KR20160006110A - Organic light emitting display device and method of fabricating the same - Google Patents

Abstract

The present invention relates to an organic light emitting display device, and a manufacturing method thereof. The method for manufacturing the organic light emitting display device comprises the following steps of: forming auxiliary electrode with a multi-layered structure of heterogeneous metals having different etching speeds; and forming a void inside the auxiliary electrode when both electrodes are formed, thereby simplifying a process, increasing contact reliability between a negative electrode and the auxiliary electrode, and decreasing resistance of the negative electrode.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic electroluminescence display device and a method of manufacturing the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting display device and a method of manufacturing the same, and more particularly, to a top emission organic light emitting display device and a method of manufacturing the same.

Recently, there is a growing interest in information display, and as the demand for portable information media increases, research and commercialization of a lightweight flat panel display (FPD) has been focused on.

In such a flat panel display device, a liquid crystal display device (LCD) is one of the remarkable display devices which is light and consumes less power.

As another display device, an organic light emitting display device has a self-emission type and therefore is superior in viewing angle and contrast ratio to a liquid crystal display device. In addition, since a backlight is not required, it is possible to make a light-weight thin type, and it is also advantageous in terms of power consumption. It has the advantage of being able to drive DC low voltage and has a fast response speed.

Hereinafter, the basic structure and operating characteristics of the organic light emitting display will be described in detail with reference to the drawings.

1 is a diagram for explaining the principle of light emission of a general organic light emitting diode.

An organic light emitting display generally includes an organic light emitting diode having a structure as shown in FIG.

1, an organic light emitting diode includes an anode 18 as a pixel electrode, a cathode 28 as a common electrode, and organic compound layers 31, 32, 35, 36, and 37 formed therebetween Respectively.

The hole injection layer 31, the hole transport layer 32, the emission layer 35, the electron transport layer 34, and the hole transport layer 34 are formed on the organic compound layers 31, 32, 35, an electron transport layer 36 and an electron injection layer 37.

When the positive and negative driving voltages are applied to the anode 18 and the cathode 28, the organic light emitting diode having the structure described above is driven by the holes passing through the hole transport layer 32 and the electron transport layer 36 The electrons passed through the light emitting layer 35 move to form an exciton. When excitons are transited from an excited state to a ground state, that is, a stable state, light of a predetermined wavelength is generated.

An organic light emitting display displays an image by arranging sub-pixels in which organic light emitting diodes having the above-described structure are formed in a matrix form and selectively controlling the sub-pixels with a data voltage and a scan voltage.

At this time, the organic light emitting display device is divided into an active matrix method using a passive matrix or a switching element using a TFT. The active matrix method selectively turns on the active element TFT to select the sub-pixel and maintains the emission of the sub-pixel with the voltage held in the storage capacitor.

In addition, the organic light emitting display may be classified into a top emission type, a bottom emission type, and a dual emission type depending on a direction in which light is emitted.

The top emission type organic light emitting display device is a type in which light is emitted in a direction opposite to the substrate on which the sub-pixels are arranged. Such a front emission type organic light emitting display device has an advantage that the aperture ratio can be increased as compared with the backlight emission method in which light is emitted toward the substrate on which the sub-pixels are arranged.

In such a top emission type organic light emitting display, an anode is formed under the organic compound layer and a cathode is formed on the organic compound layer through which light is transmitted.

At this time, the cathode must be formed thin to be realized as a semi-transparent film having a low work function. Therefore, the cathode has a high resistance.

As described above, in the front emission type organic light emitting display, a voltage drop (IR drop) occurs due to a high specific resistance of the cathode. Accordingly, voltages of different levels are applied to each sub-pixel, resulting in non-uniformity of luminance or image quality. In particular, as the size of the display panel increases, the voltage drop may increase.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and it is an object of the present invention to provide an organic light emitting display device capable of preventing voltage drop of a cathode while simplifying a process in a top emission type organic light emitting display, .

It is another object of the present invention to provide an organic light emitting display capable of preventing voltage drop of a cathode while improving reliability of a contact between the cathode and the auxiliary electrode, and a method of manufacturing the same.

Other objects and features of the present invention will be described in the following description of the invention and the claims.

According to an aspect of the present invention, there is provided an organic light emitting display including: a first electrode disposed in each sub-pixel of a substrate; An auxiliary electrode spaced apart from the first electrode and having a contact void formed by at least two metal layers having different etching rates; And a second electrode that is in direct contact with the auxiliary electrode through the contact space.

At this time, the etching rate of the metal layer disposed on the upper layer among the auxiliary electrodes may be slower than the etching rate of the metal layer disposed on the lower layer.

At this time, the metal layer disposed on the upper layer may include at least one of ITO, Ag, Ag alloy or MoTi.

The metal layer disposed on the lower layer may include Cu.

At least one end of the metal layer disposed on the upper layer may be configured to protrude more than one end of the metal layer disposed on the lower layer to form the contact space

At this time, the second electrode may be configured to contact the side surface of the metal layer disposed on the lower layer.

At this time, the second electrode may be configured to contact the back surface of the protruding upper layer.

The auxiliary electrode may further include a metal layer disposed on the lowest layer of the lower layer.

At least one end of the metal layer disposed on the lowermost layer may be configured to protrude from at least one end of the metal layer disposed on the upper layer to form the contact void.

At this time, the second electrode may be configured to contact the upper surface of the protruded lowest layer protrusion.

The metal layer disposed on the lowermost layer may include MO or MoTi.

The metal layer disposed on the upper layer may be made of the same material as the first electrode.

And a connection electrode disposed under the first electrode and having the same structure as the metal layer disposed in the lowermost layer and the lower layer.

According to another aspect of the present invention, there is provided an organic light emitting display including: a first electrode disposed in each of a plurality of sub-pixels of a substrate; An auxiliary electrode spaced apart from the first electrode and having at least two layers and an end of at least one layer disposed in an upper layer of the at least two layers, the auxiliary electrode being disposed inside the end of the upper layer; An organic compound layer on the upper layer of the first electrode and the auxiliary electrode; And a second electrode covering the organic compound layer and electrically connected to the at least one layer of the auxiliary electrode.

At this time, the upper layer of the auxiliary electrode may be made of a material whose etching rate is slower than the at least one layer of the auxiliary electrode.

At this time, the auxiliary electrode may include at least three layers, and the lowermost layer disposed at a lower portion of the at least one of the at least three layers may be exposed to the outside of the uppermost layer .

At this time, the at least one layer of the auxiliary electrode may be made of a material having a relatively high etch rate among the at least three layers.

A method of fabricating an organic light emitting display according to an exemplary embodiment of the present invention includes forming a driving thin film transistor on a substrate; Forming an auxiliary electrode pattern made of at least two metal layers different from each other on the substrate; Forming a first electrode patterned on the substrate on which the auxiliary electrode pattern is formed, etching the auxiliary electrode pattern together with the auxiliary electrode pattern to form an auxiliary electrode composed of at least two different metal layers; Forming an organic compound layer on the first electrode and the auxiliary electrode; And forming a second electrode on the substrate on which the organic compound layer is formed, wherein at least one metal layer disposed on the lowest metal layer among the at least two metal layers different from each other during the patterning is etched inward The end of the at least one metal layer is disposed inside the end of the metal layer disposed at the lowermost layer to form a contact void and the second electrode and the auxiliary electrode are directly connected to each other through the contact void, Can be contacted.

At this time, the second electrode may be formed to directly contact the upper surface of the metal layer disposed at the lowermost layer of the auxiliary electrode and the side surface of the at least one metal layer.

An organic electroluminescent display device and a method of manufacturing the same according to an embodiment of the present invention include forming an auxiliary electrode in a multi-layer structure of dissimilar metals having different etching rates, forming a contact void in the auxiliary electrode during the formation of the anode, And a direct contact is made. Thus, the resistance of the cathode can be reduced while simplifying the process.

The organic electroluminescent display device and the method of manufacturing the same according to an embodiment of the present invention can reduce the defects and improve the productivity and improve the luminance uniformity and reliability of the organic electroluminescent display device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining a principle of light emission of a general organic light emitting diode. FIG.
2 is a view for explaining a sub-pixel structure of an organic light emitting display device;
3 is a cross-sectional view schematically showing a part of a structure of an organic light emitting display device according to a first embodiment of the present invention.
4 is a plan view schematically showing a part of a pixel portion of an organic light emitting display according to a first embodiment of the present invention.
5 is a cross-sectional view schematically showing a part of a structure of an organic light emitting display according to a second embodiment of the present invention.
6A to 6E are sectional views sequentially showing a method of manufacturing an organic light emitting display according to a second embodiment of the present invention shown in FIG.
FIGS. 7A to 7C are cross-sectional views illustrating the mask process shown in FIG. 6C; FIG.
8 is a cross-sectional view schematically showing a part of a structure of an organic light emitting display according to a third embodiment of the present invention.
9A to 9E are sectional views sequentially illustrating a method of manufacturing an organic light emitting display device according to a third embodiment of the present invention shown in FIG.
FIGS. 10A to 10C are cross-sectional views illustrating the mask process shown in FIG. 9C. FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the present embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification. The dimensions and relative sizes of the layers and regions in the figures may be exaggerated for clarity of illustration.

It will be understood that when an element or layer is referred to as being another element or "on" or "on ", it includes both intervening layers or other elements in the middle, do. On the other hand, when a device is referred to as "directly on" or "directly above ", it does not intervene another device or layer in the middle.

The terms spatially relative, "below," "lower," "above," "upper," and the like, And may be used to easily describe the correlation with other elements or components. Spatially relative terms should be understood to include, in addition to the orientation shown in the drawings, terms that include different orientations of the device during use or operation. For example, when inverting an element shown in the figures, an element described as "below" or "beneath" of another element may be placed "above" another element. Thus, the exemplary term "below" can include both downward and upward directions.

The terminology used herein is for the purpose of describing embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprise "and / or" comprising ", as used in the specification, means that the presence of stated elements, Or additions.

2 is a view illustrating a sub-pixel structure of an organic light emitting display device.

2, the organic light emitting display includes a gate line GL arranged in a first direction and a data line DL spaced apart from each other in a second direction crossing the first direction and a driving power line VDDL Sub-pixel region is defined by the sub-pixel region.

A switching thin film transistor ST, a driving thin film transistor DT, a storage capacitor C and an organic light emitting diode OLED may be included in one sub-pixel region.

The switching thin film transistor ST is switched in accordance with a gate signal supplied to the gate line GL to supply a data signal to the data line DL to the driving thin film transistor DT.

The driving thin film transistor DT is switched according to a data signal supplied from the switching thin film transistor ST to control a current flowing from the driving power supply line VDDL to the organic light emitting diode OLED.

The storage capacitor C is connected between the gate electrode of the driving thin film transistor DT and the base power line VSSL to store a voltage corresponding to the data signal supplied to the gate electrode of the driving thin film transistor DT, The ON state of the driving transistor DT is maintained constant for one frame.

The organic light emitting diode OLED is electrically connected between the source electrode or the drain electrode of the driving thin film transistor DT and the base power supply line VSSL and is turned on by the current corresponding to the data signal supplied from the driving thin film transistor DT. do.

3 is a cross-sectional view schematically showing a part of a structure of an organic light emitting display according to a first embodiment of the present invention. 4 is a plan view schematically showing a part of a pixel portion of an organic light emitting display according to a first embodiment of the present invention.

3 shows an organic light emitting display device of a top emission type using a TFT having a coplanar structure as an example. However, the present invention is not limited to a TFT having a coplanar structure.

3 and 4, the organic light emitting display device of the top emission type according to the first embodiment of the present invention includes a substrate 110, a driving thin film transistor DT, an organic light emitting diode and an auxiliary electrode line VSSLa, As shown in FIG.

First, the driving thin film transistor DT includes a semiconductor layer 124, a gate electrode 121, a source electrode 122, and a drain electrode 123.

The semiconductor layer 124 is formed on a substrate 110 made of an insulating material such as a transparent plastic or a polymer film.

The semiconductor layer 124 may be an amorphous silicon film or a polycrystalline silicon film crystallized from amorphous silicon, an oxide semiconductor, an organic semiconductor, or the like.

At this time, a buffer layer (not shown) may be further formed between the substrate 110 and the semiconductor layer 124. The buffer layer may be formed to protect a thin film transistor formed in a subsequent process from impurities such as alkali ions flowing out from the substrate 110. [

The semiconductor layer a gate insulating film (115a) made of silicon nitride (SiNx) or silicon oxide (SiO _2), such as above 124, are formed. A gate line (not shown) and a first sustain electrode (not shown) including a gate electrode 121 are formed thereon.

The gate electrode 121 and the gate line and the first sustain electrode may be formed of a first metal material having low resistance characteristics such as aluminum (Al), copper (Cu), molybdenum (Mo), chrome (Cr) ), Titanium (Ti), nickel (Ni), neodymium (Nd), or alloys thereof.

An inter insulation layer 115b made of a silicon nitride film, a silicon oxide film, or the like is formed on the gate electrode 121, the gate line, and the first sustain electrode. A data line (not shown), a driving voltage line (not shown) and source / drain electrodes 122 and 123 and a second sustain electrode (not shown) are formed thereon.

The source electrode 122 and the drain electrode 123 are spaced apart from each other by a predetermined distance and are electrically connected to the semiconductor layer 124. More specifically, a semiconductor layer contact hole exposing the semiconductor layer 124 is formed in the gate insulating film 115a and the interlayer insulating film 115b, and the source / drain electrodes 122 and 123 are formed through the semiconductor layer contact holes. And is electrically connected to the semiconductor layer 124.

At this time, the second sustain electrode overlaps a part of the first sustain electrode below the interlayer insulating film 115b to form a storage capacitor.

The data line, the driving voltage line, the source / drain electrodes 122 and 123 and the second sustain electrode may be formed of a second metal material having low resistance characteristics such as aluminum (Al), copper (Cu), molybdenum (Mo) And may be formed of a single layer or multiple layers of chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd)

A planarization film 115c made of a silicon nitride film, a silicon oxide film or the like is formed on the substrate 110 on which the data lines, the driving voltage lines, the source / drain electrodes 122 and 123 and the second sustain electrodes are formed.

Next, the organic light emitting diode may include a first electrode 118, an organic compound layer 130, and a second electrode 128.

The organic light emitting diode is electrically connected to the driving thin film transistor DT. More specifically, a drain contact hole exposing the drain electrode 123 of the driving thin film transistor DT is formed in the planarization film 115c formed on the driving thin film transistor DT. The organic light emitting diode is electrically connected to the drain electrode 123 of the driving thin film transistor DT through the drain contact hole.

That is, the first electrode 118 is formed on the planarization film 115c and is electrically connected to the drain electrode 123 of the driving TFT DT through the drain contact hole.

The first electrode 118 supplies a current (or voltage) to the organic compound layer 130.

In addition, the first electrode 118 serves as an anode. Accordingly, the first electrode 118 may include a transparent conductive material having a relatively large work function. For example, the first electrode 118 may include indium tin oxide (ITO) or indium zinc oxide (IZO). In order to improve the reflection efficiency, the first electrode 118 may further include a reflective layer (not shown) formed of a metallic material having a high reflection efficiency. For example, the metal material with high reflection efficiency may include aluminum (Al), silver (Ag), gold (Au), platinum (Pt), chromium (Cr)

A bank 115d is formed on the substrate 110 on which the first electrode 118 is formed. At this time, the bank 115d surrounds the edge of the first electrode 118 and defines a first opening, and may be made of an organic insulating material or an inorganic insulating material. The bank 115d may also be made of a photosensitizer containing a black pigment, in which case the bank 115d serves as a light shielding member.

At this time, in the first embodiment of the present invention, the bank 115d further includes a second opening exposing a part of the auxiliary electrode 125, which will be described later.

An organic compound layer 130 is formed between the first electrode 118 and the second electrode 128. The organic compound layer 130 emits light by the combination of the holes supplied from the first electrode 118 and the electrons supplied from the second electrode 128.

3, the organic compound layer 130 is formed on the entire surface of the substrate 110, but the present invention is not limited thereto. The organic compound layer 130 may be formed only on the first electrode 118.

The organic compound layer 130 may have a multi-layer structure including an auxiliary layer for improving the luminous efficiency of the light emitting layer in addition to the light emitting layer.

The second electrode 128 is formed on the organic compound layer 130 to provide electrons to the organic compound layer 130.

The second electrode 128 serves as a cathode. Accordingly, the second electrode 128 may be made of a transparent conductive material. For example, the transparent conductive material may include ITO or IZO. The second electrode 128 may further include a thin metal film (not shown) made of a metal material having a low work function on the side contacting the organic compound layer 130. For example, a low work function metal material may include magnesium (Mg), silver (Ag), and compounds thereof.

In the case of the top emission type, the second electrode 128 is formed to have a thin thickness because the work function is low and the semi-transmissive property must be satisfied. Therefore, the resistance of the second electrode 128 is increased, and a voltage drop (IR drop) occurs due to a high resistance.

Accordingly, in the first embodiment of the present invention, the auxiliary electrode line VSSLa and the first electrode 118 may be formed on the planarization layer 115c to reduce the resistance of the second electrode 128. [ That is, the auxiliary electrode line VSSLa and the first electrode 118 may be formed on the same layer. The auxiliary electrode line VSSLa may include an auxiliary electrode 125 and a spacer 140.

The auxiliary electrode 125 is formed on the same layer as the first electrode 118. As shown in FIG. 4, for example, the auxiliary electrode 125 may extend in the longitudinal direction and may be connected to an external VSS pad (not shown).

The auxiliary electrode 125 may be formed of the same material as the first electrode 118, but is not limited thereto.

The auxiliary electrode 125 is connected to the second electrode 128. At this time, an electrode contact hole exposing the auxiliary electrode 125 is formed in the organic compound layer 130 located in the second opening. The auxiliary electrode 125 is electrically connected to the second electrode 128 through the electrode contact hole.

The spacer 140 is formed on the auxiliary electrode 125.

At this time, the spacer 140 may have a reverse taper shape in which the sectional area decreases from the upper portion to the lower portion. At this time, the angle between the side surface of the spacer 140 and the auxiliary electrode 125 may be 20 to 80 degrees, but is not limited thereto.

The spacer 140 forms an electrode contact hole for exposing the auxiliary electrode 125 to the organic compound layer 130. The organic compound layer 130 is formed only on the upper portion of the spacer 140 by the shading effect and is not formed on the exposed surface of the auxiliary electrode 125 under the spacer 140. [ That is, the organic compound layer 130 is deposited on the substrate 110 by the linear evaporation, but is not formed under the upper portion of the spacer 140 by the spacer 140 having the inverted taper shape. Thus, an electrode contact hole is formed in the organic compound layer 130, to which the auxiliary electrode 125 and the second electrode 128 are connected.

An organic compound layer 130 and a second electrode 128 are sequentially stacked on the spacer 140.

The organic light emitting display according to the first embodiment of the present invention may have a limited contact region a connected between the second electrode 128 and the auxiliary electrode 125. Particularly, a method of using a deposition mask for forming the organic compound layer 130 may be difficult to implement in a large-area panel. This is because the contact between the second electrode 128 and the auxiliary electrode 125 is performed after the organic compound layer 130 is deposited. After the auxiliary electrode 125 is formed, the organic compound layer 130 is entirely deposited Since the second electrode 128 is deposited, the contact region a is inevitably limited.

Therefore, in the second and third embodiments of the present invention, after the auxiliary electrode is formed in a multi-layered structure of dissimilar metals having different etching rates (or etch rates), the contact area voids are formed so as to be in direct contact with the negative electrode. Accordingly, the resistance of the cathode can be reduced while simplifying the process, which will be described in detail with reference to the drawings.

5 is a cross-sectional view schematically showing a part of a structure of an organic light emitting display according to a second embodiment of the present invention.

5 shows an organic light emitting display device of a top emission type using a TFT having a coplanar structure as an example. However, the present invention is not limited to a TFT having a coplanar structure.

5, the organic light emitting display device of the top emission type according to the second embodiment of the present invention includes a substrate 210, a driving thin film transistor DT, an organic light emitting diode, and an auxiliary electrode line VSSLa .

The driving thin film transistor DT includes a semiconductor layer 224, a gate electrode 221, a source electrode 222 and a drain electrode 223 in the same manner as in the first embodiment described above.

The semiconductor layer 224 is formed on a substrate 201 made of an insulating material such as a transparent plastic or a polymer film.

The semiconductor layer 224 may be formed of an amorphous silicon film or a polycrystalline silicon film crystallized from amorphous silicon, an oxide semiconductor, or an organic semiconductor.

At this time, a buffer layer (not shown) may be further formed between the substrate 210 and the semiconductor layer 224. The buffer layer may be formed to protect a thin film transistor formed in a subsequent process from impurities such as alkali ions flowing out from the substrate 210. [

Semiconductor layer 224, gate insulating film (215a) made of silicon nitride (SiNx) or silicon oxide (SiO _2), such as above are formed. A gate line (not shown) and a first sustain electrode (not shown) including a gate electrode 221 are formed on the gate insulating film 215a.

The gate electrode 221 and the gate line and the first sustain electrode may be formed of a first metal material having low resistance characteristics such as aluminum (Al), copper (Cu), molybdenum (Mo), chrome (Cr) ), Titanium (Ti), nickel (Ni), neodymium (Nd), or alloys thereof.

An interlayer insulating film 215b made of a silicon nitride film, a silicon oxide film or the like is formed on the gate electrode 221, the gate line, and the first sustain electrode. A data line (not shown), a driving voltage line (not shown) and source / drain electrodes 222 and 223 and a second sustain electrode (not shown) are formed thereon.

The source electrode 222 and the drain electrode 223 are spaced apart from each other by a predetermined distance, and are electrically connected to the semiconductor layer 224. At this time, a semiconductor layer contact hole exposing the semiconductor layer 224 is formed in the gate insulating film 215a and the interlayer insulating film 215b, and the source / drain electrodes 222 and 223 are formed through the semiconductor layer contact holes. (Not shown).

At this time, the second sustain electrode overlaps a part of the first sustain electrode below the interlayer insulating film 215b to form a storage capacitor.

The data line, the driving voltage line, the source / drain electrodes 222 and 223 and the second sustain electrode may be formed of a second metal material having low resistance characteristics such as aluminum (Al), copper (Cu), molybdenum (Mo) And may be formed of a single layer or multiple layers of chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd)

A planarization film 215c made of a silicon nitride film, a silicon oxide film or the like is formed on the substrate 210 on which the data lines, the driving voltage lines, the source / drain electrodes 222 and 223 and the second sustain electrodes are formed.

Next, the organic light emitting diode may include a first electrode 218, an organic compound layer 230, and a second electrode 228.

The organic light emitting diode is electrically connected to the driving thin film transistor DT. More specifically, a drain contact hole exposing the drain electrode 223 of the driving thin film transistor DT is formed in the planarization film 215c formed on the driving thin film transistor DT. The organic light emitting diode is electrically connected to the drain electrode 223 of the driving thin film transistor DT through the drain contact hole.

That is, the first electrode 218 is formed on the planarization film 215c and is electrically connected to the drain electrode 223 of the driving TFT DT through the connection electrode 208 and the drain contact hole.

The first electrode 218 supplies a current (or voltage) to the organic compound layer 230, and defines a light emitting region having a predetermined area.

In addition, the first electrode 218 serves as an anode. Accordingly, the first electrode 218 may be made of a transparent conductive material having a relatively large work function. For example, the first electrode 218 may include upper and lower first electrodes 218c and 218a formed of indium-tin-oxide (ITO) or indium zinc oxide (IZO) . In order to improve the reflection efficiency, the first electrode 218 may further include a reflection layer 218b made of a metal material having high reflection efficiency. For example, the metal material with high reflection efficiency may include aluminum (Al), silver (Ag), gold (Au), platinum (Pt), chromium (Cr)

Therefore, the first electrode 218 according to the second embodiment of the present invention includes the upper and lower first electrodes 218c and 218a and the reflective layer 218b between the upper first electrode 218c and the lower first electrode 218a ). ≪ / RTI > However, the present invention is not limited thereto.

A bank 215d is formed on the substrate 210 on which the first electrode 218 is formed. At this time, the bank 215d may surround the periphery of the first electrode 218 to define a first opening and may be made of an organic insulating material or an inorganic insulating material. The bank 215d may also be made of a photosensitizer containing a black pigment, wherein the bank 215d serves as a light shielding member.

In the second embodiment of the present invention, the bank 215d further includes a second opening that exposes a part of the auxiliary electrode 225, which will be described later.

At this time, the auxiliary electrode 225 according to the second embodiment of the present invention may be formed as a lower layer and a lowest layer auxiliary (different etch rates) of different metals with different etch rates (or etch rates) Upper and lower layer auxiliary electrodes 225c, 225b, and 225a including electrodes 225b and 225a. In addition, the second electrode 228 is contacted with the auxiliary electrode 225 itself when the second electrode 228 is deposited.

The etching rate can be defined as the thickness or amount of a substance dissolved per unit time and can be expressed as an etching rate by relatively comparing the etching rates of the two materials. Usually, when the etching rate of two materials is expressed, the higher the etching rate, the higher the etch rate.

However, the present invention is not limited to this. The auxiliary electrode 225 according to the second embodiment of the present invention may have at least two layers including upper and lower auxiliary electrodes 225c and 225b of different metals, And the electrode 225b may be disposed inside the upper layer auxiliary electrode 225c.

The upper, lower and lower layers auxiliary electrodes 225c, 225b and 225a are formed by using at least three kinds of metals and the etch rates of the metals constituting the lower layer and the lowermost layer auxiliary electrodes 225b and 225a are made higher than those of the upper layer auxiliary electrode And the etchant used for patterning the second electrode 225c and the first electrode 218 are different from each other.

That is, the lowermost auxiliary electrode 225a is made of a metal that is not etched when the first electrode 218 is patterned, such as MoTi or Ti. For example, the lowermost auxiliary electrode 225a may be made of a metal that does not damage the etchant of the Ag alloy. However, the present invention is not limited to this, and the lowermost auxiliary electrode 225a may be formed of a metal having the lowest etching speed when the first electrode 218 is patterned.

The patterning of the first electrode 218 made of an Ag alloy may be performed using a phosphoric acid etchant, a nitric acid etchant, a phosphoric acid + nitric acid etchant, a phosphoric acid + acetic acid etchant, a nitric acid + acetic acid etchant or a phosphoric acid + Nitric acid + acetic acid etchant can be used.

For reference, Ag can be precipitated by etching with phosphoric acid or nitrate anions (depending on the chemical reaction below).

2Ag + NO ₃ ^- + 3H ^- -> 2Ag ⁺ + HNO ₂ + H ₂ O

_{2Ag + N 3 PO 4 + 2H} + -> 2Ag + + H 3 PO 4 + 2H 2 O

MoTi can not be etched with these Ag alloys. In the case of MoTi or Ti, H ₂ O ₂ and F components are required in the etchant to carry out the etching process.

The oxidation process by H ₂ O ₂ system is as follows.

_{Mo + 3H 2 O 2 ->} MoO 3 + 3H 2 O

_{Ti + 2H 2 O 2 ->} TiO 2 + 2H 2 O

Then, MoO ₃ and TiO ₂ are dissolved and etched by F ^- ions as follows.

MoO ₃ + 3KHF ₂ -> MoF ₆ + 3KOH

TiO ₂ + 2KHF ₂ -> TiF ₄ + 2KOH

The lower layer auxiliary electrode 225b is made of a metal having the highest etch rate (or etch rate) at the time of patterning the first electrode 218, such as Cu, and thus is etched most quickly into the etchant of the Ag alloy .

The upper auxiliary electrode 225c may have the same three layer structure as the first electrode 218 and may be patterned at the same etching rate when the first electrode 218 is patterned. For example, the metal layer constituting the upper layer auxiliary electrode 225c may include at least one of ITO, Ag, Ag alloy, or MoTi.

MoTi of the lowermost layer auxiliary electrode 225a is not etched during the ITO / Ag alloy / ITO etching of the first electrode 218 and Cu of the lower layer auxiliary electrode 225b is more etched than ITO / Ag alloy / ITO It is etched at high speed. A predetermined contact void V is formed in the auxiliary electrode 225 as the ITO / Ag alloy / ITO of the upper auxiliary electrode 225c is etched at the same rate as that of the first electrode 218.

The organic compound layer 230 is not deposited in the contact space V when the organic compound layer 230 is evaporated by subsequent evaporation. A metal for the second electrode 228 is also deposited in the contact space V during metal deposition for the second electrode 228 by sputtering to form a second electrode 228 having a relatively large contact area b, Is contacted with the auxiliary electrode 225.

At this time, the upper layer auxiliary electrode 225c is patterned to expose a part of the lowermost layer auxiliary electrode 225a, so that the contact between the second electrode 228 and the auxiliary electrode 225 can be smoothly performed. That is, one end of the upper layer auxiliary electrode 225c may protrude from one end of the lower layer auxiliary electrode 225b to form the contact space V, and one end of the lowermost layer auxiliary electrode 225a may be constituted by the lower layer auxiliary electrode 225b, May be configured to protrude more than one end of the contact portion (225b) to form the contact space (V).

Among the multilayer structure of the auxiliary electrode 225, the double layer structure of Cu / MoTi can be applied not only to the auxiliary electrode 225 but also to the connection electrode 208 and the pad electrode (not shown). Accordingly, the connection electrode 208 may be composed of upper and lower connection electrodes 208b and 208a.

5, the connection electrode 208 is formed on the upper portion of the drain electrode 223. However, the present invention is not limited thereto. The connection electrode 208 of the present invention may be formed over the entire light emitting region in substantially the same form as the first electrode 218.

In this way, according to the second embodiment of the present invention, when the first electrode 218 is patterned using the etching rate difference between the upper, lower and the lowest auxiliary electrodes 225c, 225b, and 225a, The second electrode 228 and the auxiliary electrode 225 have a relatively large contact area b and can make direct contact with each other. Particularly, both the surface of the lowermost layer auxiliary electrode 225a and the side surface of the lower layer auxiliary electrode 225b are used as the contact region b, thereby improving the reliability of the contact. Further, the second electrode 228 may be configured to contact the back surface of the protrusion of the upper layer auxiliary electrode 225c.

In addition, unlike the first embodiment of the present invention, the organic light emitting display according to the second embodiment of the present invention directly contacts between the second electrode 228 and the auxiliary electrode 225, .

That is, as described above, the top emission type organic light emitting display device has a high resistance of the second electrode, resulting in non-uniformity of luminance within the panel when a large area is realized. In order to compensate for this, an auxiliary electrode is required, but an organic compound is deposited on the auxiliary electrode during deposition of the organic compound layer, so that no contact is made between the second electrode and the auxiliary electrode. In order to solve this problem, a structure for assisting the contact between the second electrode and the auxiliary electrode is required, thereby increasing the number of masks and the process.

The organic light emitting display according to the second embodiment of the present invention includes a second electrode 228 and an auxiliary electrode 225 formed by forming a contact space V in the auxiliary electrode 225 when the first electrode 218 is patterned, ), It is possible to reduce the resistance of the second electrode 228 while simplifying the process. The decrease of the resistance can make the current supplied to each sub-pixel in the panel constant and improve the luminance uniformity.

The organic compound layer 230 is formed between the first electrode 218 and the second electrode 228, as in the first embodiment of the present invention described above. The organic compound layer 230 emits light by the combination of the holes supplied from the first electrode 218 and the electrons supplied from the second electrode 228.

5, the organic compound layer 230 is formed on the entire surface of the substrate 210, but the present invention is not limited thereto. The organic compound layer 230 may be formed only on the first electrode 218.

The organic compound layer 230 may have a multi-layer structure including a sub-layer for improving the luminous efficiency of the light-emitting layer in addition to the light-emitting layer.

The second electrode 228 is formed on the organic compound layer 230 to provide electrons to the organic compound layer 230.

And the second electrode 228 serves as a cathode. Accordingly, the second electrode 228 may be made of a transparent conductive material. For example, the transparent conductive material may include ITO or IZO. The second electrode 228 may further include a thin metal film (not shown) made of a metal material having a low work function on the side contacting the organic compound layer 230. For example, a low work function metal material may include magnesium (Mg), silver (Ag), and compounds thereof.

Hereinafter, a method of manufacturing an organic light emitting display according to a second embodiment of the present invention will be described in detail with reference to the drawings.

6A to 6E are cross-sectional views sequentially illustrating a method of manufacturing an organic light emitting display according to a second embodiment of the present invention shown in FIG.

7A to 7C are cross-sectional views specifically showing the mask process shown in FIG. 6C.

As shown in FIG. 6A, a substrate 210 made of a transparent glass material or an insulating material such as a transparent plastic or a polymer film excellent in flexibility is prepared.

Although not shown in detail, a TFT and a storage capacitor are formed in red, green, and blue sub-pixels of the substrate 210, respectively.

First, a buffer layer (not shown) is formed on the substrate 210.

In this case, the buffer layer may be formed to protect the thin film transistor from impurities such as alkali ions flowing out from the substrate 210 when the semiconductor layer is crystallized, and may be formed of a silicon oxide film.

Next, a semiconductor thin film, an insulating film, and a first conductive film (or metal layer) are formed on a substrate 210 on which a buffer layer is formed.

The semiconductor thin film can be formed of amorphous silicon, polycrystalline silicon, an oxide semiconductor, an organic semiconductor or the like.

At this time, the polycrystalline silicon may be formed by depositing amorphous silicon on the substrate 210 and then using various crystallization methods. When an oxide semiconductor is used as the semiconductor thin film, a predetermined heat treatment process can be performed after depositing the oxide semiconductor.

The first conductive film may be formed of one of aluminum (Al), copper (Cu), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium A low resistance opaque conductive material such as an alloy thereof can be used. At this time, the first conductive layer may have a multilayer structure including two conductive layers having different physical properties. One of the conductive films may be a metal having a low resistivity so as to reduce signal delay or voltage drop. For example, an aluminum-based metal, a silver-based metal, a copper-based metal, or the like.

Thereafter, the semiconductor thin film, the insulating film, and the first conductive film are selectively removed through a photolithography process to form a semiconductor layer 224 made of a semiconductor thin film.

At this time, a gate insulating film 215a made of an insulating film is formed on the semiconductor layer 224.

A gate line (not shown) and a first sustain electrode (not shown) including a gate electrode 221 made of a first conductive film are formed thereon.

Next, an interlayer insulating film 215b made of a silicon nitride film, a silicon oxide film, or the like is formed on the entire surface of the substrate 210 on which the gate line including the gate electrode 221 and the first sustain electrode are formed.

Then, the interlayer insulating film 215b is selectively patterned through a photolithography process to form a semiconductor layer contact hole exposing the source / drain region of the semiconductor layer 224.

Next, a second conductive film is formed on the entire surface of the substrate 210 on which the interlayer insulating film 215b is formed. Then, the data lines (that is, the source / drain electrodes 222 and 223, the driving voltage line (not shown), the data line (not shown), and the like) made of the second conductive film are selectively removed by selectively removing the second conductive film through the photolithography process. And a second sustain electrode (not shown).

At this time, the second conductive film may be formed of aluminum (Al), copper (Cu), molybdenum (Mo), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium Nd) or their alloys can be used. At this time, the second conductive layer may have a multilayer structure including two conductive layers having different physical properties. One of the conductive films may be made of a metal having a low resistivity, for example, an aluminum-based metal, a silver-based metal, a copper-based metal, or the like so as to reduce signal delay or voltage drop.

At this time, the source / drain electrodes 222 and 223 are electrically connected to the source / drain regions of the semiconductor layer 224 through the semiconductor layer contact holes. The second sustain electrode overlaps a part of the first sustain electrode below the interlayer insulating film 215b to form a storage capacitor.

Next, a planarizing film 215c made of a silicon nitride film, a silicon oxide film, or the like is formed on the substrate 210 on which the source / drain electrodes 222 and 223, the driving voltage line, the data line, and the second sustain electrode are formed.

Then, the planarization film 215c is selectively patterned through a photolithography process to form a drain contact hole H exposing the drain electrode 223.

Next, as shown in FIG. 6B, a third conductive film and a fourth conductive film are formed on the entire surface of the substrate 210 on which the planarization film 215c is formed. Thereafter, the third conductive film and the fourth conductive film are selectively removed through a photolithography process to form the connection electrode 208 and the auxiliary electrode pattern 225 ', which are composed of the third conductive film and the fourth conductive film.

The connection electrode 208 may be composed of a lower layer connection electrode 208a and an upper layer connection electrode 208b each made of a third conductive layer and a fourth conductive layer of dissimilar metals having different etching rates from the first electrode to be formed later . In addition, the auxiliary electrode pattern 225 'includes a first auxiliary electrode pattern 225a' and a second auxiliary electrode pattern 225b 'each made of a third conductive film and a fourth conductive film having different etching rates from the first electrode Lt; / RTI >

As described above, the etch rate of each of the third conductive film and the fourth conductive film constituting the connection electrode 208 and the auxiliary electrode pattern 225 'is higher than the etchant used for patterning the upper auxiliary electrode, that is, Respectively.

For example, the third conductive film is made of a metal such as MoTi or Ti that is not etched when the first electrode is patterned, and is free from damage to the etchant of the Ag alloy. However, the present invention is not limited to this, and the third conductive film may be formed of a metal having the lowest etching speed when the first electrode is patterned.

The fourth conductive layer may be formed of a metal having the highest etching rate at the time of patterning the first electrode, such as Cu. At this time, the Ag alloy is etched most quickly. Therefore, the fourth conductive film is etched most of the other conductive films so as to form the contact space V.

Next, as shown in Fig. 6C, a mask process is performed to form the contact space V. The cross-sectional views shown in Figs. 7A to 7C specifically show the mask process.

7A, a fifth conductive layer 250, a sixth conductive layer 260, and a seventh conductive layer (not shown) are formed on the entire surface of the substrate 210 having the connection electrode 208 and the auxiliary electrode pattern 225 ' 270 are formed.

However, the present invention is not limited thereto. For example, only a single layer of the fifth conductive layer 250 may be formed on the entire surface of the substrate 210 on which the connection electrode 208 and the auxiliary electrode pattern 225 'are formed.

The fifth conductive layer 250 and the seventh conductive layer 270 may be formed of a transparent conductive material such as ITO or IZO.

The sixth conductive layer 260 may be formed of aluminum (Al), silver (Ag), gold (Au), platinum (Pt), chromium (Cr), or an alloy containing them.

7B, a photoresist pattern 280 made of photoresist is formed on the substrate 210 on which the seventh conductive layer 270 is formed through a photolithography process.

At this time, the photoresist pattern 280 is patterned so as to be overlapped with a part of the auxiliary electrode pattern 225 'below it, that is, not overlapped with another part of the auxiliary electrode pattern 225' The second auxiliary electrode pattern 225b 'is etched in a portion where the second auxiliary electrode pattern 225b' is not formed.

In FIG. 7B, the photoresist pattern 280 is patterned so as not to overlap with the left part of the auxiliary electrode pattern 225 '. However, the present invention is not limited thereto. The photoresist pattern 280 may be patterned so as not to overlap with the right portion of the auxiliary electrode pattern 225 ', or may be patterned so as not to overlap with the left and right portions.

Next, as shown in FIGS. 6C and 7C, by selectively removing the fifth conductive film, the sixth conductive film, and the seventh conductive film, a first conductive film, a sixth conductive film, Electrode 218 is formed.

In this case, the first electrode 218 is composed of a lower layer first electrode 218a, a reflective layer 218b, and an upper layer first electrode 218c each made of a fifth conductive film, a sixth conductive film and a seventh conductive film .

For example, when the fifth conductive film, the sixth conductive film, and the seventh conductive film are made of ITO / Ag alloy / ITO, the first auxiliary electrode pattern 225a 'is formed during ITO / Ag alloy / ITO etching according to the above- ) MoTi is not etched. The Cu of the second auxiliary electrode pattern 225b 'is etched at a higher rate than the ITO / Ag alloy / ITO to pattern the auxiliary electrode 225 having a predetermined contact space V.

At this time, the patterning of the first electrode 218 made of an Ag alloy may be performed by using a phosphoric acid etchant, a nitric acid etchant, a phosphoric acid + nitric acid etchant, a phosphoric acid + acetic acid etchant, a nitric acid + acetic acid etchant, Total + nitrate + acetic acid etchant can be used. In addition, as described above, MoTi can not be etched with such an Ag alloy etchant. Therefore, MoTi of the first auxiliary electrode pattern 225a 'is not etched during the ITO / Ag alloy / ITO etching. At this time, the auxiliary electrode 225 may be formed by a combination of a third conductive film and a fourth conductive film, for example, a lowermost layer auxiliary electrode 225a and a lower layer auxiliary electrode 225b formed of MoTi and Cu, and a fifth conductive film, And a seventh conductive film, for example, an upper layer auxiliary electrode 225c made of ITO / Ag alloy / ITO.

In this case, the first electrode 218 and the upper layer auxiliary electrode 225c are patterned in the shape of the photoresist pattern, while the lowermost layer auxiliary electrode 225a is not etched. The lower layer auxiliary electrode 225b is etched at a higher rate than the upper layer auxiliary electrode 225c so that the lower layer auxiliary electrode 225b is etched between the upper layer auxiliary electrode 225c and the lowermost layer auxiliary electrode 225a, (V) is formed.

That is, one end of the upper layer auxiliary electrode 225c may protrude from one end of the lower layer auxiliary electrode 225b to form the contact space V, and one end of the lowermost layer auxiliary electrode 225a may be constituted by the lower layer auxiliary electrode 225b, May be configured to protrude more than one end of the contact portion (225b) to form the contact space (V).

When one end of the upper layer auxiliary electrode 225c is etched to a side of about 0.5 to 2.0 μm, one end of the lower layer auxiliary electrode 225b may be exposed to the lower layer when the etchant of the above-described Ag alloy is etched, Lt; RTI ID = 0.0 > pm < / RTI >

The first electrode 218, which is an anode, is electrically connected to the drain electrode 223 of the driving thin film transistor through the connection electrode 208.

At this time, the first electrode 218 is formed corresponding to each of red, green and blue sub-pixels on the substrate 210.

Next, as shown in FIG. 6D, a predetermined bank 215d is formed on the substrate 210 on which the first electrode 218 is formed.

At this time, the bank 215d may surround the periphery of the first electrode 218 to define an opening, and may be made of an organic insulating material or an inorganic insulating material. The bank 215d may also be made of a photosensitizer containing a black pigment, wherein the bank 215d serves as a light shielding member.

6E, an organic compound layer 230 is formed on the substrate 210 on which the banks 215d are formed by evaporation.

The organic compound layer 230 is not deposited in the contact space V in the auxiliary electrode 225 because the upper layer auxiliary electrode 225c serves as a blocking layer.

At this time, although not shown in detail, a hole injecting layer and a hole transporting layer may be sequentially formed on the substrate 210 for this purpose.

At this time, the hole injection layer and the hole transport layer are formed in common to red, green, and blue sub-pixels to smoothly inject and transport holes. At this time, any one of the hole injecting layer and the hole transporting layer may be omitted.

Next, a light emitting layer can be formed on the substrate 210 on which the hole transporting layer is formed.

At this time, the light emitting layer may include a red light emitting layer, a green light emitting layer, and a blue light emitting layer corresponding to red, green, and blue sub-pixels.

Next, an electron transporting layer can be formed on the substrate 210 on which the light emitting layer is formed.

At this time, the electron transporting layer is formed in common to the red, green and blue sub-pixels on the upper side of the light emitting layer, and plays a role of facilitating transport of electrons.

At this time, an electron injection layer may be further formed on the electron transport layer to smoothly inject electrons.

Then, a second electrode 228 made of an eighth conductive film is formed on the substrate 210 having the electron transporting layer formed thereon by sputtering.

At this time, since the eighth conductive film is deposited also in the contact space V when the eighth conductive film is deposited by sputtering, a contact is formed between the second electrode 228 and the auxiliary electrode 225 with a relatively large contact area.

At this time, since the contact is made not only on the upper surface of the lowermost layer auxiliary electrode 225a but also on the side surface of the lower layer auxiliary electrode 225b, the reliability of the contact can be increased. Further, the second electrode 228 may be configured to contact the back surface of the protrusion of the upper layer auxiliary electrode 225c. The organic light emitting diode is sealed with a predetermined thin film sealing layer on the thus fabricated organic light emitting diode.

A polarization film may be provided on the top surface of the thin film sealing layer to reduce reflection of external light of the organic light emitting display device to improve contrast.

8 is a cross-sectional view schematically showing a part of a structure of an organic light emitting display according to a third embodiment of the present invention.

In this case, the organic light emitting display according to the third embodiment of the present invention shown in FIG. 8 includes a contact space formed on both sides of the auxiliary electrode, and the connection electrode is patterned substantially in the same shape as the first electrode And has substantially the same structure as that of the organic light emitting display according to the second embodiment of the present invention.

8 shows an organic light emitting display device of a top emission type using a TFT having a coplanar structure as an example. However, the present invention is not limited to a TFT having a coplanar structure.

8, the organic light emitting display device of the top emission type according to the third embodiment of the present invention includes a substrate 310, a driving thin film transistor DT, an organic light emitting diode, and an auxiliary electrode line VSSLa .

The driving thin film transistor DT includes a semiconductor layer 324, a gate electrode 321, a source electrode 322 and a drain electrode 323 in the same manner as in the first and second embodiments described above.

At this time, a buffer layer (not shown) may be further formed between the substrate 310 and the semiconductor layer 324.

Semiconductor layer 324, gate insulating film (315a) made of silicon nitride (SiNx) or silicon oxide (SiO _2), such as above are formed. A gate line (not shown) and a first sustain electrode (not shown) including a gate electrode 321 are formed thereon.

An interlayer insulating film 315b made of a silicon nitride film, a silicon oxide film, or the like is formed on the gate electrode 321, the gate line, and the first sustain electrode. A data line (not shown), a driving voltage line (not shown), source / drain electrodes 322 and 323, and a second sustain electrode (not shown) are formed thereon.

The source electrode 322 and the drain electrode 323 are spaced apart from each other by a predetermined distance, and are electrically connected to the semiconductor layer 324. More specifically, a semiconductor layer contact hole exposing the semiconductor layer 324 is formed in the gate insulating film 315a and the interlayer insulating film 315b, and the source / drain electrodes 322 and 323 are formed through the semiconductor layer contact holes. And is electrically connected to the semiconductor layer 324.

At this time, the second sustain electrode overlaps a part of the first sustain electrode under the interlayer insulating film 315b to form a storage capacitor.

A planarization film 315c made of a silicon nitride film, a silicon oxide film or the like is formed on the substrate 310 on which the data lines, the driving voltage lines, the source / drain electrodes 322 and 323 and the second sustain electrodes are formed.

Next, the organic light emitting diode may include a first electrode 318, an organic compound layer 330, and a second electrode 328.

The organic light emitting diode is electrically connected to the driving thin film transistor DT. More specifically, a drain contact hole exposing the drain electrode 323 of the driving thin film transistor DT is formed in the planarization film 315c formed on the driving thin film transistor DT. The organic light emitting diode is electrically connected to the drain electrode 323 of the driving thin film transistor DT through the drain contact hole.

That is, the first electrode 318 is formed on the planarization film 315c and is electrically connected to the drain electrode 323 of the driving TFT DT through the connection electrode 308 and the drain contact hole.

The first electrode 318 supplies current (or voltage) to the organic compound layer 330, and defines a light emitting region having a predetermined area.

Also, the first electrode 318 serves as an anode. Accordingly, the first electrode 318 may be made of a transparent conductive material having a relatively large work function. For example, the first electrode 318 may include upper and lower first electrodes made of Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO). In order to improve the reflection efficiency, the first electrode 318 may further include a reflection layer made of a metal material having high reflection efficiency. For example, the metal material having high reflectance may include aluminum (Al), silver (Ag), gold (Au), platinum (Pt), chromium (Cr), or an alloy containing them.

At this time, in FIG. 8, for convenience of description, the first electrode 318 is shown without distinguishing between the upper and lower first electrodes and the reflective layer.

As such, the first electrode 318 according to the third embodiment of the present invention may have a triple-layer structure of a reflective layer between an upper and lower first electrode and an upper first electrode and a lower first electrode. However, the present invention is not limited thereto.

A bank 315d is formed on the substrate 310 on which the first electrode 318 is formed. At this time, the bank 315d surrounds the edge of the first electrode 318 and defines a first opening, and may be made of an organic insulating material or an inorganic insulating material. The bank 315d may also be made of a photoresist containing a black pigment, in which case the bank 315d serves as a light shielding member.

In the third embodiment of the present invention, the bank 315d further includes a second opening that completely exposes the auxiliary electrode 325 to be described later.

The auxiliary electrode 325 according to the third exemplary embodiment of the present invention may include a lower layer and a lower layer auxiliary electrode 325b and 325a having different etch rates with respect to the etchant of the first electrode 318, And the lower layer and the lowest layer auxiliary electrodes 325c, 325b, and 325a. The second electrode 328 may be in contact with the auxiliary electrode 325 itself when the second electrode 328 is deposited.

However, the present invention is not limited thereto, and the auxiliary electrode 325 according to the third exemplary embodiment of the present invention may include at least two or more layers including upper and lower auxiliary electrodes 325c and 325b of dissimilar metals And the lower layer auxiliary electrode 325b is disposed inside the upper layer auxiliary electrode 325c.

The upper, lower and lower layer auxiliary electrodes 325c, 325b and 325a are formed by using at least three kinds of metals and the etch rates of the metals constituting the lower layer and the lowermost layer auxiliary electrodes 325b and 325a are set so that the upper layer auxiliary electrode And the etchant used for patterning the second electrode 325c and the first electrode 318 are different from each other.

That is, the lowermost auxiliary electrode 325a is made of a metal that is not etched when the first electrode 318 is patterned, such as MoTi or Ti. For example, the lowermost auxiliary electrode 325a may be formed of a metal without damaging the etchant of the Ag alloy. However, the present invention is not limited thereto, and the lowest auxiliary electrode 325a may be formed of a metal having the lowest etch rate when the first electrode 318 is patterned.

As described above, the patterning of the first electrode 318 made of an Ag alloy may be performed by using a phosphoric acid etchant, a nitric acid etchant, a phosphoric acid + nitric acid etchant, a phosphoric acid + acetic acid etchant, a nitric acid + acetic acid etchant Or phosphate-based + nitric acid + acetic acid-based etchant.

The lower layer auxiliary electrode 325b is made of a metal having the highest etching rate at the time of patterning the first electrode 318, such as Cu, so that the etchant of the Ag alloy is most quickly etched.

The upper auxiliary electrode 325c may have the same single or triple layer structure as the first electrode 318 and may be patterned at the same etch rate when patterning the first electrode 318. [ For example, the metal layer constituting the upper layer auxiliary electrode 325c may include at least one of ITO, Ag, Ag alloy or MoTi.

MoTi of the lowermost layer auxiliary electrode 325a is hardly etched during the ITO / Ag alloy / ITO etching of the first electrode 318, and Cu of the lower layer auxiliary electrode 325b is less than ITO / Ag alloy / ITO It is etched at a faster rate. A predetermined contact space V is formed in the auxiliary electrode 325 as the ITO / Ag alloy / ITO of the upper auxiliary electrode 325c is etched at the same rate as that of the first electrode 218.

At this time, as described above, in the third embodiment of the present invention, the contact spaces V may be formed on both sides of the auxiliary electrode 325. In this case, the contact reliability can be further improved . In other words, both ends of the upper layer auxiliary electrode 325c may protrude from both ends of the lower layer auxiliary electrode 325b to form the contact space V, May be configured to protrude more than both ends of the contact portion (325b) to form the contact space (V).

The auxiliary electrode 325 may have a multi-tapered shape. In particular, a sacrificial layer may be introduced into the lower end of the auxiliary electrode 325 to form a multi-tapered shape.

The organic compound layer 330 is not deposited in the contact space V when the organic compound layer 330 is evaporated by the subsequent evaporation. On the other hand, a metal for the second electrode 328 is also deposited in the contact space V on both sides of the auxiliary electrode 325 during metal deposition for the second electrode 328 by sputtering to have a relatively wide contact area c, And the two electrodes 328 are brought into contact with the auxiliary electrode 325.

In particular, the organic compound layer 330 is not deposited in the contact space V in the auxiliary electrode 325 because the upper layer auxiliary electrode 325c serves as a blocking layer.

Among the multilayer structure of the auxiliary electrode 325, the Cu / MoTi 2 middle layer structure can be applied not only to the auxiliary electrode 325 but also to the connection electrode 308 and the pad electrode (not shown). Accordingly, the connection electrode 308 may be composed of upper and lower connection electrodes 308b and 308a.

At this time, the connection electrode 308 may be formed over the entire light emitting region in substantially the same shape as the first electrode 318 on the upper portion.

In this way, according to the third embodiment of the present invention, the contact hole 325 is formed in the auxiliary electrode 325 when the first electrode 318 is patterned by using the etching rate difference between the upper, lower and the lowest auxiliary electrodes 325c, 325b, The second electrode 328 and the auxiliary electrode 325 have a relatively large contact area b and can make direct contact with each other. Particularly, both the surface of the lowermost auxiliary electrode 325a as well as the side of the lower layer auxiliary electrode 325b are used as the contact area c and the contact area c is present on both sides of the auxiliary electrode 325, Effect can be obtained. Further, the second electrode 328 may be configured to contact the back surface of the protrusion of the upper layer auxiliary electrode 325c.

In addition, unlike the first embodiment of the present invention, the organic light emitting display according to the third embodiment of the present invention directly contacts between the second electrode 328 and the auxiliary electrode 325, .

The organic compound layer 330 is formed between the first electrode 318 and the second electrode 328, as in the first and second embodiments of the present invention described above. The organic compound layer 330 emits light by the combination of the holes supplied from the first electrode 318 and the electrons supplied from the second electrode 228.

8, the organic compound layer 330 is formed on the entire surface of the substrate 310. However, the present invention is not limited thereto. The organic compound layer 330 may be formed only on the first electrode 318.

The organic compound layer 330 may have a multi-layer structure including a sub-layer for improving the light-emitting efficiency of the light-emitting layer in addition to the light-emitting layer.

The second electrode 328 is formed on the organic compound layer 330 to provide electrons to the organic compound layer 330.

And the second electrode 328 serves as a cathode. Accordingly, the second electrode 328 may be made of a transparent conductive material. For example, the transparent conductive material may include ITO or IZO. The second electrode 328 may further include a thin metal film (not shown) made of a metal material having a low work function on the side contacting the organic compound layer 330. For example, a low work function metal material may include magnesium (Mg), silver (Ag), and compounds thereof.

Hereinafter, a method of manufacturing an organic light emitting display according to a third embodiment of the present invention will be described in detail with reference to the drawings.

FIGS. 9A to 9E are cross-sectional views sequentially illustrating a method of manufacturing an organic light emitting display according to a third embodiment of the present invention shown in FIG.

10A to 10C are cross-sectional views specifically showing the mask process shown in FIG. 9C.

As shown in FIG. 9A, a substrate 310 made of a transparent glass material or an insulating material such as a transparent plastic or a polymer film excellent in flexibility is prepared.

Although not shown in detail, a TFT and a storage capacitor are formed in red, green, and blue sub-pixels of the substrate 310, respectively.

As described above, a semiconductor layer 324 made of a semiconductor thin film is formed on the substrate 310 through a photolithography process.

At this time, a gate insulating film 315a made of an insulating film is formed on the semiconductor layer 324.

A gate line (not shown) and a first sustain electrode (not shown) including a gate electrode 321 made of a first conductive film are formed thereon.

Next, an interlayer insulating film 315b made of a silicon nitride film, a silicon oxide film, or the like is formed on the entire surface of the substrate 310 on which the gate line including the gate electrode 321 and the first sustain electrode are formed.

Then, the interlayer insulating film 315b is selectively patterned through a photolithography process to form a semiconductor layer contact hole exposing the source / drain regions of the semiconductor layer 324.

Next, a second conductive film is formed on the entire surface of the substrate 310 on which the interlayer insulating film 315b is formed. Then, data lines (that is, source / drain electrodes 322 and 323), a driving voltage line (not shown), a data line (not shown), and the like are formed by selectively removing the second conductive film through a photolithography process. And a second sustain electrode (not shown).

At this time, the source / drain electrodes 322 and 323 are electrically connected to the source / drain regions of the semiconductor layer 324 through the semiconductor layer contact holes. The second sustain electrode overlaps with a part of the first sustain electrode below the interlayer insulating film 315b to form a storage capacitor.

Next, a planarizing film 315c made of a silicon nitride film, a silicon oxide film, or the like is formed on the substrate 310 on which the source / drain electrodes 322 and 323, the driving voltage line, the data line, and the second sustain electrode are formed.

Then, the planarization film 315c is selectively patterned through a photolithography process to form a drain contact hole H for exposing the drain electrode 323.

Next, as shown in FIG. 9B, a third conductive film and a fourth conductive film are formed on the entire surface of the substrate 310 on which the planarization film 315c is formed. Thereafter, the third conductive film and the fourth conductive film are selectively removed through a photolithography process to form the connection electrode 308 and the auxiliary electrode pattern 325 ', which are composed of the third conductive film and the fourth conductive film.

The connection electrode 308 may be composed of a lower layer connection electrode 308a and an upper layer connection electrode 308b, each of which is composed of a first electrode to be formed later and a third conductive film and a fourth conductive film of dissimilar metals having selective etching ratios have.

The auxiliary electrode pattern 325 'includes a first auxiliary electrode pattern 325a' and a second auxiliary electrode pattern 325b 'each made of a third conductive film and a fourth conductive film having different etch rates from the first electrode Lt; / RTI >

As described above, the etching rates of the third conductive film and the fourth conductive film constituting the connecting electrode 308 and the auxiliary electrode pattern 325 'are different from each other in the etchant used for patterning the upper auxiliary electrode, Respectively.

For example, the third conductive film is made of a metal such as MoTi or Ti that is not etched when the first electrode is patterned, and is free from damage to the etchant of the Ag alloy. However, the present invention is not limited to this, and the third conductive film may be formed of a metal having the lowest etching speed when the first electrode is patterned.

The fourth conductive layer may be formed of a metal having the highest etching rate during patterning of the first electrode, such as Cu, and thus the metal layer may be etched most quickly with the Ag alloy etchant. Therefore, the fourth conductive film is etched most of the other conductive films so as to form the contact space V.

Next, as shown in Fig. 6C, a mask process is performed to form the contact space V. The cross-sectional views shown in Figs. 10A to 10C specifically show the mask process.

The fifth conductive layer 350 is formed on the entire surface of the substrate 310 on which the connection electrode 308 and the auxiliary electrode pattern 325 'are formed.

In this case, the fifth conductive layer 350 may be formed of a material selected from the group consisting of aluminum (Al), silver (Ag), gold (Au), platinum (Pt), and the like, between the upper and lower layers made of a transparent conductive material such as ITO or IZO, , Chromium (Cr), or a reflective layer made of an alloy containing them, and is shown in Fig. 10a as a single layer for convenience.

However, the present invention is not limited thereto, and the fifth conductive layer 350 may be a single layer, two layers, or four or more layers.

10B, a predetermined photoresist pattern 380 made of photoresist is formed on the substrate 310 on which the fifth conductive layer 350 is formed through a photolithography process.

At this time, the photoresist pattern 380 of a certain region, that is, the region where the auxiliary electrode is to be formed, is patterned in substantially the same shape as the auxiliary electrode pattern 325 'under the region.

Next, as shown in FIGS. 9C and 10C, the fifth conductive film is selectively removed to form the first electrode 318 made of the fifth conductive film.

At this time, as described above, the first electrode 318 may be composed of a lower first electrode made of a fifth conductive film, a reflective layer, and an upper first electrode.

In this case, when the fifth conductive film is made of ITO / Ag alloy / ITO, the MoTi of the first auxiliary electrode pattern 325a 'is not etched during the ITO / Ag alloy / ITO etching according to the above-mentioned etching conditions. The Cu of the second auxiliary electrode pattern 325b 'is etched at a faster rate than the ITO / Ag alloy / ITO, so that the auxiliary electrode 325 having a predetermined contact space V is patterned.

At this time, the patterning of the first electrode 318 made of an Ag alloy may be carried out using a phosphoric acid etchant, a nitric acid etchant, a phosphoric acid + nitric acid etchant, a phosphoric acid + acetic acid etchant, a nitric acid + acetic acid etchant, Phosphoric acid + nitric acid + acetic acid etchant can be used. In addition, as described above, MoTi can not be etched with such an Ag alloy etchant. Therefore, MoTi of the first auxiliary electrode pattern 325a 'is not etched during ITO / Ag alloy / ITO etching.

At this time, the auxiliary electrode 325 is formed by a combination of a third conductive film and a fourth conductive film, for example, a lowermost layer auxiliary electrode 325a and a lower layer auxiliary electrode 325b, which are made of MoTi and Cu, and a fifth conductive film, And an upper layer auxiliary electrode 325c made of Ag alloy / ITO.

In this case, the first electrode 318 and the upper layer auxiliary electrode 325c are patterned in the shape of the photoresist pattern, while the lowermost layer auxiliary electrode 325a is hardly etched. The lower layer auxiliary electrode 325b is etched at a higher rate than the upper layer auxiliary electrode 325c and the lower layer auxiliary electrode 325b is etched between the upper layer auxiliary electrode 325c and the lowest layer auxiliary electrode 325a, The contact space V is formed.

In other words, both ends of the upper layer auxiliary electrode 325c may protrude from both ends of the lower layer auxiliary electrode 325b to form the contact space V, May be configured to protrude more than both ends of the contact portion (325b) to form the contact space (V).

When one end of the upper layer auxiliary electrode 325c is etched to about 0.5 to 2.0 μm on one side of the upper layer auxiliary electrode 325b, Lt; RTI ID = 0.0 > pm < / RTI >

The first electrode 318, which is an anode, is electrically connected to the drain electrode 323 of the driving thin film transistor through the connection electrode 308.

At this time, the first electrode 318 is formed corresponding to each of the red, green and blue sub-pixels on the substrate 310.

Next, as shown in FIG. 9D, a predetermined bank 315d is formed on the substrate 310 on which the first electrode 318 is formed.

9E, an organic compound layer 330 is formed on the substrate 310 on which the banks 315d are formed by evaporation.

The organic compound layer 330 is not formed in the contact space V in the auxiliary electrode 325 because the upper layer auxiliary electrode 325c acts as a blocking layer.

A second electrode 328 made of a sixth conductive film is formed on the substrate 310 on which the organic compound layer 330 is formed by sputtering.

At this time, since the sixth conductive film is also deposited in the pair of contact spaces V when the sixth conductive film is deposited by sputtering, the contact between the second electrode 328 and the auxiliary electrode 325 .

At this time, the contact is made not only on the upper surface of the lower layer auxiliary electrode 325a but also on the side surface of the lower layer auxiliary electrode 325b, and at the same time, the contact is made on both sides of the auxiliary electrode 325, thereby enhancing the reliability of the contact. Further, the second electrode 328 may be configured to contact the back surface of the protrusion of the upper layer auxiliary electrode 225c.

The organic light emitting diode is sealed with a predetermined thin film sealing layer on the thus fabricated organic light emitting diode.

A polarizing film may be provided on the upper surface of the thin film sealing layer to reduce reflection of external light of the organic light emitting display device to improve contrast.

While a great many are described in the foregoing description, it should be construed as an example of preferred embodiments rather than limiting the scope of the invention. Therefore, the invention should not be construed as limited to the embodiments described, but should be determined by equivalents to the appended claims and the claims.

110, 210, 310: substrate 118, 218, 318:
125, 225, 325: auxiliary electrode 128, 228, 328:
208, 308:

Claims (19)

A first electrode disposed on each of the sub-pixels of the substrate;
An auxiliary electrode spaced apart from the first electrode and having a contact void formed by at least two metal layers having different etching rates; And
And a second electrode that is in direct contact with the auxiliary electrode through the contact void. The organic light emitting display as claimed in claim 1, wherein the etching rate of the metal layer disposed on the upper layer of the auxiliary electrode is lower than the etching rate of the metal layer disposed on the lower layer. The organic light emitting display device according to claim 2, wherein the metal layer disposed on the upper layer includes at least one of ITO, Ag, Ag alloy, and MoTi. The organic light emitting display device according to claim 2, wherein the metal layer disposed on the lower layer includes Cu. The organic light emitting display according to claim 2, wherein at least one end of the metal layer disposed on the upper layer is configured to protrude more than one end of the metal layer disposed on the lower layer to form the contact space. The organic electroluminescent display device according to claim 5, wherein the second electrode is configured to be in contact with a side surface of the metal layer disposed on the lower layer. The organic light emitting display as claimed in claim 6, wherein the second electrode is configured to be in contact with a rear surface of the protruded upper layer. 6. The organic light emitting display as claimed in claim 5, wherein the auxiliary electrode further comprises a metal layer disposed on a lowest layer of the lower layer. 9. The organic light emitting display device according to claim 8, wherein at least one end of the metal layer disposed at the lowermost layer protrudes more than at least one end of the metal layer disposed on the upper layer to form the contact void. . The organic light emitting display as claimed in claim 9, wherein the second electrode is configured to be in contact with the upper surface of the protruded lowest layer protrusion. The organic light emitting display as claimed in claim 8, wherein the metal layer disposed at the lowermost layer includes MO or MoTi. 9. The organic light emitting display as claimed in claim 8, wherein the metal layer disposed on the upper layer is made of the same material as the first electrode. The organic light emitting display as claimed in claim 8, further comprising a connection electrode disposed under the first electrode and having the same structure as the metal layer disposed in the lowermost layer and the lower layer. A first electrode disposed in each of the plurality of sub-pixels of the substrate;
An auxiliary electrode spaced apart from the first electrode and having at least two layers and an end of at least one layer disposed in an upper layer of the at least two layers, the auxiliary electrode being disposed inside the end of the upper layer;
An organic compound layer on the upper layer of the first electrode and the auxiliary electrode; And
And a second electrode covering the organic compound layer and electrically connected to the at least one layer of the auxiliary electrode. 15. The organic light emitting display as claimed in claim 14, wherein the upper layer of the auxiliary electrode is made of a material whose etching rate is slower than the at least one layer of the auxiliary electrode. 16. The plasma display panel of claim 15, wherein the auxiliary electrode further comprises at least three layers and a bottom layer disposed at a lower portion of the at least one layer of the at least three layers, the bottom layer being further outward Wherein the organic electroluminescent display device is exposed. 17. The organic light emitting display as claimed in claim 16, wherein the at least one layer of the auxiliary electrode is made of a material having a relatively high etch rate among the at least three layers. Forming a driving thin film transistor on a substrate;
Forming an auxiliary electrode pattern made of at least two metal layers different from each other on the substrate;
Forming a first electrode patterned on the substrate on which the auxiliary electrode pattern is formed, etching the auxiliary electrode pattern together with the auxiliary electrode pattern to form an auxiliary electrode composed of at least two different metal layers;
Forming an organic compound layer on the first electrode and the auxiliary electrode; And
And forming a second electrode on the substrate on which the organic compound layer is formed,
Wherein at least one metal layer disposed on a metal layer disposed on a lowermost layer among the at least two metal layers different from each other is etched inward to pattern the end of the at least one metal layer And is disposed inside to form a contact void,
Wherein the second electrode and the auxiliary electrode are in direct contact with each other through the contact void. The method according to claim 18, wherein the second electrode is formed to directly contact the upper surface of the metal layer disposed on the lowest layer of the auxiliary electrode and the side surface of the at least one metal layer.

Images