such as polyimide, styrene, methyl mathacrylate, or polytetrafluoroethylene to be.

Each of the first and second anode electrodes 146 and 122 emits red, green, or blue light in each of the light emitting regions P surrounded by the bank 155. An organic light emitting layer 163 is formed.

A metal material having a low work function value such as a metal material such as aluminum (Al), an aluminum alloy (AlNd), silver (Ag), magnesium (Mg), gold Au, and an aluminum magnesium alloy (AlMg). The cathode electrode 167 is made of a material in which one or more of Al and Mg are mixed.

At this time, the organic light emitting layer 163 formed between the anode electrodes 146 and 122 and the cathode electrode 167 forms the organic light emitting diode E.

Although not shown in the drawing, a multilayer structure (not shown) is formed between the anode electrodes 146 and 122 and the organic light emitting layer 163 and between the organic light emitting layer 163 and the cathode electrode 167 to improve the luminous efficiency of the organic light emitting layer 163, A first light emission compensation layer (not shown) and a second emission compensation layer (not shown) may be further formed.

At this time, the first emission compensation layer (not shown) of a plurality of layers is sequentially stacked from the anode electrodes 146 and 122, and may be a hole injection layer and a hole transporting layer, 2 emission compensation layer (not shown) may be formed of an electron transporting layer and an electron injection layer from the organic light emitting layer 163.

The first emission compensation layer (not shown) and the second emission compensation layer (not shown) of the multi-layer structure may be formed on the entire surface of the display region in a plate form or may be formed separately for each pixel region .

Meanwhile, a second substrate 170 for encapsulation is provided corresponding to the first substrate 110 of the organic electroluminescent device 101 according to the embodiment of the present invention.

The first substrate 110 and the second substrate 170 are provided with an adhesive agent (not shown) made of a sealant or a frit along an edge thereof. The adhesive agent (not shown) And the second substrate 170 is adhered to maintain the panel state.

At this time, a vacuum state is formed between the first substrate 110 and the second substrate 170 which are spaced apart from each other, or an inert gas atmosphere may be obtained by being filled with an inert gas.

The second substrate 170 for the encapsulation may be made of plastic having a flexible property, or may be made of a glass substrate.

Meanwhile, although the organic EL device 101 according to the above-described embodiment includes the second substrate 170 for encapsulation in a form spaced apart from the first substrate 110, The second substrate 170 may be configured to contact the second electrode 167 provided on the uppermost layer of the first substrate 110 in the form of a film including an adhesive layer.

As another modification according to the embodiment of the present invention, an organic insulating film (not shown) or an inorganic insulating film (not shown) is further provided on the second electrode 167 to prevent moisture and oxygen penetration The organic insulating film (not shown) or the inorganic insulating film 162 may be used as an encapsulation film (not shown). In this case, the second substrate 170 may be omitted.

In the double-sided display type organic electroluminescent device having such a structure, light emitted from the second substrate surface is emitted to the first pixel region, and light emitted from the second substrate region is emitted to the first substrate surface So that the emitted light is emitted.

Therefore, the user can selectively view the image through the first substrate surface or view the image through the second substrate surface through the double-sided display type organic electroluminescent device according to the embodiment of the present invention, The effect of improving the width of the image viewing is obtained.

Further, there is provided an organic electroluminescent device that responds to both-side display of a display device.

Hereinafter, a method for manufacturing a double-sided display type organic electroluminescent device according to an embodiment of the present invention having the above-described structure will be described.

FIGS. 5A to 5Q and 6A to 6Q are cross-sectional views illustrating a manufacturing process of a double-sided display type organic electroluminescent device according to an embodiment of the present invention. Referring to FIG. 5A, Fig.

In order to simplify the description, the first and second pixel regions P1 and P2 may be formed by arranging regions in which switching and driving thin film transistors (not shown, DTr1 and DTr2) are formed in the first and second pixel regions P1 and P2, The regions where the organic light emitting layer 163 is formed are defined as first and second light emitting regions EA1 and EA2 and the switching and driving thin film transistors have the same stacking structure. The region in which the storage capacitor StgC is formed is referred to as a storage region StgA without discrimination of the driving thin film transistors (not shown) (DTr1, DTr2).

First, as shown in FIGS. 5A and 6A, a silicon nitride (SiNx) or silicon oxide (SiO ₂ ) which is an inorganic insulating material is deposited on a transparent insulating substrate 110, for example, a glass substrate or a flexible plastic substrate A buffer layer 111 is formed.

When the amorphous silicon is recrystallized into polysilicon, the buffer layer 111 may be formed of alkali ions, for example, potassium ions (K +), potassium ions (K +), or the like existing in the insulating substrate 110 due to heat generated by laser irradiation or heat treatment. Sodium ions (Na < + >), and the like may occur. In order to prevent the film characteristics of the semiconductor layer made of polysilicon from being deteriorated by the alkali ions.

At this time, the buffer layer 111 may be omitted depending on what kind of material the substrate 110 is made of.

Thereafter, amorphous silicon is deposited on the buffer layer 111 to form a pure amorphous silicon layer (not shown) on the entire surface of the substrate 110.

Next, the pure amorphous silicon layer (not shown) is crystallized to improve the mobility characteristics of the pure amorphous silicon layer (not shown) to form a pure polysilicon layer 180.

At this time, it is preferable that the crystallization process is a solid phase crystallization (SPC) or a crystallization process using a laser.

The solid phase crystallization (SPC) process may be performed by, for example, thermal crystallization through heat treatment in an atmosphere at 600 ° C. to 800 ° C., alternating magnetic (Magnetic) crystallization in a temperature atmosphere of 600 ° C. to 700 ° C. using an alternating- Field Crystallization) process, and the crystallization using the laser is preferably an excimer laser annealing (ELA) method using an excimer laser or a sequential lateral solidification (SLS) crystallization.

5A). Next, as shown in FIGS. 5B and 6B, the polysilicon layer (180 in FIG. 5A) is subjected to photoresist coating, exposure using an exposure mask, development of exposed photoresist, A masking process is performed and patterned to form a polysilicon semiconductor layer 113 in the device region DA and a polysilicon semiconductor pattern 114 in the storage region StgA. At this time, the storage region StgA is formed only in the first pixel region P1, but the storage region StgA is also formed in the second pixel region P2.

At this time, the semiconductor pattern 114 becomes a first storage electrode (115 of FIG. 5r) after the conductive property is improved by doping with impurities.

Next, as shown in FIGS. 5C and 6C, an inorganic insulating material such as silicon nitride (SiNx) or silicon oxide (SiO ₂ ) is deposited on the entire surface of the semiconductor pattern 114 and the polysilicon semiconductor layer 113 A gate insulating film 116 is formed.

Next, a transparent conductive material such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) is deposited on the gate insulating layer 116 to form a first transparent conductive material layer 185, (Al), aluminum (Al), aluminum alloy (AlNd), molybdenum (Mo), and molybdenum (Mo) on the first transparent conductive material layer 185, (MoTi) to form a first metal layer 186 having a single layer or a multilayer structure of more than two layers.

Thereafter, a photoresist is applied on the first metal layer 186 to form a first photoresist layer 181 and a light transmission area TA and a blocking area BA ) And exposure is performed using a diffraction exposure mask 191 or a half-tone exposure mask (not shown) having a semi-transmissive area HTA that is smaller than the transmissive area TA and has a larger light transmission amount than the blocking area BA do.

Next, as shown in FIGS. 5D and 6D, by developing the exposed first photoresist layer (181 in FIGS. 5C and 6C), a first photoresist having a first thickness over the first metal layer 186 A pattern 181a and a second photoresist pattern 181b having a second thickness thinner than the first thickness are formed.

The first photoresist pattern 181a has a gate wiring (not shown) and a portion where the seek gate electrode (118 in FIG. 5C) is to be formed and the second pixel region P2 in each of the device regions DA1 and DA2. And the second photoresist pattern 181b is formed to correspond to the storage region StgA.

Next, as shown in Figs. 5E and 6E, the first metal layer (186 in Figs. 5D and 6D) exposed at the outside of the first and second photoresist patterns 181a and 181b and the first metal layer (Not shown) and a gate electrode 118 in each of the device regions DA1 and DA2 are formed on the gate insulating film 116 by removing the transparent conductive material layer 185 (FIGS. 5D and 6D) And a storage pattern 119 having the same dual layer structure as the gate electrode 118 is formed in the storage region StgA at the same time in the storage region StgA and in the second light emitting region EA2, (121).

At this time, the gate electrode 118 is formed corresponding to the central portion of the semiconductor layer 113 of the polysilicon, so that the gate electrode 118 is formed outside the upper layer 118a of the gate electrode 118 on both sides of the semiconductor layer 113 of the polysilicon So that the exposed structure is formed.

Next, as shown in FIGS. 5F and 6F, ashing is performed to remove the second photoresist pattern (181b in FIG. 5E) having the second thickness, so that the storage layer (StgA) Thereby exposing the storage pattern 119 of FIG.

The first photoresist pattern 181a is also reduced in thickness by the ashing process, but the upper layer (not shown) 118a of the gate wiring (not shown), the gate electrode 118 and the anode pattern, ≪ / RTI >

5G and 6G, the upper layer (119b in FIG. 5F) of the storage pattern 119 exposed by removing the second photoresist pattern 181b (FIG. 5E) is etched and removed Thereby forming a second storage electrode 119 having a single-layer structure made of a transparent conductive material in the storage region StgA.

Next, the substrate 110 on which the second storage electrode 119 of a single layer structure made of a transparent conductive material is formed is doped with a high concentration p-type or n-type impurity to form the polysilicon in the storage region StgA. The p-type or n-type impurity is doped into the semiconductor pattern (114 of FIG. 5G) to form the first storage electrode 115 having improved conductivity.

At this time, the first storage electrode 115 and the second storage electrode 119 of the storage region StgA form a storage capacitor StgC by using the gate insulating layer 116 as a dielectric layer.

The doping of the p-type or n-type impurity does not pass through the metal material, but the gate insulating film 116 made of the transparent conductive material and the inorganic insulating material passes therethrough so that the impurity is diffused to the semiconductor pattern (114 of FIG. 5F) .

Further, by doping the p-type or n-type impurity, exposure to the outside of the gate electrode 118 in each of the device regions DA1 and DA2 in addition to the semiconductor pattern (114 in FIG. 5F) positioned in the storage region StgA Type p type or n type impurity is also implanted into the semiconductor layer 113 of the polysilicon layer of the polysilicon layer 113 so that the semiconductor layer 113 of each polysilicon has the ohmic region 113b ).

At this time, since the dopant is not doped in the central part of the semiconductor layer 113 of the polysilicon by the gate electrode 118 having the bilayer structure, the active area 113a is formed by maintaining the state of pure polysilicon still.

Next, as shown in Figs. 5H and 6H, a strip is advanced to form a first photoresist pattern (Fig. 5G and Fig. 5B) remaining on the gate wiring (not shown) and the gate electrode 118 and the anode pattern 6g of 181a are removed to expose the gate wiring (not shown), the gate electrode 118 and the anode pattern 121 in a bilayer structure.

Thereafter, an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon oxide (SiO ₂ ) is formed on the gate electrode 118 and the anode pattern 121 having a bilayer structure and the second storage electrode 119 having a single- Silicon nitride (SiN x) is deposited to form an interlayer insulating film 123.

A masking process is performed on the interlayer insulating layer 123 to form a semiconductor layer contact hole 125 exposing the ohmic region 113b of the semiconductor layer 113 by patterning with the gate insulating layer 116 do.

Next, as shown in FIGS. 5I and 6I, a low resistance metal material such as copper (Cu), a copper alloy (AlNd), aluminum (Al), or the like is formed on the entire surface of the interlayer insulating film 123 on which the semiconductor layer contact hole 125 is formed. A second metal layer (not shown) is formed by depositing one or more of Al, Al, AlNd, Mo, and MoTi.

Thereafter, a data line (not shown) for defining the pixel regions P1 and P2 is formed at the boundary of the pixel region P by crossing the gate line (not shown) by patterning the second metal layer (not shown) And at the same time, power supply wiring (not shown) is formed so as to be spaced apart from the data wiring (not shown).

At the same time, in the device regions DA1 and DA2, the source and drain electrodes 133 and 136a, which are in contact with the ohmic region 113b of the semiconductor layer 113 through the semiconductor layer contact hole 125, , 136b).

At this time, the drain electrode 136b, which constitutes the driving TFT DT2 in the second device region DA2, has one end extended to the second light emitting region EA2, Is formed so as to be in contact with one end of an anode pattern (121 in Fig. 6H) provided in the region EA2.

The semiconductor layer 113, the gate insulating film 116, the gate electrode 118, the interlayer insulating film 123, and the source and drain electrodes (the gate electrode 118 and the interlayer insulating film 123), which are sequentially stacked in the device regions DA1 and DA2, 133, (136a, 136b) constitute a switching thin film transistor (not shown) or a driving thin film transistor (DTr).

Meanwhile, in the second light emitting region EA2, a portion of the drain electrode 136b of the driving thin film transistor DTR2 provided in the second device region DA2 during the process of patterning the second metal layer (not shown) The upper layer 121b of the anode pattern (121 of FIG. 6H) is removed together except for the portion which is in contact with the end portion, thereby forming a second anode electrode 122 having a single layer structure of a transparent conductive material.

 Next, as shown in Figs. 5J and 6J, the source and drain electrodes 133 (136a and 136b), the data wiring (not shown), the power supply wiring (not shown) and the second anode electrode 122 A drain contact 136a for exposing the drain electrode 136a of the driving thin film transistor DTr1 in the first device region DA1 is formed by applying an organic insulating material such as photo-acryl, for example, A protective layer 140 having a hole 143 is formed.

At this time, the drain electrode 136b of the driving thin film transistor DTr2 provided in the second device region DA2 is already in contact with the second anode electrode 122 at one end, .

When the protective layer 140 is formed, halftone or diffraction exposure is performed using an exposure mask (not shown) having a transmissive region, a blocking region, and a transflective region, so that the central portion of the second luminescent region EA2 And is formed to have a thin thickness relative to other regions.

 Next, as shown in FIGS. 5K and 6K, a metal material such as aluminum (Al), aluminum alloy (AlNd) or silver (Ag) having excellent reflectivity is first deposited on the protective layer 140 (ITO), which is a transparent conductive material having a high work function value, is deposited to form a second metal layer 145 (145a, 145b) having a bilayer structure on the entire surface.

The third metal layer 145 (145a, 145b) is also formed in the second emission region EA2 in the process of patterning the third metal layer 145. However, since the second metal layer 145 is formed on the protection layer 140, (Not shown).

Then, as shown in FIGS. 5L and 6L, the third metal layer 145 (FIG. 5K and FIG. 6K) is patterned by a mask process to form the first light emitting region EA1 of the first pixel region P1, A lower layer 146a which is in contact with the drain electrode 136a of the driving thin film transistor DTr1 provided in the first device region DA1 through the drain contact hole 143 and is made of a metal material having excellent reflectivity, A first anode electrode 146 having a double layer structure of an upper layer 146b made of a transparent conductive material having a high work function value is formed.

At this time, in the second light emitting area EA2, the third metal layer 145 (145a, 145b) is removed to expose the protective layer 140 having a thinner thickness than the other area.

Next, as shown in FIGS. 5M and 6M, dry etching is performed in a state where a first anode electrode 146 having a bilayer structure is formed in the first light emitting region EA1 to form the second light emitting region EA2, The second anode electrode 122 is exposed by removing the protective layer 140 having a small thickness.

Next, as shown in FIGS. 5N and 6N, an organic insulating material, for example, an organic insulating material is formed on the first and second anode electrodes 146 and 122 provided in the first and second light emitting regions EA1 and EA2, respectively The pixel regions P1 and P2 may be patterned by applying any one of polyimide, styrene, methyl mathacrylate and polytetrafluoroethylene, The bank 155 is formed so as to border the luminescent regions EA1 and EA2 more precisely.

At this time, the bank 155 is formed so as to overlap the edges of the first and second anode electrodes 146 and 122 provided in the first and second light emitting regions EA1 and EA2.

Next, as shown in FIGS. 5O and 6O, the first substrate 110 on which the banks 155 are formed is exposed to a solid organic state on the banks 155 and the first and second anode electrodes 146 and 122, The luminescent material is thermally evaporated using a shadow mask (not shown), or an organic luminescent material in a liquid state is surrounded by the bank 155 using an inkjet apparatus (not shown) or a nozzle coating apparatus (not shown) The organic light emitting layer 163 is formed by jetting or dropping in correspondence to the light emitting regions EA1 and EA2 in the pixel regions P1 and P2.

Although an organic light emitting layer 163 having a single layer structure is formed on the first and second anode electrodes 146 and 122 in the drawing, the organic light emitting layer 163 may include a plurality of Layer structure.

In this case, the same method as that for forming the single-layer organic light-emitting layer 163 is performed, or a method for performing front-side deposition in the display region is performed to form a hole injection layer (not shown) of the organic light- An electron transporting layer (not shown) and an electron injection layer (not shown) are formed on the organic light emitting layer 163, and a hole transporting layer (not shown) (Not shown) may be selectively formed.

Next, as shown in FIGS. 5P and 6P, a metal material having a relatively low work function value such as aluminum (Al), an aluminum alloy (AlNd), silver (Ag), magnesium (Mg ), Gold (Au), and aluminum magnesium alloy (AlMg) are mixed and deposited on the entire surface of the display region to form the cathode electrode 167. Thus, the double-sided display type organic electroluminescent device The first substrate 110 is completed.

At this time, the anode electrodes 146 and 122, the organic light emitting layer 163, and the cathode electrode 167, which are sequentially stacked in the pixel regions P1 and P2, form the organic electroluminescent diode E by the above-described method.

Next, as shown in FIGS. 5Q and 6Q, the second substrate 170 is opposed to the first substrate 110 in order to encapsulate the organic light emitting diode E, A face seal (not shown) made of any one of frit, organic insulating material, and polymer material having a transparent and adhesive property is disposed between the first substrate 110 and the second substrate 170, (Not shown) along the edges of the first substrate 110 in a vacuum or an inert gas atmosphere, or the first substrate 110 and the second substrate 170 are bonded together And then the first and second substrates 110 and 170 are bonded together to complete the double-sided display type organic light emitting device 101 according to the embodiment of the present invention.

Alternatively, an inorganic insulating material or an organic insulating material may be deposited or coated on the second electrode 167 of the first substrate 110, or an adhesive layer (not shown) may be resumed to attach a film (not shown) When used as an encapsulation film (not shown), the second substrate 170 may be omitted.

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

110: first substrate
111: buffer layer
113: semiconductor layer
113a, 113b: an active region and an ohmic region
116: gate insulating film
118: gate electrode
118a, 118b: a lower layer (of the gate electrode)
122: second anode electrode
123: Interlayer insulating film
125: semiconductor layer contact hole
133: source electrode
136: drain electrode
140: Protective layer
145: third metal layer
145a, 145b: a lower layer (of the third metal layer)
DA2: second element region
DTr2: driving thin film transistor
P2: second pixel region

Claims (14)

A substrate on which a plurality of first pixel regions and a second pixel region are defined;
A driving and switching thin film transistor provided in each element region in each of the first and second pixel regions;
A protective layer formed over the driving and switching thin film transistors;
An organic light emitting diode (OLED) connected to the drain electrode of the driving thin film transistor and provided in each of the light emitting regions in the first and second pixel regions,
Wherein the organic light emitting diode is disposed on the passivation layer and emits light on the first pixel region, and the organic light emitting diode is disposed in the second pixel region through a first opening provided in the passivation layer Type organic electroluminescent device is formed on the gate insulating film and emits light at the bottom.
The method according to claim 1,
The organic light emitting diode includes a first electrode, an organic light emitting layer, and a second electrode,
The first electrode included in the first pixel region has a double layer structure of a lower layer made of a metal material and an upper layer made of a transparent conductive material,
Wherein the first electrode provided in the second pixel region has a single layer structure of a transparent conductive material.
The method according to claim 1,
Wherein the passivation layer has a drain contact hole exposing a drain electrode of the driving thin film transistor in the first pixel region, and the drain electrode and the first electrode are in contact with each other through the drain contact hole,
Wherein the drain electrode of the driving thin film transistor in the second pixel region is connected to the first electrode formed on the gate insulating layer, the one end of the drain electrode extending to the light emitting region.
The method according to claim 1,
The driving and switching film transistors included in the respective device regions of the first and second pixel regions may be formed of a stacked structure of a polysilicon semiconductor layer, a gate insulating film, a gate electrode, and an interlayer insulating film, Type organic electroluminescent device.
5. The method of claim 4,
The semiconductor layer of the polysilicon includes an active region corresponding to the gate electrode and an ohmic region doped with impurities on both sides of the active region,
Wherein the interlayer insulating film has a semiconductor layer contact hole exposing the respective ohmic regions and a second opening corresponding to the light emitting region of the second pixel region and exposing the first electrode together with the first opening,
Wherein each of the source and drain electrodes is in contact with an ohmic region of each semiconductor layer through the semiconductor layer contact hole.
5. The method of claim 4,
Wherein each of the gate electrodes comprises a lower layer of a transparent conductive material and an upper layer of a low resistance metal material.
The method according to claim 6,
Wherein a storage region is further defined in each of the first and second pixel regions and a first storage electrode made of polysilicon doped with impurities forming the ohmic region is formed in the same layer in which the semiconductor layer is formed, A second storage electrode having a single layer structure corresponding to the first storage electrode is formed on the interlayer insulating layer and is made of the same material as a lower layer of the gate electrode so that the first storage electrode and the second storage electrode overlap each other, Wherein the gate insulating layer is a storage capacitor.
8. The method of claim 7,
A gate wiring connected to the gate electrode of the switching thin film transistor over the gate insulating film and extending in one direction;
A data line connected to the source electrode of the switching thin film transistor and intersecting the gate line above the interlayer insulating film; a power line connected to the driving thin film transistor and spaced apart from the data line;
Lt; RTI ID = 0.0 > 1, < / RTI >
9. The method of claim 8,
Wherein a bank is formed at a boundary between the first and second pixel regions, the bank overlapping an edge of each of the first electrodes.
Forming a polysilicon semiconductor layer on each of the device regions defined in the first and second pixel regions on the substrate on which the first pixel region and the second pixel region are defined;
Forming a gate insulating film over the semiconductor layer of the polysilicon;
A gate electrode having a bilayer structure of a lower layer made of a transparent conductive material and an upper layer made of a metal material over each of the device regions above the gate insulating film and an anode pattern having the same double layer structure as the gate electrode corresponding to the second pixel region ;
Forming an ohmic region in the semiconductor layer by doping the impurity using the gate electrode as a doping-preventing mask;
Forming an interlayer insulating film having a contact hole on the gate electrode and exposing the ohmic region of each semiconductor layer and a first opening corresponding to the anode pattern of the second pixel region;
A source electrode and a drain electrode that are in contact with the ohmic region and are spaced apart from each other through the semiconductor layer contact holes are formed on the interlayer insulating film to form a switching and driving thin film transistor in each device region, The drain electrode of the driving thin film transistor having one end thereof is extended to be in contact with one end of the anode pattern, and the upper layer of the anode pattern is removed to form a first anode electrode;
And a drain contact hole having a first thickness over the switching and driving thin film transistor and exposing a drain electrode of a driving thin film transistor provided in the first pixel region, wherein a second thickness corresponding to the anode pattern is smaller than the first thickness Forming a protective layer on the substrate;
Forming a second anode electrode having a double layer structure of a lower layer of a metal material and an upper layer of a transparent conductive material in the first pixel region on the protective layer;
Removing the protective layer having the second thickness to expose the first anode electrode;
Forming an organic light emitting layer corresponding to the first and second anode electrodes;
Forming a cathode electrode over the organic light emitting layer
Lt; RTI ID = 0.0 > 1, < / RTI >
11. The method of claim 10,
Wherein forming the semiconductor layer includes forming a first storage electrode made of the same material as the semiconductor layer in a storage region in each of the first and second pixel regions,
Wherein forming the ohmic region in each semiconductor layer comprises doping the first storage electrode with an impurity,
Wherein the step of forming the gate electrode comprises forming a single layer of a second storage electrode on the gate insulating layer, the second storage electrode being made of the same material as the lower layer of the gate electrode corresponding to the first storage region. A method of manufacturing a light emitting device.
12. The method of claim 11,
Forming the gate electrode and the anode pattern of the double layer structure and the second storage electrode of the single layer structure,
Sequentially forming a transparent conductive material layer and a metal layer on the gate insulating layer;
Forming a first photoresist pattern of a first thickness over the low resistance metal layer and a second photoresist pattern of a second thickness thinner than the first thickness;
Forming a storage pattern having an anode pattern and a bilayer structure with the gate electrode of the bilayer structure by removing the transparent conductive material layer located under the metal layer exposed to the outside of the first and second photoresist patterns;
Exposing the storage pattern by ashing and removing the second photoresist pattern;
Forming a first layer of a transparent conductive material on the first storage electrode by etching and removing an upper layer of the storage pattern;
Removing the first photoresist pattern by advancing the strip
Lt; RTI ID = 0.0 > 1, < / RTI >
11. The method of claim 10,
Wherein forming the gate electrode includes forming a gate wiring connected to the gate electrode of the switching thin film transistor and extending in one direction,
Wherein the step of forming the source and drain electrodes comprises: forming a power line interconnection with the gate line and a data line connected to the source electrode of the switching thin film transistor; / RTI >
11. The method of claim 10,
Forming a buffer layer on the substrate before forming the semiconductor layer;
Forming a bank on the boundary of the first and second pixel regions and overlapping edges of the first and second anode electrodes
Lt; RTI ID = 0.0 > 1, < / RTI >

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