KR102564169B1 - Organic light emitting diodes, Head mounted display including the same, and method for manufacturing the same. - Google Patents

Abstract

The present invention relates to organic light emitting diodes (OLEDs), and more particularly to OLEDs used in head mounted displays.
A feature of the present invention is that the organic light emitting layer and the anode electrode are formed to have the same thickness in all subpixels, and in particular, the anode electrode is located on the same plane in each subpixel, thereby improving the efficiency of the process and the contact electrode By forming different thicknesses for each sub-pixel, a micro-cavity effect can also be implemented, thereby improving the light extraction efficiency of the OLED and also improving the color purity.

Description

Organic light emitting display device, head mounted display including the same, and manufacturing method thereof

The present invention relates to organic light emitting diodes (OLEDs), and more particularly to OLEDs used in head mounted displays.

Recently, as society has entered the information age in earnest, interest in information displays that process and display large amounts of information has increased, and as the demand for using portable information media has increased, the display field has developed rapidly. In response to this, various lightweight and thin flat panel display devices have been developed and are in the spotlight.

Specific examples of such a flat panel display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), and an electroluminescence display. Electroluminescence display device (ELD), organic light emitting diodes (OLED), and the like. These flat panel display devices show excellent performance in thinning, lightening and low power consumption, : It is rapidly replacing the CRT).

Among the above flat panel display devices, an organic light emitting display device (hereinafter, referred to as an OLED) is a self-emitting device and does not require a backlight used in a liquid crystal display device, which is a non-light emitting device, and thus can be lightweight and thin.

In addition, it has excellent viewing angle and contrast ratio compared to liquid crystal displays, is advantageous in terms of power consumption, can be driven at low DC voltage, has a fast response speed, is resistant to external shocks because the internal components are solid, and has a wide operating temperature range. It has advantages.

In particular, since the manufacturing process is simple, there is an advantage in that production costs can be significantly reduced compared to conventional liquid crystal display devices.

On the other hand, in recent OLEDs, side leakage current due to the end of the anode electrode has become a problem.

In addition, since the organic light emitting layer is non-uniformly formed at the edge of the anode electrode, a short circuit between the anode electrode and the organic light emitting layer may occur.

This, in the end, causes quality deterioration problems of OLED such as image non-uniformity.

The present invention is to solve the above problems, and a first object is to provide an OLED capable of improving process efficiency while implementing a micro-cavity effect.

In addition, the second purpose is to prevent side leakage current of OLED, and the third purpose is to minimize the occurrence of a step difference between the anode electrode and the insulating film, thereby finally preventing the quality of OLED from deteriorating. to be

In order to achieve the object as described above, the present invention provides a substrate including first to third sub-pixels, a driving thin film transistor provided for each of the first to third sub-pixels, and a driving thin film transistor positioned above the driving thin film transistor. an interlayer insulating film, first to third contact electrodes having different thicknesses and positioned above the interlayer insulating film, corresponding to the first to third sub-pixels, respectively, and positioned above the first to third contact electrodes A reflective electrode, a protective layer positioned above the reflective electrode and having a different thickness corresponding to the first and second sub-pixels, and positioned above the reflective electrode and the protective layer, the first first to third anode electrodes positioned on the same plane corresponding to the first to third sub-pixels, an organic light emitting layer positioned above the first to third anode electrodes, and a cathode electrode positioned above the organic light emitting layer; and wherein the thickness of the passivation layer corresponding to the first and second sub-pixels is inversely proportional to the thickness of the first and second contact electrodes.

In this case, the passivation layer positioned corresponding to the first and second sub-pixels includes first and second anode contact holes exposing the first and second reflective electrodes, respectively, and the first and second anodes The electrodes are in contact with the first and second reflective electrodes through the first and second anode contact holes, respectively, and a protective layer is positioned on the third reflective electrode in correspondence to the third sub-pixel. The passivation layer positioned corresponding to the third sub-pixel includes a third anode contact hole exposing the third reflective electrode, and the third anode electrode contacts the third reflective electrode through the third anode contact hole. do.

The passivation layer covers side surfaces of the first to third contact electrodes and the first to third reflective electrodes, and the side surfaces of the anode electrode are covered by banks positioned above the passivation layer.

In addition, the first to third contact electrodes are in contact with the drain electrode of the driving thin film transistor, respectively, and the first to third contact electrodes are a single layer or a single layer containing at least one of titanium (Ti) and titanium nitride (TiN). It consists of a multilayer structure, or indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (indium gallium oxide: IGO), and aluminum zinc oxide (aluminum zinc oxide: AZO) is composed of a single-layer or multi-layer structure including at least one.

Here, the present invention includes an organic light emitting display device, a display storage case accommodating the organic light emitting display device, and a lens disposed on one side of the storage case and providing an image of the organic light emitting display device, wherein the organic light emitting display device is provided. A light emitting display device includes a substrate including first to third sub-pixels, driving thin film transistors respectively provided for each of the first to third sub-pixels, an interlayer insulating film positioned over the driving thin film transistor, and the interlayer insulating film. First to third contact electrodes positioned upward and having different thicknesses corresponding to the first to third sub-pixels, reflective electrodes positioned above the first to third contact electrodes, and upper portions of the reflective electrodes A passivation layer positioned to correspond to the first and second sub-pixels and having a different thickness from each other, and a passivation layer positioned above the reflective electrode and the passivation layer, respectively corresponding to the first to third sub-pixels. and first to third anode electrodes positioned on the same plane, an organic light emitting layer positioned above the first to third anode electrodes, and a cathode electrode positioned above the organic light emitting layer, wherein the first and third anode electrodes are positioned on the same plane. The thickness of the passivation layer corresponding to the two sub-pixels is in inverse proportion to the thickness of the first to third contact electrodes, providing a head-mounted display.

In addition, the present invention includes the steps of forming first to third contact electrodes having different thicknesses for each of the first to third sub-pixels on the interlayer insulating film, and the first to third contact electrodes are formed on top of the first to third contact electrodes, respectively. Forming a reflective electrode; forming a protective layer on the first to third reflective electrodes; planarizing the protective layer; forming first and second anode contact holes in a layer, and forming first to third anode electrodes on the third reflective electrode and the passivation layer, corresponding to the first to third sub-pixels, respectively. and sequentially forming an organic light emitting layer and a cathode electrode on top of the first to third anode electrodes.

At this time, in the planarization step, after forming the protective layer on the substrate, an etchback process, a reflow process, or a chemical mechanical polishing (CMP) process is used.

As described above, according to the present invention, the organic light emitting layer, the anode electrode, and the reflective electrode are formed to have the same thickness in all subpixels, and in particular, the anode electrode is positioned on the same plane in each subpixel, thereby increasing the efficiency of the process. However, by forming the thickness of the contact electrode differently for each sub-pixel, a micro-cavity effect can also be implemented, thereby improving the light extraction efficiency of the OLED and improving the color purity.

In addition, it is possible to reduce the step due to the anode electrode, and it is possible to prevent the occurrence of defects in the organic light emitting layer due to the step, so that there is an effect of preventing short circuit between the anode electrode and the cathode electrode or the organic light emitting layer. . Through this, there is an effect of preventing quality deterioration problems such as image non-uniformity from being caused.

In addition, the end of the reflective electrode is covered by the protective layer and the end of the anode electrode is covered by the bank, thereby preventing side leakage current from flowing through the organic light emitting layer from the end of the anode electrode or the reflective electrode. Accordingly, there is an effect of improving the quality of light emission by implementing low-power, high-resolution and preventing unwanted light emission from adjacent sub-pixels.

In addition, compared to OLEDs in which the thickness of the anode electrode is differently formed for each sub-pixel, all sub-pixels can have the same transmittance, and also the transmittance itself can be improved, so that an OLED with improved light efficiency can be provided. there is

1 is a plan view showing the structure of a unit pixel including three sub-pixels in an OLED according to an embodiment of the present invention;
2 is a cross-sectional view showing the structure of a unit pixel including three sub-pixels of an OLED according to an embodiment of the present invention, cut along the line II-II in FIG. 1;
Figure 3 is an enlarged view of a part of Figure 2;
4a to 4b are scanning electron microscope (SEM) photographs comparing the surface roughness of the reflective electrode according to the presence or absence of a protective layer between the reflective electrode and the anode electrode.
5 is experimental data obtained by comparing and measuring different transmittances according to the thickness of the anode electrode.
6 is experimental data obtained by comparatively measuring transmittance of OLEDs according to an embodiment of the present invention.
7a to 7f are process cross-sectional views showing a method of manufacturing an OLED according to an embodiment of the present invention according to a process flow.
8 is a view showing a head-mounted display to which an OLED according to an embodiment of the present invention is applied.
9 is a cross-sectional view of the display storage case when viewed from the side.

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

1 is a plan view showing the structure of a unit pixel including three sub-pixels in an OLED according to an embodiment of the present invention.

And, FIG. 2 is a cross-sectional view showing the structure of a unit pixel including three sub-pixels of an OLED according to an embodiment of the present invention cut along the line II-II in FIG. 1 .

On the other hand, the OLED 100 according to the embodiment of the present invention is divided into a top emission type and a bottom emission type according to the transmission direction of the emitted light. Hereinafter, in the present invention, the top emission type Let me explain with an example.

As shown in FIG. 1, in the OLED 100 according to an embodiment of the present invention, one unit pixel P includes blue, green, and red sub-pixels B-SP, G-SP, and R-SP. Each of the sub-pixels (B-SP, G-SP, R-SP) includes a light emitting area EA, and a bank 119 is disposed along the edge of the light emitting area EA to provide non-light emitting area (NEA) is formed.

Here, for convenience of explanation, each of the subpixels (B-SP, G-SP, R-SP) is shown as being positioned side by side with the same width, but each subpixel (B-SP, G-SP, R-SP) SP) can have various structures with different widths.

At this time, switching and driving thin film transistors STr and DTr are provided on the non-emission area NEA of each sub-pixel B-SP, G-SP and R-SP, and each sub-pixel B-SP and G- A light emitting diode E including an anode electrode 200, an organic light emitting layer 113, and a cathode electrode 115 is disposed on the light emitting area EA in the SP and R-SP, respectively.

Here, the switching thin film transistor (STr) and the driving thin film transistor (DTr) are connected to each other, and the driving thin film transistor (DTr) is connected to the light emitting diode (E).

Looking at this in more detail, the gate line (SL), data line (DL), and power line (VDD) are disposed on the substrate 101 to define each sub-pixel (B-SP, G-SP, R-SP). do.

The switching thin film transistor (STr) is formed at the intersection of the gate line (SL) and the data line (DL). function to select

The switching thin film transistor STr includes a gate electrode SG branching from the gate line GL, a semiconductor layer (not shown), a source electrode SS, and a drain electrode SD.

Also, the driving thin film transistor DTr serves to drive the light emitting diode E of the sub-pixels B-SP, G-SP, and R-SP selected by the switching thin film transistor STr. The driving thin film transistor DTr has a gate electrode DG connected to the drain electrode SD of the switching thin film transistor STr, a semiconductor layer 103, a source electrode DS connected to the power supply line VDD, and a drain It includes an electrode (DD).

The drain electrode DD of the driving thin film transistor DTr is connected to the anode electrode 211 of the light emitting diode E.

An organic light emitting layer 217 is interposed between the anode electrode 211 and the cathode electrode 219 .

Referring to FIG. 2 for a more detailed look, a semiconductor layer 103 is positioned on the switching region TrA of each subpixel (B-SP, G-SP, R-SP) on the substrate 101. The layer 103 is made of silicon, and its central portion is composed of an active region 103a constituting a channel, and source and drain regions 103b and 103c doped with high-concentration impurities on both sides of the active region 103a.

A gate insulating film 105 is positioned above the semiconductor layer 103 .

A gate electrode DG corresponding to the active region 103a of the semiconductor layer 103 and a gate line GL extending in one direction, although not shown, are provided above the gate insulating layer 105 .

In addition, the first interlayer insulating film 109a is positioned on the upper part including the gate electrode DG and the gate line GL, and at this time, the first interlayer insulating film 109a and the gate insulating film 105 below the first interlayer insulating film 109a form an active region. (103a) First and second semiconductor layer contact holes 116 exposing source and drain regions 103b and 103c located on both sides, respectively, are provided.

Next, on the top of the first interlayer insulating film 109a including the first and second semiconductor layer contact holes 116, the source and drain regions spaced apart from each other and exposed through the first and second semiconductor layer contact holes 116 ( Source and drain electrodes DS and DD contacting 103b and 103c, respectively, are provided.

Then, the source and drain electrodes DS and DD and the drain electrode of the driving thin film transistor DTr ( The second interlayer insulating layer 109b including the first drain contact hole PH1 exposing the DD) is positioned.

At this time, a semiconductor layer 103 including source and drain electrodes DS and DD and source and drain regions 103b and 103c in contact with these electrodes DS and DD and a gate located on the semiconductor layer 103 The insulating film 105 and the gate electrode DG form a driving thin film transistor DTr.

Meanwhile, although not shown in the drawings, the switching thin film transistor (STr) has the same structure as the driving thin film transistor (DTr) and is connected to the driving thin film transistor (DTr).

Here, the switching thin film transistor (STr) and the driving thin film transistor (DTr) are amorphous silicon thin film transistors (a-Si TFT), polycrystalline silicon thin film transistors (p-Si TFT), and monocrystalline silicon thin film according to the type of semiconductor layer 103. It can be divided into a transistor (c-Si TFT), an oxide thin film transistor (oxide TFT), etc. In the drawing, the semiconductor layer 103 is shown as an example of a top gate type, and as a modification thereof, pure and impurity It may be provided as a bottom gate type made of amorphous silicon. At this time, when the semiconductor layer 103 is made of an oxide semiconductor layer, a light blocking layer (not shown) may be further positioned under the semiconductor layer 103, and a buffer layer (not shown) is between the light blocking layer (not shown) and the semiconductor layer 103. city) can be located.

In addition, a drain electrode is formed on the upper portion of the second interlayer insulating film 109b corresponding to the switching region TrA of each sub-pixel B-SP, G-SP, and R-SP through the first drain contact hole PH1. A first metal pattern 107a in contact with (DD) is provided, and a third drain contact hole PH2 exposing the first metal pattern 107a is provided above the first metal pattern 107a. An interlayer insulating film 119c is positioned.

A second metal pattern 107b contacting the first metal pattern 107a through the second drain contact hole PH2 is provided above the third interlayer insulating layer 119c, and the second metal pattern 107b is disposed above the second metal pattern 107b. is positioned a fourth interlayer insulating layer 119d including a third drain contact hole PH3 exposing the second metal pattern 107b.

Here, the first and second metal patterns 107a and 107b may form a storage metal in the storage area, may be connected to a storage supply line or a ground wire, or may be connected to each subpixel (B-SP, G-SP, R-SP) may be a voltage supply line for supplying any one of a plurality of driving voltages.

An anode electrode 211 electrically connected to the second metal pattern 107b through the third drain contact hole PH3 is positioned above the fourth interlayer insulating layer 109d.

The anode electrode 211 is connected to the drain electrode DD of the driving thin film transistor DTr and is made of, for example, a transparent material having a relatively high work function value to form the anode of the light emitting diode E.

This anode electrode 211 is located for each sub-pixel (B-SP, G-SP, R-SP), and the anode electrode 211 located for each sub-pixel (B-SP, G-SP, R-SP) ) Between them, a bank (bank: 119) is located. That is, the anode electrode 111 is separated for each sub-pixel (B-SP, G-SP, R-SP) by using the bank 119 as a boundary for each sub-pixel (B-SP, G-SP, R-SP). have a structure.

Also, an organic light emitting layer 217 is positioned on top of the anode electrode 211. The organic light emitting layer 217 is a common layer commonly formed in the subpixels (B-SP, G-SP, R-SP), and emits white light. It may be a white light emitting layer that emits light.

In this case, the organic light emitting layer 217 may be formed in a tandem structure of two or more stacks. Each of the stacks may include a hole transporting layer, at least one light emitting layer, and an electron transporting layer. In addition, a charge generation layer may be formed between the stacks. The charge generation layer is formed on the n-type charge generation layer adjacent to the lower stack and the p-type charge generation layer adjacent to the upper stack. A charge generating layer may be included.

Also, the n-type charge generation layer injects electrons into the lower stack, and the p-type charge generation layer injects holes into the upper stack. The n-type charge generating layer may be an organic layer in which an organic host material capable of transporting electrons is doped with an alkali metal such as Li, Na, K, or Cs, or an alkaline earth metal such as Mg, Sr, Ba, or Ra, The p-type charge generation layer may be doped with a dopant in an organic host material having hole transport capability.

A cathode electrode 219 is positioned on the front surface of the organic light emitting layer 217, and the cathode electrode 219 also, like the organic light emitting layer 217, sub-pixels (B-SP, G-SP, R-SP) It may be made of a common layer commonly formed on.

At this time, the anode electrode 211, the organic light emitting layer 217, and the cathode electrode 219 form the light emitting diode E.

When a predetermined voltage is applied to the anode electrode 211 and the cathode electrode 219 according to the selected signal, the holes injected from the anode electrode 211 and the electrons provided from the cathode electrode 219 are organic. It is transported to the light emitting layer 217 to form excitons, and when these excitons transition from an excited state to a ground state, light is generated and emitted in the form of visible light.

At this time, since the emitted light passes through the transparent cathode electrode 219 and goes out, the OLED 100 implements an arbitrary image.

Here, the OLED 100 according to the embodiment of the present invention is a top emission type in which light emitted from the organic light emitting layer 217 is output to the outside through the cathode electrode 219. At this time, the anode electrode ( 211) A reflective electrode 213 made of an opaque conductive material is further included below.

That is, since the reflective electrode 213 is positioned under the anode electrode 211, the reflective electrode 213 functions as a semi-transmissive mirror and a reflective mirror with the cathode electrode 219, so that the emitted light from the organic light emitting layer 217 The light is resonated between the cathode electrode 219 and the reflective electrode 213.

Here, the anode electrode 211 is for supplying holes to the organic light emitting layer 217 and is formed of a conductive material having a high work function. The anode electrode 211 is indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide ( It may include at least one selected from the group including indium gallium oxide (IGO), and aluminum zinc oxide (AZO).

The anode electrode 211 may reduce a difference in work function from the organic light emitting layer 217 positioned above, so that holes may easily enter the organic light emitting layer 217 region.

The reflective electrode 213 reflects light emitted from the organic light emitting layer 217 toward the cathode electrode 219 and is formed of a conductive layer having excellent reflectivity. The reflective electrode 213 may be silver (Ag) or an alloy containing silver (Ag), for example, silver or APC (Ag/Pd/Cu).

In addition, it may be aluminum (Al) or an alloy containing aluminum (Al).

Further, a contact electrode 215 is further disposed under the reflective electrode 213, and the contact electrode 215 may be formed in a single-layer or multi-layer structure including at least one of titanium (Ti) and titanium nitride (TiN). there is.

or indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO) ), and aluminum zinc oxide (AZO).

The contact electrode 215 comes into contact with the second metal pattern 107b through the third drain contact hole PH3 of the fourth interlayer insulating layer 109d and is electrically connected to the driving thin film transistor DTr.

Here, the first to fourth interlayer insulating films 109a, 109b, 109c, and 109d may be made of silicon nitride (SiNx) or silicon oxide (SiOx), or may be made of an organic insulating material for planarization of the substrate 101. there is.

For example, the first to fourth interlayer insulating films 109a, 109b, 109c, and 109d may be made of acrylic resin, epoxy resin, phenolic resin, polyamides resin, or polyether resin. At least one of polyimides resin, unsaturated polyesters resin, poly-phenylenethers resin, polyphenylenesulfides resin and benzocyclobutene It may be formed of a material, but is not limited thereto.

The contact electrode 215 serves to improve the adhesion of the reflective electrode 213 by reducing adhesive stress between the reflective electrode 213 and the fourth interlayer insulating film 109d.

Also, the cathode electrode 219 may be formed of a semi-transmissive conductive material such as magnesium (Mg), silver (Ag), or an alloy of magnesium (Mg) and silver (Ag).

Therefore, the light emission efficiency of the OLED 100 according to the embodiment of the present invention can be increased by a micro cavity effect. We will look into this in more detail later.

In addition, an encapsulation layer 103 in the form of a thin thin film is placed on the driving thin film transistor DTr and the light emitting diode E to be encapsulated.

Here, the encapsulation layer 103 is used by stacking at least two inorganic encapsulation layers 103a and 103c in order to prevent external oxygen and moisture from penetrating into the OLED 100. At this time, two inorganic encapsulation layers are used. It is preferable that an organic encapsulation layer 103b is interposed between (103a and 103c) to supplement the impact resistance of the inorganic encapsulation layers 103a and 103c.

A color filter encapsulation substrate 102 is provided on the encapsulation layer 103, and a plurality of black matrices (BM) and color filters (B-CF, G-CF, R-CF) are provided on the color filter encapsulation substrate 102. is provided, and the black matrix (BM) and color filters (B-CF, G-CF, R-CF) emit light from the blue, green, and red sub-pixels (B-SP, G-SP, R-SP). It serves as a barrier that spatially separates blue light, green light, and red light.

That is, the color filters (B-CF, G-CF, R-CF) provided on the color filter encapsulation substrate 102 correspond to the blue sub-pixel (B-SP), so that the blue color filter (B-CF) position, the green color filter (G-CF) is positioned corresponding to the green sub-pixel (G-SP), and the red color filter (R-CF) is positioned corresponding to the red sub-pixel (R-SP). do.

Here, the black matrix (BM) can be omitted.

Here, in addition to the color filters (B-CF, G-CF, R-CF), a wavelength conversion layer including quantum dots may be provided, and the quantum dots may include CdS, CdSe, CdTe, ZnS, ZnSe, GaAs, GaP, and GaAs-P. , Ga-Sb, InAs, InP, InSb, AlAs, AlP, or AlSb.

Alternatively, the color filters (B-CF, G-CF, R-CF) themselves may be made of color filters containing quantum dots.

Here, in the OLED 100 according to the embodiment of the present invention, even though the contact electrode 215 is formed to have a different thickness for each sub-pixel (B-SP, G-SP, R-SP), the anode electrode 211 Each sub-pixel (B-SP, G-SP, R-SP) is located on the same plane.

This causes the protective layer 200 to be positioned above the reflective electrode 213, and the anode electrode 211 reflects through the first and second anode contact holes 201a and 201b provided in the protective layer 200, respectively. It is possible by placing it on the protective layer 200 while being in contact with the electrode 213 .

Through this, the OLED 100 according to the embodiment of the present invention can increase the light emission efficiency by implementing the micro-cavity effect, and can reduce the step by the anode electrode 211 while implementing the micro-cavity effect. It is possible to prevent defects in the organic light emitting layer 213 from occurring.

This, in turn, can prevent a short circuit between the anode electrode 211 and the cathode electrode 219 or the organic light emitting layer 217 from occurring, thereby preventing quality deterioration problems of the OLED 100 such as image non-uniformity from occurring. can

In addition, as the end of the anode electrode 211 is covered by the bank 119 and the end of the reflective electrode 213 is wrapped by the protective layer 200, the end of the anode electrode 211 and the reflective electrode 213 It is possible to prevent side leakage current from flowing through the organic light emitting layer 217 from the organic light emitting layer 217, thereby realizing low power and high resolution, and at the same time undesirable light emission from adjacent subpixels (B-SP, G-SP, R-SP). By preventing this from occurring, the light emission quality can be improved.

This will be described in more detail with reference to FIG. 3 .

FIG. 3 is an enlarged view of a portion of FIG. 2 and schematically shows how light is emitted from each sub-pixel by a micro-cavity effect.

4a to 4b are scanning electron microscope (SEM) photographs comparing the surface roughness of the reflective electrode according to the presence or absence of a protective layer between the reflective electrode and the anode electrode, and FIG. 5 is a transmittance different from the thickness of the anode electrode. 6 is experimental data obtained by comparing and measuring transmittance of OLEDs according to an embodiment of the present invention.

As shown in FIG. 3, blue, green, and red subpixels B-SP, G-SP, and R-SP form one unit pixel (P in FIG. 2), and each subpixel B-SP , G-SP, R-SP) includes anode electrodes 211a, 211b, and 211c, an organic light emitting layer 217 sequentially positioned above the anode electrodes 211a, 211b, and 211c, and a cathode electrode 219. A light emitting diode (E) is provided.

Here, the anode electrodes 211a, 211b, and 211c are positioned to correspond to each sub-pixel (B-SP, G-SP, and R-SP), and each sub-pixel (B-SP, G-SP, and R-SP) It has a separated structure. Reflective electrodes 213a, 213b, 213c and contact electrodes 215a, 215b, 215c are sequentially positioned below the anode electrodes 211a, 211b, 211c.

The anode electrodes 211a, 211b, and 211c, the reflective electrodes 213a, 213b, and 213c, and the contact electrodes 215a, 215b, and 215c are formed in a vertical structure. The side surfaces of the reflective electrodes 213a, 213b, and 213c and the contact electrodes 215a, 215b, and 215c form an angle θ of 90 degrees with respect to the fourth interlayer insulating film 109d.

The contact electrodes 215a, 215b, and 215c are in contact with the second metal layer 107b through the third drain contact hole PH3 provided in the fourth interlayer insulating film 109d, through which the contact electrodes 215a, 215b, and 215c ) comes into contact with the drain electrode (DD in FIG. 2) of the thin film transistor (DTr in FIG. 2).

Here, the anode electrodes 211a, 211b, and 211c are a metal oxide such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO), ZnO:Al or SnO ₂ :Sb. made of conductive polymers such as mixtures of metals and oxides, poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDT), polypyrrole and polyaniline, and the like. can In addition, it may be made of carbon nano tube (CNT), graphene, silver nano wire, or the like.

In addition, the reflective electrodes 213a, 213b, and 213c may be formed of a metal material having a high reflectivity such as aluminum (Al) or silver (Ag), and a contact electrode 215a is disposed below the reflective electrodes 213a, 213b, and 213c. , 215b, and 215c) are further disposed. The contact electrodes 215a, 215b, and 215c may have a single-layer or multi-layer structure including at least one of titanium (Ti) and titanium nitride (TiN), or indium tin oxide (indium tin oxide). oxide: ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), and aluminum zinc oxide ( aluminum zinc oxide: AZO) may be made of a single-layer or multi-layer structure including at least one.

Here, in the OLED (100 in FIG. 2 ) according to the embodiment of the present invention, the contact electrodes 215a, 215b, and 215c are formed to have different thicknesses for each subpixel (B-SP, G-SP, and R-SP). For example, the contact electrode 215a positioned corresponding to the blue sub-pixel B-SP may have a first thickness and the contact electrode 215b positioned corresponding to the green sub-pixel G-SP. may have a second thickness lower than the first thickness, and the contact electrode 215c positioned corresponding to the red sub-pixel R-SP may have a third thickness lower than the second thickness.

Above the contact electrodes 215a, 215b, and 215c, reflective electrodes 213a, 213b, and 213c having the same thickness for each sub-pixel (B-SP, G-SP, and R-SP) are positioned. A protective layer 200 is provided on top of (213a, 213b, 213c).

At this time, the protective layer 200 flattens the surfaces of the reflective electrodes 213a, 213b, and 213c for each sub-pixel (B-SP, G-SP, and R-SP).

That is, the protective layer 200 may not be positioned above the first reflective electrode 213a corresponding to the blue sub-pixel B-SP where the first contact electrode 215a having the first thickness is positioned, or A protective layer 200 having a very thin first thickness may be located.

In this case, the first reflective electrode 213a may directly contact the anode electrode 211a positioned above the protective layer 200, or may be formed through a third anode contact hole (not shown) provided in the protective layer 200. can be contacted through

In addition, a second thickness thicker than the first thickness is placed above the second reflective electrode 213b corresponding to the green sub-pixel G-SP where the second contact electrode 215b having a second thickness smaller than the first thickness is located. A protective layer 200 having is located.

Here, the second thickness of the protective layer 200 corresponds to a first total thickness obtained by subtracting the second thickness from the first thickness of the second contact electrode 215b plus the first thickness of the protective layer 200. .

In addition, a protective layer having a third thickness thicker than the second thickness ( 200) may be located, and the third thickness of the protective layer 200 is formed by adding a second sum thickness obtained by subtracting the third thickness from the first thickness of the third contact electrode 215c to the first sum thickness.

Accordingly, the surfaces of the protective layer 200 including the surfaces of the first to third reflective electrodes 213a, 213b, and 213c all form the same plane.

Here, the protective layer 200 may be made of silicon nitride (SiNx) or silicon oxide (SiOx), or may be made of an organic insulating material for planarization of the substrate 101 .

For example, the protective layer 200 may include polyacrylates resin, epoxy resin, phenolic resin, polyamides resin, polyimides resin, and unsaturated polyester. It may be formed of one or more of unsaturated polyesters resin, poly-phenylenethers resin, polyphenylenesulfides resin, and benzocyclobutene, but is not limited thereto. .

The anode electrodes 211a, 211b, and 211c are positioned above the first to third reflective electrodes 213a, 213b, and 213c or/and the protective layer 200, and the anode electrodes 211a, 211b, and 211c As the first to third reflective electrodes 213a, 213b, and 213c or/and the passivation layer 200 all form the same plane, each sub-pixel (B-SP, G-SP, R-SP) has the same plane. will be located on the

Here, the anode electrodes 211b and 211c in the green sub-pixel G-SP and the red sub-pixel R-SP are first and second anode contact holes 201a and 201b provided in the protective layer 200. Through this, they come into contact with the second and third reflective electrodes 213b and 213c, respectively.

Through this, it is possible to improve the efficiency of the process of forming the anode electrodes 211a, 211b, and 211c, and also to reduce the step difference caused by the anode electrodes 211a, 211b, and 211c, so that the organic light emitting layer 217 due to the step difference ) can prevent this defect from occurring.

That is, the upper part of the anode electrodes 211a, 211b, and 211c having a structure separated for each subpixel (B-SP, G-SP, and R-SP) is provided for each subpixel (B-SP, G-SP, R-SP). As a common layer of the SP), the organic light emitting layer 217 and the cathode electrode 219 are sequentially positioned, and the anode electrodes 211a, 211b, and 211c are used for each sub-pixel (B-SP, G-SP, R-SP) As each is located on the same plane, it is possible to prevent a step difference from occurring between the anode electrodes 211a, 211b, and 211c and the protective layer 200 for each subpixel (B-SP, G-SP, and R-SP). can

Here, in order to implement the micro-cavity effect, it is necessary to form different heights of the anode electrodes 211a, 211b, and 211c for each sub-pixel (B-SP, G-SP, and R-SP). , 211c) may cause a short circuit of the organic light emitting layer 217 located above the anode electrodes 211a, 211b, 211c or a short circuit of the cathode electrode 219, which causes image unevenness and the like. This causes a quality degradation problem of the OLED (100 in FIG. 2).

However, as in the embodiment of the present invention, the thickness of the contact electrodes 215a, 215b, and 215c is adjusted, and the protective layer 200 is placed on top of the contact electrodes 215a, 215b, and 215c and the reflective electrodes 213a, 213b, and 213c. By placing the anode electrodes 211a, 211b, and 211c on the same plane for each subpixel B-SP, G-SP, and R-SP, each subpixel (B-SP, G-SP) The steps formed by the anode electrodes 211a, 211b, and 211c for each SP and R-SP are minimized.

Therefore, it is possible to prevent quality deterioration of the OLED (100 in FIG. 2), such as image non-uniformity, caused by the step difference between the anode electrodes 211a, 211b, and 211c.

In addition, as the ends of the reflective electrodes 213a, 213b, and 213c of the anode electrodes 211a, 211b, and 211c are covered by the protective layer 200, the organic light emitting layer ( 217), it is possible to prevent side leakage current through which current flows, realizing low power and high resolution and preventing unwanted light emission from adjacent sub-pixels (B-SP, G-SP, R-SP). It is possible to improve the quality of light emission by preventing it.

Here, the 119 code shown is located along the edges of the anode electrodes 211a, 211b, and 211c, and the anode electrodes 211a, 211b, and 211c are respectively assigned to each subpixel (B-SP, G-SP, and R-SP). As a bank defined by division, the bank 119 is located above the protective layer 200 and covers only the side surfaces of the ends of the anode electrodes 211a, 211b, and 211c.

The bank 119 may be formed of a material selected from black resin, graphite powder, gravure ink, black spray, and black enamel, which are organic insulating materials. In addition, the bank 119 may be formed in a structure in which materials having different refractive indices are stacked. Alternatively, a fence (not shown) may be positioned in addition to the bank 119, and the fence (not shown) may be made of an organic material. For example, it may be made of acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

Also, the fence (not shown) may be made of an inorganic material such as silicon nitride (SiNx) or silicon oxide (SiOx). At this time, a fence (not shown) may be further positioned below the bank 119 to cover the ends of the anode electrodes 211a, 211b, and 211c.

As mentioned above, the OLED (100 in FIG. 2 ) according to the embodiment of the present invention implements the micro-cavity effect by adjusting the thickness between the anode electrodes 211a, 211b, and 211c and the cathode electrode 219, By enhancing a specific wavelength through the micro-cavity effect, the color purity and light efficiency of the OLED (100 in FIG. 2) can be improved.

That is, since the wavelength of light emitted for each sub-pixel (B-SP, G-SP, R-SP) is different, in order to implement the micro-cavity effect, each sub-pixel (B-SP, G-SP, R-SP) The resonance distance must be set for each wavelength of light emitted from SP).

The resonance distance may be set to a value corresponding to a multiple of the half wavelength of the emitted light. Since the wavelengths of visible red light, visible green light, and visible blue light are different from each other, the blue sub-pixel (B-SP), green sub-pixel (G-SP), and red sub-pixel (R-SP) have different resonance distances. should be set

For example, since the wavelength of blue visible light is about 460 nm, the resonance distance in the blue sub-pixel (B-SP) should be a multiple of about 230 nm. Accordingly, the distance between the anode electrode 211c and the cathode electrode 219 in the blue sub-pixel B-SP may be set to a multiple of about 230 nm.

In addition, since the wavelength of green visible light is about 530 nm, the resonance distance in the green sub-pixel (G-SP) should be a multiple of about 265 nm. Accordingly, the distance between the anode electrode 211b and the cathode electrode 219 in the green sub-pixel G-SP may be set to a multiple of about 265 nm. In addition, since the wavelength of red visible light is about 620 nm, the resonance distance in the red sub-pixel R-SP should be a multiple of about 310 nm. Accordingly, the distance between the anode electrode 211a and the cathode electrode 219 in the red sub-pixel R-SP may be set to a multiple of about 310 nm.

Here, in the OLED (100 in FIG. 2 ) according to the embodiment of the present invention, as the organic light emitting layer 217 is made of the same layer for each sub-pixel (B-SP, G-SP, R-SP), the organic light emitting layer 217 The thickness of 217 is formed equally in all sub-pixels (B-SP, G-SP, R-SP).

Therefore, in the OLED (100 in FIG. 2 ) according to an embodiment of the present invention, the heights of the contact electrodes 215a, 215b, and 215c are formed differently for each subpixel (B-SP, G-SP, and R-SP), The distance between the reflective electrodes 213a, 213b, and 213c and the cathode electrode 219 can be adjusted for each sub-pixel (B-SP, G-SP, R-SP), thereby realizing a micro-cavity effect.

That is, in the blue sub-pixel (B-SP), as the contact electrode 215a has a first thickness, the distance between the reflective electrode 213a and the cathode electrode 219 may be set to a multiple of about 230 nm. The distance between the electrode 213a and the cathode electrode 219 may be made of only the thickness of the organic light emitting layer 217 or may include the first thickness of the protective layer 200 .

In the green sub-pixel G-SP, as the contact electrode 215b has a second thickness, the distance between the reflective electrode 213b and the cathode 219 may be set to a multiple of about 265 nm. At this time, the green sub-pixel The distance between the reflective electrode 213b and the cathode electrode 219 in (G-SP) may include the thickness of the organic light emitting layer 217 and the second thickness of the protective layer 200, and the red subpixel (R- SP), since the contact electrode 215c has a third thickness, the distance between the reflective electrode 213c and the cathode electrode 219 may be set to a multiple of about 310 nm. At this time, in the red subpixel R-SP A distance between the reflective electrode 213c and the cathode electrode 219 may include the thickness of the organic emission layer 217 and the third thickness of the protective layer 200 .

That is, in the OLED (100 in FIG. 2 ) according to an embodiment of the present invention, the organic light emitting layer 217 and the anode electrodes 211a, 211b, and 211c are provided in all sub-pixels (B-SP, G-SP, and R-SP). It is formed to have the same thickness, and in particular, the efficiency of the process can be improved by ensuring that the anode electrodes 211a, 211b, and 211c are positioned on the same plane in each subpixel (B-SP, G-SP, and R-SP). However, by forming the contact electrodes 215a, 215b, and 215c differently for each sub-pixel (B-SP, G-SP, and R-SP), a micro-cavity effect can also be realized.

Through this, the light extraction efficiency of the OLED (100 in FIG. 2) can be improved, and the color purity is also improved.

In addition, it is possible to reduce the step difference due to the anode electrodes 211a, 211b, and 211c, and it is possible to prevent the occurrence of defects in the organic light emitting layer 217 due to the step difference, and thus the anode electrodes 211a, 211b, and 211c 219 or a short circuit of the organic light emitting layer 217 can also be prevented. Through this, it is possible to prevent quality deterioration problems such as image non-uniformity of the OLED (100 in FIG. 2 ) from being caused.

In addition, as the ends of the anode electrodes 211a, 211b, and 211c are covered by the bank 119, and the ends of the reflective electrodes 213a, 213b, and 213c are covered by the protective layer 200, the anode electrode (211a, 211b, 211c) and the reflective electrodes (213a, 213b, 213c) from the ends of the current flowing through the organic light emitting layer 217 can prevent the generation of side leakage current, realizing low power and high resolution and at the same time adjacent Light emission quality may be improved by preventing unwanted light emission from occurring in the sub-pixels (B-SP, G-SP, R-SP). In addition, as the thicknesses of the anode electrodes 211a, 211b, and 211c and the reflective electrodes 213a, 213b, and 213c located for each sub-pixel (B-SP, G-SP, and R-SP) are all the same, the anode electrode It is also possible to prevent a problem in which resistance or surface roughness varies according to the thicknesses of the reflective electrodes 213a, 213b, and 213c and the thicknesses of the reflective electrodes 211a, 211b, and 211c.

In particular, when the surface roughness of the reflective electrodes 213a, 213b, and 213c increases, the resonance distance is distorted by the surface roughness of the reflective electrodes 213a, 213b, and 213c in realizing the micro-cavity effect, so that the OLED ( Characteristic degradation of 100 in FIG. 2 may occur.

That is, FIG. 4a is a scanning electron microscope (SEM) photograph showing the surface of the reflective electrode having a large surface roughness, and FIG. As a scanning electron microscope (SEM) photograph showing the surface, it can be confirmed that the surface roughness of the reflective electrodes 213a, 213b, and 213c of FIG. 4a is greater than that of FIG. 4b.

As such, in the OLED (100 in FIG. 2 ) according to an embodiment of the present invention, as the thicknesses of the anode electrodes 211a, 211b, and 211c and the reflective electrodes 213a, 213b, and 213c are all formed the same, the anode electrode ( It is possible to prevent an increase in resistance or surface roughness according to the thickness of the 211a, 211b, and 211c and the reflective electrodes 213a, 213b, and 213c, thereby finally reducing the characteristics of the OLED (100 in FIG. 2). Problems can also be avoided.

In particular, in some sub-pixels (B-SP, G-SP, R-SP), the protective layer 200 is further interposed between the anode electrodes 211a, 211b, and 211c and the reflective electrodes 213a, 213b, and 213c, so that the anode In the process of patterning the electrodes 211a, 211b, 211c, it is possible to prevent the reflective electrodes 213a, 213b, and 213c from being damaged by the etchant of the anode electrodes 211a, 211b, and 211c. It is possible to prevent surface roughness of 213a, 213b, and 213c) from increasing.

In addition, the OLED (100 in FIG. 2 ) according to the embodiment of the present invention has a similar transmittance for each sub-pixel compared to an OLED in which the thickness of the anode electrode is formed differently for each sub-pixel in order to implement the micro-cavity effect. Transmittance is also more improved compared to OLED in which the thickness of the anode electrode is formed differently for each sub-pixel, which can be confirmed with reference to FIGS. 5 and 6 attached.

Prior to describing FIGS. 5 and 6, Sample 1 is an experimental result of measuring the transmittance according to the wavelength of a 200 Å indium-tin-oxide (ITO) electrode, and Sample 2 is an experiment result of measuring a 600 Å indium-tin oxide (ITO) electrode. -This is the result of measuring the transmittance according to the wavelength of the Indium Tin Oxide (ITO) electrode. Sample 3 is the result of measuring the transmittance according to the wavelength of the 800Å Indium Tin Oxide (ITO) electrode. am.

And, Sample 4 is the experimental result showing the transmittance of glass according to the wavelength, Sample 5 is the experimental result showing the transmittance of the Indium Tin Oxide (ITO) electrode located on the top of the glass according to the wavelength, and Sample 6 is an experimental result showing the transmittance of the protective layer 200 positioned above the glass according to the silver wavelength.

Here, in Sample 5, the indium-tin-oxide (ITO) electrode is made of 800 Å, and the protective layer 200 of Sample 6 is designed to be made of silicon oxide (SiOx).

Looking at FIG. 5 first, it can be seen that a difference in transmittance according to the wavelength of Samples 1, 2, and 3 occurs.

This is because when an anode electrode made of indium tin oxide (ITO) is designed to have a different thickness for each sub-pixel in order to implement a micro-cavity effect, light is emitted by the difference in transmittance of the anode electrode for each sub-pixel. This means that there is a difference in efficiency.

In contrast, in the OLED (100 in FIG. 2 ) according to the embodiment of the present invention, all of the anode electrodes 211a, 211b, and 211c positioned separately for each sub-pixel (B-SP, G-SP, and R-SP) are As it is formed to have the same thickness, it is possible to prevent a transmittance difference from occurring for each sub-pixel (B-SP, G-SP, R-SP) according to the thickness of the anode electrodes 211a, 211b, and 211c as described above. .

In addition, referring to FIG. 6, it can be confirmed that Sample 6 has a higher transmittance than Sample 5. Compared to OLEDs in which the thickness of the anode electrode made of indium-tin-oxide (ITO) is thick, the anode electrodes 211a, 211b, and 211c and the reflective electrodes 213a and 213b are formed as in the embodiment of the present invention. , 213c) with the protective layer 200 interposed therebetween, and adjusting the thickness of the protective layer 200 according to the thickness of the contact electrodes 215a, 215b, and 215c, the OLED (100 in FIG. 2) can further improve the transmittance. means there is

As described above, the OLED (100 in FIG. 2 ) according to the embodiment of the present invention includes the organic light emitting layer 217 and the anode electrodes 211a, 211b, 211c) is formed to have the same thickness, and especially the anode electrodes 211a, 211b, and 211c are positioned on the same plane in each subpixel (B-SP, G-SP, and R-SP), thereby improving process efficiency. While it can be improved, the micro-cavity effect can also be realized by forming the thickness of the contact electrodes 215a, 215b, and 215c differently for each sub-pixel (B-SP, G-SP, and R-SP). 2 of 100) while improving the light extraction efficiency, the color purity is also improved.

In addition, it is possible to reduce the step difference due to the anode electrodes 211a, 211b, and 211c, and it is possible to prevent the occurrence of defects in the organic light emitting layer 217 due to the step difference, and thus the anode electrodes 211a, 211b, and 211c 219 or a short circuit of the organic light emitting layer 217 can also be prevented. Through this, it is possible to prevent quality deterioration problems such as image non-uniformity of the OLED (100 in FIG. 2 ) from being caused.

In addition, as the ends of the anode electrodes 211a, 211b, and 211c are covered by the bank 119, and the ends of the reflective electrodes 213a, 213b, and 213c are covered by the protective layer 200, the anode electrodes 211a, 211b, 211c) and the reflective electrodes 213a, 213b, and 213c from the ends through the organic light-emitting layer 217, it is possible to prevent side leakage current from occurring, realizing low-power and high-resolution and simultaneously displaying adjacent sub-pixels (B- SP, G-SP, R-SP) can improve the quality of light emission by preventing unwanted light emission from occurring.

In addition, the anode electrodes 211a, 211b, and 211c and the reflective electrodes 213a, 213b, and 213c are formed to have the same thickness for each sub-pixel (B-SP, G-SP, and R-SP), so that the anode electrode 211a , 211b, 211c) and the problem of resistance or surface roughness due to the thickness of the reflective electrodes 213a, 213b, 213c can also be solved, and in addition, in OLEDs in which the thickness of the anode electrode is formed differently for each sub-pixel Compared to that, all sub-pixels (B-SP, G-SP, R-SP) can have the same transmittance, and the transmittance itself can be improved, providing an OLED (100 in FIG. 2) with improved light efficiency. can

7a to 7f are process cross-sectional views illustrating a method of manufacturing an OLED according to an embodiment of the present invention according to a process flow.

Prior to the description, the manufacturing method of the OLED (100 in FIG. 2) according to the embodiment of the present invention is characterized by the process of forming the light emitting diode (E), and the process of forming the driving thin film transistor (DTr) is the conventional manufacturing method. Since it is not significantly different from the method, the contents thereof will be omitted, and the main part of the present invention, the manufacturing part of the light emitting diode (E) will be mainly described.

As shown in FIG. 7A, a driving thin film transistor (DTr), a drain electrode (DD) of the driving thin film transistor (DTr), and first to fourth interlayer insulating films (109a, 109b, 109c, 109d) are formed on the substrate 101. Contact electrodes 215a, 215b, and 215c are formed for each subpixel (B-SP, G-SP, and R-SP) to be connected through the first to third drain contact holes (PH1, PH2, and PH3) provided in do.

At this time, the contact electrodes 215a, 215b, and 215c are formed to have different thicknesses for each subpixel (B-SP, G-SP, and R-SP). For example, a contact positioned in a blue subpixel (B-SP) The electrode 215a has a first thickness, and the contact electrode 215b positioned in the green subpixel G-SP has a second thickness smaller than the first thickness and positioned in the red subpixel R-SP. The contact electrode 215c is formed to have a third thickness smaller than the second thickness.

Next, as shown in FIG. 7B, the reflective electrodes 213a and 213b are disposed above the contact electrodes 215a, 215b, and 215c formed to have different thicknesses for each sub-pixel (B-SP, G-SP, and R-SP). , 213c), as shown in FIG. 7C, a protective layer 200 is formed on the reflective electrodes 213a, 213b, and 213c.

Here, the protective layer 200 is formed on the substrate 101 by using SOG (Spin On Glass), followed by an etchback, reflow process, or a mechanical removal process and a chemical removal process. A planarization process is performed using chemical mechanical polishing (CMP) mixed with the processing method of.

At this time, in the blue sub-pixel (B-SP) where the contact electrode 215a having the first thickness is located, the protective layer 200 is not positioned above the reflective electrode 213a, and the reflective electrode 213a is exposed to the outside. The surface of the protective layer 200 positioned in the green sub-pixel G-SP and the red sub-pixel R-SP may be exposed, the surface of the reflective electrode 213a positioned in the blue sub-pixel B-SP. to be flush with the surface.

Next, as shown in FIG. 7D , the reflection is reflected on the green sub-pixel G-SP and the red sub-pixel R-SP where the protective layer 200 is positioned above the reflective electrodes 213a, 213b, and 213c, respectively. After forming the first and second anode contact holes 201a and 201b exposing the electrodes 213b and 213c, as shown in FIG. 7E, in the blue sub-pixel B-SP, the upper part of the reflective electrode 213a In addition, anode electrodes 211a, 211b, and 211c are formed above the protective layer 200 in the green sub-pixel G-SP and the red sub-pixel R-SP.

The anode electrodes 211b and 211c of the green sub-pixel (G-SP) and the red sub-pixel (R-SP) are positioned below the protective layer 200 through the first and second anode contact holes 201a and 201b, respectively. reflective electrodes 213b and 213c respectively.

Then, as shown in FIG. 7F, after forming the bank 119 on the substrate 101 on which the anode electrodes 211a, 211b, and 211c are formed, the anode electrodes 211a, 211b, and 211c and the upper part of the bank 119 Thus, the organic light emitting layer 217 and the cathode electrode 219 are sequentially formed.

Through this, the manufacturing method of the light emitting diode (E) of the OLED (100 in FIG. 2) according to the embodiment of the present invention is completed.

Here, although not shown in the drawing, a via metal (not shown) may be separately formed in each of the contact holes 116, PH1, PH2, PH3, 201a, and 201b. The via metal (not shown) is tungsten can be made with

When a via metal (not shown) is formed in each of the contact holes 116, PH1, PH2, PH3, 201a, and 201b, first and second anode contact holes 201a and 201b of the protective layer 200 next to FIG. 7d ) A step of forming a via metal (not shown) may be further added.

8 is a view showing a head-mounted display to which an OLED according to an embodiment of the present invention is applied, and FIG. 9 is a cross-sectional view of a display storage case when viewed from the side.

As shown, the head-mounted display (HMD) to which the OLED (100 in FIG. 2) is applied according to an embodiment of the present invention includes a display storage case 310, a left eye lens 320a and a right eye lens (not shown), and a head Includes a mounting band (not shown).

The display storage case 310 accommodates the display device and provides images of the display device to the left eye lens 320a and the right eye lens (not shown).

Also, the display device may be an OLED ( 100 in FIG. 2 ) according to an embodiment of the present invention.

The display storage case 310 may be designed to provide the same image to the left eye lens 320a and the right eye lens (not shown). Alternatively, the display storage case 310 may be designed so that the left eye image is displayed on the left eye lens 320a and the right eye image is displayed on the right eye lens (not shown).

An organic light emitting display device for the left eye disposed in front of the left eye lens 320a and an organic light emitting display device for the right eye disposed in front of the right eye lens 320b may be accommodated in the display storage case 310 . The structure of FIG. 9 may be applied to a virtual reality device.

The organic light emitting display device for the left eye may display a left eye image, and the organic light emitting display device for the right eye may display a right eye image. As a result, the left eye image displayed on the organic light emitting display device for the left eye is shown to the left eye LE of the user through the left eye lens 320a, and the right eye image displayed on the organic light emitting display device for the right eye is displayed through the right eye lens (not shown). Through this, it can be shown to the right eye of the user.

In addition, a magnifying lens may be additionally disposed between the left eye lens 320a and the organic light emitting display device for the left eye and between the right eye lens (not shown) and the organic light emitting display device for the right eye. In this case, images displayed on the organic light emitting display device for the left eye and the organic light emitting display device for the right eye may be magnified and seen by the user due to the magnifying lens.

In the display storage case 310, as shown in FIG. 9, a half mirror 313 disposed in front of the left eye lens 320a and the right eye lens (not shown) and an organic light emitting display device 314 disposed on the half mirror 313 are can be stored. The structure of FIG. 9 may be applied to an augmented reality device.

The organic light emitting display device 314 displays an image in the direction of the mirror reflector 313, and the mirror reflector 313 totally reflects the image of the organic light emitting display device 314 toward the left eye lens 320a and the right eye lens. Accordingly, an image displayed on the organic light emitting display device 314 may be provided to the left eye lens 320a and the right eye lens (not shown).

Magnifying lenses may be additionally disposed between the left eye lens 320a and the half mirror 313 and between the right eye lens (not shown) and the half mirror 313 . In this case, images displayed on the organic light emitting display device for the left eye and the organic light emitting display device for the right eye may be magnified and seen by the user due to the magnifying lens.

The head-mounted band is fixed to the display storage case 310. The head-mounted band is exemplified as being formed to surround the top and both sides of the user's head, but is not limited thereto. The head-mounted band is for fixing the head-mounted display to the user's head, and may be formed in the form of a spectacle frame or a helmet.

As described above, the OLED (100 in FIG. 2 ) according to the embodiment of the present invention includes the organic light emitting layer 217 and the anode electrodes 211a, 211b, 211c) is formed to have the same thickness, and especially the anode electrodes 211a, 211b, and 211c are positioned on the same plane in each subpixel (B-SP, G-SP, and R-SP), thereby improving process efficiency. While it can be improved, the micro-cavity effect can also be realized by forming the thickness of the contact electrodes 215a, 215b, and 215c differently for each sub-pixel (B-SP, G-SP, and R-SP). 2 of 100) while improving the light extraction efficiency, the color purity is also improved.

In addition, it is possible to reduce the step difference due to the anode electrodes 211a, 211b, and 211c, and it is possible to prevent the occurrence of defects in the organic light emitting layer 217 due to the step difference, and thus the anode electrodes 211a, 211b, and 211c 219 or a short circuit of the organic light emitting layer 217 can also be prevented. Through this, it is possible to prevent quality deterioration problems such as image non-uniformity of the OLED (100 in FIG. 2 ) from being caused.

In addition, as the ends of the anode electrodes 211a, 211b, and 211c are covered by the bank 119, and the ends of the reflective electrodes 213a, 213b, and 213c are covered by the protective layer 200, the anode electrodes 211a, 211b, 211c) and the reflective electrodes 213a, 213b, and 213c from the ends through the organic light-emitting layer 217, it is possible to prevent side leakage current from occurring, realizing low-power and high-resolution and simultaneously displaying adjacent sub-pixels (B- SP, G-SP, R-SP) can improve the quality of light emission by preventing unwanted light emission from occurring.

In addition, the anode electrodes 211a, 211b, and 211c and the reflective electrodes 213a, 213b, and 213c are formed to have the same thickness for each sub-pixel (B-SP, G-SP, and R-SP), so that the anode electrode 211a , 211b, 211c) and reflection electrodes 213a, 213b, 213c, the problem that resistance or surface roughness varies due to the thickness can also be solved, and each sub-pixel (B-SP, G-SP, R- Compared to OLEDs in which the anode electrodes 211a, 211b, and 211c have different thicknesses for each SP), all sub-pixels (B-SP, G-SP, and R-SP) can have the same transmittance, and the transmittance itself can be Therefore, it is possible to provide an OLED (100 in FIG. 2 ) with improved light efficiency.

The present invention is not limited to the above embodiments, and can be practiced with various changes without departing from the spirit of the present invention.

107b: second metal pattern
109d: fourth interlayer insulating film
119: bank
211a, 211b, 211c: first to third anode electrodes
213a, 213b, 213c: first to third reflective electrodes
215a, 215b, 215c: first to third contact electrodes
217: organic light emitting layer
219: cathode electrode

Claims (13)

a substrate including first to third sub-pixels;
driving thin film transistors provided for each of the first to third sub-pixels;
an interlayer insulating film positioned above the driving thin film transistor;
first to third contact electrodes having different thicknesses and positioned above the interlayer insulating film to correspond to the first to third sub-pixels;
first to third reflective electrodes positioned above the first to third contact electrodes;
a protective layer positioned above the second and third reflective electrodes;
first to third anode electrodes positioned above the passivation layer and above the third reflective electrode;
an organic light emitting layer positioned above the first to third anode electrodes;
It includes a cathode electrode positioned above the organic light emitting layer,
The thickness of the passivation layer positioned on the first and second sub-pixels is in inverse proportion to the thickness of the first and second contact electrodes, and the thickness of the first and second contact electrodes and the third reflective electrode respectively disposed on the first and second contact electrodes. The first to third anode electrodes are disposed on the same plane.
According to claim 1,
First and second anode contact holes exposing the first and second reflective electrodes are formed in the passivation layer disposed on the first and second sub-pixels, respectively, so that the first and second anode electrodes are respectively connected to the first and second reflective electrodes. An organic light emitting display device in contact with the first and second reflective electrodes through first and second anode contact holes.
delete According to claim 1,
The protective layer covers side surfaces of the first to third contact electrodes and the first to third reflective electrodes.
According to claim 1,
Side surfaces of the first to third anode electrodes are covered by banks positioned above the passivation layer.
According to claim 1,
The first to third contact electrodes are in contact with the drain electrode of the driving thin film transistor, respectively.
According to claim 6,
The first to third contact electrodes have a single-layer or multi-layer structure including at least one of titanium (Ti) and titanium nitride (TiN), or indium tin oxide (ITO) and indium zinc oxide (indium zinc oxide). At least one of zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), and aluminum zinc oxide (AZO) An organic light emitting display device having a single-layer or multi-layer structure comprising:
An organic light emitting display device according to any one of claims 1, 2, and 4 to 7;
a display storage case accommodating the organic light emitting display device; and
A head-mounted display having a lens disposed on one side of the storage case and providing an image of the organic light emitting display device.
providing a substrate including first to third sub-pixels;
forming an interlayer insulating film on the substrate;
forming first to third contact electrodes having different thicknesses for each of the first to third sub-pixels on the interlayer insulating layer;
forming first to third reflective electrodes in the first to third sub-pixels, respectively;
forming a protective layer on the first to third reflective electrodes;
planarizing the passivation layer;
forming first and second anode contact holes in the passivation layer corresponding to the first and second sub-pixels;
forming first to third anode electrodes corresponding to the first to third sub-pixels on the same flattened plane above the third reflective electrode and the passivation layer;
and sequentially forming an organic light emitting layer and a cathode electrode on top of the first to third anode electrodes.
According to claim 9,
The flattening step is
A method of manufacturing an organic light emitting display device using an etchback process, a reflow process, or a chemical mechanical polishing (CMP) process after forming the protective layer on a substrate.

a substrate including first to third sub-pixels;
thin film transistors disposed in each of the first to third sub-pixels;
first to third contact electrodes disposed on each of the first to third sub-pixels to have different thicknesses and connected to the thin film transistor;
first to third reflective electrodes respectively disposed on the first to third contact electrodes;
a protective layer disposed on at least two or more of the first to third sub-pixels;
first to third anode electrodes disposed in the first to third sub-pixels on the upper portion of the passivation layer;
an organic light emitting layer positioned above the first to third anode electrodes;
It includes a cathode electrode positioned above the organic light emitting layer,
The passivation layer positioned on each of the first to third sub-pixels is formed to have a different thickness, and the first to third contact electrodes are disposed on the same plane.
12. The organic light emitting display device of claim 11, wherein a thickness of the passivation layer of the first to third sub-pixels is inversely proportional to a thickness of the first to third contact electrodes.
13. The organic light emitting display device of claim 12, wherein the first anode electrode is directly formed on a top surface of the first contact electrode.