KR101750562B1 - Organic Light Emitting Display Device and Method for fabricating the same - Google Patents

Abstract

The present invention discloses an organic electroluminescence display device and a method of manufacturing the same. According to another aspect of the present invention, there is provided a method of fabricating an organic light emitting display device including sequentially forming a first metal layer, a buffer layer, and a semiconductor layer on a substrate; Forming a first storage electrode, an active layer, and a pixel electrode on a substrate having the first metal layer, the buffer layer, and the semiconductor layer formed thereon according to a photolithography process and an etching process; A gate insulating film is formed on the substrate on which the first storage electrode, the active layer, and the pixel electrode are formed, and then a second metal film is formed. Then, a photolithography process and an etching process are performed to form a gate insulating film Forming a second storage electrode on a gate electrode and a gate insulating film corresponding to the first storage electrode; Forming an ohmic contact layer on both sides of the active layer by performing an ion implantation process on the substrate having the gate electrode formed thereon; Forming an interlayer insulating film on the substrate on which the gate electrode is formed, and forming a contact hole in a region corresponding to the ohmic contact layer; Forming a third metal film on the substrate on which the contact hole is formed, and then performing a photolithography process and an etching process to form a source electrode, a drain electrode, and a data line; And forming a protective layer on the substrate on which the source electrode and the drain electrode are formed, and then performing a contact hole process to remove and expose the protective layer over the pixel electrode.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an organic light emitting display device,

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

2. Description of the Related Art Recently, various flat panel display devices capable of reducing weight and volume, which are disadvantages of cathode ray tubes (CRTs), have been developed. As a flat panel display device, a liquid crystal display ("LCD"), a field emission display ("FED"), a plasma display panel ("PDP" (Organic Light Emitting Display Device).

The PDP has a disadvantage in that it is most advantageous in a large screen because of its relatively simple structure and manufacturing process, but has a low luminous efficiency, low luminance and high power consumption. Since the LCD uses a semiconductor process, it is difficult to make a large screen and the power consumption is large due to the backlight unit. In addition, the LCD has a disadvantage that optical loss is large and the viewing angle is narrow due to optical elements such as a polarizing filter, a prism sheet, and a diffusion plate. On the other hand, the organic light emitting display device has advantages of high response speed, high luminous efficiency, high luminance and wide viewing angle.

The organic light emitting display device is driven by a voltage as low as about 5 to 20 V as compared with an inorganic light emitting display device requiring a high voltage of 100 to 200 V, so that the organic light emitting display device can be driven by DC low voltage. Since the organic light emitting display device has excellent characteristics such as a wide viewing angle, a high speed response, and a high contrast ratio, a pixel of a graphic display, a pixel of a television image display or a surface light source It is thin, light and has good color and is suitable for next generation flat panel displays.

The driving method of the organic light emitting display device can be classified into a passive matrix type and an active matrix type.

The passive matrix organic electroluminescent display device has a simple structure and a simple manufacturing method. However, the passive matrix organic electroluminescent display device has a drawback in that it has difficulty in increasing the power consumption and size of the display device, and the aperture ratio is lowered as the number of wirings is increased.

On the other hand, the active matrix organic light emitting display device has advantages of high luminous efficiency and high image quality.

1 is a circuit diagram schematically showing pixels of an active matrix type organic light emitting display device.

Referring to FIG. 1, an active matrix organic light emitting display device includes an organic light emitting diode (OLED), a plurality of thin film transistors (TFT), and a storage capacitor Cst.

The TFT includes a driving TFT DR_TFT for controlling the OLED and a switching TFT SW_TFT for controlling the driving TFT DR_TFT. The OLED, the switching TFT (SW_TFT), the driving TFT (DR_TFT), and the storage capacitor (Cst) are all formed on the same plane. That is, all elements are formed on the same layer on the substrate.

When the scan signal (Scan) is supplied through the gate line (GL), the switching TFT (SW_TFT) is turned on and the driving TFT (DR_TFT) is turned on, The data signal Data supplied from the data line DL is supplied to the gate electrode of the transistor Tr2. The driving TFT DR_TFT turned on by the data signal Data drives the OLED through the high potential driving voltage VDD supplied to one end and the low potential driving voltage Vss supplied to the other end. The storage capacitor Cst forms a capacitor between the data signal DATA supplied through the switching TFT SW_TFT and the high potential driving voltage VDD to make the driving TFT DR_TFT even after the switching TFT SW_TFT is turned off, Thereby making it possible to stably maintain the turn-on state.

Such an active matrix organic electroluminescent display device includes an active layer forming step, a storage forming step, a gate electrode forming step, a contact hole forming step, a source / drain electrode forming step, a protective film forming step, a pixel electrode forming step, and a bank / Forming process, etc. Since the mask process is carried out 7 to 9, the process is complicated and the productivity is low.

An object of the present invention is to provide an organic electroluminescence display device and a method of manufacturing the same, in which a storage electrode and a pixel electrode are simultaneously formed to reduce the number of mask processes.

It is another object of the present invention to provide an organic light emitting display device in which a storage electrode is formed of a metal and a doping process is removed, and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a method of fabricating an organic light emitting display, including: sequentially forming a first metal layer, a buffer layer, and a semiconductor layer on a substrate; Forming a first storage electrode, an active layer, and a pixel electrode on a substrate having the first metal layer, the buffer layer, and the semiconductor layer formed thereon according to a photolithography process and an etching process; A gate insulating film is formed on the substrate on which the first storage electrode, the active layer, and the pixel electrode are formed, and then a second metal film is formed. Then, a photolithography process and an etching process are performed to form a gate insulating film Forming a second storage electrode on a gate electrode and a gate insulating film corresponding to the first storage electrode; Forming an ohmic contact layer on both sides of the active layer by performing an ion implantation process on the substrate having the gate electrode formed thereon; Forming an interlayer insulating film on the substrate on which the gate electrode is formed, and forming a contact hole in a region corresponding to the ohmic contact layer; Forming a third metal film on the substrate on which the contact hole is formed, and then performing a photolithography process and an etching process to form a source electrode, a drain electrode, and a data line; And forming a protective layer on the substrate on which the source electrode and the drain electrode are formed, and then performing a contact hole process to remove and expose the protective layer over the pixel electrode.

Further, an organic light emitting display device of the present invention includes: a substrate; A first storage electrode formed on the substrate, an active layer, and a pixel electrode; A second storage electrode formed above the first story electrode with a gate insulating film interposed therebetween; a gate electrode formed on the active layer with a gate insulating film interposed therebetween; A source electrode and a drain electrode electrically connected to the ohmic contact layer of the active layer with an interlayer insulating film interposed therebetween; And a protective film formed on the substrate on which the source electrode and the drain electrode are formed, wherein the drain electrode and the pixel electrode are directly in contact with each other, and an insulating layer pattern and a metal film pattern are laminated between the active layer and the substrate .

The organic light emitting display device of the present invention has the effect of reducing the number of mask processes by simultaneously forming the storage electrode and the pixel electrode.

In addition, the organic light emitting display device of the present invention has the effect of removing the doping process by forming the storage electrode as a metal.

1 is a circuit diagram schematically showing pixels of an active matrix type organic light emitting display device.
2A to 2H are views illustrating a manufacturing process of an organic light emitting display according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the size and thickness of the device may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

Although the following description has been made with reference to an array substrate applied to an organic electroluminescence display device, the same can be applied to an array substrate of a liquid crystal display device.

2A to 2H are views illustrating a manufacturing process of an organic light emitting display according to the present invention.

The drawings and description below describe the manufacturing process steps of TFTs, storage regions and pixel electrodes among the pixels of the organic light emitting display device of the present invention.

2A to 2H, a metal film 101, a buffer layer 102, and a semiconductor layer 103 are sequentially formed on a transparent insulating substrate 100. In this case,

The metal film 101 is a transparent conductive material, and may be any one of ITO, ITZO, and IZO. The buffer layer 102 may be an SiO ₂ -based insulating film or an SiN x -based insulating film. The semiconductor layer 103 is crystallized into a polysilicon film by a heat treatment process after forming an amorphous silicon film.

That is, a metal layer 101, a buffer layer 102 and an amorphous silicon layer are successively formed on the insulating substrate 100, and then the amorphous silicon layer is crystallized to form a semiconductor layer 103.

A first photoresist pattern 200a and a second photoresist pattern 200b having different thicknesses are formed on the surface of the insulating substrate 100 by using a halftone mask or a diffraction mask, (103).

The first photoresist pattern 200a formed on the TFT portion is thicker than the second photoresist pattern 200b formed on the pixel portion and the storage region. This is because the semiconductor layer 103, the buffer layer 102, and the metal film 101 must be etched first and then the semiconductor layer 103 must be etched to further form the active layer of the TFT.

As described above, when the first photosensitive film pattern 200a and the second photosensitive film pattern 200b are formed on the insulating substrate 100, as shown in FIG. 2B, the first photosensitive film pattern 200a and the second photosensitive film pattern 200b, And the etching process is performed using the pattern 200b as a mask.

The semiconductor layer 103 is subjected to the dry etching process, and the wet etching process is performed in the same chamber to etch the buffer layer 102 and the metal film 101.

A first storage electrode 112 is formed in the storage region through the etching process and a buffer layer pattern 102a and a semiconductor layer pattern 103a are stacked on the first storage electrode 112. [

An active layer 114, an insulating layer pattern 108 and a metal film pattern 150 are formed under the first photoresist pattern 200a through a dry etching process and a wet etching process. That is, in the present invention, the insulating layer pattern 108 and the metal film pattern 150 are laminated on the lower side of the active layer 114.

A pixel electrode 110 is formed on the insulating substrate 100 and a buffer layer pattern 102a and a semiconductor layer pattern 103a are formed on the pixel electrode 110 in the pixel region. That is, in the present invention, the pixel electrode 110 and the first storage electrode 112 are formed on the insulating substrate 100.

As described above, when the first storage electrode 112, the active layer 114, and the pixel electrode 110 are formed on the insulating substrate 100, as shown in FIG. 2C, the ashing process and the etching process .

The second photoresist pattern 200b having a relatively small thickness is removed by the ashing process and the thickness of the first photoresist pattern 200a is reduced so that the third photoresist pattern 200c is formed on the active layer 114. [

Then, an additional etching process is performed using the third photoresist pattern 200c as a mask so as to have the width of the active layer 114 of the TFT. At this time, on the first storage electrode 112 and the pixel electrode 110 The buffer layer pattern 102a and the semiconductor layer patterns 103a which are stacked are etched and removed.

Accordingly, the first storage electrode 112 and the pixel electrode 110 formed on the insulating substrate 100 are completely exposed to the outside.

When the etching process is completed as described above, a strip process is performed to remove the third photoresist pattern 200c existing on the active layer 114, as shown in FIG. 2D.

2E, a gate insulating film 120 is formed in the entire region of the insulating substrate 100, and then a metal such as Al, AlNd, Mo Ti, or W, or two or more metals or alloys A metal film selected from Ti / AlTi, Cu / MoTi, Mo / AlNd, MoTi / Cu / MoTi and ITO / Cu / MoTi is formed on the gate insulating film 120 and then a photolithography process and an etching process are performed .

A second storage electrode 122 is formed on the gate insulating film 120 corresponding to the first storage electrode 112 by an etching process and a gate insulating film 120 is formed on the gate insulating film 120 corresponding to the active layer 114. [ 130).

As described above, when the gate electrode 130 is formed, the ion implantation process is performed on both side edge regions of the active layer 114 using the gate electrode 130 as a mask to form the ohmic contact layer 115a.

The ohmic contact layer 115a is formed at a position to be in contact with a source / drain electrode to be formed later.

As described above, when the gate electrode 130 is formed on the insulating substrate 100, an interlayer insulating film 125 is formed in the entire region of the insulating substrate 100, as shown in FIG. 2F. When the interlayer insulating layer 125 is formed on the insulating substrate 100, a contact hole is formed in a region corresponding to the ohmic contact layer 115a according to a photolithography process.

Accordingly, the ohmic contact layer 115a formed on both side edges of the active layer 114 is exposed to the outside. In addition, in the contact hole process, the gate insulating layer 120 and the interlayer insulating layer 125 formed on the pixel portion are removed to expose the pixel electrode 110.

As described above, when the contact hole process is completed, a single layer or double layer of a metal such as Al, Mo, Cr, Cu, Al alloy, Mo alloy, Cu alloy, or the like is formed over the entire area of the insulating substrate 100, Structure is formed by a sputtering process.

Then, a photolithography process and a wet etching process are performed to form a source electrode 170a, a drain electrode 170b, and a data line (not shown).

In this case, the drain electrode 170b is directly in contact with the pixel electrode 110 in the pixel portion.

As described above, when the source and drain electrodes 170a and 170b are formed on the insulating substrate 100, the protective film 180 is formed on the entire region of the insulating substrate 100, as shown in FIG. 2H.

Then, the contact hole process is performed to remove the protective film 180 formed on the pixel portion. As described above, when the pixel electrode 110 of the pixel portion is exposed to the outside, a light emitting diode and an electrode layer can be formed to form a light emitting diode.

When a red, green, and blue organic light emitting layer is formed on the upper substrate, a protective film (not shown) is formed on the drain electrode 170b for electrical contact between the organic light emitting diode electrode including the organic light emitting layer and the drain electrode 170b of the thin film transistor. A contact hole can be formed in the contact hole 180.

When the organic light emitting diode is formed on the upper substrate, the drain electrode 170b may be electrically connected to the organic light emitting diode electrode of the upper substrate using a conductive spacer.

As described above, in the present invention, the storage electrode is formed of metal and is patterned simultaneously with the pixel electrode, thereby reducing the number of mask processes.

In addition, in the prior art, the storage electrode is formed of a doped semiconductor layer and a separate doping process is performed. However, in the present invention, a storage electrode is formed using a metal, thereby removing the doping process.

100: insulating substrate 110: pixel electrode
112: first storage electrode 114: active layer
122: second storage electrode 130: gate electrode
170a: source electrode 170b: drain electrode

Claims (11)

Sequentially forming a first metal film, a buffer layer and a semiconductor layer on a substrate;
Forming a first storage electrode, an active layer, and a pixel electrode on a substrate having the first metal layer, the buffer layer, and the semiconductor layer formed thereon according to a photolithography process and an etching process;
A gate insulating film is formed on the substrate on which the first storage electrode, the active layer, and the pixel electrode are formed, and then a second metal film is formed. Then, a photolithography process and an etching process are performed to form a gate insulating film Forming a second storage electrode on a gate electrode and a gate insulating film corresponding to the first storage electrode;
Forming an ohmic contact layer on both sides of the active layer by performing an ion implantation process on the substrate having the gate electrode formed thereon;
Forming an interlayer insulating film on the substrate on which the gate electrode is formed, and forming a contact hole in a region corresponding to the ohmic contact layer;
Forming a third metal film on the substrate on which the contact hole is formed, and then performing a photolithography process and an etching process to form a source electrode, a drain electrode, and a data line; And
Forming a protective layer on the substrate on which the source electrode and the drain electrode are formed, and then performing a contact hole process to remove and expose the protective layer over the pixel electrode,
The step of simultaneously forming the first storage electrode, the active layer,
Forming a first photoresist pattern on a region where the active layer is to be formed by using a halftone mask or a diffraction mask and forming a first photoresist pattern on a region where the first storage electrode and the pixel electrode are to be formed, Forming a photoresist pattern;
Forming a first storage electrode, an active layer and a pixel electrode by performing an etching process using the first and second photoresist pattern as masks; And
A third buffer layer pattern formed on the first storage electrode and the pixel electrode and a second buffer layer pattern formed on the pixel electrode using the third storage layer pattern as a mask, And removing the layer pattern.
delete The method of claim 1, wherein the first photoresist pattern is thicker than the second photoresist pattern.
The method according to claim 1, wherein the second metal film is made of any one of AlNd, Mo Ti, and W, or two or more metals or alloys (Ti / AlTi, Cu / MoTi, Mo / AlNd, MoTi / Cu / MoTi, / MoTi). ≪ / RTI >
The method according to claim 1, wherein the third metal film has a single layer or a double layer structure of Al, Mo, Cr, Cu, Al alloy, Mo alloy, Cu alloy.
The method of claim 1, wherein the drain electrode and the pixel electrode are directly contacted.
The method of claim 1, wherein forming the semiconductor layer comprises:
Forming a first metal film, a buffer layer, and an amorphous silicon film on the substrate;
And crystallizing the amorphous silicon film to form a polysilicon film.
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