KR20140079684A - Organic Light Emitting Display Device and Method for Manufacturing The Same - Google Patents

Abstract

A manufacturing method for an organic light emitting display device according to an aspect of the present invention includes the steps of: forming a base electrode layer on a substrate divided into a plurality of sub-pixels; forming a first photoresist pattern on the base electrode layer; etching the base electrode layer exposed by the first photoresist pattern; forming a second photoresist pattern by removing the first photoresist pattern by a predetermined thickness; etching the base electrode layer exposed by the second photoresist pattern; removing the photoresist layers; and forming a common electrode layer including a single transparent layer in every sub-pixel area.

Description

Technical Field [0001] The present invention relates to an organic light emitting display device,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a method of manufacturing an organic light emitting display, and more particularly, to a method of manufacturing an active organic light emitting display.

BACKGROUND ART [0002] With the advent of the information age and the accelerated research on flat panel display devices, there has been an increasing demand for the use of organic light emitting diodes (OLEDs), which are next generation flat panel display devices Development is progressing actively.

Since the organic electroluminescent display device is a self-emission type, a backlight is not required as in the case of a liquid crystal display device, so that it can be thin and light compared to a liquid crystal display device. In addition, it has advantages such as low voltage driving, high luminous efficiency, close color of natural color, wide viewing angle, and fast response speed, which is advantageous for realizing high quality moving image.

However, since the organic electroluminescent display device has no backlight, a more complicated driving circuit is applied to the liquid crystal display device for accurate gradation display. In each sub-pixel defined as the intersection of the gate line and the data line, the gate signal transmitted through the gate line reaches the gate electrode of the switching thin film transistor, and the data signal transferred from the data line by the gate electrode moves to the driving thin film transistor . The data signal arriving at the gate electrode of the driving thin film transistor transfers the driving current transferred from the power supply line to the anode electrode of the corresponding sub pixel to drive the organic light emitting layer.

As described above, the organic light emitting display device includes a switching thin film transistor and a driving thin film transistor and basically requires two or more thin film transistors. In order to maintain the emission of light emitted from the sub pixel for a desired time, Circuit is formed.

The aperture ratio of the organic light emitting display device is remarkably reduced by the thin film transistor and the compensation circuit, whereby the intensity of light emitted to the outside can be reduced and the light extraction efficiency can be reduced.

In addition, the light emitted from the organic light emitting display device is transmitted through the multi-layered film formed inside the organic light emitting display device and then externally emitted while being largely lost due to total internal reflection and the like, Optical loss occurs. The amount of light emitted by the subpixels exceeding 50% may be lost and the luminance and light extraction efficiency may be lowered.

An object of the present invention is to provide an organic light emitting display having improved light extraction efficiency and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a method of manufacturing an organic light emitting display, including: forming a base electrode layer on a substrate divided into a plurality of subpixels; Forming a first photoresist pattern on the base electrode layer; Etching the base electrode layer exposed by the first photoresist pattern; Removing the first photoresist pattern by a predetermined thickness to form a second photoresist pattern; Etching the base electrode layer exposed by the second photoresist pattern; Removing the photoresist layer; And forming a common electrode layer including a single transparent layer for each sub-pixel region.

According to another aspect of the present invention, there is provided a method of manufacturing an organic light emitting display including a substrate divided into a plurality of pixels; A thin film transistor formed on the substrate; A planarization layer formed on the thin film transistor; And an anode electrode formed on the planarization layer and connected to the thin film transistor, wherein the anode electrode includes at least one of a base electrode layer and a common electrode layer.

According to the present invention, it is possible to improve the light efficiency by forming a resonance structure having different distances for each subpixel in the organic light emitting device.

Further, according to the present invention, by forming the resonance structure through the diffraction exposure and the ashing process, the number of masks and the number of processes can be reduced.

According to the present invention, a common electrode layer is formed on the base electrode layer to compensate for damage to the base electrode layer that may occur during the process, thereby improving the connectivity between the anode electrode and the thin film transistor.

1 is a cross-sectional view illustrating an organic light emitting display device according to an embodiment of the present invention;
2 is a cross-sectional view illustrating an organic light emitting display device according to another embodiment of the present invention;
3 is a cross-sectional view illustrating a resonant structure of an organic light emitting display according to an embodiment of the present invention;
4A to 4G are cross-sectional views illustrating a method of manufacturing an organic light emitting display according to an exemplary embodiment of the present invention; And
5A and 5B are cross-sectional views illustrating a method of manufacturing an organic light emitting display according to another embodiment of the present invention.

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

1, an organic light emitting display according to an exemplary embodiment of the present invention includes a substrate 110, a thin film transistor 120, a lower insulating layer 130, a planarization layer 140, An anode electrode 160, a bank layer 170, an organic light emitting layer 180, and a cathode electrode 190.

First, the substrate 110 may be formed of glass, a transparent flexible material, or an opaque insulating material. The transparent flexible material may be formed of polyimide, polyetherimide (PEI), and polyethyeleneterephthalate (PET). In the case of a bottom emission type in which light is emitted through the substrate 110, the top emission type in which the substrate 110 is transparent, but light is emitted to the outside of the cathode electrode layer 190, The substrate 110 is not necessarily transparent, and may be formed of various materials.

Next, the thin film transistor 120 is formed on the substrate 110. The thin film transistor 120 may be a driving thin film transistor connected to the anode electrode 160.

In general, a switching thin film transistor and a driving thin film transistor (TFT) are required for the organic light emitting layer 180 to emit light according to image information of a data signal inputted according to a scan signal.

In a switching thin film transistor, when a scan signal is applied to a gate electrode extending in a gate line, a data signal is received from a source electrode extending in the data line, and the data signal is transferred to a gate electrode of the drive transistor.

In the driving thin film transistor, a current passed through the power supply line by the received data signal is transmitted to the anode electrode 160 through the drain electrode, and the emission of the organic light emitting layer 180 of the pixel is controlled by the current do.

In addition, a compensating circuit is provided for each pixel in order to prevent abnormal driving which may be caused by delay and phase changes of various electric signals, and an additional thin film transistor may be included in the compensating circuit. In addition, A storage electrode may be included to maintain light emission of the organic light emitting layer 180.

Next, the lower insulating layer 130 is formed on the thin film transistor 120. The lower insulating layer 130 is formed on the metal wiring including the gate line, the data line and the compensation circuit necessary for driving the organic light emitting layer 180 as well as the thin film transistor 120, And metal wiring from various chemical substances and insulating them from inside the device. The lower protective layer 130 may be formed of a material including silicon nitride (SiNx).

Next, the planarization layer 140 is formed on the lower insulating layer 130. [ A thin film transistor 120 and a metal interconnection are formed under the lower insulating layer 130, and the surface of the thin film transistor 120 is not flat. Accordingly, the planarization layer 140 functions to planarize the surface for stable formation of the upper lamination structure including the anode electrode 160 and the organic emission layer 180 to be formed thereon. The planarization layer 140 may be formed of an acryl-based material including a photoacid (PAC) or a material having a property of forming a flat film.

Next, an upper insulating layer 150 is formed on the planarization layer 140. The upper insulating layer 150 is formed of a material having a large difference in refractive index from the anode electrode 160 to induce a total reflection phenomenon. Accordingly, a part of the light that is transmitted through the lower portion of the anode electrode 160 among the emitted light can be reflected back to improve the light efficiency. The upper insulating layer 150 may be formed of a material including silicon nitride (SiNx) as well as the lower protective layer 130.

Next, an anode electrode 160 is formed on the upper insulating layer 150. The anode electrode 160 is electrically connected to the organic light emitting layer 180 formed in each pixel to supply holes to the organic light emitting layer 180. When electrons supplied from the cathode electrode 190 are combined with holes supplied from the anode electrode 160 to emit light in the organic light emitting layer 180, light is emitted to the upper and lower portions of the anode electrode 160, The direction of light output is changed. In the case of the bottom emission type, the cathode electrode 190 can be utilized as a reflector since light should be emitted downward from the anode electrode 160. In the case of the top emission type, since the light should be emitted upward in the anode electrode 160, the reflector may be formed inside the anode electrode 160 or the substrate 110 itself may be formed of opaque metal, 190) direction. Alternatively, a reflector may be formed between the substrate 110 and the anode electrode 160, and light may be emitted to the outside through the transparent cathode electrode 190.

The anode electrode 160 includes a base electrode layer 161 and a common electrode layer 165. A part of the base electrode layer 161 is selectively etched for each subpixel so that the height of the base electrode layer 161 is different.

The base electrode layer 161 includes a lower transparent layer 162, a reflective layer 163 and an upper transparent layer 164 and is connected to the thin film transistor 120.

A lower transparent layer 162 is formed between the reflective layer 163 and the upper insulating layer 150. Silicon nitride (SiNx), which is a material forming the reflective layer 163 and silicon nitride (SiNx), which is a material forming the upper insulating layer 150, may have an adhesive force to cause lifting. At this time, the lower transparent layer 162 is formed of a conductive oxide The phenomenon can be prevented. The adhesion between the reflective layer 163 and the upper insulating layer 150 can be compensated for because the conductive oxide is excellent in adhesion to an insulating material such as silicon nitride (SiNx) including a metal.

The reflective layer 163 is formed between the lower transparent layer 162 and the upper transparent layer 164 and may be formed of one of silver (Ag), copper (Cu), and tin (Sn) , And tin (Sn). The reflective layer 163 transmits a part of the light emitted from the organic light emitting layer 180 or the light reflected from the cathode electrode 190 to the outside and reflects the remaining light toward the cathode electrode 190. At this time, if the distance between the reflective layer 163 and the cathode electrode 190 is an integral multiple of the half wavelength of the light emitted from the corresponding pixel, the light is amplified through the constructive interference. If the reflection process is repeated, The external extraction efficiency of the light emitted from the organic light emitting layer 180 can be improved.

Since the reflective layer 163 is spaced apart from the cathode electrode 190 by a distance corresponding to an integral multiple of the half wavelength of the light, the reflective layer 163 may be formed only in the sub-pixel that emits light other than white. Therefore, in the case of the WRGB (White, Red, Green, Blue) method in which four subpixels of red, green, blue and white constitute one pixel, the reflective layer 163 is not formed in the white subpixel. Since the white light includes all the wavelength regions of visible light, when the reflective layer 163 is formed on the white subpixel, the distance between the reflective layer 163 and the cathode electrode 190 is set to a specific color having a wavelength satisfying an integral multiple of a half- Is more amplified than the light of the other colors and white light is not emitted and can be distorted and emitted as the color of the amplified light.

The position of the reflective layer 163 may vary depending on whether the organic light emitting display device is a bottom emission type or a top emission type. In the case of the bottom emission type, the position of the reflective layer 163 may be positioned below the anode electrode 160 or on the same layer as the anode electrode 160 as described above, emission type, it may be located on the same layer as the cathode electrode 190 or on the cathode electrode 190.

The upper transparent layer 164 is selectively formed for each subpixel, and is formed on the reflective layer 163. The thickness of the anode electrode 160 is set to be larger than that of the subpixel in which the upper transparent layer 164 is not formed. The distance between the reflective layer 163 and the cathode electrode 190 is changed by changing the thickness of the anode electrode 160. This is because an integer multiple of the half wavelength of the light emitted from each sub- .

Since the lower transparent layer 162 and the upper transparent layer 164 must serve as the anode electrode 160, the lower transparent layer 162 and the upper transparent layer 164 are formed of a transparent conductive material, and generally have a work function of indium tin oxide (ITO ), Indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and the like. Alternatively, the lower transparent layer 162 and the upper transparent layer 164 may be formed of a material having a lower work function than indium tin oxide but including a transparent conductive oxide such as zinc oxide or tin oxide. Since the lower transparent layer 162 is in contact with the thin film transistor 120 directly, indium tin oxide (ITO), indium zinc oxide (IZO) or the like having a higher work function than zinc oxide (tin oxide) It is preferably formed of indium tin zinc oxide (ITZO).

In addition, the anode electrode 160 includes a common electrode layer 165.

The common electrode layer 165 may be formed of a single layer and may be formed of a transparent conductive oxide as in the lower transparent layer 162 and the upper transparent layer 164. Since the common electrode layer 165 is formed on the base electrode layer 161 or the base electrode layer 161 is not etched in the white subpixel as described above, .

The common electrode layer 165 is formed on the base electrode layer 161 that can be damaged by a plurality of photolithography processes and is formed to cover the damaged region of the base electrode layer 161 to thereby complement the damage of the base electrode layer 161 There is an effect that can be done.

Next, the bank layer 170 is formed on the anode electrode 160. The bank layer 170 defines an area where the organic light emitting layer 180 and the anode electrode 160 can contact with each other, thereby determining the light emitting area and the anode electrode 160, which is an area where electrons and holes can be relatively more crowded, The edge regions of the organic emission layer 180 and the cathode electrode 190 can be isolated from each other to ensure uniformity of luminance.

Next, the organic light emitting layer 180 is formed of a multi-layered thin film made of an organic material, and can emit light of a specific color according to subpixels. When a method of representing color is an RGB method, a sub pixel emitting red, green and blue light constitutes one pixel. When a method of expressing color is a WRGB method, a sub-pixel emitting red, green, A pixel can be one pixel.

In addition, a sub pixel emitting yellow, cyan, and magenta may be a unit for representing a gray level by forming one pixel.

Finally, the cathode electrode 190 is formed on the organic light emitting layer 180. The cathode electrode 190 may be a kind of common electrode because it applies the same voltage to all the pixels. Thus, it can be formed as a single layer that covers the entire surface of the substrate 110 without being patterned. In order to prevent a driving problem due to an increase in resistance, an auxiliary electrode may be connected to the upper or lower portion of the cathode electrode 190 to reduce the resistance.

The cathode electrode 190 may be formed of a material such as silver (Ag), aluminum (Al), molybdenum (Mo), or an alloy of silver (Ag) and magnesium (Mg) having high electrical conductivity and low work function Alloy. In the case of the top emission type, since the light emitted from the organic light emitting layer 180 must be transmitted through the cathode electrode 190, it can be formed thin to a thickness of several hundreds of angstroms (A) or less.

The cathode electrode 190 is electrically connected to the organic light emitting layer 180 formed in each pixel to supply electrons to the organic light emitting layer 180. When electrons supplied from the cathode electrode 190 are combined with holes supplied from the anode electrode 160 to emit light in the organic light emitting layer 180, light is emitted to the upper and lower portions of the anode electrode 160, The cathode electrode 190 may be formed of an opaque metal to serve as a reflector, or a reflector (not shown) may be formed to correspond to the organic light emitting layer 180 in a region opposite to the light emitting direction. The cathode electrode 190 should be formed of a conductive material having light transmittance and the reflector may be formed inside the anode electrode 160 or may be formed on the substrate 110 And the substrate 110 itself is formed of an opaque metal so that the emitted light can be emitted in the direction of the cathode electrode 190.

2 is a cross-sectional view illustrating an organic light emitting display according to another embodiment of the present invention.

As shown in FIG. 2, the organic light emitting display according to another embodiment of the present invention includes a common electrode layer 165 connected to the thin film transistor 120.

Although the base electrode layer 161 of the anode electrode 160 is connected to the thin film transistor 120 in FIG. 1, the common electrode layer 165 is connected to the thin film transistor 120 in FIG. When the common electrode layer 165 is connected to the thin film transistor 120, it is possible to prevent the base electrode layer 161 from reducing the contact region with the thin film transistor 120 due to damage during the process. That is, when a part of the region where the base electrode layer 161 and the thin film transistor 120 are connected is damaged due to infiltration of etchant or the like, the common electrode layer 165 includes the base electrode layer 161 and the base electrode layer 161 The anode electrode 160 and the thin film transistor 120 can be connected with each other.

3 is a cross-sectional view illustrating a resonance structure of an organic light emitting display according to an exemplary embodiment of the present invention.

3, the resonant structure of the organic light emitting display according to an exemplary embodiment of the present invention includes an organic light emitting layer 180, an anode 160, a cathode 190, and an anode 160 Reflective layer 163.

The resonance phenomenon refers to a repetitive reflection phenomenon between the reflective layer 163 and the cathode electrode 190 of the light emitted from the organic light emitting layer 180 and can improve the light extraction efficiency of the light emitted from the organic light emitting layer 180 have.

An organic light emitting display device includes a plurality of pixels each emitting light having a different color, and the plurality of pixels generally include three colors of light of red, green, and blue Pixels that emit light of different colors such as white, cyan, magenta, light blue, dark blue, orange, and yellow, And may also form pixels with red, green, and blue as well as combinations of subpixels of different colors. For example, one pixel can be formed by a combination of three colors of yellow, cyan and magenta.

Among the combinations of the hues, the most common red, green, and blue subpixel combination will be described as an example.

Light of each color such as red, green, and blue light has a specific peak wavelength band, and the peak wavelength band is generally expressed as a wavelength of light of a specific color. 3 illustrates the resonance phenomenon of the red and green emission light emitted from the red and green subpixels formed by the RGB method in the bottom emission type, but the present invention is not limited thereto, and various colors having a specific peak wavelength Can be resonated with the principle shown in Fig.

The red light L1 emitted from the organic light emitting layer 180 is repeatedly reflected between the reflective layer 163 and the cathode electrode 190 while the amplitude is amplified through the constructive interference, And then emitted to the outside of the substrate 110. The reflective layer 163 and the cathode electrode 190 are separated by a distance corresponding to an integral multiple of the half wavelength of the red light L1 and the light extraction efficiency can be improved through the constructive interference as described above. Although not shown in the drawing, in the top emission type, light emitted from the organic light emitting layer 180 is emitted to the top of the cathode electrode 190.

In the case of the WRGB method, the white light emitted from the organic light emitting layer 180 passes through a red color refiner (not shown) formed between the anode electrode 160 and the substrate 110 to be converted into red light, . At the same time, a part of the white light reflected by the reflective layer 163 of the anode electrode 160 repeats the process of being re-reflected by the cathode electrode 190 at a distance corresponding to an integral multiple of the half wavelength of the red light, The amplitude of the red light is increased and the light of the remaining wavelength other than the red light is output to the outside of the substrate 110 without repeating the process of repeating the process of reflecting the amplified red light as described above And then emitted to the outside through the rear reflective layer 163, so that the light extraction efficiency can be improved.

In the WRGB method, a color refiner is formed on the outside of the cathode electrode 190 in the case of the top emission type, and only the direction in which the red light is emitted to the outside is the direction of the cathode electrode 190.

The distance from the reflective layer 163 to the cathode electrode 190 should be an integral multiple of approximately 327.5 nm which is half of 655 nm because the wavelength band is approximately 655 nm since the wavelength band is approximately 610 to 700 nm in the case of the red visible light ray. A phenomenon may occur.

3, green light L2 emitted from the organic light emitting layer 180 is repeatedly reflected between the reflective layer 163 and the cathode electrode 190, amplified through constructive interference, The light is emitted to the outside of the light source 110. The reflective layer 163 and the cathode electrode 190 are separated by a distance corresponding to an integral multiple of the half wavelength of the green light L2 and the light extraction efficiency can be improved through the constructive interference as described above. Although not shown in the drawing, in the top emission type, light emitted from the organic light emitting layer 180 is emitted to the top of the cathode electrode 190.

In the case of the WRGB method, the white light emitted from the organic light emitting layer 180 passes through a red color refiner (not shown) formed between the anode electrode 160 and the substrate 110 to be changed to a green light, . At the same time, a part of the white light reflected by the reflective layer 163 of the anode electrode 160 is reflected again by the cathode 190 spaced a distance corresponding to an integral multiple of the half wavelength of the green light, The amplitude of the green light is increased and the light of the remaining wavelength other than the green light is emitted to the outside of the substrate 110 without repeating the process of repeating the process of reflecting the green light having the increased amplitude as described above And then emitted to the outside through the rear reflective layer 163, so that the light extraction efficiency can be improved.

In the WRGB method, in the case of the front emission type, the color refiner is formed outside the cathode electrode 190, and the difference is only in that the direction in which the green light is emitted to the outside is the direction of the cathode electrode 190.

The distance from the reflective layer 163 to the cathode electrode 190 should be an integral multiple of about 267.5 nm which is half of 535 nm since the wavelength band of the green visible light ray is about 500 to 570 nm A resonance phenomenon may occur.

The distance from the reflective layer 163 to the cathode electrode 190 is an integral multiple of about 237.5 nm which is half of 475 nm because the wavelength band is about 450 to 500 nm in the case of the blue visible light ray. A resonance phenomenon may occur.

4A to 4G are cross-sectional views illustrating a method of manufacturing an organic light emitting display according to an embodiment of the present invention.

As shown in FIG. 4A, a substrate 110 thin film transistor 120 is first formed. The thin film transistor 120 includes a source electrode (not shown) and a drain electrode (not shown) formed of a metal, and the source electrode and the drain electrode include a group including molybdenum (Mo), chromium (Cr) And may be formed using any one of a sputtering method and a vacuum evaporation method.

Next, silicon nitride (SiN x) is deposited on the thin film transistor 120 to form the lower insulating layer 130. The lower insulating layer 130 may be formed of a transparent insulating material in addition to the nitride nitride (SiNx), or may be formed using a Plasma Enhanced Chemical Vapor Deposition (PECVD) method.

Next, a photoacid (PAC) is deposited on the lower insulating layer 130 to form a planarization layer 140. The planarization layer 140 has a function of flattening the unevenness of the lower structure, and accordingly, the uniformity of the film formation on the surface must be very excellent.

Next, the upper insulating layer 150 is formed on the planarization layer 140 with the same material as the lower insulating layer 130. The upper insulating layer 150 may be formed by plasma enhanced chemical vapor deposition (PECVD) as well as the lower insulating layer 130 by various methods.

Next, as shown in FIG. 4B, the upper insulating layer 150, the lower insulating layer 130, and the planarization layer 140 are patterned to expose a portion of the thin film transistor 120 for each sub-pixel. Preferably, the drain electrode (not shown) of the thin film transistor 120 is exposed.

Next, as shown in FIG. 4C, a base electrode layer 161 is formed on the planarization layer 140. The base electrode layer 161 includes a lower transparent layer 162, a reflective layer 163, and an upper transparent layer 164, which may be sequentially stacked. The reflective layer 163 may be formed of an alloy including silver (Ag), and may include copper (Cu), tin (Sn), and the like. Further, the reflection layer 163 may be formed as a thin film to partially transmit light and reflect the other light. The thickness of the reflection layer 163 is not limited to the above description, and can be formed within several hundreds of angstroms (A) for the most optimal reflectivity.

Further, when the organic electroluminescent display device includes white subpixels, it is preferable that the reflective layer 163 is not formed in the white subpixels. This is because, as described above, the white light includes light of various wavelengths, so that when the reflection of white light is repeated in the reflection layer 163 to cause a resonance phenomenon, color distortion may occur. However, a similar structure having a lower reflectance than that of the reflection layer 163 or the reflection layer 163 may be formed within a range in which the color distortion of the white light does not occur, and the wavelength of the two colors of the complementary color relationship may be amplified, When the light is emitted to the outside, it can be set to be emitted as white light.

Next, as shown in FIG. 4D, a photoresist is deposited on the base electrode layer 161, the first halftone mask M1 is aligned with the substrate 110, The first photoresist pattern PR1 is formed through processes such as exposure and development. Since the photolithography process is performed using the halftone mask M, the first photoresist pattern PR1 is formed to have a different step according to the degree of opening of the halftone mask M. [ The first photoresist pattern PR1 located in the sub pixel to be etched in the upper transparent layer 164 of the base electrode layer 161 is formed to have the first thickness T1 and it is necessary to etch the base electrode layer 161 It is preferable that the first photoresist pattern PR1 located in the sub-pixel without the second thickness T2 is formed with a second thickness T2 smaller than the first thickness T1. The first photoresist pattern PR1 formed in a region where the anode electrode 160 is connected to the thin film transistor 120 is formed to have a second thickness T2 so that the anode electrode 160 is connected to the thin film transistor 120, So that the base electrode layer 161 formed in the region connected to the first electrode layer 160 is not etched.

On the other hand, the base electrode layer 161 exposed first in the first photoresist pattern PR1 is etched to expose the upper insulating layer 150. Since the upper transparent layer 164 and the lower transparent layer 162 are conductive oxides, they are etched using oxalic acid to etch the upper transparent layer 164 and the lower transparent layer 162, and the reflective layer 163 is formed of silver (Ag), copper (Cu) It is etched using a dedicated etchant capable of etching these metals.

Next, as shown in FIG. 4E, the first photoresist pattern PR1 of a predetermined thickness is removed through an ashing process to leave the second photoresist pattern PR2 of the third thickness T3. The ashing process is a process in which only the photoresist pattern is removed by burning, and a separate mask is not required. That is, when the first photoresist pattern PR1 of the second thickness T2 is removed through the ashing process, in the sub-pixels covered by the first photoresist pattern PR1 of the second thickness T2, The insulating layer 150 is exposed and the sub pixels covered with the first photoresist pattern PR1 of the first thickness T1 are still covered with the first photoresist pattern PR1, A third thickness T3 obtained by subtracting the second thickness T2 from the first thickness T1.

Next, as shown in FIG. 4F, the upper transparent layer 164 of the sub-pixel in which the anode electrode 160 is exposed through the ashing process is etched using oxalic acid. In this case, if the lower transparent layer 162 is left unetched in FIG. 4D and then the upper transparent layer 164 of the subpixel in which the anode electrode 160 is exposed after the ashing process is etched at the same time, an advantage of reducing one etching process .

4G, the second photoresist pattern PR2 is removed through a strip process, and a common electrode layer 165 is formed on the remaining base electrode layer 161 and the upper insulating layer 150. Then, .

Thereafter, the common electrode layer 165 is etched for each sub-pixel to form the anode electrode 160.

5A to 5B are cross-sectional views illustrating a method of fabricating an organic light emitting display according to another embodiment of the present invention.

FIGS. 5A and 5B show a process of forming the anode electrode 160 by using the second halftone mask M2 different from the first halftone mask M1. The second halftone mask is formed by a third photoresist pattern PR3 which is a photoresist pattern formed on the base electrode layer 161 by opening the region where the thin film transistor 120 and the anode electrode 160 are connected, The base electrode layer 161 corresponding to the region is exposed and then removed by etching. Then, the finally formed common electrode layer 165 may be connected to the thin film transistor 120. When the common electrode layer 165 is connected to the thin film transistor 120, defective connection between the base electrode layer 161 and the thin film transistor 120 can be prevented and complemented through a plurality of etching processes.

It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

110: substrate 120: thin film transistor
130: lower insulating layer 140: planarization layer
150: upper insulating layer 160: anode electrode
161: base electrode layer 162: lower transparent layer
163: reflective layer 164:
165: common electrode layer 170: bank layer
180: organic light emitting layer 190: cathode electrode

Claims (12)

Forming a base electrode layer on a substrate divided into a plurality of subpixels;
Forming a first photoresist pattern on the base electrode layer;
Etching the base electrode layer exposed by the first photoresist pattern;
Removing the first photoresist pattern by a predetermined thickness to form a second photoresist pattern;
Etching the base electrode layer exposed by the second photoresist pattern;
Removing the photoresist layer; And
And forming a common electrode layer including a single transparent layer for each sub-pixel region. The method according to claim 1,
Wherein the base electrode layer includes a lower transparent layer formed on the substrate, a reflective layer formed on the lower transparent layer, and an upper transparent layer formed on the reflective layer,
Wherein the step of etching the base electrode layer exposed by the first photoresist pattern sequentially etches the upper transparent layer and the reflective layer of the base electrode layer exposed by the first photoresist pattern. A method of manufacturing a light emitting display device. 3. The method of claim 2,
And etching the upper transparent layer and the lower transparent layer of the base electrode layer exposed by the second photoresist pattern at the same time as etching the base electrode layer exposed by the second photoresist pattern. A method of manufacturing a light emitting display device. 3. The method of claim 2,
Wherein a part of the subpixels emits white light and the reflective layer of the base electrode layer formed in subpixels emitting the white light is exposed and etched by the first photoresist pattern. ≪ / RTI > The method of claim 3,
Wherein the upper transparent layer and the lower transparent layer are conductive oxides. The method of claim 3,
Wherein the reflective layer comprises one of silver (Ag), copper (Cu), and tin (Sn). A substrate divided into a plurality of pixels;
A thin film transistor formed on the substrate;
A planarization layer formed on the thin film transistor; And
And an anode electrode formed on the planarization layer and connected to the thin film transistor,
Wherein the anode electrode comprises at least one of a base electrode layer and a common electrode layer. 8. The method of claim 7,
Wherein the thin film transistor is connected to the base electrode layer of the anode electrode. 8. The method of claim 7,
And the thin film transistor is connected to the common electrode layer among the anode electrodes. 8. The method of claim 7,
Wherein the pixel includes a lower transparent layer, a reflective layer formed on the lower transparent layer, and an upper transparent layer formed on the reflective layer, wherein the common Wherein the electrode layer comprises a single transparent layer. 11. The method of claim 10,
Wherein the anode electrode corresponding to the first subpixel includes the base electrode layer and the common electrode layer, and the anode electrode corresponding to the second subpixel and the third subpixel includes the base electrode layer And the common electrode layer. 11. The method of claim 10,
Wherein the pixel further comprises a fourth sub-pixel emitting white light, and the anode electrode corresponding to the fourth sub-pixel includes the common electrode layer.

Images